Headache PCAs

Headache PCAs. CTV Head With IV Contrast CTV head with IV contrast can be useful in the initial imaging evaluation of new headache during pregnancy or peripartum period, as this patient demographic is at a higher risk for thromboembolic complications such as CVT, especially in the postpartum period [12,49]. In pregnant patients requiring contrast-enhanced evaluation of the dural venous sinuses, CTV is the modality of choice because iodinated contrast agents are generally considered safer than gadolinium-based contrast agents (GBCA) with regard to potential effects on the fetus. After an initial head CT, a concurrent or follow-up CTV is useful in suspected cases of venous thrombosis. MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period. In some scenarios, brain MRA may be useful following or in conjunction with brain MRI when evaluating for cerebrovascular etiologies of headache such as RCVS [12,52]. Headache MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy.


Headache PCAs

Headache PCAs. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy. MRI Head Without IV Contrast MRI head without IV contrast can be useful in the initial imaging evaluation of new headache during pregnancy or peripartum period. There are multiple etiologies that can cause secondary headaches in pregnant women. For TCH, there is the possibility of arterial pathologies such as aneurysmal SAH or RCVS, especially in the postpartum period (also refer to Variant 1). Structural lesions include intracranial neoplasms and lesions originating from the pituitary gland. Another condition to consider is intracranial hypertension, especially in an obese female (also refer to variant 4). Preeclampsia and eclampsia are diseases of pregnancy that can present with headache and with findings of PRES on neuroimaging [47,49-51]. Brain MRI is the study of choice to evaluate for vasogenic edema due to endothelial dysfunction in PRES. It is best seen on FLAIR and T2-weighted imaging, which is more sensitive for abnormalities in the posterior fossa than head CT, which is abnormal in 45% of patients with PRES. In the setting of headache with new onset seizures, MRI can potentially detect the causative mass/lesion or PRES to support a diagnosis of eclampsia. [49,50]. Lesions originating from the pituitary gland are also readily detectable on MRI [30,49]. MRV Head With IV Contrast There is no relevant literature to support the use of MRV head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy.


Headache PCAs

Headache PCAs. MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy. MRV Head Without IV Contrast MRV head without IV contrast can be useful in the initial imaging evaluation of new headache during pregnancy or peripartum period, because this patient demographic is at a higher risk for thromboembolic complications such as CVT, especially in the postpartum period [12,49]. After an initial brain MRI, a concurrent or follow-up MRV is useful in suspected cases of venous thrombosis. Because the recommendation is to avoid administering IV GBCA during pregnancy, this is typically performed using a noncontrast technique such as time-of-flight or phase-contrast imaging. Over the course of the last 2 decades, several studies have demonstrated a higher incidence of neuropathology for selected patients with certain red and orange flags. For example, a British literature review demonstrated that in the primary care setting, the risk of a brain tumor with a headache presentation is 0.09%; however, when the headache was associated with abnormal findings on neurologic examination, with aggravation by exertion, with vomiting, or Headache Posttraumatic onset headaches are defined as those that develop within a 7-day interval of trauma by the ICHD-3; this subset of headaches is defined as chronic or persistent if they persist beyond 3 months [23,55]. Headache One study examining 3,630 patient records noted clinically significant abnormal noncontrast CT scans in 7 patients who had a normal neurologic examination. In this study, these 7 patients described their headaches as severe and nonremitting. The study concludes that noncontrast head CT may be useful for patients suffering from severe and unremitting headaches [62].


Acute Pelvic Pain in the Reproductive Age Group.  Introduction/Background Premenopausal patients with acute pelvic pain often pose a diagnostic dilemma. They may exhibit additional nonspecific signs and symptoms, the most common being nausea, vomiting, and leukocytosis. The differential considerations encompass gynecological and obstetrical causes (eg, hemorrhagic ovarian cysts, pelvic inflammatory disease [PID], ovarian torsion, ectopic pregnancy, spontaneous abortion, or labor and placental abruption), as well as nongynecological etiologies (eg, appendicitis, inflammatory bowel disease, infectious enteritis, diverticulitis, urinary tract calculi, pyelonephritis, and pelvic thrombophlebitis). The choice of imaging modality is determined by the most likely clinically suspected differential diagnosis, because each modality differs in the ability to depict disease in the various pelvic organs. Thus, a thorough clinical evaluation of the patient is required to determine the index of suspicion among the various etiologies. Diagnostic considerations should be based upon the correlation of history, physical examination, and laboratory testing before a radiologic examination is chosen. Details on risk to the fetus, as well as guidelines on screening for pregnancy, minimizing radiation exposure, and risk assessment, can be found throughout this document. Special Imaging Considerations Details on risk to the fetus, guideline on screening for pregnancy, minimizing radiation exposure, and risk assessment can be found in the ACR-SPR Practice Parameter for Imaging Pregnant or Potentially Pregnant Adolescents and Women with Ionizing Radiation [1]. Use of contrast in MRI during pregnancy should be done with caution, because the gadolinium-chelate molecules are excreted in the amniotic fluid and may remain there for an indeterminate amount of time before finally being reabsorbed and eliminated [2].


Acute Pelvic Pain in the Reproductive Age Group. Gadolinium is considered a pregnancy category C drug (it should be administered only if the potential benefit outweighs the risk) because animal studies have revealed adverse effects. Among 26 patients who had exposure to gadopentetate-dimeglumine in the periconceptional and first trimester period, only one congenital birth anomaly was found (hemangiomas) [3]. However, no well-controlled studies of the teratogenic effects of these media in 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 Acute Pelvic Pain in the Reproductive Age Group pregnant patients have been performed. Thus, if the information requested from the MRI study with intravenous (IV) contrast cannot be acquired using other modalities and is needed to potentially affect the care of the patient or fetus during the pregnancy, and the ordering physician believes that it is not prudent to wait until the patient is no longer pregnant, IV contrast may be administered and the rationale diligently documented. It is recommended that informed consent be obtained from the patient after discussion with the referring physician [4]. Acute Pelvic Pain in the Reproductive Age Group Generally, MRI of the pelvis may provide sufficient anatomic coverage without including the entire abdomen as with MRI of the abdomen and pelvis and, thus, may be used in selected cases as a second-line imaging modality. Cesarean scar pregnancy was accurately diagnosed in 95.5% of cases using contrast-enhanced MRI compared with 88.6% using US in a retrospective analysis of 44 patients with cesarean section scar pregnancy.


Acute Pelvic Pain in the Reproductive Age Group. This suggests that contrast-enhanced MRI could be used as a reliable adjunct for diagnosing cesarean scar pregnancy in select cases or if US is inconclusive or nondiagnostic. The typical findings of a gestational sac embedded in the anterior lower part of the uterus in the sagittal T2-weighted views were identified in all the patients. However, MRI examinations were performed approximately 5 days after the US examinations, which may have resulted in some bias, and same- day studies might have yielded similar sensitivity between both modalities [6]. Please refer to the Special Imaging Considerations section above for a discussion about the use of gadolinium-based contrast in the setting of pregnancy. In the early 1990s, Doppler imaging was suggested as a tool allowing for increased detection rate of ectopic pregnancy, increasing sensitivity from 71% to 87% [11]; however, a recent study evaluating the correlation between adnexal sonographic findings and tubal rupture found no statistically significant correlation. Nonspecific adnexal Acute Pelvic Pain in the Reproductive Age Group findings allows earlier detection of ectopic pregnancy than previously reported findings of detection of a yolk sac or embryonic heartbeat [12]. US Pelvis Transabdominal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible. A transabdominal-only approach could serve as an alternative if a transvaginal approach is not feasible. TVUS and transabdominal US (TAUS) of the pelvis are the most useful imaging modalities for initial assessment when an obstetrical or gynecological etiology is suspected [13]. US Pelvis Transvaginal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible. TVUS is the most useful method to evaluate the endometrium, early pregnancy, and adnexa [14].


Acute Pelvic Pain in the Reproductive Age Group. TVUS is currently considered the single best diagnostic modality to assess for ectopic pregnancy [15]. In a retrospective study of 1,880 patients presenting to the emergency department with first trimester pain or vaginal bleeding, an overall accuracy of TVUS diagnosis was 78%, with a specificity above 90% but a low sensitivity of 35%. The sensitivity for ectopic and intrauterine pregnancy diagnosis is even lower in the absence of a yolk sac, 13% for ectopic pregnancy and 4% for intrauterine pregnancy. However, specificity is preserved in the absence of the yolk sac and remains above 90% [18]. A meta-analysis of 14 studies with 12,101 patients with ectopic pregnancy showed a positive likelihood ratio of 111 for the finding of adnexal mass without an intrauterine pregnancy on TVUS. This makes TVUS the single best diagnostic modality for evaluating patients with suspected ectopic pregnancy. A lack of adnexal abnormalities on TVUS decreases the likelihood of ectopic pregnancy with a negative likelihood ratio of 0.12 [15]. CT findings of tubo-ovarian abscess (TOA) include a thick-walled fluid density in adnexal location, septations within the mass, indistinct borders between the uterus and adjacent bowel loops, and gas bubbles within the mass. Other findings include thickening and anterior displacement of the round ligament, which suggest adnexal origin rather than gastrointestinal tract origin. Findings of a tubular cystic lesion with multiple satellite lesions were pathologically proven to be pyosalpinx in 10 of 14 cases [23]. The presence of a right ovarian vein entering a right pelvic abscess had a 100% specificity and 94% sensitivity to TOA and may help differentiate from peri-appendiceal abscess [24]. In the setting of endometriosis, CT evaluation may demonstrate secondary signs of architectural distortion, thickening of bowel serosa, or even bowel obstruction, although the imaging findings may not be specific to deep pelvic endometriosis.


Acute Pelvic Pain in the Reproductive Age Group. Findings of irregular peripherally enhancing adnexal cyst usually accompanied by hemorrhagic pelvic free fluid might also indicate a ruptured hemorrhagic cyst. Acute Pelvic Pain in the Reproductive Age Group MRI Pelvis Without and With IV Contrast There is no relevant literature to support the use of pelvic MRI without and with IV contrast as the initial imaging modality for the evaluation of acute pelvic pain. However, MRI can be useful for equivocal cases of ovarian torsion, PID, TOA, and other gynecological causes of acute pelvic pain in patients of reproductive age such as fibroid torsion or necrosis or in patients that are unable to tolerate TVUS. For MRI evaluation of adnexal torsion, a meta-analysis including 18 studies (1,654 patients, 665 cases) reported a pooled sensitivity of 81% and specificity of 91% [22]. An enlarged ovary with or without an underlying mass and a twisted pedicle suggest adnexal torsion (with multiplanar MRI acquisitions potentially necessary for better detection of the twisted pedicle). Other findings may include subacute ovarian hematoma (better assessed with T1- weighted sequences with fat saturation), abnormal or absent ovarian enhancement, ascites, deviation of the uterus to the side of the twist, engorged vessels on the twisted side, and fallopian tube thickening [21]. A prospective cohort study with 187 patients evaluated with MRI for PID showed a sensitivity, specificity, PPV, negative predicative value (NPV), and accuracy with conventional MRI findings (T1-weighted, T2-weighted with fat saturation, postcontrast sequences) of 90.7%, 93.3%, 98.3%, 70.0%, and 91.2%, respectively. Adding DWI yielded a sensitivity, specificity, PPV, NPV, and accuracy of 98.4%, 93.3%, 98.4%, 93.3%, and 97.5%, respectively, with overall increased accuracy, sensitivity, and NPV [25].


Acute Pelvic Pain in the Reproductive Age Group. MRI with DWI and contrast-enhanced sequences showed a sensitivity of 83.3% for ovarian torsion, 100% for endometriotic cysts, 100% for hemorrhagic cysts, 83.3% for TOA, and 87.5% for dermoid cysts in a prospective study on 74 patients evaluated with TVUS and MRI. Overall sensitivity of MRI in these pathological entities was 94.6% [26]. A TOA is characterized by an ill-defined adnexal mass with thick regular or irregular enhanced walls containing fluid. The signal intensity was variable from low signal intensity on T1-weighted images to intermediate or high signal intensity on T2-weighted images. The solid component (if present) may include thickened septa or wall, papillary projection, and various degrees of solid portions, which enhance after contrast injection. The sensitivity, specificity, PPV, NPV, and accuracy of MRI findings for predicting TOA were 47.1%, 91.4%, 84.2%, 64%, and 69.6%, respectively, in the absence of DWI and apparent diffusion coefficient (ADC) values [27]. Deep pelvic endometriosis may be identified as T2 hypointense fibrosis, most commonly seen at the torus uterinus and along the uterosacral ligaments, which may or may not contain T1 hyperintense hemorrhagic foci or T2 hyperintense glands. Other findings may include T2 hypointense obliteration of the fat planes anteriorly to the rectum/sigmoid colon, posteriorly to the vaginal wall or cervix, and obliteration the pouch of Douglas. The sensitivity, specificity, PPV, NPV, and accuracy of MRI for deep pelvic endometriosis were 90.3%, 91%, 92.1%, 89%, and 90.8%, respectively [28]. US Duplex Doppler Pelvis Doppler US imaging is integral for evaluation of abnormal vascularity (in case of inflammation) or lack of vascularity (in case of ovarian torsion). This document considers Doppler imaging to be a standard component of pelvic US.


Acute Pelvic Pain in the Reproductive Age Group. A meta-analysis reported a similar pooled sensitivity and specificity in diagnosing adnexal torsion using Doppler US (7 studies, 845 patients, sensitivity 80% and specificity 88%) compared with the grayscale US only (12 studies, 1,187 patients, sensitivity 79% and specificity 76%) [22]. Ovarian torsion may lead to adnexal necrosis and infertility, so early detection is essential. A prospective study on 159 patients showed that all patients with adnexal torsion had absent flow or abnormal flow pattern in the ovarian Acute Pelvic Pain in the Reproductive Age Group vein. In 13 patients whose only abnormality was absent or abnormal ovarian venous flow with normal grayscale US appearance and normal arterial blood flow, 8 of those patients (62%) had adnexal torsion or subtorsion [29]. In cases of adnexal torsion, a whirlpool sign can be located either lateral or medial to the affected ovary. A larger volume of the ovarian or paraovarian mass was associated with a greater probability of a lateral whirlpool sign in a small retrospective study of 30 patients [30]. A retrospective study of 22 patients evaluated for adnexal torsion with whirlpool sign on US, 90.0% of whom had adnexal torsion confirmed on laparoscopy [31]. Power Doppler TVUS was 100% sensitive and 80% specific in PID diagnosis (overall accuracy 93% in a study of 30 patients with PID and 20 patients with hydrosalpinx as a control group) [32]. Specific US signs of PID, including wall thickness >5 mm, cogwheel sign, incomplete septa, and the presence of cul-de-sac fluid, discriminated patients with acute PID from the control group of patients with hydrosalpinx. Doppler US findings of hyperemia and lower pulsatility index allowed further discrimination between PID and hydrosalpinx with a high level of significance (P < . 01) [32]. US Pelvis Transvaginal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible.


Acute Pelvic Pain in the Reproductive Age Group. TVUS and TAUS of the pelvis is the most useful imaging modality for initial assessment when an obstetrical or gynecological etiology is suspected [13]. A combined transabdominal and transvaginal approach is typically used for pelvic US imaging. TVUS demonstrated a sensitivity of 83.3% for ovarian torsion, 84% for endometriotic cyst, 88.2% for hemorrhagic cysts, 58.3% for TOA, and 62.5% for dermoid cysts in a prospective study on 74 patients evaluated with TVUS and MRI. Overall sensitivity of TVUS for these pathological entities was 78.4% [26]. For the diagnosis of adnexal torsion with US, a meta-analysis of 12 studies including 1,187 patients reported a pooled sensitivity of 79% and a pooled specificity of 76%, with negative and positive likelihood ratios of 0.29 and 4.35, respectively [22]. Signs of ovarian torsion on US have varying accuracy: the sensitivity and specificity are 21% and 100% for ovarian tissue edema; 52% and 91% for absence of intraovarian vascularity; 76% and 99% for absence of arterial flow; and 100% and 97% for absence or abnormal venous flow [29]. Other signs indicating torsion are a unilaterally enlarged ovary with central afollicular stroma and multiple uniform 8 to 12 mm peripheral follicles (found in up to 74% of cases); ovarian enlargement is defined as a maximal ovarian dimension of >4 cm or volume >20 cm3 in a premenopausal patient. However, up to 5% of torsed ovaries have been reported to be of normal size [21]. PID can be difficult to diagnose because the symptoms are often subtle and mild. In a small prospective study of 52 patients, the detection rate of moderate-to-severe salpingitis with US was 100%, compared with 25% in the case of mild salpingitis. Bilateral adnexal masses were seen 82% of the time in patients with PID versus 17% for those with other diagnoses. The positive likelihood ratio was 4.8, and the negative likelihood ratio was 0.22.


Acute Pelvic Pain in the Reproductive Age Group. In cases of salpingitis, the masses lying adjacent to the ovaries were on average 2 to 3 cm in diameter, solid (n = 14), unilocular cystic (n = 4), multilocular cystic (n = 3), or multilocular solid (n = 1), with thick walls and well vascularized at color Doppler [33]. Other specific TVUS findings, including wall thickness >5 mm, cogwheel sign, incomplete septa, and the presence of cul-de-sac fluid, differentiated patients with PID from the control group of hydrosalpinx [32]. Pelvic US has a reported sensitivity of 93% and a specificity of 98% for identification of TOA, a complication of PID. A tubo-ovarian complex is an inflammatory pelvic mass with no pus collection in which adherent, inflamed, edematous ovary, and tubes cannot be separated with the endovaginal probe. TOA demonstrates loss of the normal boundaries of the structures by pus-filled tissue with typical features of complex adnexal mass of varying echogenicity with debris, septations, and irregular margins. Other findings of TOA are pyosalpinx and loculated and speckled echogenic fluid in the cul-de-sac [35]. Evaluation of endometriosis in 104 patients revealed, with respect to rectosigmoid and retrocervical sites, a sensitivity of 98% and 95%, a specificity of 100% and 98%, a PPV of 100% and 98%, an NPV of 98% and 97%, and an accuracy of 99% and 97% with TVUS, demonstrating better results than MRI [36]. A small retrospective case series of 8 pregnant patients with inconclusive findings on MRI and persistent or worsening severe abdominal pain found CT of the abdomen and pelvis useful to diagnose internal hernia, intestinal volvulus, perforation of acute appendicitis, and hemoperitoneum. However, only 75% of these patients received IV contrast for their imaging study [38]. MRI abdomen and pelvis may be appropriate if index of suspicion is high for appendicitis or bowel abnormalities, especially late in pregnancy.


Acute Pelvic Pain in the Reproductive Age Group. The rate of nonvisualization of the appendix on MRI is lower than US and reported to be 30.9% in a retrospective cohort study of 171 pregnant patients. Patients with nonvisualization of the appendix on MRI were more likely to be beyond the first trimester [40]. Evaluation for appendicitis with pelvic MRI in 51 pregnant patients for which a previous US did not demonstrate the appendix showed an overall sensitivity of 100%, a specificity of 93.6%, and a prevalence-adjusted PPV and NPV of 1.4% and 100%, respectively, with an accuracy of 94.0% [41]. Another recent study in 49 pregnant patients showed that in 88% of patients, appendicitis was ruled out, and surgery was prevented when MRI was performed after inconclusive US. MRI diagnosed all cases with acute appendicitis, with one case remaining inconclusive. The overall statistical performance of MRI shows a similar NPV of 100% with PPV of 83.3% [42]. Visualization of the normal appendix on MRI may be sometimes challenging. However, a retrospective study in 58 pregnant patients with suspected appendicitis showed that if MRI study was of sufficient diagnostic quality, with no ancillary signs of appendicitis, there were no cases of acute appendicitis. This was true despite the lack of visualization of the appendix in up to 50% of cases by at least 1 of 3 radiologists participating in the study. Therefore, if appendix is not visualized, the recommendation for interpretation is to word the report as low risk for appendicitis rather than indeterminate for excluding appendicitis [43]. The T1 bright appendix sign, defined as a high-intensity signal filling more than half the length of the appendix on T1-weighted imaging, was shown to be a specific sign for a normal appendix in a retrospective study of 125 pregnant patients. The sensitivity, specificity, PPV, and NPV are 44.9%, 95.5%, 97.6%, and 30.0%, respectively.


Acute Pelvic Pain in the Reproductive Age Group. In this study, all 4 patients with a borderline size appendix with appendicitis showed negative T1 bright appendix sign [44]. The addition of DWI showed no significant improvement to MRI detection of appendicitis in a retrospective study of 125 pregnant patients [45]. Evaluation of urinary causes of pain in pregnant patients can be performed with static-fluid MR urography without gadolinium administration. Physiological hydronephrosis can be diagnosed by extrinsic compression of the middle third of the ureter by a gravid uterus, no filling defect, and a collapsed ureter below it; whereas ureteral obstruction by a calculus can demonstrate renal edema or perirenal/periureteral fluid, and in cases with distal calculi, MR urography would show a double kink sign with constriction at the pelvic brim and at the vesicoureteral junction with a standing column of urine in the pelvic ureter. Small calculi were only identified using high resolution T2- weighted sequences [46]. Evaluation for pelvic deep vein thrombosis is limited with Doppler US, as demonstrated in a small study of 27 patients with median gestational age of 29 weeks in which 3 cases of pelvic deep vein thrombosis were diagnosed with time-of-flight MRI sequences after normal US. Deep vein thrombosis was extending more cranially into the pelvis in 65% of women than on the US, suggesting that MRI has an important role as a complementary technique in diagnosing deep vein thrombosis during pregnancy [47]. Acute Pelvic Pain in the Reproductive Age Group US Abdomen and Pelvis Transabdominal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging and both should be performed when possible. A transabdominal-only approach for the pelvis could serve as an alternative if the transvaginal approach is not feasible. The sensitivity, specificity, and accuracy of abdominal US for the diagnosis of appendicitis in 38 pregnant patients were 61.2%, 80%, and 63.8%, respectively [48].


Acute Pelvic Pain in the Reproductive Age Group. US performance for the evaluation of appendicitis in pregnant patients appears to be similar to the same-age nonpregnant patients, as shown in a case-control study with 67 pregnant patients compared with 133 nonpregnant young patients. PPV was 94% in the pregnant group and 91% in the nonpregnant group, with corresponding NPV of 40% and 43% [49]. This is even though the appendix is not visualized on US in 68% to 97% of patients [40]. US with graded compression of the appendix has similar accuracy to nonenhanced CT; however, it is more limited in the third trimester due to the large size of the gravid uterus [39]. This may be a useful initial imaging approach if pregnancy location and gestational age are unknown at the time of an acute presentation. US Duplex Doppler Adnexa A combined transabdominal and TVUS approach is typically used for pelvic US imaging. This document considers Doppler imaging to be a standard component of pelvic US. In a recent single-center retrospective study of 790 patients, CT of the abdomen and pelvis with IV contrast demonstrated a statistically significant improved yield (ie, a study with no indeterminate findings) of 97.5% compared with US of 15.8%. The negative appendectomy rate was also significantly lower at 3.3% for the CT group in comparison with 17.7% with US diagnosis [51]. With the increased interest in nonoperative antibiotic management of uncomplicated appendicitis, appendicoliths are important to detect. Higher failure rates of conservative management are seen in the presence of appendicoliths. Furthermore, appendicoliths are associated with increased inflammation and risk of perforation. Appendicoliths are readily identified with CT and found in nearly 40% of adults with proven appendicitis, compared with slightly more than 4% of those without appendicitis [52].


Acute Pelvic Pain in the Reproductive Age Group. In another study, 84% of cases with noninflamed appendix showed luminal filling when positive oral contrast reaches the cecum, thus excluding diagnosis of appendicitis with high certainty. Therefore, the use of positive oral contrast may augment diagnostic accuracy and confidence in cases of suspected acute appendicitis. No appendix filling with contrast was noted in proven acute appendicitis cases [53]. Diluted oral contrast with 1-hour or 3-hour regimens has a similar diagnostic performance [54]. Nevertheless, no difference was found in the sensitivity, specificity, or average interpretation time when neutral oral contrast was administered compared with positive oral contrast [55]. Single-institution randomized trials showed that low-dose CT was noninferior to standard-dose CT in regard to the negative appendectomy rate, the appendiceal perforation rate, or the proportion of patients needing additional imaging tests [56,57]. CT Abdomen and Pelvis Without IV Contrast CT of the abdomen and pelvis without IV contrast remains a useful tool for the diagnosis of appendicitis. Evaluation for appendicitis with a nonenhanced CT was shown to be conclusive in up to 75% of cases in a study of 536 patients, with a reported sensitivity, specificity, PPV, and NPV of 90%, 96%, 84.8%, and 97.4%, respectively. However, in the 132 (25%) inconclusive cases (ie, no definitive diagnosis of appendicitis or normal appendix), the initial noncontrast CT study was followed by contrast-enhanced CT with a sensitivity, specificity PPV, and NPV of 95.6%, 92.3%, 73%, and 99%, respectively [58]. MRI Abdomen and Pelvis Without and With IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without and with IV contrast as the initial imaging modality for the evaluation of acute pelvic pain. However, MRI can be useful for equivocal cases of appendicitis and renal obstruction.


Acute Pelvic Pain in the Reproductive Age Group. In a small study of 51 patients, a combination of DWI and T2-weighted images increased the accuracy for the diagnosis of appendicitis, with decreased ADC values correlating with appendicitis. The presence of low ADC in the peri-appendiceal fat was also notable in the presence of complicated appendicitis [63]. That is contrary to the study of 125 pregnant patients in which the addition of DWI showed no significant improvement to MRI detection of appendicitis [45]. MRI performed similarly to abdominal US, followed by abdominal and pelvic CT if findings on US were negative or inconclusive for the detection of perforated appendicitis with low sensitivities (57% for MRI and 48% for US followed by the conditional CT). The missed diagnoses of perforated appendicitis were misclassified as simple appendicitis [64]. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without IV contrast as the initial imaging modality for the evaluation of acute pelvic pain. However, MRI can be useful for equivocal cases of 13 Acute Pelvic Pain in the Reproductive Age Group appendicitis and renal obstruction. MR urogram without IV contrast was shown to have a 95% sensitivity and 100% specificity for the detection of hydronephrosis, and it has good agreement to determine the level of obstruction as compared to IV urography. The correct diagnosis was made in 94% of patients with MR urogram without IV contrast [65]. US Abdomen and Pelvis Transabdominal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible. A transabdominal-only approach for the pelvis could serve as an alternative if the transvaginal approach is not feasible.


Acute Pelvic Pain in the Reproductive Age Group. US may be used for the evaluation of suspected appendicitis in adults with a pooled sensitivity of 83% (95% confidence interval [CI], 78%-87%) and a pooled specificity of 93% (95% CI, 90%- 96%), as shown in a meta-analysis of 31 studies with 4,341 patients. In the meta-analysis, CT demonstrated a higher pooled sensitivity of 94% (95% CI, 92%-95%) and a similar specificity of 94% (95% CI, 92%-95%) in that study [50]. In low pretest probability populations, a negative or equivocal US for appendicitis can be used with confidence to exclude this condition without the need for further imaging, with an NPV of 100% and 96%, respectively. However, in cases of moderate or high pretest probability of acute appendicitis and equivocal US, the sensitivity of the US falls to 63% and, thus, should not be solely used to exclude appendicitis [66]. A combination of abdominal US and clinical features successfully predicted uncomplicated appendicitis in 94% of 678 patients in a retrospective cohort study [67]. Evaluation for appendicitis with graded compression of the appendix increases specificity and decreases negative appendectomy rates, as shown in a retrospective study of more than 1,000 patients, with a sensitivity of 83%, a specificity of 100%, and a negative appendectomy rate of 8.4% [68]. Evaluation of renal stones with US is limited. A study of 50 patients demonstrated a sensitivity of 52% to 57% in the right kidney and 32% to 39% in the left kidney when compared with CT for detection of renal stones by US. This study also showed no significant impact of body mass index on the detection of renal stones [69]. A multicentric study of 144 patients showed that in 75% of cases, the presence or absence of hydronephrosis on US correctly predicted the presence or absence of a ureteral stone on CT. Hydronephrosis on US had a PPV of 77% for the presence of a ureteral stone and an NPV of 71% for the absence of a ureteral stone [70].


Suspected Retroperitoneal Bleed

Suspected Retroperitoneal Bleed.  Introduction/Background Retroperitoneal bleeding is a hemorrhage into the retroperitoneal space, the space located posterior to the parietal peritoneum and anterior to the transversalis fascia. Retroperitoneal bleeding can occur spontaneously (Wunderlich syndrome), including in association with anticoagulation therapies, or be secondary to trauma, aortic rupture, or bleeding from a visceral vessel or mass. Retroperitoneal bleeding can also be iatrogenic, as a complication from surgeries or transfemoral catheterization procedures [1,2]. The retroperitoneum contains a portion of the duodenum, kidneys, adrenal glands, proximal ureters, pancreas, and vascular structures, including the abdominal aorta and proximal renal vasculature. This anatomy provides a variable source of potential bleeding. In the setting of trauma, retroperitoneal bleeding can also be the result of pelvic or spine fractures. Recognition of retroperitoneal bleeding from pelvic fractures is important given that it is associated with an increased need for transfusions and rapid intervention [3]. Vascular bleeding in the retroperitoneum can be from aortic aneurysmal rupture or visceral vessel rupture. The latter can be seen, for example, in the setting of pseudoaneurysms secondary to duodenal or pancreatic inflammation or infection [4]. Retroperitoneal bleeding is also the second most common site of major, or clinically relevant, bleeding seen among cancer patients [5]. Bleeding can be due to the malignancy itself or interventions and treatment, including surgery, upper endoscopy, chemotherapy, or anticoagulation. The many causes for retroperitoneal bleeding can make the diagnosis and management clinically challenging. Assessing for the clinical signs of retroperitoneal bleeding can be difficult given that the location of bleeding is not readily accessible to physical examination and often has an obscured etiology. This can result in the delayed diagnosis of retroperitoneal bleeding [6,7].


Suspected Retroperitoneal Bleed

Suspected Retroperitoneal Bleed. Clinically, retroperitoneal bleeding can present with diffuse abdominal, back, or lower quadrant abdominal pain, abdominal distension, and palpation of a flank mass [2,7]. However, these clinical findings are nonspecific for the diagnosis and further contribute to the difficulty in diagnoses. The management of retroperitoneal bleeding depends on the cause and size of bleed, hemodynamic status and stability of the patient, and the presence of active bleeding [6,7]. Treatment options include fluid resuscitation and close monitoring, angiographic embolization, and surgery. Retroperitoneal bleeding of significant volume can be concealed in the potential space and result in hypovolemic shock, necessitating blood transfusions with urgent angiographic or surgical treatment [1]. 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 Suspected Retroperitoneal Bleed All elements are essential: (1) timing, (2) reconstructions/reformats, and (3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. OR Discussion of Procedures by Variant Variant 1: Clinically suspected retroperitoneal bleed. Initial imaging. Aortography Abdomen and Pelvis Angiography of the abdomen and pelvis provides the benefit of being able to simultaneously diagnose active bleeding and treat retroperitoneal bleeding with transcatheter arterial embolization (TAE) [9].


Suspected Retroperitoneal Bleed

Suspected Retroperitoneal Bleed. Angiography has high spatial and temporal resolution for evaluating vascular structures and the source of the bleed. Initial utilization of aortography of the abdomen and pelvis in patients with clinically suspected retroperitoneal bleed is best reserved for patients who are hemodynamically unstable with a high index of clinical suspicion for retroperitoneal hemorrhage. Urgent aortography may be appropriate in cases of known active arterial bleeding or when there is a known contained vascular injury that would be amendable to concomitant diagnosis and treatment. In a study by Fitzpatrick et al [4] of patients with retroperitoneal bleeding related to pancreatitis, all angiographic cases were diagnostic of the bleeding vessel with TAE, with success measured by observation of cessation of bleeding and clinical stabilization. In that study, cessation of bleeding with embolization was achieved in all cases as determined by observation on angiography. Detection of active bleeding with conventional angiography requires a bleeding rate of 0.5 to 1.0 mL/min. Limitations of angiography also include that it is invasive, and risks include hematoma or bleeding at access site, iatrogenic dissections, and infection [10]. CT Abdomen and Pelvis CT is helpful for the diagnosis of retroperitoneal hematoma given its speed, high spatial resolution, and noninvasiveness. CT can depict blood, localize areas of bleeding, and evaluate for recent or active extravasation of contrast material [7]. Because of its speed and ability to scan large areas, it is especially useful to localize the area of bleeding and identify a possible cause, such as groin access, pelvic fracture, or mass [6]. Noncontrast CT can be appropriate to expeditiously confirm or exclude bleeding and is especially helpful in patients with compromised renal function or when there is concern for additional contrast load if further intervention with angiography may be considered.


Suspected Retroperitoneal Bleed

Suspected Retroperitoneal Bleed. The attenuation of the hematoma on noncontrast CT can help determine the relative acuity, with high attenuation and mixed attenuation indicating acute to subacute bleeding and rebleeding, and low attenuation suggesting subacute to chronic blood products. Findings such as sentinel clot can be helpful to suggest an area of bleeding if an active blush is not observed at the time of scanning. CT also serves well as the initial examination to follow-up clinically suspected rebleeding or to evaluate for changes in hematoma size or to evaluate for a subsequent complication, such as infection and abscess formation [6]. Given these attributes of CT imaging, it is appropriate for initial imaging in the suspicion of retroperitoneal bleeding. Limitations of CT include the inability to simultaneously intervene. CTA Abdomen and Pelvis CT angiography (CTA) is usually performed to detect the site of active retroperitoneal bleeding in cases of known or clinically suspected acute bleeding. Like CT, CTA provides the exact location of hematoma. CTA has better sensitivity than invasive angiography for detecting active bleeding and is known to detect bleeding rates as low as 0.3 mL/min. In evaluation of active bleeding, Tani et al [9] identified active extravasation of contrast in 78.9% to 84.2% of cases, with a sensitivity in CT for detection of active bleeding of 59.5% and positive predictive value compared to TAE of 62.9% to 71.0%. If the bleeding is intermittent, the sensitivity of CTA decreases. In patients Suspected Retroperitoneal Bleed with a history of aortic aneurysm and suspected rupture as cause of retroperitoneal hematoma, a CTA examination can provide confirmation and valuable preoperative information for endovascular or surgical repair, including size, extent, visceral disease, and anatomic vessel variants [11]. CTA is appropriate in the initial evaluation of bleeding with the benefit of detecting active bleeding and vascular sources.


Suspected Retroperitoneal Bleed

Suspected Retroperitoneal Bleed. CTA has the same limitations as CT as a diagnostic modality only, not allowing for intervention as with TAE. MRI Abdomen and Pelvis MRI has very high soft-tissue contrast and is very helpful in evaluation of the retroperitoneal structures. However, the length of examination time makes it less than ideal for initial imaging in cases of suspected retroperitoneal bleeding. MRI is helpful in further workup of patients with known hematoma when there is a suspicion of bleeding being from an underlying mass or lesion, such as patients with neoplasm in the pancreas, kidneys, or adrenal glands [12]. MRI in these cases can also be helpful to distinguish anatomically between blood and suspected underlying neoplasm, while characterizing bleeding acuity by differentiating acute and early subacute blood (isointense to hyperintense signal on T1-weighted and dark on T2-weighted sequences) from chronic blood (hypointense signal). MRI can be used to follow size of retroperitoneal hematomas in which sequential examinations may be needed, but the length of examination makes it usually not appropriate for diagnosis of retroperitoneal bleeding when compared to CT for initial diagnosis. Radiography Abdomen and Pelvis Abdominal radiography findings are highly nonspecific and have low sensitivity in detecting retroperitoneal bleeding. Radiography is often the initial examination in patients who present with palpable mass or abdominal pain, without clinical suspicion of hemorrhage as the cause of these clinical signs and symptoms [13]. Radiographs can show displacement of bowel loops or obscuration of the psoas muscle contour if there is large volume of retroperitoneal hematoma. Radiographs can evaluate for mispositioned lines or cannula as the potential etiology of bleeding. Two important limitations of radiography include the inability to evaluate if the bleeding is active or not and the limitation in identification of the source of the bleeding.


Suspected Retroperitoneal Bleed

Suspected Retroperitoneal Bleed. Additionally, up to a moderate volume hematoma may not exert enough mass effect to prompt discovery on radiography. These limitations make radiography usually not appropriate for initial diagnosis of retroperitoneal bleed. RBC Scan Abdomen and Pelvis Tc-99m-labeled red blood cell (RBC) scintigraphy is highly sensitive in detecting active bleeding, with detection of bleeding rates as low as 0.1 mL/min [14]. RBC scintigraphy has been shown to be more sensitive to detect active ongoing bleeding in cases of gastrointestinal location of bleeding that may not be confirmed on CTA, allowing for a localized intervention to occur such as with TAE. However, its utilization in initial suspicion of retroperitoneal bleeding and hematoma is limited and usually not appropriate because of the longer time of examination (from order placement to scan completion) and better sensitivity in the retroperitoneal location provided by other imaging procedures. US Abdomen and Pelvis Ultrasound (US) can be helpful in the overall evaluation of acute patients because of its noninvasiveness and portability [15]. Contrast enhanced US, which utilizes microbubbles of gas in a phospholipid membrane, has been shown to be effective in identifying postsurgical complications, including retroperitoneal hematoma [16]. US performed is 99% sensitive and 98% specific for detecting abdominal aortic aneurysm AAA in the emergency department setting [17]. The speed and accuracy of this approach is therefore useful to detect if abdominal aortic aneurysm is present when a ruptured aneurysm is a differential diagnosis in the emergency or critical care setting. US helps only to detect the presence or absence of abdominal aortic aneurysm, not the presence of rupture, and does not provide significant information regarding alternative etiologies of retroperitoneal bleeding.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs.  Special Imaging Considerations Several studies have looked for ways to shorten typical shoulder conventional MRI or MR arthrogram protocols while maintaining diagnostic accuracy. Isotropic 3-D imaging has been increasingly used as a substitute for conventional multiplanar 2-D MRI, with a similar sensitivity and specificity for rotator cuff tear and labral abnormalities at a lower scan time [7,8]. Faster scans can also be performed using 2-D fast spin echo sequences with parallel imaging, which produce similar findings as seen on conventional MRI [9]. OR aPanel Vice-chair, University of Virginia Health System, Charlottesville, Virginia. bPanel Chair, Mayo Clinic Arizona, Phoenix, Arizona. cUniversity of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. dStanford University, Stanford, California, Primary care physician. eMayo Clinic, Rochester, Minnesota. fHospital for Special Surgery, New York, New York. gUniversity of Nebraska Medical Center, Omaha, Nebraska; American College of Emergency Physicians. hThe Centers for Advanced Orthopaedics, George Washington University, Washington, District of Columbia; American Academy of Orthopaedic Surgeons. iUniversity of Michigan Health System, Ann Arbor, Michigan; Committee on Emergency Radiology-GSER. jDuke University Medical Center, Durham, North Carolina. kUniversity of Missouri Health Care, Columbia, Missouri. lCleveland Clinic, Cleveland, Ohio. mThe University of Texas MD Anderson Cancer Center, Houston, Texas; Commission on Nuclear Medicine and Molecular Imaging. nPenn State Milton S. Hershey Medical Center, Hershey, Pennsylvania and Uniformed Services University of the Health Sciences, Bethesda, Maryland. oSpecialty Chair, VA San Diego Healthcare System, San Diego, California. 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.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. 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 Chronic Shoulder Pain Discussion of Procedures by Variant Variant 1: Chronic shoulder pain. Initial imaging. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the initial evaluation of chronic shoulder pain. CT Arthrography Shoulder There is insufficient evidence to support the use of CT arthrography shoulder in the initial evaluation of chronic shoulder pain. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with intravenous (IV) contrast in the initial evaluation of chronic shoulder pain. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the initial evaluation of chronic shoulder pain. CT Shoulder Without IV Contrast There is insufficient evidence to support the use of CT shoulder without IV contrast in the initial evaluation of chronic shoulder pain. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT skull base to mid-thigh in the initial evaluation of chronic shoulder pain. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures There is insufficient evidence to support the use of image-guided anesthetic +/- corticosteroid injection of the shoulder in the initial evaluation of chronic shoulder pain. MR Arthrography Shoulder There is insufficient evidence to support the use of MR arthrography shoulder in the initial evaluation of chronic shoulder pain. MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the initial evaluation of chronic shoulder pain.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. MRI Shoulder Without IV Contrast There is insufficient evidence to support the use of MRI shoulder without IV contrast in the initial evaluation of chronic shoulder pain. US Shoulder The literature suggests that radiographic evaluation should generally be the first imaging study ordered in patients with shoulder pain [1,10-14]. Some practitioners may use ultrasound (US) as an initial imaging study when rotator cuff disease/impingement is suggested by the clinical examination. Chronic Shoulder Pain Variant 2: Chronic shoulder pain. Suspect rotator cuff disorders or subacromial subdeltoid bursitis (no prior surgery). Initial radiographs normal or inconclusive. Next imaging study. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. CT Arthrography Shoulder CT arthrography has shown good diagnostic performance for depicting rotator cuff tendon tears with a reported respective sensitivity and specificity of 99% and 100% for the supraspinatus tendon, 97.4% and 99.5% for the infraspinatus tendon, and 64.7% and 98.2% for the subscapularis tendon [15]. CT arthrography provides a comparable alternative to MR arthrography in the evaluation of rotator cuff tendon tears [16,17]. CT arthrography is able to detect very subtle articular surface cuff defects, but, because of lack of contrast extension from the glenohumeral joint space, it is less effective at demonstrating bursal surface or intrasubstance tears, which are typically well seen with MRI or US [18]. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when rotator cuff disorder or subacromial subdeltoid bursitis is suspected.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. CT Shoulder Without IV Contrast CT shoulder without IV contrast is of limited utility when evaluating for rotator cuff tear or subacromial subdeltoid bursitis. Noncontrast CT can sometimes demonstrate fatty infiltration of rotator cuff muscles with a corresponding rotator cuff tear, although the overall sensitivity of this finding is low [19]. CT may demonstrate a high-riding humeral head or remodeling of the acromial undersurface in patients with large rotator cuff tears. However, this finding is generally seen on initial radiographs, and CT does not allow for characterization of the underlying tear because CT lacks the soft-tissue contrast resolution necessary to adequately evaluate the rotator cuff tear itself. CT may be able to directly demonstrate some large rotator cuff tears as well as fatty infiltration of the rotator cuff musculature; however, it was found to have a sensitivity of 20% for full thickness rotator cuff tears in one small study [19]. Large amounts of fluid in the subacromial subdeltoid bursa can sometimes be visualized with CT. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Corticosteroid injection is sometimes used before advanced imaging is obtained but may serve as a better diagnostic tool in patients with subacromial subdeltoid bursitis as opposed to those patients with suspected rotator cuff tear.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. US image-guided injection with local anesthetic and corticosteroid into the subacromial-subdeltoid bursa has been shown to result in improvement in pain and range of motion in patients with rotator cuff symptoms [20,21]. Subacromial bursal injections are used by some as a diagnostic tool to evaluate for rotator cuff pathology [22], although the diagnostic utility of this approach is unclear in the literature. Glenohumeral joint injection has been found to not have significant diagnostic utility for patients with suspected rotator cuff tear [23]. MR Arthrography Shoulder MR arthrography provides greater sensitivity and specificity compared to conventional MRI in evaluating partial thickness articular surface tears [24-26]. Partial bursal and purely intrasubstance tears should have similar rates of detection on conventional MRI and MR arthrography because the diagnosis is dependent on the same fluid-sensitive sequences [27]. Extension of intra-articular gadolinium into the subacromial subdeltoid bursa can sometimes differentiate a high-grade partial tear from a full thickness tear [28]. However, the advantages of MR arthrography over conventional MRI for detecting rotator cuff tear must be weighed against the invasive nature of the arthrogram procedure [29]. Arthrograms with saline have been shown in some studies to have similar accuracy for rotator cuff tear as those performed with dilute gadolinium [30,31]. Some authors suggest that adding an abduction external rotation imaging position to an MR arthrogram improves the accuracy in diagnosing partial articular surface tears [32,33], although this positioning is often omitted because of patient discomfort. Chronic Shoulder Pain MRI Shoulder Without and With IV Contrast IV injection of gadolinium can be used to enhance the highly vascular synovium producing an indirect arthrogram effect [34].


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. Indirect MR arthrography has been shown to have a slightly higher specificity for diagnosing articular- surface partial thickness tears of the supraspinatus and infraspinatus tendons, as well as a greater specificity for diagnosing subscapularis tendon tears [35], relative to noncontrast MRI, and has shown high accuracy relative to arthroscopy [36]. Although the accuracy of indirect MR arthrography has been described in the literature, it is not commonly used in clinical practice. MRI Shoulder Without IV Contrast MRI of the shoulder is a highly accurate tool in the assessment of the rotator cuff. MRI findings of tendinopathy consist of intermediate increased signal and tendon thickening [28]. Rotator cuff tears, particularly full thickness tears, can be reliably identified using conventional MRI with high sensitivity and specificity [37-39]. Sensitivity and specificity for detecting partial thickness bursal surface tears is similar for conventional MRI and MR arthrography [27]. Although MR arthrography may have a slightly higher sensitivity and specificity than conventional MRI for diagnosing rotator cuff tears, particularly partial thickness articular surface tears, this difference in accuracy must be weighed against the need for an invasive arthrogram procedure [29]. Tendon retraction, muscle atrophy, and fatty infiltration are associated important findings that are well seen on MRI and predict reparability of rotator cuff tear [40]. Axial images can be helpful in determining rotator cuff tear shape [41], which can aid in the selection of a particular surgical technique. In addition to evaluating the rotator cuff itself, MRI can detect extra-articular abnormalities that may predispose to shoulder impingement such as acromioclavicular degenerative change or a subacromial spur. Fluid accumulation within the subacromial subdeltoid bursa is visualized on MRI and is often a nonspecific finding seen with a rotator cuff tear or an underlying inflammatory disorder [42].


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. Radiography Shoulder Additional Views The rotator cuff tendons cannot be directly assessed radiographically, regardless of the view. Secondary findings of rotator cuff tear such as a high-riding humeral head or changes at the greater tuberosity can be seen on standard radiographic views. There have been several reports assessing special views for the evaluation of potential impingement from the anterior acromion. Outlet views can be used to determine acromial shape and have been shown to be more accurate than a single-slice MRI [43]. The Rockwood and cassette tilt views are angled frontal projections that can be used to detect anterior acromial osteophytes [44]. The subacromial subdeltoid bursa is a soft- tissue potential space and is not directly visualized on radiographs. There is a peribursal fat plane between the rotator cuff tendons and the deltoid muscle; however, obliteration of the peribursal fat stripe is not a specific indicator of shoulder pathology and may be seen in normal subjects [42]. US Shoulder US has been found to have a high accuracy in assessing rotator cuff disease [38,45], including the subscapularis tendon [46]. Meta-analyses have found a sensitivity of US ranging from 85% to 95% and a specificity ranging from 72% to 92%, which is similar to noncontrast MRI and slightly lower than MR arthrography [24,47]. Fatty infiltration within the rotator cuff muscles can be adequately demonstrated with US [48]. US may; however, be less accurate than MRI in measuring tear size and the degree of retraction in larger tears [49]. US allows excellent evaluation of the bursae situated about the shoulder, particularly the subacromial subdeltoid bursa [50]. Color flow imaging can demonstrate hyperemia in cases of bursitis with a significant inflammatory component [51]. Variant 3: Chronic shoulder pain. Radiographs demonstrate calcific tendinopathy or calcific bursitis. Next imaging study.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinosis or calcific bursitis. Cases with intraosseous extension of calcium hydroxyapatite can potentially demonstrate increased radionuclide uptake due to bony inflammatory change, which can potentially be confused with a neoplastic process and result in diagnostic confusion. CT Arthrography Shoulder There is insufficient evidence to support the use of CT arthrography shoulder in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. Hyperdense intratendinous calcium may resemble intratendinous contrast from a partial thickness articular-sided rotator cuff tear, which could potentially result in diagnostic confusion. The role of CT arthrography is limited to cases in which there is concern Chronic Shoulder Pain for a concomitant rotator cuff tear and, even in this situation, may be lacking in utility in cases of partial thickness interstitial or bursal surface tear [18]. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with contrast in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. CT Shoulder Without IV Contrast Calcific hydroxyapatite deposition in the rotator cuff tendons is easily visualized by CT; however, the diagnosis of calcium hydroxyapatite is typically able to be made on radiographs alone.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. CT can be helpful in evaluating osseous involvement [52] and is the most accurate modality in evaluating the consistency of the deposit, which may be helpful when planning intervention [53] but is not routinely obtained. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. Areas of calcium hydroxyapatite deposition in tendon, bursa, or bone can result in increased FDG uptake, which can potentially be confused with a neoplastic process and result in diagnostic confusion. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures If calcium hydroxyapatite is seen on radiographs, calcium hydroxyapatite lavage with imaging guidance can be performed both for both therapeutic and diagnostic purposes. US or, less commonly, fluoroscopy can be used for guidance. US-guided calcium lavage has been shown to be a highly effective percutaneous treatment in patients with suspected calcific tendinitis [54-62]. Outcomes are similar whether the procedure is performed with the 1 or 2 needle technique [63]. Injection of corticosteroid into the subacromial subdeltoid bursa as part of the barbotage procedure has been shown to have significant impact on pain and function 3 months after the procedure [64,65]. The degree of calcium removal does not necessarily correlate with pain improvement from the procedure [66]. Lavage may be less effective at providing pain relief for patients with intraosseous migration of calcium hydroxyapatite [67]. Given the high efficacy of calcium hydroxyapatite lavage in the rotator cuff, if patient symptoms do not resolve following calcium hydroxyapatite lavage, then other diagnostic entities for shoulder pain should be considered and further imaging evaluation can be performed subsequently.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. MR Arthrography Shoulder Calcium hydroxyapatite may be difficult to visualize on MRI given the lack of contrast between hypointense calcium and an adjacent normal tendon. However, MR arthrography can be used to identify a concomitant rotator cuff tear. In the setting of calcific tendonitis, 93% of rotator cuff tears are partial thickness [68]. Given the improved ability of MR arthrography to detect partial thickness articular-surface tears of the rotator cuff compared to conventional shoulder MRI [24-26], there may be an advantage to performing MR arthrography in patients with calcific tendinopathy [69]. MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. MRI Shoulder Without IV Contrast The signal void of calcium hydroxyapatite deposition can be difficult to distinguish from the hypointense signal in normal rotator cuff tendon, thus making identification of calcific tendonitis by MRI alone difficult in some cases. However, MRI can be used in calcific tendonitis cases to evaluate the extent of adjacent soft-tissue and bone abnormalities as well as exclude other causes of shoulder pain. Patients with calcific tendonitis on radiographs have up to a 56% incidence of concomitant rotator cuff tear seen on MRI [68]. Intraosseous migration of calcium hydroxyapatite can produce extensive marrow edema, which can be confused with a neoplastic process [52,70]. Radiography Shoulder Additional Views Calcium hydroxyapatite deposition in tendon or bursa is typically well seen on conventional radiographic projections, without a need for specialized additional views. Chronic Shoulder Pain US Shoulder US is reported to be 98% sensitive and 94% specific for calcium hydroxyapatite in the rotator cuff tendons [71], although identification may be challenging if the area of calcium deposition is small.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. At times US may have difficulty distinguishing calcific deposits from heterotopic ossification because both can result in dense shadowing at US. US can be used if there is concern for concomitant rotator cuff tendon tear and may be a better modality than MRI in this situation given the difficulty of distinguishing calcium from normal tendon at MRI. Variant 4: Chronic shoulder pain. Suspect labral pathology or shoulder instability. Initial radiographs normal or inconclusive. Next imaging study. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when labral pathology or shoulder instability is suspected. CT Arthrography Shoulder CT arthrograms have been shown to be an accurate modality in the assessment of shoulder instability because of its depiction of osseous, cartilaginous, and labroligamentous injuries [18,72]. Labral evaluation in the postoperative setting may be better with CT arthrography than MRI in patients with metallic suture anchors [73] and has been used to evaluate for healing after superior labrum anterior-to-posterior (SLAP) repair [74]. Dual-energy CT arthrography has a similar diagnostic performance as MR arthrography [75]. Although CT arthrography aids in the evaluation of underlying soft tissues, the injected contrast may limit evaluation of the underlying osseous structures, and cortical fragments in the injected contrast solution often have a similar attenuation to cortical bone [76]. Other limitations include the need for an invasive arthrography procedure and poor assessment of bone marrow edema [72]. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when labral pathology or shoulder instability is suspected.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when labral pathology or shoulder instability is suspected. CT Shoulder Without IV Contrast CT is helpful for assessing bony glenoid deficiency as well as the size of a Hill-Sachs deformity when surgery is a consideration but is not effective at evaluating the labrum. CT is often preferable to MRI when evaluating for small fracture fragments of the glenoid rim and assessing bone stock in patients with recurrent dislocation [77-79]. Three- dimensional reconstructions can be used to quantify osseous defect width and glenoid surface area [80,81]. CT can also be used to measure the size of a Hill-Sachs defect [82,83], which has become more important with the development of the glenoid track concept for determining instability [84,85]. In the postoperative setting, CT can be used to evaluate integration of bone graft from a coracoid transfer with the underlying glenoid [86,87]. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when labral pathology or shoulder instability is suspected. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Patients with labral tears have been found to have no significant decrease in pain with glenohumeral injection relative to other patients, and, in fact, patients with labral tears may have less pain relief than those with an intact labrum [23]. Thus, corticosteroid injection does not have a significant diagnostic benefit in distinguishing patients with labral tears from other pathology. Chronic Shoulder Pain accuracy for a labral tear as those performed with dilute gadolinium [30,31].


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. Although diagnosing recurrent labral tears after prior labral repair is challenging, MR arthrography is particularly helpful in this scenario in which discrete fluid or gadolinium signal within or underlying the labrum, absent labrum, and paralabral cyst are all highly suggestive of recurrent tear [94], with a greater sensitivity than seen with conventional MRI [73]. MRI Shoulder Without and With IV Contrast IV injection of gadolinium can be used to enhance the highly vascular synovium producing an indirect arthrogram effect [34]. Indirect arthrography has been found to have a sensitivity of 74% and a specificity of 67% for SLAP tear, which is lower than for direct MR arthrography [89]. Although the accuracy of indirect MR arthrography has been described in the literature, it is not commonly used in clinical practice. MRI Shoulder Without IV Contrast Conventional MRI with 3T imaging is highly accurate for the detection of a labral tear, with a sensitivity of 83% and a specificity of 99% to 100% for a labral tear [90]. MR arthrography adds additional benefit to conventional shoulder MRI because it may identify some labral tears that are not seen with conventional MRI [95]. The increased accuracy with MR arthrography should be balanced against the need for an invasive arthrogram procedure. Although evaluation of glenoid bony integrity is typically better with CT imaging, some practitioners have used ultrashort or zero echo time sequences [96-98], 3-D sequences [99], or conventional MRI sequences [100] to measure glenoid bone loss with a high concordance to CT images. Radiography Shoulder Additional Views There are several options for additional radiographic views in patients with suspected instability [1]. The West Point and Garth views can demonstrate the anterior inferior glenoid at a better advantage in patients with a suspected Bankart fracture. A Stryker notch view can sometimes demonstrate a Hill-Sachs lesion that is difficult to see on conventional projections.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. Although these additional projections are used by some practitioners, they do not usually alleviate the need for advanced imaging. US Shoulder The posterior labrum can be reliably visualized with US, with posterior labral tears potentially visualized particularly if the joint is distended [101]. However, US is of limited benefit in assessing the anterior labroligamentous complex, superior labrum, articular surface, and subchondral bone. Variant 5: Chronic shoulder pain. Suspect adhesive capsulitis. Initial radiographs normal or inconclusive. Next imaging study. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. CT Arthrography Shoulder There is insufficient evidence to support the use of CT arthrography shoulder in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. CT Shoulder Without IV Contrast There is insufficient evidence to support the use of CT shoulder without IV contrast in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. FDG-PET/CT Skull Base to Mid-Thigh Increased PET uptake in the rotator interval and inferior joint capsule is moderately associated with adhesive capsulitis [102-104]. However, this is generally an incidental finding on PET examinations performed for other reasons, and PET/CT is not typically performed specifically for this indication. Chronic Shoulder Pain


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Image-guided injection of the glenohumeral joint for adhesive capsulitis can be performed with either fluoroscopy or US guidance. Image-guided corticosteroid injection has been shown to have a significant reduction in pain and an improvement in the range of motion for patients with adhesive capsulitis [105,106]. Use of US guidance for glenohumeral corticosteroid injection may be more accurate and produce a greater improvement in pain and functional scores relative to blind injection [107]. Patients with adhesive capsulitis have been found to be the only group with a statistically better outcome after glenohumeral joint injection than other patients; thus a positive response to a glenohumeral injection can be suggestive of the presence of adhesive capsulitis in the appropriate clinical context [23]. Fluoroscopic injection can also demonstrate diagnostic findings suggestive of adhesive capsulitis including joint space capacity <10 mL, diminished axillary recess, and irregularity of the capsular margin [108]. MR Arthrography Shoulder Mengiardi et al [109] reported that thickening of the coracohumeral ligament (specificity 95%, sensitivity 59%), thickening of the joint capsule (specificity 86%, sensitivity 64%), and obliteration of the subcoracoid triangle (specificity 100%, sensitivity 32%) are characteristic MR arthrography findings in adhesive capsulitis. However, fluid within the rotator interval or along the axillary recess due to the arthrogram injection itself can serve as a limitation to detecting findings of adhesive capsulitis on MRI arthrography. MRI Shoulder Without and With IV Contrast Contrast-enhanced MRI can increase the conspicuity of axillary recess capsular thickening [110] and rotator interval soft-tissue thickening [111], although there are conflicting data on the relationship of this capsular enhancement with patient symptoms [112].


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. MRI Shoulder Without IV Contrast Zhao et al [113] showed that coracohumeral ligament thickening, anterior capsule thickening, and obliteration of the subcoracoid fat are the most characteristic findings of adhesive capsulitis on conventional MRI. Chi et al [114] found a sensitivity of 77% and a specificity of 53% for adhesive capsulitis with only coracohumeral ligament thickening on noncontrast MRI, with a lower sensitivity (23%) but a higher specificity (87%) in patients who had all 3 findings of adhesive capsulitis, including coracohumeral ligament thickening, rotator interval infiltration, and axillary recess thickening. Radiography Shoulder Additional Views There is insufficient evidence to support the use of additional radiographic views in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. US Shoulder US in the setting of potential adhesive capsulitis is often used to exclude rotator cuff tear. Although there are several US findings that can be seen in patients with adhesive capsulitis, US is not typically performed specifically for this indication. Thickening of the coracohumeral ligament, increased rotator interval soft tissue, and decreased external rotation on dynamic US are all highly sensitive and specific findings for adhesive capsulitis [115]. Thickening of the axillary recess capsule can be accurately measured with US and is associated with adhesive capsulitis [116]. Hyperemia with Doppler imaging, particularly with microflow imaging, can also be seen in the subcoracoid fat triangle in patients with adhesive capsulitis [117]. One study found that findings of adhesive capsulitis on US were correlated with clinical assessment, whereas findings on MRI were not [108]. Variant 6: Chronic shoulder pain. Suspect biceps tendon abnormality. Initial radiographs normal or inconclusive. Next imaging study.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. CT Arthrography Shoulder Reports on the accuracy of CT arthrography for biceps tendinopathy are variable. Teixeira et al [118] reported a sensitivity of 74% to 79% and a specificity of 93% to 95% for tendinopathy as well as 100% sensitivity and 93% specificity for complete biceps ruptures. However, Rol et al [119] reported a correlation of only 45% to 65% with subsequent arthroscopy in a study consisting mostly of patients who underwent CT arthrography. CT arthrography diagnosis of biceps tendinopathy is primarily based off the change in tendon caliber. Chronic Shoulder Pain CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. CT Shoulder Without IV Contrast There is limited literature regarding the use of noncontrast CT to specifically evaluate the biceps tendon. In a small study, pooled sensitivity and specificity for proximal biceps lesions including degeneration, tendon subluxation, and tendon tear using CT were shown to be 31% and 95%, respectively [120]. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Image-guided injection of the biceps tendon sheath using US guidance may be useful in patients with biceps pain for both diagnostic and therapeutic purposes [22].


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. Although either fluoroscopy or US can be used as imaging guidance for biceps tendon injection, US guidance is more accurate [121]. US is more accurate in injection location placement compared with blind injections with a lower risk of intratendinous injection [122,123]. Many patients with sonographically normal biceps tendons may obtain pain relief with US-guided injection, suggesting that injection response may diagnostically identify patients with biceps pathology that is not seen by US [124]. MR Arthrography Shoulder MR arthrography may improve the accuracy of MRI in the detection of long head of the bicep tears, although results are mixed. Zanetti et al [125] found MR arthrography to be sensitive and moderately specific in the diagnosis of long head of the biceps tendon disorders with a sensitivity of 92% and a specificity of 56%. However, Loock et al [126] found a lower sensitivity and specificity for MR arthrography detection of biceps abnormalities, with only a 49% sensitivity for tendinopathy. Accuracy for middle-aged patients may be lower [127]. MR arthrography is moderately accurate at assessing for biceps tendon subluxation, with a sensitivity of 61% to 87% and a specificity of 83% to 92% [128]. MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. MRI Shoulder Without IV Contrast Standard noncontrast MRI is limited in detecting bicep abnormalities, including tendinopathy or tearing of the long head of the biceps. Studies have shown MRI to both under- and overdiagnose intra-articular biceps pathology [129- 131], with sensitivities and specificities of 28% and 84% (partial tear) and 56% and 98% (complete), respectively [130].


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. Using diagnostic criteria of having 2 or more signs of biceps tendinopathy (contour irregularity, diameter change, or abnormal signal) has a sensitivity of 78% and a specificity of 94% [132]. It has been reported that normal appearing tendons on MRI frequently have histopathologic findings of tendinopathy [133,134]. Biceps tendon subluxation can be diagnosed by displacement of the biceps tendon over the lesser tuberosity [135] and is highly associated with tearing of the subscapularis tendon [136]. MRI has a greater specificity for biceps tendon abnormality if there is a coexisting rotator cuff tear [129,137]. Radiography Shoulder Additional Views There is insufficient evidence to support the use of additional radiographic views in the evaluation of chronic shoulder pain when a biceps tendon abnormality is suspected. US Shoulder Apart from the biceps anchor, the intra-articular and extra-articular portions of the biceps tendon are well seen on routine US imaging. Tendinopathy, tears and rupture, tenosynovitis, subluxation, and frank dislocation are readily assessed [138,139]. Provocative maneuvers may be helpful while observing in real time to assess the degree of subluxation. Chronic Shoulder Pain Variant 7: Chronic shoulder pain. Initial radiographs demonstrate osteoarthritis. Next imaging study. The presence of glenohumeral osteoarthritis on initial radiographs does not typically require additional imaging unless additional pathology is suspected, such as a rotator cuff tear or surgery is a consideration. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis. CT Arthrography Shoulder CT arthrography can be helpful in the preoperative planning of total shoulder arthroplasty in patients with severe glenohumeral arthritis.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. CT arthrography provides excellent imaging of osseous detail allowing for characterization of glenoid morphology, version, and bone loss. Unlike nonarthrogram CT, CT arthrography allows for adequate characterization of a rotator cuff tear [16,17], which may alter the chosen arthroplasty type. Arthrogram contrast also outlines the articular cartilage surface, demonstrating areas of cartilage loss, which cannot be directly visualized with conventional CT. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis. CT Shoulder Without IV Contrast CT can be helpful in evaluating osseous morphology in cases in which arthroplasty surgery is under consideration for treatment of severe glenohumeral arthritis. CT images are commonly obtained to classify the morphology of the glenoid according to the Walch classification system [140]. CT measurements of glenoid version, glenoid bone loss, and humeral head subluxation demonstrate high interrater reliability [141]. CT can potentially demonstrate rotator cuff muscle fatty infiltration, which is often associated with rotator cuff tears; however, overall sensitivity for full thickness rotator cuff tears is only 20% for noncontrast CT [19]. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Intra-articular corticosteroid injection using either fluoroscopy or US guidance is often used in the conservative management of glenohumeral arthritis [122] and may be performed in some situations before advanced imaging is obtained. The diagnostic utility of glenohumeral corticosteroid injection for confirming osteoarthritis as a source of pain is limited, because patients with osteoarthritis have a similar degree of pain improvement (74% rate of clinically relevant improvement at 1 month) as patients with other underlying causes of shoulder pain [23]. MR Arthrography Shoulder The role of MR arthrography relative to conventional shoulder MRI in the setting of osteoarthritis has not been specifically studied. However, MR arthrography may have use in characterizing the degree of chondral loss, the presence of a full thickness rotator cuff tear, and characterizing glenoid morphology. MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis. MRI Shoulder Without IV Contrast MRI can be used to detect the degree of glenohumeral chondral loss, although the diagnosis of arthritis is generally easily made with conventional radiographs [142]. MRI can demonstrate the presence of a partial or full thickness rotator cuff tear, which is frequently associated with osteoarthritis. Although CT is most frequently used for evaluating glenoid morphology, glenoid version measured by MRI is generally similar to that measured with CT [143]; however, MRI may be less accurate than CT at identifying the Walch classification of glenoid morphology [144]. Chronic Shoulder Pain Radiography Shoulder Additional Views Glenohumeral osteoarthritis is typically well visualized on conventional radiographic views, without the need for special views.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. A standard axillary view can demonstrate posterior subluxation of the humeral head and abnormal glenoid morphology in patients with severe osteoarthritis [145-147]. A measurement of the critical shoulder angle can be drawn on routine AP radiographs by measuring the angle between a line along the glenoid surface and a line from the inferior glenoid to the lateral acromial margin; patients with a higher measurement may be at high risk of having a full thickness rotator cuff tear [148]. US Shoulder Although secondary signs of osteoarthritis such as osteophytes, joint effusion, and intra-articular bodies can be seen with US [142], it is not typically performed for this indication. Variant 8: Chronic shoulder pain. History of prior rotator cuff repair. Suspect rotator cuff disorders or subacromial subdeltoid bursitis. Initial radiographs normal or inconclusive. Next imaging study. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. CT Arthrography Shoulder As in the native shoulder, CT arthrography can be used to evaluate for rotator cuff tear after surgery. In patients with metal in the shoulder, CT arthrography can be beneficial in detecting supraspinatus tears that may be obscured by metal artifact [73]. Gadolinium contrast can potentially be drawn up into a mixture with iodinated contrast at the time of the arthrogram procedure, thus allowing for a shift from MRI to CT if artifact on MRI precludes evaluation. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected.


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. CT Shoulder Without IV Contrast There is insufficient evidence to support the use of CT shoulder without IV contrast in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when a rotator cuff disorder or subacromial subdeltoid bursitis is suspected. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Image-guided corticosteroid injection may be useful for therapeutic purposes in patients with recurrent pain after rotator cuff repair. US-guided injection of corticosteroid into the glenohumeral joint has been found to improve pain and range of motion in patients with prior rotator cuff repair, without increasing the risk of recurrent rotator cuff tear [149]. There is insufficient evidence to support the use of image guided injection for diagnostic purposes in evaluation for recurrent cuff tear, but it may be of use for diagnosis in patients with suspected subacromial subdeltoid bursitis. MR Arthrography Shoulder MR arthrography is useful in the evaluation of the postoperative rotator cuff. MR arthrography can improve diagnostic accuracy over conventional MRI in patients who have had prior rotator cuff repair due to joint distention and improved signal-to-noise ratio [150].


Chronic Shoulder Pain PCAs

Chronic Shoulder Pain PCAs. Of note, contrast within the subacromial subdeltoid bursa on routine and MR arthrogram examinations is a nonspecific finding that can potentially be seen in a nonwatertight rotator cuff repair [151]. T2 hyperintensity of the repaired rotator cuff tendon is a common postoperative finding, particularly in the first 2 years after surgery, and does not reflect adequacy of tendon healing or clinical outcome [152]. Chronic Shoulder Pain MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when a rotator cuff disorder or subacromial subdeltoid bursitis is suspected. MRI Shoulder Without IV Contrast MRI is useful in the evaluation of the postoperative rotator cuff. The shift from metallic to bioabsorbable suture anchors tends to result in fewer cases with metal artifact implications [153]. For patients with metallic suture anchors, there are a variety of commercially available metal artifact reduction sequences, which can limit artifact. MRI can demonstrate complications with suture anchors such as osteolysis or migration [154], even if the suture anchors are nonmetallic. MRI can also demonstrate potential improvements in muscle atrophy and fatty infiltration after rotator cuff repair [155,156]. Radiography Shoulder Additional Views There is insufficient evidence to support the use of additional radiographic views in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. US Shoulder An advantage of US evaluation of the postoperative shoulder is the absence of metal-induced artifact when examining the rotator cuff and adjacent soft tissues. Patients who have undergone rotator cuff repair may show discrete defects on US imaging that may persist for years with some potential for delayed healing [157].


Dialysis Fistula Malfunction

Dialysis Fistula Malfunction.  Introduction/Background Chronic kidney disease is a common disease that as of 2018 affected 14.9% of the surveyed adult United States population [1]. Chronic kidney disease can result in end stage renal disease, a condition with high morbidity and mortality that affects 725,000 patients in the United States as of 2016 [2]. End stage renal disease patients account for 7.2% of paid Medicare claims at a cost of $35.4 billion, a cost that is increasing every year [2]. In the United States, hemodialysis persists as the single most prevalent mode of renal replacement therapy. Hemodialysis care alone resulted in $28 billion in Medicare costs in 2016 [2]. A stenosis that develops secondary to neointimal hyperplasia becomes the primary precipitator of a vascular access failure. Such stenoses augment pressure within the access and decrease blood flow. If the stenosis is hemodynamically significant and left untreated, it can result in thrombosis of the access. Access thrombosis is the primary cause of loss of vascular access patency and is associated with an increase in health care expenditure and compromise of quality of life [9]. The occurrence of a stenosis is an event that recurs throughout the life of the access. While a vein-graft anastomosis in a patient with an AVG or juxta-anastomotic region in a patient with an AVF represent the sites with high propensity for stenosis formation, these lesions may occur at any point within the 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 Dialysis Fistula Malfunction access system, notwithstanding central and feeding arteries.


Dialysis Fistula Malfunction

Dialysis Fistula Malfunction. A stenotic lesion can provoke access dysfunction regardless of its site within the access circuit [9]. Arteriovenous (AV) access dysfunction includes 3 distinct classes of events, namely thrombotic flow-related complications or dysfunction, nonthrombotic flow-related complications or dysfunction, and infectious complications [5]. Thrombotic flow-related complications or dysfunction include those events exclusively related to thrombus formation that provokes a clinically important decrease in intra-access flow and in turn threatens the required access patency needed to achieve requisite hemodialysis. These include stenoses and thromboses, and routinely result in specific heralding clinical signs and symptoms. Nonthrombotic flow-related complications or dysfunction include those events that may or may not threaten the flow or patency of an access circuit, but which are related to associated clinical symptoms and signs, such as in the case of steal syndrome or AV access cannulation site aneurysms. Finally, infectious complications or dysfunction include infections that involve the vascular access whether intraluminally, extraluminally, or peri-access, including the cannulation site, and that provoke clinically significant infectious symptoms and signs [5]. To preempt adverse outcomes and identify lesions with the vascular access before they provoke complications, the KDOQI guidelines suggests that the performance of the following be considered, namely 1) monitoring, supported by physical examination. Such abnormal clinical signs and symptoms may include changes in the access thrill or bruit, prolonged bleeding after decannulation post dialysis, or arm swelling.