Perilesional Hyperintensity on T1‐Weighted Images in Intra‐Axial Brain Masses other than Cavernous Malformations

摘要

ABSTRACT BACKGROUND AND PURPOSE Hyperintensity on T1‐weighted imaging in perilesional vasogenic edema has been reported as a useful sign for differentiating cavernous malformation from other hemorrhagic intra‐axial masses. In this study, we investigated the frequency of perilesional hyperintensity on T1‐weighted imaging in patients with intra‐axial hemorrhagic and nonhemorrhagic brain masses. METHODS The study was performed with the approval of the institutional review board. Magnetic resonance images of 218 patients with 282 intra‐axial brain masses (129 metastases, 46 gliomas, 18 primary central nervous system lymphomas [PCNSLs], 25 intracerebral hemorrhages, 50 cavernous malformations, and 14 patients with brain abscesses) were evaluated. The signal intensity in perilesional area was qualitatively evaluated on T1‐weighted sequences. In addition, signal intensity in perilesional area was quantitatively measured on T1‐weighted sequences and normalized to the contralateral white matter. RESULTS Hyperintensity on T1‐weighted imaging in perilesional vasogenic edema was found in 12 (9%) of 129 metastases, 8 (16%) of 50 cavernous malformations, 1 (4%) in 25 nonneoplastic intracerebral hemorrhages, and none of the patients with high‐grade glioma, PCNSL, or abscess. All of the lesions with perilesional hyperintensity showed either acute or subacute hemorrhage. Pairwise comparison of qualitative hyperintensity on T1‐weighted imaging demonstrated no significant difference between the groups. Perilesional hyperintensity on T1‐weighted imaging showed high specificity in both metastasis and cavernous malformation groups (94%). CONCLUSION Perilesional hyperintensity on T1‐weighted imaging is not limited to cavernous malformations and frequently evident with melanoma and other hemorrhagic metastasis to the brain. In our experience, it was not seen in high‐grade glioma, PCNSL, and brain abscess.