Cavernous malformation


Image 1

Clinical History: 
A 60 year-old woman with myelopathic symptoms, status/post cervical decompression, with follow-up cervical MR revealing a lesion in the pons.

Cavernous malformation

MR Technique: 
5 mm axial FSE (15 echoes) and GRE (FLASH) pre-contrast T2- and post-contrast SE T1-weighted images are presented, acquired at 1.5 T on a Siemens Espree MR system. Sequence parameters were TR/ TE = 5800/96, 800/26 (with a flip angle of 20°) and 635/17 respectively. Scan times were 3:47, 4:29 and 2:22 min:sec.

Imaging Findings:
A large lesion is seen in the right pons demonstrating mixed low and high signal intensity on T1- and T2-weighted images, with marked low signal intensity throughout on the gradient echo T2-weighted image (consistent with hemosiderin). There are areas of mild punctate enhancement post-contrast. These findings are typical of a cavernous malformation. Additional findings, not shown, included a similar size lesion in the right frontal lobe, and two tiny lesions seen only on the gradient echo scans in the left parietal lobe.

The classic appearance of a cavernous malformation on MR is that of mixed signal intensity on both T1- and T2-weighted images, a ‘popcorn’ appearance, representing hemorrhage of various ages, in combination with a complete hypointense hemosiderin rim. The latter is best visualized on gradient echo T2* weighted images, which emphasize the susceptibility effect of the hemosiderin. Post-contrast there may be mild to no enhancement. 2/3rd of cases are solitary, 1/3rd multiple (familial). In the latter, visualization on T2* GRE scans of multiple additional punctate hypointense foci is common.