Findings
- Large heterogeneous lesion centered in the dorsal right thalamus measuring 4 x 2 cm with central T2 signal hyperintensity, central restricted diffusion, a rim of peripheral T2 signal hypointensity, and peripheral enhancement
- Surrounding T2/FLAIR hyperintensity in the ventral right thalamus, posterior limb of the right internal capsule, posterior right parahippocampal gyrus, right cerebral peduncle, right aspect of the midbrain, and posterior body and splenium of the corpus callosum
- Associated mass effect with 5 mm right to left midline shift and compression of the third ventricle
- Patchy areas of T2/FLAIR signal hyperintensity and restricted diffusion involving the bilateral parasagittal parietal and occipital lobes, the inferior left temporooccipital region, and both cerebellar hemispheres with diffuse leptomeningeal enhancement and multifocal sulcal FLAIR signal hyperintensity
- Additional areas of restricted diffusion in the bilateral hippocampi and splenium of the corpus callosum
- Left frontal approach ventricular drain terminating in the left lateral ventricle near the foramen of Monro with slit-like appearance of the left lateral ventricle
- Susceptibility artifact and restricted diffusion along the intracranial course of the drain as well as in the left greater than right lateral ventricles
- Small amount of extraaxial susceptibility artifact overlying the left frontal lobe
- Bilateral periventricular T2/FLAIR signal hyperintensity
- Right greater than left mastoid effusions
Diagnosis
Abscess/cerebritis, meningitis, cytotoxic lesion of the corpus callosum (CLOCC)
Sample Report
Findings concerning for a right thalamic abscess measuring 4 x 2 cm with surrounding vasogenic edema and associated mass effect with 5 mm right to left midline shift and compression of the third ventricle.
Left frontal approach ventricular drain terminating in the left lateral ventricle near the foramen of Monro without evidence of hydrocephalus. Small amount of hemorrhage along the extra-axial and intraparenchymal course of the catheter with restricted diffusion along the catheter track suggestive of devitalized tissue. Likely residual transependymal edema related to now improved hydrocephalus.
Findings consistent with meningitis and small volume subarachnoid exudate or proteinaceous material. No discrete extraaxial empyema/abscess. Patchy areas of T2/FLAIR signal hyperintensity and restricted diffusion involving the bilateral parasagittal parietal and occipital lobes, the inferior left temporooccipital region, and both cerebellar hemispheres may relate to cerebritis and/or areas of infarct.
Additional areas of restricted diffusion in the bilateral hippocampi likely relate to seizure activity. Areas of restricted diffusion in the splenium of the corpus callosum likely relate to seizure activity or infection.
Discussion
References