title: Distinction between glioma progression and post-radiation change by combined physiologic MR imaging.
abstract: BACKGROUND
  Magnetic resonance (MR) diffusion-weighted imaging (DWI), dynamic susceptibility contrast-enhanced perfusion imaging (DSC), and MR spectroscopy (MRS) techniques provide specific physiologic information that may distinguish malignant glioma progression from post-radiation change, yet no single technique is completely reliable. We propose a simple, multiparametric scoring system to improve diagnostic accuracy beyond that of each technique alone.
  
  
  METHODS
  Fifteen subjects with lesions suspicious for glioma progression following radiation therapy who had also undergone 3-tesla DWI, DSC, and MRS studies of the lesion were retrospectively reviewed. Minimum apparent diffusion coefficient (ADC) ratio, maximum regional cerebral blood volume (rCBV) ratio, and maximum MRS choline/creatine (Cho/Cr) and choline/N-acetyl-aspartate (Cho/NAA) metabolic peak-height ratios were quantified within each lesion. Each parameter (ADC ratio, rCBV ratio, and combined Cho/Cr and Cho/NAA ratios) was scored as either glioma progression (one point) or radiation change (zero point) based upon thresholds derived from our own data. For each lesion, the combined parameters yielded a multiparametric score (0 to 3) for prediction of tumor progression or post-radiation change.
  
  
  RESULTS
  Optimum thresholds for ADC ratio (1.30), rCBV ratio (2.10), and either combined Cho/Cr (1.29) and Cho/NAA (1.06) yielded diagnostic accuracies of 86.7%, 86.7%, and 84.6%, respectively (p < 0.05). A combined multiparametric score threshold of 2 improved diagnostic accuracy to 93.3% (p < 0.05).
  
  
  CONCLUSIONS
  In this small series combining 3-T DWI, DSC, and MRS diagnostic results using a simple, multiparametric scoring system has potential to improve overall diagnostic accuracy in distinguishing glioma progression from post-radiation change beyond that of each technique alone.
authors.affiliation: Department of Radiology, University of Washington, 1959 NE Pacific, Seattle, WA, 98195, USA. matsusue@grape.med.tottori-u.ac.jp
authors.forename: Eiji
authors.initials: E
authors.lastname: Matsusue
authors.forename: James R
authors.initials: JR
authors.lastname: Fink
authors.forename: Jason K
authors.initials: JK
authors.lastname: Rockhill
authors.forename: Toshihide
authors.initials: T
authors.lastname: Ogawa
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Maravilla
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001810:Blood Volume; D001921:Brain / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000532:radiotherapy; D002560:Cerebrovascular Circulation; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005910:Glioma / Q000175:diagnosis* / Q000473:pathology / Q000532:radiotherapy; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D055420:Perfusion Imaging / Q000379:methods*; D010865:Pilot Projects; D012189:Retrospective Studies
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline