Coronal T2 and Axial GRE images of Brain: Mild dilatation of both lateral ventricles due to pressure effect of the lesion on 3rd ventricle. There is blooming of the lesion on GRE sequence. |
Axial and coronal Contrast enhanced T1 wt images with fat supression: There is intense homogenous enhancement of the lesion. |
Reference: Hemangioma from Head to Toe: MR Imaging with Pathologic Correlation, March 2004 RadioGraphics, 24, 367-385.
· Manifest in two different modes:
1. Inherited (typically multiple and bilateral)
2. Solitary and sporadic
· Unlike AVMs, cavernous angiomas have no intervening brain tissue between vascular spaces - hence the descriptive term Blood Sponge.
· MRI is far more sensitive than angiography in detecting these lesions.
· Cavernous malformations typically have little or no mass effect, unless they are complicated by hemorrhage.
· Similarly, surrounding vasogenic edema does not occur unless there are hemorrhagic complications.
· Cavernous angiomas may have internal areas of thrombosis or hemorrhage.
· These blood products are typically of various ages, representing hemorrhage in various states of degradation.
· There may be conversion of hemoglobin to methemoglobin, which produces foci of hyperintensity on T1-weighted MR images.
· Hemosiderin may be cleared from the central area of a cavernous angioma and deposited around the periphery. This peripheral hemosiderin causes significant T2 shortening, producing a black “halo” around the lesion.
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