Advanced

AJNR - American Journal of Neuroradiology

A, T2-weighted image through the mesencephalon shows a hyperintense lesion on the left side, along with a hyperintense region with central hypointense specks (arrow) in the right perimesencephalic cistern, merging with the lateral margin of the midbrain.

B, On T1-weighted image, the cisternal lesion appears isointense relative to white matter, with central hypointensity; the left midbrain lesion also appears isointense.

C, MT-SE T1-weighted image shows the left midbrain lesion and the right cisternal lesion as hyperintense, with central hypointensity extending to the remaining margins of the midbrain (arrow).

D, Postcontrast MT-SE T1-weighted image shows these meningeal and parenchymal lesions with marked enhancement.

A, T2-weighted image through the lateral ventricles show lesions with hypointense core and peripheral hyperintensity in left parietal region (arrow).

B, On T1-weighted image, these are not visible.

C, On MT-SE T1-weighted image, the lesions have a hyperintense rim with subtle central hypointensity. A focal area of meningeal hyperintensity is apparent in the left parietal region (arrow).

D, Both lesions show enhancement on postcontrast MT-SE T1-weighted image. A cortical enhancing lesion is only visible on this sequence (arrow).

A–D, T2-weighted (A), T1-weighted (B), MT-SE T1-weighted (C), and postcontrast MT-SE T1-weighted (D) images. In A, an image through the region of the pons shows a poorly defined T2 hyperintense parenchymal lesion in the dorsal aspect of the pons. In D, there is meningeal enhancement (arrow) in the basal cisterns. In A and B, there is no suggestion of meningeal thickening/involvement. ROIs placed for calculation of the MT ratio at same positions in B, C, and D are shown as black dots (arrowheads).

A–D, T2-weighted (A), T1-weighted (B), MT-SE T1-weighted (C), and postcontrast MT-SE T1-weighted (D) images. In D, image through the basal cisterns shows enhancing meningeal thickening. In C, there is hyperintensity in the region that is enhancing in D. This hyperintensity is not visible in A and B.

A–D, T2-weighted (A), T1-weighted (B), MT-SE T1-weighted (C), and postcontrast MT-SE T1-weighted (D) images. In C, image through the pons shows periparenchymal hyperintensity that enhances in D. These are not visible in A and B.

A–D, T2-weighted (A), T1-weighted (B), MT-SE T1-weighted (C), and postcontrast MT-SE T1-weighted (D) images. In A, image through the supraventricular region shows subtle areas of hypointensity with a hyperintense rim (arrow) in the cortex and subcortical white matter. In B, these lesions are isointense with the parenchyma. In C, the lesions seen in A have a hyperintense rim with subtle or no hypointense core. The other lesions seen as hyperintense dots in the subcortical and deep white matter (arrow) are not visible in A. In D, the hyperintensity is increased in some of the lesions (black arrow); however, one lesion in the right occipital cortex, which shows enhancement (white arrow), was not visible on A, B, or C.

A–D, T2-weighted (A), T1-weighted (B), MT-SE T1-weighted (C), and postcontrast MT-SE T1-weighted (D) images. In A, image through the supraventricular part of the cerebrum shows multiple T2 hypointense granulomas (arrows) along with other lesions in different stages of evolution. In B, the T2 hypointense lesions are not visible; in C, they are barely visible; and in D, they show rim enhancement.