Female Infertility

Female Infertility. Another study of only 19 women discovered HSG and sonohysterography were both 100% sensitive, and conventional TVUS was only 52% sensitive for detecting intrauterine adhesions compared with hysteroscopy [69]. Additional studies have shown HSG to be 75% to 81% sensitive and 80% specific compared with hysteroscopy in diagnosing intrauterine adhesions [70,71]. Antibiotic administration or prophylactic use of antibiotics is at the discretion of the referring physician if there is a prior history of PID or if hydrosalpinx is noted at the time of the study. Although HSG may provide useful information about the uterine cavity, such as the presence of adhesions, it is not reliable in categorizing MDAs and has been largely replaced by MRI and 3-D US for assessment of the uterine cavity in recurrent pregnancy loss. Female Infertility MRI Pelvis MRI provides accurate assessment of uterine abnormalities potentially contributing to infertility such as MDA [67], adenomyosis [72], and leiomyomas [73]. On both TVUS and MRI, a fundal cleft >1 cm can be used to diagnose a bicornuate uterus and differentiate it from a septate uterus (fundal cleft <1 cm) [67]. A fundal indentation <5 mm above the interostial line can also be used for identification of a bicornuate uterus [74]. In 24 cases of surgically proven MDA, MRI was 100% accurate, 2-D TVUS was 92% accurate, and hysterosalpingogram was only 16.7% accurate in the classification of MDA [67]. MRI demonstrates 78% to 88% sensitivity and 67% to 93% specificity in detecting adenomyosis, typically thickening of the junctional zone, often with T2 hyperintense foci [72]. Nondegenerated fibroids are classically well circumscribed with low T2 signal. The imaging features of degenerated fibroids can vary greatly on MRI, however [73]. Although MRI may be useful in detecting intrauterine adhesions, no large studies comparing its efficacy to hysteroscopy have been performed [75].


Female Infertility

Female Infertility. When comparing diagnostic modalities to hysterectomy for the detection of intracavitary abnormalities, MRI, SIS, and hysteroscopy were equally effective and superior to TVUS [76]. US Pelvis Color Doppler Power Doppler has been shown to be useful in detecting stalks within endometrial polyps and peripheral or rim vascularity in submucosal fibroids [77]. Color Doppler has also been shown to be useful in differentiating the central vascular pattern of adenomyosis from the peripheral vascularity of fibroids [78]. This procedure is not performed in isolation but in conjunction with TVUS. US Pelvis Transvaginal On both TVUS and MRI, an external fundal cleft >1 cm can be used to diagnose a bicornuate uterus and differentiate it from a septate uterus (fundal cleft <1 cm) [67]. A fundal indentation <5 mm above the interostial line can also be used for identification of a bicornuate uterus [74]. In 24 cases of surgically proven MDA, MRI was 100% accurate, 2-D TVUS was 92% accurate, and hysterosalpingogram was only 16.7% accurate [67]. For detecting intrauterine adhesions, a study of 19 women showed that HSG and sonohysterography were both 100% sensitive, and conventional TVUS was only 52% sensitive compared with hysteroscopy [69]. In another study of 133 women undergoing infertility evaluation who underwent both hysteroscopy and TVUS, TVUS detected submucosal fibroids in 10 of the 11 patients diagnosed with submucosal fibroids at hysteroscopy, yielding a sensitivity of 91% and specificity of 100% [79]. When comparing diagnostic modalities with hysterectomy for the detection of intracavitary abnormalities, MRI, SIS, and hysteroscopy were equally effective and superior to TVUS [76]. US Sonohysterography Contrast sonohysterography or SIS provides an assessment of the uterine cavity. Although the endometrium can be assessed by TVUS, SIS is particularly useful in assessing potential causes of infertility, including intrauterine adhesions, endometrial polyps, and leiomyomas [52].


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer.  Introduction/Background Vulvar cancer is a rare gynecologic malignancy. In the United States, it is estimated that approximately 6,120 women will present with vulvar cancer, and 1,350 will succumb to their disease in 2020 [1]. Most patients are diagnosed with early-stage disease, and the majority of tumors originate in the labia majora [2,3]. The 5-year survival rate is 86% for patients with vulvar-confined disease but is reduced to 57% for patients with regional lymph node metastases, and 17% for patients with distant metastases [4]. Squamous cell carcinoma (SCC) is the predominant histotype of vulvar cancer, accounting for 90% of cases; thus, it is the focus of this discussion. Up to 69% of vulvar cancer is attributed to chronic human papillomavirus (HPV) infection, in particular high-risk strains such as HPV-16 and HPV-18 [5]. Other risk factors include older age, tobacco use, chronic inflammation of the vulva, and immune-compromised state [6]. The International Federation of Obstetrics and Gynecology (FIGO) and The American Joint Committee on Cancer (AJCC) TNM systems are both used to stage vulvar cancer and are closely aligned [7-9]. Initial evaluation of patients with vulvar lesions consists of careful clinical examination and punch biopsies of all suspicious vulvar lesions. Care must be taken to include the underlying stroma and to avoid necrotic areas. Lesion size, location relative to the midline, relationship to the adjacent organs (urethra, vagina, anus), and presence of multifocal disease are noted on physical examination. Clinical palpation of groin lymph nodes is performed, although this approach is limited by the high false-negative rate [10]. The status of inguinofemoral lymph nodes (IFLNs) is the most important prognostic factor in vulvar cancer. The likelihood of lymph node metastases is estimated by primary tumor size, depth of stromal invasion, and presence of lymphovascular space invasion [11-15].


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. Traditionally, IFLN assessment entailed complete lymphadenectomy. High morbidity of this procedure and the fact that only a third of patients with early-stage disease have lymph node metastases at diagnosis led to a major shift toward less invasive assessment strategies including a combination of imaging, sentinel lymph node (SLN) mapping, and/or biopsy [16-21]. The SLN is the lymph node at the highest risk of metastasis because it is the first lymph node to receive lymphatic drainage from the primary tumor. Several prospective multi-institutional trials established the feasibility, safety, and effectiveness of SLN evaluation in early- stage vulvar cancer [16,19-23]. The peer-reviewed literature about the role of imaging in vulvar cancer is limited, likely because vulvar cancer is uncommon. Many studies report on patients with combined histotypes of vulvar cancer, wide range of disease stages, primary and recurrent disease, and vulvar and vaginal cancers combined. The imaging techniques are not uniform, and the descriptions of imaging studies are often limited with regard to the area imaged and the use of intravenous (IV) contrast. The above limits our ability to draw conclusions and provide evidence-based imaging recommendations. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Staging and Follow-up of Vulvar Cancer Special Imaging Considerations Vaginal gel is optional with MRI pelvis without and with IV contrast or MRI pelvis without IV contrast. Vaginal gel may be useful to delineate the extent of vaginal involvement by primary tumor.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. Variant 2: Initial staging of pretreatment vulvar cancer: Primary tumor is less than or equal to 4 cm with greater than 1 mm stromal invasion, confined to vulva or perineum, or with minimal involvement of the urethra, vagina, or anus. For early-stage disease, present-day surgical approach consists of conservative vulvar resection (with at least 1 cm of tumor-free margin) and IFLN assessment carried out via two separate incisions [6]. If no lymph node metastases Staging and Follow-up of Vulvar Cancer are apparent at clinical assessment, the extent of lymph node evaluation is determined by the size of the primary tumor, the depth of stromal invasion, and location of the primary tumor relative to the midline [6]. If clinical and/or imaging evaluation shows no apparent IFLN metastases, SLN mapping is performed as detailed below. If IFLN metastases are suspected based on clinical and/or imaging evaluation, either minimally invasive lymph node sampling with US-guided FNAB and/or IFLN dissection may be performed. CT Abdomen and Pelvis CT of the abdomen and pelvis is not indicated in patients with clinical early-stage disease. There is no relevant literature detailing the role of CT in the evaluation of primary tumor size and extent, which is likely explained by the limited soft-tissue contrast of CT. Lymph node morphologic characteristics including size enlargement and abnormal pattern of enhancement are the main criteria used to detect lymph node metastases on CT. If IFLN metastases are suspected on imaging, SLN mapping is not recommended. Instead, complete lymphadenectomy or, alternatively, US-guided FNAB is performed [6]. Normal imaging findings do not exclude IFLN metastases (because of inadequate sensitivity) and do not alleviate the need for SLN mapping and sampling. CT Chest, Abdomen, and Pelvis CT of the chest, abdomen, and pelvis is not indicated in patients with clinical early-stage disease.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. There is no relevant literature detailing the role of CT in the evaluation of primary tumor size and extent, which is likely explained by the limited soft-tissue contrast of CT. Lymph node enlargement and abnormal pattern of enhancement are the main criteria used to detect lymph node metastases on CT. If IFLN metastases are suspected on imaging, SLN mapping is not recommended. Instead, complete lymphadenectomy or, alternatively, US-guided FNAB is performed [6]. Normal imaging findings do not exclude IFLN metastases (because of inadequate sensitivity) and do not alleviate the need for SLN mapping and sampling. CT Pelvis CT of the pelvis is not indicated in patients with clinical early-stage disease. There is no relevant literature about the role of CT in the evaluation of primary tumor size and extent, likely explained by the limited soft-tissue contrast of CT. Lymph node enlargement and abnormal pattern of enhancement are the main criteria used to detect lymph node metastases on CT. If IFLN metastases are suspected on imaging, SLN mapping is not recommended. Instead, complete lymphadenectomy or, alternatively, US-guided FNAB is performed [6]. Normal imaging findings do not Staging and Follow-up of Vulvar Cancer exclude IFLN metastases (because of inadequate sensitivity) and do not alleviate the need for SLN mapping and sampling. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT is not indicated in patients with clinical early-stage disease. There is no relevant literature about the role of FDG-PET/CT in the evaluation of primary tumor size and extent. If findings on FDG-PET/CT are suspicious for lymph node metastases, SLN mapping is not recommended. Instead, complete lymphadenectomy or, alternatively, US-guided FNAB is performed [6]. Normal imaging findings do not exclude IFLN metastases (because of inadequate sensitivity) and do not alleviate the need for SLN mapping and sampling.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. Several recent studies examined the value of FDG-PET/CT in the detection of lymph node metastases. Kamran et al [27] retrospectively evaluated the performance of FDG-PET/CT prior to lymphadenectomy in 20 patients with primary vulvar SCC (size unspecified) and >1 mm of stromal invasion. They found that on a patient-by-patient basis, FDG-PET/CT demonstrated a sensitivity of 50%, specificity of 100%, PPV of 100%, and NPV of 57.1%. Crivellaro et al [28] retrospectively evaluated 29 patients with clinical early-stage primary vulvar cancer (primary tumors <4 cm and stromal invasion >1 mm) who were imaged with FDG-PET/CT prior to lymphadenectomy. The sensitivity, specificity, PPV, and NPV of FDG-PET/CT was 53%, 85%, 73%, 76%, and 67% on a groin-based analysis, and 50%, 67%, 59%, 59% on a patient-based analysis, respectively. The authors concluded that FDG- PET/CT had low sensitivity and moderate specificity for detecting IFLN metastases in early-stage disease. Combination of radiocolloid (usually Tc-99m sulfur colloid) and blue dye (most commonly isosulfan blue 1%) has a superior SLN detection rate (97.7%) compared with either Tc-99m sulfur colloid (94%) or blue dye (68.7%) alone [21,23]. Radiocolloid is injected intradermally around the tumor 2 to 4 hours prior to surgery. Preoperative lymphoscintigraphy may help with approximate SLN localization, whereas the intraoperative handheld gamma probe allows more precise SLN detection and localization. Blue dye is injected in the operating room 15 to 30 Staging and Follow-up of Vulvar Cancer minutes prior the procedure and localizes transiently to SLN aiding intraoperative visualization and removal of blue-stained lymph nodes [6]. If the SLN is negative for metastatic spread on pathologic evaluation, lymphadenectomy is omitted [6]. If an ipsilateral SLN is not identified, complete lymphadenectomy is recommended [6].


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. If SLN is involved by tumor, management options include bilateral lymphadenectomy or external beam radiation therapy (EBRT) with or without chemotherapy [6]. In situations when lymph node metastases are suspected because of imaging, SLN is not recommended. Instead, complete lymphadenectomy or, alternatively, US-guided FNAB is performed [6]. MRI Pelvis MRI with IV contrast is the best available imaging modality to define local extent of primary tumor because MRI has superior soft-tissue contrast and multiplanar capability. MRI is considered for patients with primary tumors >2 cm and >1 mm of stromal invasion, or primary tumors with close proximity to or involvement of the urethra, vagina, and anus because MRI can aid primary treatment planning [6]. In addition to primary tumor size/extent, MRI can assess IFLN basins [32-34]. Similar to CT and FDG-PET/CT, if findings on MRI are suspicious for lymph node metastases, SLN is not recommended. Instead, complete lymphadenectomy or, alternatively, US-guided FNAB is indicated [6]. Normal findings do not reliably exclude IFLN metastases (because of inadequate sensitivity) and do not alleviate the need for SLN sampling. Hawnaur et al [35] used unenhanced MRI to evaluate IFLN in 10 patients with primary vulvar cancer. Lymph node metastases were diagnosed if any of the following criteria were present: long-axis diameter >21 mm, short-axis diameter >10 mm, long- to short-axis diameter ratio <1.3:1, irregular contour, and cystic changes within a lymph node. On a groin-based analysis, MRI had the sensitivity of 89%, specificity of 91%, PPV of 89%, NPV of 91%, and accuracy of 90%. Staging and Follow-up of Vulvar Cancer Radiography Chest There is no relevant literature to support the use of routine pretreatment radiographs in patients with clinical early- stage vulvar cancer. There is only one report regarding the role of chest radiography for the initial staging of patients with vulvar cancer.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. Andersen et al [26] prospectively evaluated 27 patients with vulvar cancer (23 primary and 4 recurrent). Chest radiographs were performed in 24 of 27 patients, and contrast-enhanced CT scan of the chest, abdomen, and pelvis was obtained in all 27 patients. Only 1 of 24 chest radiographs revealed a clinically important finding (pulmonary metastases) from an asymptomatic and at that time unknown adenocarcinoma of the cecum. Chest radiographs did not alter initial gynecologic management in any of the patients. US Duplex Doppler and US-guided Fine-Needle Aspiration Biopsy Groin There is no relevant literature to support the use of US with Doppler and US-guided FNAB for the assessment of primary tumor extent. A number of studies evaluated groin US with Doppler and US-guided FNAB for IFLN assessment [25,36-38]. Combined US and US-guided FNAB is the most accurate approach to confirm IFLN metastases that are suspected based on clinical and/or imaging assessment. The advantage of this sampling approach is that it is minimally invasive; the limitation is the potential risk of undersampling in the setting of micrometastases. The aforementioned study by Land et al [25] reported on 44 patients with primary vulvar SCC who underwent imaging with one or more of the following modalities: CT, US, and/or US-guided FNAB prior to lymphadenectomy. The sensitivity, specificity, PPV, and NPV for US alone was 87%, 69%, 48%, and 94%, respectively, and for US- guided FNAB it was 80%, 100%, 93%, and 100%, respectively. US Duplex Doppler Groin There is no relevant literature to support the use of US with duplex Doppler for the assessment of primary tumor extent. A number of studies evaluated groin US with Doppler and US-guided FNAB for IFLN assessment [25,36- 38]. Combined US and US-guided FNAB is the most accurate approach to confirm IFLN metastases that are suspected based on clinical and/or imaging assessment.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. The advantage of this sampling approach is that it is minimally invasive; the limitation is the potential risk of undersampling in the setting of micrometastases. The aforementioned study by Land et al [25] reported on 44 patients with primary vulvar SCC who were imaged with one or more of the following modalities: CT, US and/or US-guided FNAB prior to lymphadenectomy. The sensitivity, specificity, PPV, and NPV for US alone was 87%, 69%, 48%, and 94%, respectively, and for US-guided FNAB it was 80%, 100%, 93%, and 100%, respectively. Staging and Follow-up of Vulvar Cancer US-Guided Fine-Needle Aspiration Biopsy Groin There is no relevant literature to support the use of US-guided FNAB for the assessment of primary tumor extent. A number of studies evaluated groin US with Doppler and US-guided FNAB for IFLN assessment [25,36-38]. Combined US and US-guided FNAB is the most accurate approach to confirm IFLN metastases that are suspected based on clinical and/or imaging assessment. Sampling is minimally invasive. Limitations of US include its risk of undersampling of micrometastases. The aforementioned study by Land et al [25] reported on 44 patients with primary vulvar SCC who were imaged with one or more of the following modalities: CT, US, and/or US-guided FNAB prior to lymphadenectomy. The sensitivity, specificity, PPV, and NPV for US alone was 87%, 69%, 48%, and 94%, respectively, and for US-guided FNAB 80%, 100%, 93%, and 100%, respectively. Variant 3: Initial staging of pretreatment vulvar cancer: Primary tumor is greater than 4 cm or tumor of any size with more than minimal involvement of the urethra, vagina, or anus. Patients with primary tumors >4 cm or tumors of any size with more than minimal involvement of urethra, vagina, or anus (TNM larger T2/T3 or larger FIGO II, FIGO III/IVA) are treated primarily with concurrent EBRT and chemotherapy [39,40]. This group of patients has >8% risk of IFLN basin metastases and are not candidates for SLN mapping and biopsy.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. For radiation planning, IFLN assessment with imaging and subsequent IFLN lymphadenectomy or US-guided FNAB is recommended. If lymph node metastases are identified at imaging and confirmed at lymphadenectomy or US-guided FNAB, the radiation field should encompass primary tumor, pelvis, and groin nodal basin. If no lymph node metastases are detected at imaging and subsequent lymphadenectomy, reduced EBRT coverage may be considered. Patients presenting with distant metastases beyond the pelvis (TNM any T or N designation and M1 beyond pelvis or FIGO IVB) are treated primarily with chemotherapy and, when appropriate, EBRT for locoregional disease control and symptom palliation. CT Abdomen and Pelvis Contrast-enhanced CT of abdomen and pelvis may be considered in patients with primary tumors >4 cm; urethral, vaginal, or anal involvement; or clinical suspicion for lymph node metastases. However, CT of chest, abdomen, and pelvis or FDG-PET/CT is preferred in this group. Size enlargement and abnormal pattern of enhancement are the main criteria used to detect lymph node metastases on CT. Complete lymphadenectomy or, alternatively, US-guided FNAB is performed if imaging findings are suspicious for lymph node metastases [6]. CT Chest, Abdomen, and Pelvis Contrast-enhanced CT of chest, abdomen, and pelvis may be considered for patients with primary tumors >4 cm; urethral, vaginal, or anal involvement; or clinical suspicion for lymph node metastases. Size enlargement and abnormal pattern of enhancement are the main criteria used to detect lymph node metastases on CT. Complete lymphadenectomy or, alternatively, US-guided FNAB is performed if imaging findings are suspicious for lymph node metastases [6]. Staging and Follow-up of Vulvar Cancer and/or abnormal pattern of contrast enhancement were observed. CT had sensitivity of 60%, specificity of 90%, PPV of 37.5%, and NPV of 95.7% for detection of IFLN metastases.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. CT did not reveal distant metastases from vulvar cancer or alter original treatment plan in any patients. Incidental synchronous cancers were detected in 2 patients. CT Pelvis Contrast-enhanced CT of pelvis may be considered in patients with primary tumors >4 cm; urethral, vaginal, or anal involvement; or clinical suspicion for lymph node metastases. However, CT of chest, abdomen, and pelvis or FDG- PET/CT is preferred in this group. Size enlargement and abnormal pattern of enhancement are the main criteria used to detect lymph node metastases on CT. Complete lymphadenectomy or, alternatively, US-guided FNAB is performed if imaging findings are suspicious for lymph node metastases [6]. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT is considered in patients with primary tumors >4 cm; urethral, vaginal, or anal involvement; or clinical suspicion for lymph node metastases. Complete lymphadenectomy or, alternatively, US-guided FNAB is performed if imaging findings are suspicious for lymph node metastases [6]. Several recent studies examined the value of FDG-PET/CT in the detection of lymph node metastases. Kamran et al [27] retrospectively evaluated the performance of FDG-PET/CT prior to lymphadenectomy in 20 patients with primary vulvar SCC (size unspecified) and >1 mm of stromal invasion. He found that on a patient-by-patients basis, FDG-PET/CT demonstrated a sensitivity of 50%, specificity of 100%, PPV of 100%, and NPV of 57.1%. Garganese et al [41] reported on FDG-PET/CT in 47 patients with vulvar cancer (44 primary and 3 recurrent) who underwent inguinofemoral lymphadenectomy because they were not candidates for SLN evaluation because of primary tumor >4 cm (n = 12), multifocal tumor (n = 9), prior surgery (n = 16), IFLN involvement (n = 7) or recurrent disease (n = 3). On a groin-based analysis, FDG-PET/CT demonstrated a sensitivity of 56%, specificity of 88%, PPV of 38%, NPV of 93%, and accuracy of 84% in detecting nodal metastases.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. Robertson et al [30] reported on 50 patients who were enrolled in the National Oncologic PET Registry and underwent 83 FDG-PET/CT studies for suspected or known primary or recurrent vulvar or vaginal cancer. Fifty- four of 83 (65%) studies were performed in patients with vulvar cancer, the remaining 29 of 83 (35%) studies in patients with vaginal cancer. The authors did not specify numbers of patients with vulvar cancer (including primary Lymphoscintigraphy Groin Lymphoscintigraphy and SLN mapping are not indicated in patients with primary tumor >4 cm or tumor of any size with more than minimal involvement of the urethra, vagina, or anus. The aforementioned study by Land et al [25] reported on 44 patients with primary vulvar SCC who were imaged with one or more of the following modalities: CT, US, and/or US-guided FNAB prior to lymphadenectomy. The sensitivity, specificity, PPV, and NPV for US alone was 87%, 69%, 48%, and 94%, respectively, and for US-guided FNAB 80%, 100%, 93%, and 100%, respectively. MRI Pelvis MRI with IV contrast is the best available imaging modality to define local extent of primary tumor because MRI has superior soft-tissue contrast and multiplanar capability. MRI is considered for patients with primary tumors >2 cm and >1 mm of stromal invasion, or primary tumors with close proximity to or involvement of the urethra, vagina, and anus because MRI can aid primary treatment planning [6]. In addition to primary tumor, MRI can assess IFLN basins [32-34]. Similar to CT and FDG-PET/CT, if findings on MRI are suspicious for lymph node metastases, complete lymphadenectomy or, alternatively, US-guided FNAB is indicated [6]. Hawnaur et al [35] used unenhanced MRI to evaluate IFLN in 10 patients with primary vulvar cancer. Lymph node metastases were diagnosed if any of the following criteria were present: long-axis diameter >21 mm, short-axis diameter >10 mm, long- to short-axis diameter ratio <1.3:1, irregular contour, and cystic changes within a lymph node.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. On a groin-based analysis, MRI had the sensitivity of 89%, specificity of 91%, PPV of 89%, NPV of 91%, and accuracy of 90%. Staging and Follow-up of Vulvar Cancer with unenhanced MRI prior to lymphadenectomy. Two of the three criteria had to be met to diagnose lymph node metastases: 1) short-axis diameter >10 mm; 2) irregular or rounded shape; or 3) increased signal intensity on short tau inversion recovery imaging or heterogeneous signal intensity on T2-weighted imaging. Using this approach, on a groin-by-groin basis, unenhanced MRI had sensitivity of 85.7%, specificity of 82.1%, PPV of 64.3%, and NPV of 93.9%. Radiography Chest There is only one report regarding the role of chest radiography for the initial staging of patients with vulvar cancer. Andersen et al [26] prospectively evaluated 27 patients with vulvar cancer (23 primary and 4 recurrent). Chest radiographs was performed in 24 of 27 patients and contrast-enhanced CT scan of the chest, abdomen, and pelvis was performed in all 27 patients. Only 1 of 24 chest radiographs revealed a clinically important finding (ie, pulmonary metastases) from an asymptomatic and at that time unknown adenocarcinoma of the cecum. Chest radiographs did not alter initial gynecologic management in any of the patients. US Duplex Doppler and US-guided Fine-Needle Aspiration Biopsy Groin There is no relevant literature to support the use of US with Doppler and US-guided FNAB for the assessment of primary tumor extent. A number of studies evaluated groin US with Doppler and US-guided FNAB for IFLN assessment [25,36-38]. Combined US and US-guided FNAB is the most accurate approach to confirm IFLN metastases that are suspected based on clinical and/or imaging assessment. The advantage of this sampling approach is that it is minimally invasive; the limitation is the potential risk of undersampling in the setting of micrometastases.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. US Duplex Doppler Groin There is no relevant literature to support the use of US with Doppler for the assessment of primary tumor extent. A number of studies evaluated groin US with Doppler and US-guided FNAB for IFLN assessment [25,36-38]. Combined US and US-guided FNAB is the most accurate approach to confirm IFLN metastases that are suspected based on clinical and/or imaging assessment. The advantage of this sampling approach is that it is minimally invasive; the limitation is the potential risk of undersampling in the setting of micrometastases. The aforementioned study by Land et al [25] reported on 44 patients with primary vulvar SCC who were imaged with one or more of the following modalities: CT, US, and/or US-guided FNAB prior to lymphadenectomy. The sensitivity, specificity, PPV, and NPV for US alone was 87%, 69%, 48%, and 94%, respectively, and for US-guided FNAB 80%, 100%, 93%, and 100%, respectively. US-Guided Fine-Needle Aspiration Biopsy Groin There is no relevant literature to support the use of US-guided FNAB for the assessment of primary tumor extent. A number of studies evaluated groin US with Doppler and US-guided FNAB for IFLN assessment [25,36-38]. Combined US and US-guided FNAB is the most accurate approach to confirm IFLN metastases that are suspected based on clinical and/or imaging assessment. The advantage of this sampling approach is that it is minimally invasive; the limitation is the potential risk of undersampling in the setting of micrometastases. Staging and Follow-up of Vulvar Cancer the largest or most abnormal lymph node in each groin findings were found on US, US-guided FNAB prior to surgical management. The sensitivity and specificity for detecting metastatic involvement were 86% and 96% for US with Doppler alone but increased to 93% and 100% for US-guided FNAB, respectively.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. The aforementioned study by Land et al [25] reported on 44 patients with primary vulvar SCC who were imaged with one or more of the following modalities: CT, US, and/or US-guided FNAB prior to lymphadenectomy. The sensitivity, specificity, PPV, and NPV for US alone was 87%, 69%, 48%, and 94%, respectively, and for US-guided FNAB 80%, 100%, 93%, and 100%, respectively. Vulvar region, IFLN basins, multisite, and distant metastases are the most common locations of recurrence in decreasing order of frequency [13]. If the relapse is confirmed pathologically, FDG-PET/CT is recommended to detect lymph node and distant metastases, whereas MRI of pelvis aids the assessment of local tumor extent [44-46]. Treatment of recurrent vulvar cancer is determined by the tumor extent (vulva-confined, nodal recurrence, distant recurrence) and history of prior EBRT. Detailed discussion is beyond the scope of this guideline and is addressed comprehensively elsewhere [6]. In general, nonirradiated vulva-confined recurrent tumors are approached with multimodal strategy including surgical resection or IFLN dissection, and/or chemoradiotherapy. Surgery is the only potentially curative option in previously irradiated vulva-confined tumors. Similarly, if there is no prior EBRT, isolated lymph node or distant metastases are managed with multimodal approach; surgical resection and systemic therapy may be considered if there was prior EBRT. If there are multiple lymph node or distant metastases and prior EBRT, systemic therapy and best supporting care are advised [6]. CT Abdomen and Pelvis Contrast-enhanced CT of the abdomen and pelvis may be considered in patients with suspected vulvar cancer recurrence. However, contrast-enhanced CT of the chest, abdomen, and pelvis or FDG-PET/CT is preferred in this group. Size enlargement and abnormal pattern of enhancement are the main criteria used to detect lymph node metastases on CT.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. Andersen et al [26] prospectively evaluated 27 patients with vulvar cancer (23 primary and 4 recurrent) who underwent contrast-enhanced CT scan of the chest, abdomen, and pelvis prior to treatment. IFLN metastases were diagnosed if short-axis diameter was >10 mm and/or abnormal pattern of contrast enhancement were observed. CT had sensitivity of 60%, specificity of 90%, PPV of 37.5%, and NPV of 95.7% for detection of IFLN metastases. CT did not reveal distant metastases from vulvar cancer or alter original treatment plan in any patients. Incidental synchronous cancers were detected in two patients. CT Chest, Abdomen, and Pelvis Contrast-enhanced CT of the chest, abdomen, and pelvis is usually appropriate in patients with suspected vulvar cancer recurrence. Andersen et al [26] prospectively evaluated 27 patients with vulvar cancer (23 primary and 4 recurrent) who underwent contrast-enhanced CT scan of the chest, abdomen, and pelvis prior to treatment. IFLN metastases were diagnosed if short-axis diameter was >10 mm and/or abnormal pattern of contrast enhancement were observed. CT had sensitivity of 60%, specificity of 90%, PPV of 37.5%, and NPV of 95.7% for detection of IFLN metastases. CT Pelvis Contrast-enhanced CT of the pelvis may be considered in patients with suspected vulvar cancer recurrence. However, contrast-enhanced CT of chest, abdomen, and pelvis or FDG-PET/CT is preferred in this group. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT is usually appropriate in patients with suspected vulvar cancer recurrence. FDG-PET/CT, alone or in combination with MRI, can facilitate treatment planning prior to pelvic exenteration for recurrent gynecologic cancers.


Staging and Follow up of Vulvar Cancer

Staging and Follow up of Vulvar Cancer. Garganese et al [41] reported on FDG-PET/CT in 47 patients with vulvar cancer (44 primary and 3 recurrent) who underwent inguinofemoral lymphadenectomy because they were not candidates for SLN evaluation because of primary tumor >4 cm (n = 12), multifocal tumor (n = 9), prior surgery (n = 16), IFLN involvement (n = 7) or recurrent disease (n = 3). On a groin-based analysis, FDG-PET/CT demonstrated a sensitivity of 56%, specificity of 88%, PPV of 38%, NPV of 93%, and accuracy of 84% in detecting nodal metastases. MRI Pelvis MRI of the pelvis has superior soft-tissue contrast and multiplanar capability. Thus, MRI is the preferred imaging modality to define local extent of suspected or confirmed recurrent vulvar cancers, especially those in close proximity to or involving the urethra, vagina, and anus as it can aid treatment planning [6]. Contrast-enhanced imaging is advised [6]. Radiography Chest Routine radiography is usually not indicated in the evaluation of clinically suspected recurrence of vulvar cancer. There is only one report regarding the role of chest radiography for the initial staging of patients with vulvar cancer. Andersen et al [26] prospectively evaluated 27 patients with vulvar cancer (23 primary and 4 recurrent). Chest radiographs was performed in 24 of 27 patients and contrast-enhanced CT scan of the chest, abdomen, and pelvis was performed in all 27 patients. Only 1 of 24 chest radiographs revealed a clinically important finding (pulmonary metastases) from an asymptomatic and at that time unknown adenocarcinoma of the cecum. Chest radiographs did not alter initial gynecologic management in any of the patients. Staging and Follow-up of Vulvar Cancer US Duplex Doppler and US-guided Fine-Needle Aspiration Biopsy Groin There is no relevant literature to support or refute the use of US with Doppler and US-guided FNAB for the assessment of suspected vulvar cancer recurrence. Nevertheless, this procedure may be useful to confirm suspected IFLN metastases.


Hematospermia

Hematospermia.  Introduction/Background Hematospermia (HS), or hemospermia, the presence of blood in the ejaculate or semen, has been recognized for centuries. Although it is not uncommon to encounter HS in clinical practice, the exact prevalence and incidence are not known. Most men with HS are young (<40 years of age), and HS may occur either as a single episode or repeatedly over time. It is typically a cause of great anxiety to men, mainly because of the imagined possibility of underlying malignancy or venereal disease. HS may be associated with pathology in the prostate gland, seminal tract (seminal vesicles, vasa deferentia, and ejaculatory ducts), verumontanum, urethra, urinary bladder, epididymis, or testes, with cited causes reported to include prior prostatic biopsy, prostatic calculi, inflammatory or infectious conditions such as prostatitis or seminal vesiculitis, ductal obstruction, prostatic cyst formation, and rarely vascular malformations. The majority of cases of HS were thought to be idiopathic in nature; however, as a result of improved imaging techniques, the number of cases labeled as idiopathic has decreased significantly, with one of the main sites of bleeding occurring in the seminal vesicles [1-13]. Of specific etiologies, infectious or inflammatory conditions are the most common, accounting for approximately 40% of HS cases overall. An infectious or inflammatory condition of the urogenital tract is the most common etiology in men <40 years of age [1,6,9,14]. Overview of Imaging Modalities Transrectal ultrasound (ultrasound pelvis [prostate] transrectal) Transrectal ultrasound (TRUS) is a safe, inexpensive, effective, noninvasive, radiation-free imaging technique often used as the primary screening or diagnostic modality in men with HS to evaluate the prostate gland and seminal tract. Patients are typically placed in the left lateral decubitus position, and grayscale images are obtained with a 5.0- to 10-MHz TRUS transducer in axial and sagittal planes [12,13,19,20].


Hematospermia

Hematospermia. Color and power Doppler images can also be acquired, particularly when prostate cancer is suspected and prostatic biopsy is contemplated [2,8]. TRUS-guided aspiration or biopsy of the seminal vesicles or prostate gland can be performed to further elucidate the site of bleeding, to provide a definitive diagnosis if a lesion is detected, or to confirm the presence of ejaculatory duct obstruction [4,15]. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: publications@acr.org Hematospermia Magnetic resonance imaging Magnetic resonance imaging (MRI), with its excellent soft-tissue contrast, provides radiation-free, multiplanar, high-spatial-resolution anatomic evaluation of the prostate gland and seminal tract. Imaging should be performed at either 1.5T or 3T, although there is no consensus at this time on the appropriate coil selection or field strength. The fundamental advantage of 3T over 1.5T is increased signal-to-noise ratio, which improves the spatial, temporal, and spectral resolution. Comparable performance between multichannel phased array coil MRI of the prostate at 3T and endorectal phased array coil MRI at 1.5T has been reported [20]. As opposed to TRUS, MRI is operator independent and can be performed when TRUS is unsatisfactory or nondiagnostic. Subsequently, small field-of-view axial T1-weighted images and axial, sagittal, and coronal T2-weighted images are obtained for high- resolution evaluation of the prostate gland, seminal vesicles, ejaculatory ducts, and ampullary portions of the vasa deferentia, followed by large field-of-view images to evaluate for pelvic lymphadenopathy [3,7,10,21].


Hematospermia

Hematospermia. The increasing availability of 3T MRI, which offers a higher signal-to-noise ratio and improved spatial resolution, may preclude the use of an endorectal coil for evaluating the seminal tract [22]. Computed tomography Computed tomography (CT) is a noninvasive imaging modality that uses ionizing radiation to identify calcifications, gross soft-tissue masses, or cystic lesions of the prostate gland and seminal vesicles. However, it has limited value in the etiologic determination of HS given its lack of soft-tissue contrast and limitation in differentiating structural changes of the prostate and seminal tract [11,21]. Pelvic angiography Pelvic angiography can be useful to evaluate for vascular causes of HS and is mainly reserved for men with intractable HS with or without hematuria when clinical, laboratory, and noninvasive imaging evaluations have not revealed an etiology. If an arterial source of hemorrhage is identified, such as from the internal pudendal artery, transcatheter arterial embolization can be performed in the same session for therapeutic purposes [23]. Discussion of Imaging Modalities by Variant Factors that determine the extent of investigation are patient age, duration of HS, and associated symptoms and signs. However, a confounding issue is that currently there are no consensus or society guidelines on the distinction between transient or episodic HS and persistent HS. The distinction has been based on either the number of ejaculates or a specific time period, with differing opinions. Ultimately the decision to pursue further investigation will be made by the referring physician, typically a urologist. TRUS Many investigators have reported that TRUS should be used as the first-line imaging tool in this patient population. TRUS is very sensitive for detecting a variety of abnormalities that may involve the prostate gland and seminal tract in the setting of HS, reportedly demonstrating abnormalities in 82% to 95% of men with HS [4,12,13,19,21].


Hematospermia

Hematospermia. Abnormalities may include calcifications or calculi in the prostate, ejaculatory ducts, or seminal Hematospermia vesicles; seminal vesicle, ejaculatory duct, or prostatic cysts; benign prostatic hypertrophy; prostatitis; and Cowper gland masses. However, it is important to consider that some of these abnormalities can be found in asymptomatic patients, such as benign prostatic hyperplasia and prostatic calcifications, which are age-related changes, and nonobstructing prostatic cysts [10,13,28,29]. TRUS has shown utility in guiding transperineal aspiration of the seminal vesicles [4]. A recent prospective trial enrolled 106 patients with persistent HS and found the diagnostic accuracy of TRUS and transurethral seminal vesiculoscopy was 45.3% and 74.5%, respectively, although the diagnostic accuracy was higher when both modalities were combined. Vesiculoscopy was most useful in the detection of calculi and obstruction/stricture at the level of the verumontanum orifice or ejaculatory duct [19]. Computed tomography CT has very limited value in the etiologic determination of HS for the reasons described above. Pelvic angiography Angiography has been reported sparsely in the literature to be useful for vascular masses when evaluating men with intractable HS with or without hematuria when clinical, laboratory, and noninvasive imaging evaluations have not revealed the etiology. If an arterial source of hemorrhage is identified, transcatheter arterial embolization can be performed during the same session as well [23]. Although there are references that report on studies with design limitations, 3 good-quality studies provide good evidence. Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with


Dizziness and Ataxia

Dizziness and Ataxia.  aUniversity of Cincinnati Medical Center, Cincinnati, Ohio. bResearch Author, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio. cPanel Chair, Uniformed Services University, Bethesda, Maryland. dOhio State University, Columbus, Ohio. eUCONN Health, University of Connecticut, Farmington, Connecticut; Neurosurgery expert. fMontefiore Medical Center, Bronx, New York. gYale University School of Medicine, New Haven, Connecticut; Committee on Emergency Radiology-GSER. hWeill Cornell Medical College, New York, New York. iUniversity of Chicago, Chicago, Illinois. jUniversity of Arizona, Tucson, Arizona; Commission on Nuclear Medicine and Molecular Imaging. kUniversity of California Los Angeles, Los Angeles, California. lUniversity of California San Diego, San Diego, California. mOregon Health & Science University, Portland, Oregon. nUT Southwestern Medical Center, Dallas, Texas; American Academy of Neurology. oSchmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida; American College of Emergency Physicians. pThe University of Vermont Medical Center, Burlington, Vermont. qNaval Medical Center Portsmouth, Portsmouth, Virginia. rColumbia University Medical Center, New York, New York. sAssociation for Utah Community Health, Salt Lake City, Utah; American Academy of Family Physicians. tSpecialty Chair, University of Iowa Hospitals and Clinics, Iowa City, Iowa. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Dizziness and Ataxia


Dizziness and Ataxia

Dizziness and Ataxia. Special Imaging Considerations Conventional diagnostic angiography (DA) may be used in a specific subset of patients presenting with episodic vertigo if there is clinical concern for positional insufficiency of the posterior circulation. DA allows for real-time dynamic evaluation of vessel patency in various neck positions, which is difficult to accomplish via conventional CT angiography (CTA) or MR angiography (MRA) imaging. This information may inform subsequent surgical management in these patients [12]. DA also remains the reference standard for confirmation of clinically suspected VBI as well as vertebral artery dissection, both of which can present with vertigo [13,14]. In cases of vertebral artery dissection documented by DA, however, CTA demonstrated a similar sensitivity approaching 100% [14]. The risks of DA include the potential for rare, severe, or life-threatening allergic-like reactions to contrast media, renal injury related to iodinated contrast administration, potential vascular injury, or infarct due to catheter manipulation in the vessels, as well as local complications at the vascular access site to include infection, hematoma, pseudoaneurysm, or arterial occlusion. Transcranial Doppler ultrasound (US) has demonstrated differences in vascular flow parameters between patients with vertigo related to VBI, patients with vertigo unrelated to VBI, and asymptomatic controls, making this a potential diagnostic tool in the characterization of vertigo [13,15]. Brain PET using various radiotracers has shown promise in detecting presymptomatic neuronal dysfunction in patients with certain types of spinocerebellar ataxia (SCA) and in asymptomatic mutation carriers. Changes on PET were detectable sooner than alterations in morphology and signal intensity on conventional MRI. As such, PET may be a valuable adjunct to conventional brain imaging in this patient population [16,17]. OR Discussion of Procedures by Variant Variant 1: Adult. Brief episodic vertigo.


Dizziness and Ataxia

Dizziness and Ataxia. Triggered by specific head movements (eg, Dix-Hallpike maneuver). Initial imaging. Brief episodic vertigo triggered by specific head movements (eg, Dix-Hallpike maneuver) is referred to as triggered episodic vestibular syndrome (t-EVS) and is most commonly due to BPPV; however, more ominous central causes may clinically mimic BPPV and are collectively referred to as CPPV [1]. BPPV results from mobile debris (canaliths) in the vestibular labyrinth. The diagnostic criteria for BPPV are clinical and well established [18-20]. Imaging evaluation in BPPV with typical nystagmus on Dix-Hallpike testing is unnecessary. In contrast, patients with CPPV present with symptoms of t-EVS but negative or atypical Dix-Hallpike testing are at an increased risk of having an acute central cause of vertigo identified on imaging [6]. Potential causes of CPPV include mass lesions, hemorrhage, infarct, and demyelinating disease, among others [1]. Other specific t-EVS subgroups may also be at increased risk of incidental but potentially actionable findings on neuroimaging, including those with subjective symptoms but no objective signs, younger patients with post-traumatic onset of symptoms, elderly patients, those unresponsive to repositioning maneuvers, and those with short-term recurrence of symptoms [21]. Vestibular migraine may mimic a variety of causes of dizziness and vertigo, including t-EVS, but often has associated headache and other migrainous features (ie, photophobia, phonophobia, visual aura) [20,22]. Imaging is not required to Dizziness and Ataxia diagnose vestibular migraine. To summarize, most patients with t-EVS will not require imaging unless there are atypical features such as lack of nystagmus on provoking maneuvers (eg, Dix-Hallpike) or lack of response to treatment maneuvers (eg, Epley). CT Head With IV Contrast There is no relevant literature regarding the use of CT head with IV contrast in the evaluation of t-EVS.


Dizziness and Ataxia

Dizziness and Ataxia. CT Head Without and With IV Contrast There is no relevant literature regarding the use of CT head without and with IV contrast in the evaluation of t-EVS. CT Head Without IV Contrast Imaging evaluation in BPPV with typical nystagmus on Dix-Hallpike testing is unnecessary. Head CT allows for the evaluation of the intracranial structures; however, soft tissue contrast is inferior to MRI. In a single-center retrospective study of patients with episodic vertigo triggered by specific head movements but negative or atypical Dix-Hallpike testing (CPPV), CT detected acute brain lesions in 6% of cases compared with 11% with MRI [6]. CT Temporal Bone With IV Contrast There is no relevant literature regarding the use of CT temporal bone with IV contrast in the evaluation of t-EVS. CT Temporal Bone Without and With IV Contrast There is no relevant literature regarding the use of CT temporal bone without and with IV contrast in the evaluation of t-EVS. CT Temporal Bone Without IV Contrast There is no relevant literature regarding the use of CT temporal bone without IV contrast in the evaluation of t- EVS. CTA Head and Neck With IV Contrast There is no relevant literature regarding the use of CTA head and neck with IV contrast in the evaluation of t-EVS. MRA Head and Neck With IV Contrast There is no relevant literature regarding the use of MRA head and neck with IV contrast in the evaluation of t-EVS. MRA Head and Neck Without and With IV Contrast There is no relevant literature regarding the use of MRA head and neck without and with IV contrast in the evaluation of t-EVS. MRA Head and Neck Without IV Contrast Imaging evaluation in BPPV with typical nystagmus on Dix-Hallpike testing is unnecessary. MRA allows for evaluation of the course and luminal caliber of the arteries. MRA can also detect luminal filling defects, which may include thrombus, embolus, atherosclerotic plaque, dissection flap, or vascular web.


Dizziness and Ataxia

Dizziness and Ataxia. MRA of the head and neck can be performed either without intravenous (IV) contrast, with IV contrast, or as a combination of without and with IV contrast. Although imaging is not required in the setting of typical BPPV, MRA of the head and neck has been used to detect abnormalities of the carotid or vertebrobasilar arteries, which may be associated with symptoms of BPPV. The prevalence of vascular changes is higher in the elderly population with underlying comorbidities such as diabetes, hypertension, and hyperlipidemia in a small prospective study of 126 patients [23]. MRI Cervical and Thoracic Spine With IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine with IV contrast in the evaluation of t-EVS. MRI Cervical and Thoracic Spine Without and With IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine without and with IV contrast in the evaluation of t-EVS. MRI Cervical and Thoracic Spine Without IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine without IV contrast in the evaluation of t-EVS. MRI Head and Internal Auditory Canal With IV Contrast There is no relevant literature regarding the use of MRI head and internal auditory canal (IAC) with IV contrast in the evaluation of t-EVS. Dizziness and Ataxia MRI Head and Internal Auditory Canal Without and With IV Contrast Imaging evaluation in BPPV with typical nystagmus on Dix-Hallpike testing is unnecessary. MRI of the head and IACs provides evaluation of the entire brain with the addition of specific sequences tailored toward assessment of the skull base and associated cranial nerves. The addition of these sequences allows improved detection of small masses and compressive vascular lesions (ie, aneurysm, vessel tortuosity) in and around the IACs.


Dizziness and Ataxia

Dizziness and Ataxia. The addition of gadolinium-based IV contrast agents also improves the detection and characterization of masses as well as inflammatory, infectious, or demyelinating processes, which have been described in the setting of CPPV in a retrospective study of 500 patients [21]. MRI Head and Internal Auditory Canal Without IV Contrast There is no relevant literature regarding the use of MRI head and IAC without IV contrast in the evaluation of t- EVS. MRI Head With IV Contrast There is no relevant literature regarding the use of MRI head with IV contrast in the evaluation of t-EVS. MRI Head Without and With IV Contrast Imaging evaluation in BPPV with typical nystagmus on Dix-Hallpike testing is unnecessary. MRI allows detailed evaluation of the intracranial structures with improved soft tissue resolution when compared with CT. The addition of MRI of the brain following the IV administration of gadolinium-based contrast allows further characterization of any detected lesions and improves the detection and characterization of masses as well as inflammatory, infectious, or demyelinating processes, which have been described in the setting of CPPV [20]. Acute brain lesions have been reported in 6% of patients undergoing head CT and 11% of those undergoing MRI for CPPV [6]. MRI Head Without IV Contrast Imaging evaluation in BPPV with typical nystagmus on Dix-Hallpike testing is unnecessary. MRI allows detailed evaluation of the intracranial structures with improved soft tissue resolution when compared with CT. MRI of the head is not indicated for the initial diagnosis of typical BPPV. The presence of coexisting brain atrophy on MRI, however, is associated with a higher risk of prolonged dizziness following a diagnosis of BPPV and so may be of prognostic value in these patients in a retrospective study of 120 patients [24]. Variant 2: Adult. Acute persistent vertigo. Normal neurologic examination and HINTS examination is consistent with peripheral vertigo. Initial imaging.


Dizziness and Ataxia

Dizziness and Ataxia. The acute onset of persistent vertigo with associated nausea/vomiting, gait instability, nystagmus, and head-motion intolerance defines AVS. These patients may or may not have associated deficits on neurologic examination [1]. This variant will address the imaging approach to those presenting with AVS but a normal neurologic examination (isolated AVS). The approach to those with associated neurologic deficits will be discussed as a separate variant (Variant 3). Patients with vertigo of any cause are often initially evaluated in the emergency department. Although the use of CT imaging performed for this indication has dramatically increased over the past several decades, the detection rate of contributory central nervous system pathology in those with a normal neurologic examination remains very low (<1% in an emergency department in a single center, which included 3,165 patients); see Variant 8 [25]. This is not surprising because many patients with acute vertigo and a normal neurologic examination will have a benign peripheral etiology. In patients with AVS and a normal neurologic examination, the most common causes of symptoms are vestibular neuritis and labyrinthitis, neither of which has associated findings on CT imaging. The most worrisome cause of AVS to be excluded is a posterior circulation infarct involving the brainstem or cerebellum; see Variant 3. Although the prevalence of cerebrovascular disease in all patients presenting to the emergency department with dizziness or vertigo is approximately 4%, the prevalence of cerebrovascular disease in those presenting with AVS is closer to 25% and may be as high as 75% in the highest vascular risk cohorts [26]. Depending on the skill and training of the examiner, focal neurologic symptoms/signs are reportedly lacking in between one-third and two-thirds of these patients [27].


Dizziness and Ataxia

Dizziness and Ataxia. In one study, 11% of patients presenting with acute persistent vertigo but no focal neurologic symptoms/signs were found to have an acute infarct on CT or MRI of the brain [28]. Other studies estimate that 75% to 80% of patients presenting with AVS related to infarct have no associated focal neurologic deficits [29]. Isolated AVS is most commonly due to a benign peripheral cause; however, a lack of associated neurologic deficits does not exclude a central cause such as infarct. To address this, various bedside tests like the HINTS examination Dizziness and Ataxia have been developed to distinguish AVS of benign cause from posterior circulation infarct. When performed by specially trained practitioners, these tests have been shown to be even more sensitive than early MRI for the detection of infarct (100% versus 46%) [30]. Similar testing performed by nonexperts has shown more mixed results [6,31]. In another retrospective study involving 610 patients in an emergency department, not a single patient with an AVS, in whom the complete HINTS triad was consistent with peripheral vertigo, had abnormalities on CT/MRI [6]. Multiple sclerosis involving the brainstem or cerebellar peduncles is an additional but rare cause of AVS, accounting for approximately 4% of cases. Of note, nearly all of these patients also have additional abnormal neurologic findings suggesting a central lesion [32]. Even rarer causes of isolated AVS include cerebellar hemorrhage and a variety of autoimmune, infectious, and metabolic conditions [25]. Vestibular migraine may mimic a variety of causes of dizziness/vertigo, including AVS, but often has associated headache and other migrainous features (ie, photophobia, phonophobia, visual aura) [22,33]. Imaging is not required to diagnose vestibular migraine. To summarize, patients with isolated AVS may not require imaging if HINTS examination by specially trained providers is available and negative; otherwise, imaging may be required to rule out stroke.


Dizziness and Ataxia

Dizziness and Ataxia. CT Head With IV Contrast There is no relevant literature regarding the use of CT head with IV contrast in the evaluation of isolated AVS. CT Head Without and With IV Contrast There is no relevant literature regarding the use of CT head without and with IV contrast in the evaluation of isolated AVS. CT Head Without IV Contrast Imaging evaluation in isolated AVS without features of central vertigo is unnecessary. Patients with features of central vertigo or high baseline risk for stroke may be candidates for neuroimaging. Head CT allows for rapid evaluation of the intracranial structures. In isolated AVS, the detection rate of acute infarct may be as high at 11% at a single-center study involving 221 patients; therefore, noncontrast head CT may be of benefit in select patients [28]. Brain MRI may be useful for follow up evaluation if initial head CT is negative. CT Temporal Bone With IV Contrast There is no relevant literature regarding the use of CT temporal bone with IV contrast in the evaluation of isolated AVS. CT Temporal Bone Without and With IV Contrast There is no relevant literature regarding the use of CT temporal bone without and with IV contrast in the evaluation of isolated AVS. CT Temporal Bone Without IV Contrast There is no relevant literature regarding the use of CT temporal bone without IV contrast in the evaluation of isolated AVS. CTA Head and Neck With IV Contrast There is no relevant literature regarding the use of CTA head and neck with IV contrast in the evaluation of isolated AVS. MRA Head and Neck With IV Contrast There is no relevant literature regarding the use of MRA head and neck with IV contrast in the evaluation of isolated AVS. MRA Head and Neck Without and With IV Contrast There is no relevant literature regarding the use of MRA head and neck without and with IV contrast in the evaluation of isolated AVS.


Dizziness and Ataxia

Dizziness and Ataxia. MRA Head and Neck Without IV Contrast There is no relevant literature regarding the use of MRA head and neck without IV contrast in the evaluation of isolated AVS. MRI Cervical and Thoracic Spine With IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine with IV contrast in the evaluation of isolated AVS. Dizziness and Ataxia MRI Cervical and Thoracic Spine Without and With IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine without and with IV contrast in the evaluation of isolated AVS. MRI Cervical and Thoracic Spine Without IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine without IV contrast in the evaluation of isolated AVS. MRI Head and Internal Auditory Canal With IV Contrast There is no relevant literature regarding the use of MRI head and IAC with IV contrast in the evaluation of isolated AVS. MRI Head and Internal Auditory Canal Without and With IV Contrast Imaging evaluation in isolated AVS without features of central vertigo is unnecessary. Routine MRI of the head in the setting of vestibular neuritis, the most common cause of isolated AVS, is characteristically normal. Dedicated imaging of the IACs allows for improved evaluation of the vestibular nerve and may show a decreased caliber of the nerve following vestibular neuritis; however, this is not always present and is not required to establish the diagnosis [34,35]. Detection of vestibular nerve enhancement following the IV administration of gadolinium- containing contrast would also support the clinical diagnosis of vestibular neuritis [36]. Labyrinthitis, another common cause of AVS, may also have findings on contrast-enhanced MRI of the IACs; however, this is often diagnosed clinically due to the presence of associated hearing loss or tinnitus and will be discussed separately (Variant 4) [1].


Dizziness and Ataxia

Dizziness and Ataxia. MRI Head and Internal Auditory Canal Without IV Contrast There is no relevant literature regarding the use of MRI head and IAC without IV contrast in the evaluation of isolated AVS. MRI Head With IV Contrast There is no relevant literature regarding the use of MRI head with IV contrast in the evaluation of isolated AVS. MRI Head Without and With IV Contrast Imaging evaluation in isolated AVS without features of central vertigo is unnecessary. MRI of the head without and with IV contrast would be the imaging modality of choice to evaluate demyelinating, autoimmune, inflammatory, or metabolic conditions involving the brainstem or cerebellum, which would all be rare causes of isolated AVS [25]. Although brain parenchymal signal alterations would be demonstrable on precontrast imaging, the addition of gadolinium-containing IV contrast allows for the differentiation of acute and chronic demyelinating lesions as well as detection of other acute inflammation. MRI Head Without IV Contrast Imaging evaluation in isolated AVS without features of central vertigo is unnecessary. Because routine MRI of the head is characteristically normal in vestibular neuritis, MRI is not required for diagnosis. Patients with features of central vertigo or high baseline risk for stroke may be candidates for neuroimaging. In patients with isolated dizziness symptoms without associated neurological symptoms, the incidence of acute central lesions was 2.3% on MRI in a single center of 645 patients presented to the emergency department [37]. The presence of white matter abnormalities identified on MRI of the head, however, has been shown to positively correlate with the risk of developing subsequent chronic vestibular insufficiency and so may be prognostically useful especially in the elderly population [38]. Approximately 3% to 4% of patients presenting with isolated dizziness had acute stroke on MRI DWI [39]. MRI also has a better sensitivity than CT for the detection of parenchymal infarcts.


Dizziness and Ataxia

Dizziness and Ataxia. Studies of patients presenting with AVS related to infarct have shown an overall sensitivity of approximately 80% for MRI performed within 24 hours of symptom onset. Early MRI, however, may be negative in half of cases when the area of infarct is small (<10 mm in size) and located in the brainstem/cerebellum. Patients with these small areas of infarct are also those more likely to present with isolated AVS. In these cases, delaying MRI until at least 48 hours from symptom onset or repeating an initially negative MRI will improve lesion detection [29]. Variant 3: Adult. Acute persistent vertigo. Abnormal neurologic examination or HINTS examination is consistent with central vertigo. Initial imaging. Posterior circulation strokes involving the brainstem and cerebellum account for a smaller proportion of acute stroke presentations but may have severe devastating and debilitating consequences. It is estimated that 25% of AVS are caused by stroke. Approximately 20% of these patients have focal neurologic signs whereas the remainder have Dizziness and Ataxia CT Head With IV Contrast There is no relevant literature regarding the use of postcontrast head CT in the evaluation of suspected acute posterior fossa stroke. CT Head Without and With IV Contrast There is no relevant literature regarding the use of postcontrast head CT in the evaluation of suspected acute posterior fossa stroke. CT Head Without IV Contrast CT is usually performed first in the emergency setting for workup of acute stroke. Hemorrhage can be excluded rapidly to select patients for thrombolysis. Posterior fossa ischemic strokes are difficult to detect on CT with a low sensitivity (~10% at a single academic emergency department in 610 patients in a 2-year period) [6].


Dizziness and Ataxia

Dizziness and Ataxia. Overall, the diagnostic yield for head CT ordered in the emergency department for acute dizziness is low (2.2%; 1.6% for emergent findings in an academic emergency department in 448 patients), but MRI changes the diagnosis up to 16% of the time, acutely in 8% of cases [2]. CT Temporal Bone With IV Contrast There is no relevant literature regarding the use of CT temporal bone with IV contrast in the evaluation of suspected acute posterior fossa stroke. CT Temporal Bone Without and With IV Contrast There is no relevant literature regarding the use of CT temporal bone without and with IV contrast in the evaluation of suspected acute posterior fossa stroke. CT Temporal Bone Without IV Contrast There is no relevant literature regarding the use of CT temporal bone without IV contrast in the evaluation of suspected acute posterior fossa stroke. CTA Head and Neck With IV Contrast CTA head and neck may be performed for evaluation of suspected acute posterior fossa stroke, particularly those who are eligible for mechanical thrombectomy. MRA Head and Neck With IV Contrast MRA head and neck may be performed for the evaluation of acute ischemic strokes and may assist in the management of patients, particularly those who are eligible for mechanical thrombectomy. The decision between CTA and MRA for initial vascular evaluation may depend on institutional preferences. MRA Head and Neck Without and With IV Contrast MRA head and neck may be performed for the evaluation of acute ischemic strokes and may assist in the management of patients, particularly those who are eligible for mechanical thrombectomy. The decision between CTA and MRA for initial vascular evaluation may depend on institutional preferences. Dizziness and Ataxia MRI Cervical and Thoracic Spine With IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine with IV contrast in the evaluation of suspected acute posterior fossa stroke.


Dizziness and Ataxia

Dizziness and Ataxia. MRI Cervical and Thoracic Spine Without and With IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine without and with IV contrast in the evaluation of suspected acute posterior fossa stroke. MRI Cervical and Thoracic Spine Without IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine without IV contrast in the evaluation of suspected acute posterior fossa stroke. MRI Head and Internal Auditory Canal With IV Contrast There is no relevant literature regarding the use of MRI head and IAC with IV contrast in the evaluation of suspected acute posterior fossa stroke. MRI Head and Internal Auditory Canal Without and With IV Contrast There is no relevant literature regarding the use of MRI head and IAC without and with IV contrast in the evaluation of suspected acute posterior fossa stroke. MRI Head and Internal Auditory Canal Without IV Contrast There is no relevant literature regarding the use of MRI head and IAC without IV contrast in the evaluation of suspected acute posterior fossa stroke. MRI Head With IV Contrast There is no relevant literature regarding the use of postcontrast brain MRI in the evaluation of suspected acute posterior fossa stroke. MRI Head Without and With IV Contrast There is no relevant literature regarding the use of postcontrast brain MRI in the evaluation of suspected acute posterior fossa stroke. MRI Head Without IV Contrast The ability to detect an acute stroke on DWI is dependent on size [29]. False-negative MRIs with small strokes occurred 6 to 48 hours after the onset of vestibular symptoms. In this retrospective study, central oculomotor signs (odds ratio [OR] 2.8, 95% confidence interval [CI], 1.5-5.2) and focal abnormalities on clinical examination (OR 3.3, 95% CI, 1.8-6.2) are statistically significantly positive predictors for abnormal brain lesions on CT/MRI, whereas the transient nature of symptoms was associated with a reduced risk (OR 0.3, 95% CI, 0.1-0.6).


Dizziness and Ataxia

Dizziness and Ataxia. In a study of emergency department patients with dizziness, combined neurological symptoms with an OR of 16.72, P < . 01, was found to be the strongest predictor of a lesion positive on MRI [37]. In a cross-sectional study of 190 high-risk patients with dizziness, HINTS examination outperforms ABCD2 risk scores [30]. The diagnostic yield for head CT ordered in the emergency department for acute dizziness is low (2.2%; 1.6% for emergent findings), but MRI changes the diagnosis up to 16% of the time, acutely in 8% of cases [2]. Earlier MRI studies in posterior fossa stroke showed a high false-negative rate on DWI when performed within the first 24 hours of symptom onset [44,45]. This has improved with better imaging techniques over time. MRI has a higher sensitivity for acute ischemic strokes than CT, although within the first 48 hours DWI still can be falsely negative in approximately 50% of small ischemic strokes in the posterior fossa [6,46]. Some have advocated for delayed MRI (3-7 days) if initial imaging was negative [1,29]. One single-center study of 36 patients with basilar artery occlusion found DWI MRI helps predict outcome in basilar artery occlusion patients treated with intra-arterial thrombolysis [47]. Variant 4: Adult. Chronic recurrent vertigo. Associated with unilateral hearing loss or tinnitus. Initial imaging. In contrast to an isolated episode of acute vertigo, chronic recurrent vertigo suggests an intermittently symptomatic long-standing condition. When associated unilateral hearing loss or tinnitus is present, the diagnosis of MD should be considered. MD is of unknown etiology. Patients have intermittent episodes of vertigo, fluctuating sensorineural hearing loss, tinnitus, and aural fullness. Previously a purely clinical diagnosis, imaging in MD has increased in the past decade. It is associated with endolymphatic hydrops (distension of labyrinthine structures). Imaging may also Dizziness and Ataxia


Dizziness and Ataxia

Dizziness and Ataxia. be used to exclude other causes of such symptoms, such as vestibular schwannoma, superior semicircular dehiscence, and other IAC masses. Most imaging facilities are unable to perform the specific type of MRI required for evaluation of endolymphatic hydrops. Outside of academic medical centers with specialized imaging protocols, IAC MRI is usually performed to negatively exclude other causes of vertigo with unilateral hearing loss or tinnitus, rather than to make a positive imaging-based diagnosis of MD. CT Head With IV Contrast There is no relevant literature regarding the use of CT head with IV contrast in the evaluation of suspected MD. CT Head Without and With IV Contrast There is no relevant literature regarding the use of CT head without and with IV contrast in the evaluation of suspected MD. CT Head Without IV Contrast There is no relevant literature regarding the use of CT head without IV contrast in the evaluation of suspected MD. CT Temporal Bone With IV Contrast There is no relevant literature regarding the use of CT temporal bone with IV contrast in the evaluation of suspected MD. CT Temporal Bone Without and With IV Contrast There is no relevant literature regarding the use of CT temporal bone without and with IV contrast in the evaluation of suspected MD. CT Temporal Bone Without IV Contrast Superior semicircular canal dehiscence, which can present with similar symptoms to MD, can be readily diagnosed on a CT temporal bone without IV contrast. Three-dimensional CT temporal bone may be used for the evaluation of stenosis of the vestibular aqueduct [48,49] and high jugular bulb in patients with suspected MD [50]. CTA Head and Neck With IV Contrast There is no relevant literature regarding the use of CTA head and neck with IV contrast in the evaluation of suspected MD. MRA Head and Neck With IV Contrast There is no relevant literature regarding the use of MRA head and neck with IV contrast in the evaluation of suspected MD.


Dizziness and Ataxia

Dizziness and Ataxia. MRA Head and Neck Without and With IV Contrast There is no relevant literature regarding the use of MRA head and neck without and with IV contrast in the evaluation of suspected MD. MRA Head and Neck Without IV Contrast There is no relevant literature regarding the use of MRA head and neck without IV contrast in the evaluation of suspected MD. MRI Cervical and Thoracic Spine With IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine with IV contrast in the evaluation of suspected MD. MRI Cervical and Thoracic Spine Without and With IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine without and with IV contrast in the evaluation of suspected MD. MRI Cervical and Thoracic Spine Without IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine without IV contrast in the evaluation of suspected MD. Dizziness and Ataxia Highly specialized techniques with high resolution such as delayed 3-D fluid-attenuated inversion recovery (FLAIR), inversion recovery turbo spin-echo with real reconstruction (3-D real-inversion recovery), and imaged after gadolinium administration demonstrates accumulation of gadolinium in the endolymphatic sac [53-57]. Intratympanic gadolinium may also be performed but is more invasive [58,59]. Some studies used double dose contrast. Volumetric assessment with ratio of endolymph to perilymph volume in the cochlea and vestibule are performed. Endolymphatic hydrops and grading on MRI in patients with MD has shown correlation with clinical symptoms in multiple studies [52,60-64] and histopathologic specimens [65]. The vestibular endolymphatic space contacting the oval window has a high specificity and positive predictive value in differentiating MD ears from other ears in a small study [66].


Dizziness and Ataxia

Dizziness and Ataxia. Although most of the recent studies have been focused on the postgadolinium enhancement, the noncontrast portion of the MR studies can be helpful in diagnosing alternative causes such as stroke, superior semicircular dehiscence, and other IAC masses. Volumetric measure of inner ear structures has been shown to be useful [67]. Although often not specifically mentioned, a sequence (typically heavily T2-weighted) that shows both perilymph and endolymph to help determine the area of the entire labyrinth is needed, and this is performed without IV contrast. MRI Head With IV Contrast There is no relevant literature regarding the use of MRI head with IV contrast in the evaluation of suspected MD. MRI Head Without and With IV Contrast There is no relevant literature regarding the use of MRI head without and with IV contrast in the evaluation of suspected MD. MRI Head Without IV Contrast There is no relevant literature regarding the use of MRI head without IV contrast in the evaluation of suspected MD. CT Head With IV Contrast There is no relevant literature regarding the use of CT head with IV contrast in the evaluation of suspected VBI. Dizziness and Ataxia CT Head Without and With IV Contrast There is no relevant literature regarding the use of CT head without and with IV contrast in the evaluation of suspected VBI. CT Head Without IV Contrast CT head without IV contrast may be useful in the evaluation of suspected VBI, although brain MRI is expected to be more sensitive for the detection of posterior fossa infarcts. CT Temporal Bone With IV Contrast There is no relevant literature regarding the use of CT temporal bone with IV contrast in the evaluation of suspected VBI. CT Temporal Bone Without and With IV Contrast There is no relevant literature regarding the use of CT temporal bone without and with IV contrast in the evaluation of suspected VBI.


Dizziness and Ataxia

Dizziness and Ataxia. CT Temporal Bone Without IV Contrast There is no relevant literature regarding the use of CT temporal bone without IV contrast in the evaluation of suspected VBI. CTA Head and Neck With IV Contrast CTA allows for the evaluation of the course and luminal caliber of the studied arteries. CTA can also detect luminal filling defects, which may include thrombus, embolus, atherosclerotic plaque, dissection flap, or vascular web. In cases of vertebral artery dissection confirmed by conventional angiography, CTA has the highest reported sensitivity (100%), followed by MRA (77%) and Doppler US (71%), in a systematic review of 75 observational studies. Because symptomatic dissection may involve any portion of the vertebral artery, from the origin at the aortic arch branch vessels to the basilar artery, the entirety of the vessel should be included for evaluation [14]. MRA Head and Neck With IV Contrast MRA allows for evaluation of the course and luminal caliber of the arteries. MRA can also detect luminal filling defects, which may include thrombus, embolus, atherosclerotic plaque, dissection flap, or vascular web. MRA of the head and neck can be performed without IV contrast, with IV contrast, or as a combination of without and with IV contrast. Although 3-D time-of-flight MRA of the head is typically diagnostic without the use of IV gadolinium- based contrast agents, MRA of the neck is often best performed with contrast for better evaluation of the vessels with increased spatial resolution and decreased flow-related artifacts. In a study comparing the diagnostic performance of contrast-enhanced MRA of the neck to digital subtraction angiography in evaluation of vertebral artery origin stenosis, the sensitivity, specificity, and accuracy of MRA were shown to be as high as 97%, 98%, and 93%, respectively, in 49 patients [69]. However, MRA has not demonstrated significant differences in the degree of arterial stenosis between symptomatic patients with VBI and asymptomatic controls [13].


Dizziness and Ataxia

Dizziness and Ataxia. In cases of vertebral artery dissection confirmed by conventional angiography, CTA has the highest reported sensitivity (100%), followed by MRA (77%) and Doppler US (71%). The addition of nonluminal vessel wall imaging sequences likely improves the detection of nonstenotic arterial dissection, but it is unclear whether these types of lesions would result in VBI. Because symptomatic dissection may involve any portion of the vertebral artery, from the origin at the aortic arch branch vessels to the basilar artery, the entirety of the vessel should be included for evaluation [14]. MRA Head and Neck Without and With IV Contrast MRA allows for the evaluation of the course and luminal caliber of the arteries. MRA can also detect luminal filling defects, which may include thrombus, embolus, atherosclerotic plaque, dissection flap, or vascular web. MRA of the head and neck can be performed without IV contrast, with IV contrast, or as a combination of without and with IV contrast. Although 3-D time-of-flight MRA of the head is typically diagnostic without the use of IV gadolinium- based contrast agents, MRA of the neck is often best performed with contrast for better evaluation of the vessels with increased spatial resolution and decreased flow-related artifacts. In a study comparing the diagnostic performance of contrast-enhanced MRA of the neck to digital subtraction angiography in evaluation of vertebral artery origin stenosis, the sensitivity, specificity, and accuracy of MRA were shown to be as high as 97%, 98%, and 93%, respectively in 49 patients [69]. However, MRA has not demonstrated significant differences in the degree of arterial stenosis between symptomatic patients with VBI and asymptomatic controls [13]. In cases of vertebral artery dissection confirmed by conventional angiography, CTA has the highest Dizziness and Ataxia reported sensitivity (100%), followed by MRA (77%) and Doppler US (71%).


Dizziness and Ataxia

Dizziness and Ataxia. The addition of nonluminal vessel wall imaging sequences likely improves the detection of nonstenotic arterial dissection, but it is unclear whether these types of lesions would result in VBI. Because symptomatic dissection may involve any portion of the vertebral artery, from the origin at the aortic arch branch vessels to the basilar artery, the entirety of the vessel should be included for evaluation [14]. MRI Cervical and Thoracic Spine With IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine with IV contrast in the evaluation of suspected VBI. MRI Cervical and Thoracic Spine Without and With IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine without and with IV contrast in the evaluation of suspected VBI. MRI Cervical and Thoracic Spine Without IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine without IV contrast in the evaluation of suspected VBI. MRI Head and Internal Auditory Canal With IV Contrast There is no relevant literature regarding the use of MRI head and IAC with IV contrast in the evaluation of suspected VBI. MRI Head and Internal Auditory Canal Without and With IV Contrast There is no relevant literature regarding the use of MRI head and IAC without and with IV contrast in the evaluation of suspected VBI. MRI Head and Internal Auditory Canal Without IV Contrast There is no relevant literature regarding the use of MRI head and IAC without IV contrast in the evaluation of suspected VBI. MRI Head Without and With IV Contrast MRI allows for detailed evaluation of the intracranial structures with improved soft tissue resolution when compared with CT. MRI before and after the administration of gadolinium-containing IV contrast allows for the additional characterization of these tissues and improved detection of intracranial pathology.


Dizziness and Ataxia

Dizziness and Ataxia. In the setting of VBI, high- resolution vessel wall imaging of the posterior circulation using IV contrast may be of use as both a diagnostic and prognostic tool, but it is not used as initial imaging in the evaluation of suspected VBI. In a single-center study of 219 patients, when compared with MRA, atherosclerotic plaque in the basilar artery and associated luminal stenosis of >50% was more often identified on vessel wall imaging; however, the degree of narrowing was felt to be likely overestimated. Although atherosclerotic vessel narrowing can certainly result in VBI, the clinical applicability of these findings on vessel wall imaging has yet to be fully elucidated [70]. Interestingly, the degree of vessel wall enhancement in basilar artery stenosis on vessel wall imaging has been shown to correlate with the risk of subsequent infarct and may serve as a noninvasive prognostic marker in patients with VBI [71]. Additionally, alterations of perfusion parameters using arterial-spin labelling in the brain has been shown to correlate with the presence and severity of vertebrobasilar stenosis and serves as an adjunct to contrast-enhanced imaging of the vessel wall as well as luminal imaging via MRA/CTA [68]. MRI Head Without IV Contrast MRI head without IV contrast is useful in the evaluation of VBI and for the detection of posterior fossa infarcts. A negative MRI does not exclude the possibility of chronic ischemia without completed infarction and therefore does not replace the need for vascular imaging. Dizziness and Ataxia Variant 6: Adult. Chronic disequilibrium with signs of cerebellar ataxia. Initial imaging. Disequilibrium refers to a sensation of imbalance, unsteadiness, or instability. Disequilibrium in addition to loss of muscle coordination is a common finding in cerebellar ataxia, which indicates loss of coordination due to loss of normal motor control by the cerebellum.


Dizziness and Ataxia

Dizziness and Ataxia. Cerebellar ataxia includes a variety of clinical conditions characterized by neurodegeneration of the cerebellum and/or brainstem and may result from inherited or sporadic etiologies. The current classification system for the inherited cerebellar ataxias includes autosomal dominant spinocerebellar, autosomal recessive, congenital, mitochondrial, X-linked, and sporadic types. Autosomal ataxias have complex genetic heterogeneity and variable phenotypic expression, which makes diagnosis difficult [72]. Adult-onset sporadic ataxia encompasses a more heterogeneous group of etiologies, which includes toxic/nutritional, immune- mediated, infectious, degenerative, and reclassification as having a genetic basis [73]. Some patients with cerebellar ataxia may also have coexisting symptoms of central or peripheral vestibulopathy, which can further confound the clinic picture [74]. Imaging in cerebellar ataxia is aimed at primarily detecting parenchymal injury in the form of volume loss or alternations in attenuation (CT) or signal intensity (MRI). Patterns of parenchymal injury may suggest a certain ataxia subtype; however, there is a significant overlap of imaging features among various etiologies, and conventional neuroimaging may be unremarkable in early disease. As such, diagnosis relies on the combination of history, a thorough clinical neurologic examination, and imaging with confirmatory laboratory and/or genetic testing based on these findings [73]. In some forms of ataxia, detection of abnormal iron deposition or calcification may also be helpful [75,76]. Finally, imaging is also important to exclude nondegenerative central etiologies of ataxia such as mass lesion or infarct [77]. CT Head With IV Contrast There is no relevant literature regarding the use of CT head with IV contrast in the evaluation of cerebellar ataxia. CT Head Without and With IV Contrast There is no relevant literature regarding the use of CT head without and with IV contrast in the evaluation of cerebellar ataxia.


Dizziness and Ataxia

Dizziness and Ataxia. CT Head Without IV Contrast Head CT allows for evaluation of the intracranial structures; however, soft tissue contrast is inferior to MRI. Certain materials, however, are more conspicuous on CT imaging including calcification. Rare subtypes of SCA may show calcification within the brain parenchyma; however, other more common brain parenchymal changes in patients with cerebellar ataxia are best evaluated with MRI [76]. Additionally, parenchymal calcification can often be adequately detected and characterized on MRI. CT Temporal Bone With IV Contrast There is no relevant literature regarding the use of CT temporal bone with IV contrast in the evaluation of cerebellar ataxia. CT Temporal Bone Without and With IV Contrast There is no relevant literature regarding the use of CT temporal bone without and with IV contrast in the evaluation of cerebellar ataxia. CT Temporal Bone Without IV Contrast There is no relevant literature regarding the use of CT temporal bone without IV contrast in the evaluation of cerebellar ataxia. CTA Head and Neck With IV Contrast There is no relevant literature regarding the use of CTA head and neck with IV contrast in the evaluation of cerebellar ataxia. MRA Head and Neck With IV Contrast There is no relevant literature regarding the use of MRA head and neck with IV contrast in the evaluation of cerebellar ataxia. MRA Head and Neck Without and With IV Contrast There is no relevant literature regarding the use of MRA head and neck without and with IV contrast in the evaluation of cerebellar ataxia. Dizziness and Ataxia MRA Head and Neck Without IV Contrast There is no relevant literature regarding the use of MRA head and neck without IV contrast in the evaluation of cerebellar ataxia. MRI Cervical and Thoracic Spine With IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine with IV contrast in the evaluation of cerebellar ataxia.


Dizziness and Ataxia

Dizziness and Ataxia. MRI Cervical and Thoracic Spine Without and With IV Contrast There is no relevant literature regarding the use of MRI cervical and thoracic spine without and with IV contrast in the evaluation of cerebellar ataxia. MRI Cervical and Thoracic Spine Without IV Contrast MRI of the spine allows for evaluation of the spinal column as well as the soft tissues within and surrounding the spinal column including the spinal cord. Atrophy of the cervical spinal cord on MRI has been described in SCA type 1 (SCA1) and shown to be correlated with symptom severity, disease duration, and the number of pathologic cytosine, adenine, and guanine repeats, which serves at the genetic cause of SCA1 [78]. Similar atrophy has been reported in SCA type 7, Friedreich ataxia, and ataxia with vitamin E deficiency [79,80]. Spinal findings were associated with abnormalities of the brain parenchyma and generally not reported in isolation. Imaging of the spinal cord in other forms of cerebellar ataxia has either been reported as normal or, more often, not specifically described in the literature [81]. Spine MRI may be considered in patients with cerebellar ataxia and additional signs of spinal cord involvement, such as motor spasticity or sensory ataxia (see Variant 7). MRI Head and Internal Auditory Canal With IV Contrast There is no relevant literature regarding the use of MRI head and IAC with IV contrast in the evaluation of cerebellar ataxia. MRI Head and Internal Auditory Canal Without and With IV Contrast There is no relevant literature regarding the use of MRI head and IAC without and with IV contrast in the evaluation of cerebellar ataxia. MRI Head and Internal Auditory Canal Without IV Contrast There is no relevant literature regarding the use of MRI head and IAC without IV contrast in the evaluation of cerebellar ataxia. MRI Head Without and With IV Contrast MRI of the head is the preferred initial imaging modality for the evaluation of patients with cerebellar ataxia.


Dizziness and Ataxia

Dizziness and Ataxia. In cerebellar ataxia, morphologic changes (atrophy) and signal alterations primarily involve the cerebellum and brainstem. These findings are typically adequately evaluated on MRI without IV contrast; however, if there is concern for an inflammatory or neoplastic cause of cerebellar ataxia, contrast-enhanced imaging should be included. Advanced MRI techniques such as DWI/diffusion-tensor imaging and spectroscopy do not require contrast administration and have shown promise in detecting early changes in ataxia and may also be useful in distinguishing between some ataxia subtypes in some studies [82-84]. MRI Head Without IV Contrast MRI of the head is the preferred initial imaging modality for the evaluation of patients with cerebellar ataxia. In cerebellar ataxia, morphologic changes (atrophy) and signal alterations primarily involve the cerebellum and brainstem. These findings are typically adequately evaluated on MRI without IV contrast. Lack of contrast, however, may impair the ability to distinguish between degenerative and inflammatory/infectious causes of cerebellar ataxia. Advanced MRI techniques such as DWI/diffusion-tensor imaging and spectroscopy do not require contrast administration and have shown promise in detecting early changes in ataxia and may also be useful in distinguishing between some ataxia subtypes in some studies [82-84]. Variant 7: Adult. Chronic disequilibrium with signs of sensory or proprioceptive ataxia. Initial imaging. Disequilibrium refers to a sensation of imbalance, unsteadiness, or instability. Symptoms of disequilibrium may result from neurodegeneration or inflammation involving the spinocerebellar tracts, dorsal columns of the spinal Dizziness and Ataxia cord, dorsal root ganglia, or more peripheral sensory nerves. In contrast to cerebellar ataxia (see Variant 6), sensory or proprioceptive ataxia indicates loss of coordination due to loss of normal position sense and is characterized by worsening with closed eyes (eg, Romberg test).


Dizziness and Ataxia

Dizziness and Ataxia. SCAs may manifest with these symptoms if there is involvement of the described spinal structures. Peripheral neuropathy (ataxic neuropathy) can also be seen in various forms of SCA; however, cerebellar symptoms should be present [81]. The combination of cerebellar ataxia and sensory neuropathy, both of which can contribute to symptoms of disequilibrium, has also been described in cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome [85]. In these cases, neuroimaging is primarily directed at evaluating the coexisting central abnormalities of the cerebellum and brainstem (see Variant 6). There are also several known autoimmune sensory ataxic neuropathies, which result in symptoms of disequilibrium without cerebellar or brainstem involvement. Diagnostic confirmation of these neuropathies is generally via clinical evaluation and electrodiagnostic testing; however, targeted US has also been used to detect changes in size of the affected nerve in a small study [86]. Most of the studies in patients with SCA involve a small number of patients due to the rarity of the disease and particular mutations. CT Head With IV Contrast There is no relevant literature regarding the use of CT head with IV contrast in the evaluation of sensory ataxia. CT Head Without and With IV Contrast There is no relevant literature regarding the use of CT head without and with IV contrast in the evaluation of sensory ataxia. CT Head Without IV Contrast There is no relevant literature regarding the use of CT head without IV contrast in the evaluation of sensory ataxia. CT Temporal Bone With IV Contrast There is no relevant literature regarding the use of CT temporal bone with IV contrast in the evaluation of sensory ataxia. CT Temporal Bone Without and With IV Contrast There is no relevant literature regarding the use of CT temporal bone without and with IV contrast in the evaluation of sensory ataxia.


Dizziness and Ataxia

Dizziness and Ataxia. CT Temporal Bone Without IV Contrast There is no relevant literature regarding the use of CT temporal bone without IV contrast in the evaluation of sensory ataxia. CTA Head and Neck With IV Contrast There is no relevant literature regarding the use of CTA head and neck with IV contrast in the evaluation of sensory ataxia. MRA Head and Neck With IV Contrast There is no relevant literature regarding the use of MRA head and neck with IV contrast in the evaluation of sensory ataxia. MRA Head and Neck Without and With IV Contrast There is no relevant literature regarding the use of MRA head and neck without and with IV contrast in the evaluation of sensory ataxia. MRA Head and Neck Without IV Contrast There is no relevant literature regarding the use of MRA head and neck without IV contrast in the evaluation of sensory ataxia. MRI Cervical and Thoracic Spine Without and With IV Contrast MRI of the spine allows for evaluation of the spinal column as well as the soft tissues within and surrounding the spinal column including the spinal cord. Atrophy of the cervical spinal cord has been reported in several forms of degenerative ataxia, which may be a helpful diagnostic finding in patients presenting with disequilibrium [78-80]. In patients with chronic disequilibrium due to sensory ataxia and loss of proprioception that is out of proportion to Dizziness and Ataxia other sensory modalities and motor function, spine MRI is useful to evaluate the dorsal columns of the spinal cord (eg, compressive myelopathy, B12/copper deficiency, or tabes dorsalis neurosyphilis). These findings are typically adequately evaluated on MRI without IV contrast; however, if there is concern for an inflammatory or infectious neoplastic cause of sensory ataxia, contrast-enhanced imaging should be included. MRI Cervical and Thoracic Spine Without IV Contrast MRI of the spine allows for evaluation of the spinal column as well as the soft tissues within and surrounding the spinal column including the spinal cord.