Nabavizadeh S Ali, Pechersky Dasha, Schmitt J Eric, Nasrallah MacLean, Wolf Ronald, Loevner Laurie, Mamourian Alexander C
Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA.
Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL.
J Neuroimaging. 2017 Sep;27(5):531-538. doi: 10.1111/jon.12424. Epub 2017 Jan 18.
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.
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.
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%).
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.
据报道，病灶周围血管源性水肿在T1加权成像上呈高信号是鉴别海绵状血管畸形与其他轴内出血性肿块的有用征象。在本研究中，我们调查了轴内出血性和非出血性脑肿块患者病灶周围在T1加权成像上出现高信号的频率。
本研究经机构审查委员会批准后进行。对218例患有282个轴内脑肿块的患者（129例转移瘤、46例胶质瘤、18例原发性中枢神经系统淋巴瘤[PCNSL]、25例脑内出血、50例海绵状血管畸形以及14例脑脓肿患者）的磁共振图像进行评估。在T1加权序列上对病灶周围区域的信号强度进行定性评估。此外，在T1加权序列上对病灶周围区域的信号强度进行定量测量，并以对侧白质为参照进行标准化。
在129例转移瘤中有12例（9%）、50例海绵状血管畸形中有8例（16%）、25例非肿瘤性脑内出血中有1例（4%）在病灶周围血管源性水肿的T1加权成像上呈高信号，而高级别胶质瘤、PCNSL或脑脓肿患者均未出现这种情况。所有病灶周围呈高信号的病变均显示有急性或亚急性出血。对T1加权成像上定性高信号进行两两比较，各组之间无显著差异。T1加权成像上病灶周围高信号在转移瘤组和海绵状血管畸形组中均显示出高特异性（94%）。
T1加权成像上病灶周围高信号不仅限于海绵状血管畸形，在黑色素瘤及其他脑内出血性转移瘤中也经常出现。根据我们的经验，在高级别胶质瘤、PCNSL和脑脓肿中未见到这种情况。
