title: Clinical Significance of Discrepancy between Arterial Spin Labeling Images and Contrast-enhanced Images in the Diagnosis of Brain Tumors.
abstract: OBJECTIVE
  In the imaging of intra-axial brain tumors, we sometimes found areas of high signal intensity around the enhanced tumor lesions on arterial spin labeling (ASL) magnetic resonance (MR) imaging. We undertook this study to investigate the relationship between high signal intensity on ASL imaging outside the area of contrast enhancement (CE) and histological diagnosis of intra-axial brain tumors.
  
  
  METHODS
  We examined images from 28 consecutive patients with intra-axial brain tumors who underwent ASL and CE MR imaging-three with low grade glioma (LGG), 13 with high grade glioma (HGG), six with metastasis, and six with primary central nervous system lymphoma (PCNSL)-and divided imaging findings into an "ASL dominant" group when hyperintensity on ASL was found outside the CE area and a "CE dominant" group when hyperintensity on ASL was not found outside the area of enhancement. We then analyzed the relationship between imaging findings and the histological diagnosis of the tumors.
  
  
  RESULTS
  Four cases were excluded because of poor quality of ASL images, 7 cases were classified as ASL dominant, and 17 cases were classified as CE dominant. The histological diagnoses of ASL dominant cases were LGG in 3 cases, HGG in 3 cases, and PCNSL in one case. Those of CE dominant cases were HGG in 10 cases, metastasis in 5 cases, and PCNSL in 2 cases. All cases with brain metastasis were classified as CE dominant.
  
  
  CONCLUSIONS
  The high signal intensity outside the area of contrast enhancement is probably caused by increased perfusion or vascular proliferation, which indicates the presence of glioma or PCNSL and not metastasis. This finding indicates a new utility for ASL images in the diagnosis of brain tumors as a supplement to the conventional measurement of perfusion obtained from ASL images.
authors.affiliation: Department of Radiology, Institute of Health Biosciences, The University of Tokushima Graduate School.
authors.forename: Takashi
authors.initials: T
authors.lastname: Abe
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Mizobuchi
authors.forename: Wataru
authors.initials: W
authors.lastname: Sako
authors.forename: Saho
authors.initials: S
authors.lastname: Irahara
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Otomi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Obama
authors.forename: Kohei
authors.initials: K
authors.lastname: Nakajima
authors.forename: Delgerdalai
authors.initials: D
authors.lastname: Khashbat
authors.forename: Mungunkhuyag
authors.initials: M
authors.lastname: Majigsuren
authors.forename: Teruyoshi
authors.initials: T
authors.lastname: Kageji
authors.forename: Shinji
authors.initials: S
authors.lastname: Nagahiro
authors.forename: Masafumi
authors.initials: M
authors.lastname: Harada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001254:Astrocytoma / Q000175:diagnosis / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary; D003287:Contrast Media; D003937:Diagnosis, Differential; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D005909:Glioblastoma / Q000175:diagnosis / Q000473:pathology; D005910:Glioma / Q000175:diagnosis* / Q000473:pathology; D018316:Gliosarcoma / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D016403:Lymphoma, Large B-Cell, Diffuse / Q000175:diagnosis / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D018302:Neoplasms, Neuroepithelial / Q000175:diagnosis / Q000473:pathology; D059906:Neuroimaging / Q000379:methods*; D009837:Oligodendroglioma / Q000175:diagnosis / Q000473:pathology; D013113:Spin Labels
chemical_list: D003287:Contrast Media; D013113:Spin Labels; D019786:Gadolinium DTPA