CLINICAL HISTORY: 39-year-old woman with multifocal lesions suspicious for PML, JC virus positive CSF.
Parenchyma: Again seen are patchy signal abnormalities in the subcortical white matter including subcortical U fibers, most notable in the left hemisphere involving the left frontal, temporal, and inferior parietal lobes, to a lesser degree involving the right medial frontal subcortical white matter and medial right parietal subcortical white matter/cortex, and extending into left external capsule. Linear T2/FLAIR hyperintense foci in the left greater than right periventricular white matter and extending into the posterior limb of the left internal capsule are also unchanged. Associated diffusion signal abnormality abnormality on diffusion is related to T2 shine through, no hypointensity on ADC. No acute hemorrhage or infarct. No mass effect or midline shift. Postcontrast images are motion degraded, however no definite abnormal enhancement is seen postcontrast.
Additional comment: No perfusion abnormality on ASL or bolus perfusion images.
1. Subcortical white matter signal abnormality involving the left greater than right cerebral hemispheres, nonspecific though suggestive of progressive multifocal leukoencephalopathy in the setting of immunosuppression and positive JC virus in CSF. Additional linear subcortical and periventricular FLAIR signal abnormalities correlating to areas of restricted diffusion on prior exam may represent additional involvement of PML however are less typical in appearance, or represent sequela from old border zone infarcts.
2. Mild diffuse pachymeningeal enhancement. Correlate for history of recent lumbar puncture.
(Progressive multifocal leukoencephalopathy)
Study description: MR BRAIN WITH AND WITHOUT CONTRAST