instruction: hello doctor is there anyway that a it scan can determine whether an enlarged lymph node is benign or malignant
output: hi it is a structural imaging method that relies on assessment of lymphnodes lens based on their anatomy viz size shape margins and enhancement patterns among these size is still the most common criterion a short axis diameter of more than am is generally accepted as a threshold for malignancy in most studies however the diagnostic sensitivity of this standard is weakened by the fact that many a times malignant lens can be normal in size false negative and many invective nodes can be enlarged in size thus giving false positive results on imaging nowadays it is combined with pet positron emission tomography to get both anatomical and functional information it is called fusion imaging and is mainly used to diagnose and stage metastatic cancers such as lymphomas it also uses ionizing radiation rays that is another disadvantage which needs to be considered so to sum it all structural imaging methods such as ultrasound it conventional mri do not distinguish benign lens from malignant ones with 100 accuracy conversely functional imaging methods such as dwi diffusion weighted pet have low spatial resolution and are time consuming therefore now we are seeing a shift towards fusion imaging techniques such as dwi t2w1 mri pet it etc as these techniques bypass the above mentioned shortcomings