Demyelinating disease of central nervous system, unspecified [341.9], Reason for Study: ^Reason: MS? New lesions? History: S changes alternating thighs and L breast also poor balance and L iliopsoas weak There are multifocal patchy and somewhat nodular high signal intensity lesions on bilateral white matter. Overall, there are more new lesions comparing to prior scan such as periventricular white matter around right lateral ventricle, left frontal lobe lateral orbital gyrus, right basal ganglia, right thalamus and posterior limb of internal capsule on the right, right side trigone, left side trigone and the largest lesion on the right inferior parietal lobule. However, there are lesions which show interval decrease in size and signal intensity on FLAIR which include left side corpus callosum splenium, left occipital lobe and right temporal lobe lesions.On Gad enhanced scan, most of new lesions show ring enhancement and some patchy enhancement.Constellation of these findings suggest activation of demyelinating disease such as multiple sclerosis. Differential diagnosis include metastatic lesions and infectious origin including multifocal abscess which appear to be lower chance. The ventricles, sulci and cisterns are symmetric and unremarkable. The midline structures and cranial-cervical junction are normal. Normal flow voids are identified in the major intracranial vessels. The paranasal sinuses and mastoid air cells are clear.
Multifocal various sized high signal intensity lesions on bilateral white matter, overall there have been significant interval increase in size and number of lesions comparing to prior scan but there are some lesions showed decrease in the size and signal intensity on FLAIR images.Diagnostic possibility include active multiple sclerosis most likely, metastatic lesions and infectious origin as described above. 