Male, 18 years old, with seizures and abnormal CT. Assess for structural lesion, vasculitis. An oval T2 hyperintense, FLAIR hyperintense, non-diffusion restricting lesion is present within the paramedian left superior frontal gyrus. The lesion appears to be based in the cortex and/or subarachnoid space as it seems to displace an adjacent traversing vessel. The rim of this lesion is T2 hyperintense, but no significant associated parenchymal edema is noted.The lesion does not enhance. No evidence of any definite internal nodular tissue is seen. However, a punctate focus of susceptibility is present along the superior aspect of the lesion (see image 181 series 1601).No definite evidence of any additional parenchymal lesion is seen. On a single slice of the T2 weighted axial sequence, there appears to be some hyperintensity at the level of the left inferior medullary olive, but this cannot be confirmed on FLAIR or coronal T2 weighted images and may therefore be artifactual.No areas of parenchymal edema or significant mass effect are detected. No acute intracranial hemorrhage is suspected. The left lateral ventricle is mildly and uniformly larger than the right, but this is favored to represent an anatomic variation.Dedicated imaging of the medial temporal lobe structures shows symmetric morphology and signal characteristics. No discrete temporal lobe lesions are appreciated.MRA images are somewhat degraded by motion artifact, but no evidence of any high-grade stenosis, occlusion, aneurysm or vascular malformation is seen. Dedicated MRV imaging of the brain is technically inadequate. However, no loss of flow void on T2-weighted images or filling defects on postcontrast images are seen to suggest an occlusion of the dural venous sinuses.
1.A lesion is evident within the paramedian left superior frontal gyrus, centered on the cortex and/or subarachnoid space. This lesion does not enhance, and by virtue of its signal characteristics, may reflect solid tissue or proteinaceous cystic material. The lesion induces no significant edema in the adjacent parenchyma. No discrete nodular tissue is seen within this lesion, though there is a small focus of susceptibility within it.2.The differential diagnosis for this lesion is broad and would include an infectious cyst as would be seen in neuro-cysticercosis. Although no definite evidence of a scolex is seen, the small focus of susceptibility could conceivably represent a scolex. Lack of edema and enhancement would be compatible with the early vesicular stage the disease. Additional differential considerations would include low-grade primary brain tumor, and much less likely an atypical presentation of a benign developmental cyst. If prior imaging is available, these exams can be up loaded and a comparison to the present study will be made, which may help refine the differential diagnosis.3.MRA imaging of the brain is slightly motion degraded, but no significant arterial abnormalities are suspected. MRV imaging is nondiagnostic for technical reasons. However, on the basis of conventional sequences, no significant abnormalities of the intracranial venous system are suspected.