title: Perilesional Hyperintensity on T1-Weighted Images in Intra-Axial Brain Masses other than Cavernous Malformations.
abstract: 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.
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA.
authors.forename: S Ali
authors.initials: SA
authors.lastname: Nabavizadeh
authors.affiliation: Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Dasha
authors.initials: D
authors.lastname: Pechersky
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA.
authors.forename: J Eric
authors.initials: JE
authors.lastname: Schmitt
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA.
authors.forename: MacLean
authors.initials: M
authors.lastname: Nasrallah
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA.
authors.forename: Ronald
authors.initials: R
authors.lastname: Wolf
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA.
authors.forename: Laurie
authors.initials: L
authors.lastname: Loevner
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA.
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Mamourian
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology; D001922:Brain Abscess / Q000000981:diagnostic imaging* / Q000473:pathology; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Cavernous malformation; T1-weighted imaging; intra-axial; mass