title: Comparison of Diffusion Tensor Imaging and Magnetic Resonance Perfusion Imaging in Differentiating Recurrent Brain Neoplasm From Radiation Necrosis.
abstract: OBJECTIVE
  To compare differences in diffusion tensor imaging (DTI) and dynamic susceptibility-weighted contrast-enhanced (DSC) magnetic resonance (MR) perfusion imaging characteristics of recurrent neoplasm and radiation necrosis in patients with brain tumors previously treated with radiotherapy with or without surgery and chemotherapy.
  
  
  METHODS
  Patients with a history of brain neoplasm previously treated with radiotherapy with or without chemotherapy and surgery who developed a new enhancing lesion on posttreatment surveillance MRI were enrolled. DSC perfusion MRI and DTI were performed. Region of interest cursors were manually drawn in the contrast-enhancing lesions, in the perilesional white matter edema, and in the contralateral normal-appearing frontal lobe white matter. DTI and DSC perfusion MR indices were compared in recurrent tumor versus radiation necrosis.
  
  
  RESULTS
  Twenty-two patients with 24 lesions were included. Sixteen (67%) lesions were placed into the recurrent neoplasm group and eight (33%) lesions were placed into the radiation necrosis group using biopsy results as the gold standard in all but three patients. Mean apparent diffusion coefficient values, mean parallel eigenvalues, and mean perpendicular eigenvalues in the contrast-enhancing lesion were significantly lower, and relative cerebral blood volume was significantly higher for the recurrent neoplasm group compared to the radiation necrosis group (P < 0.01, P = 0.03, P < 0.01, and P < 0.01, respectively).
  
  
  CONCLUSIONS
  The combined assessment of DTI and DSC MR perfusion properties of new contrast-enhancing lesions is helpful in distinguishing recurrent neoplasm from radiation necrosis in patients with a history of brain neoplasm previously treated with radiotherapy with or without surgery and chemotherapy.
authors.affiliation: Department of Radiology, University of Michigan Health System, University of Michigan Medical Center, Room UH B1-D502, 1500 East Medical Center Drive, Ann Arbor, MI 48109. Electronic address: mascwill@med.umich.edu.
authors.forename: William R
authors.initials: WR
authors.lastname: Masch
authors.affiliation: Alta Vista Radiology, Paradise Valley, Arizona.
authors.forename: Page I
authors.initials: PI
authors.lastname: Wang
authors.affiliation: Department of Radiology-MRI, University of Michigan Health System, Ann Arbor, Michigan.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Chenevert
authors.affiliation: Department of Neurology, University of Michigan Health System, Ann Arbor, Michigan.
authors.forename: Larry
authors.initials: L
authors.lastname: Junck
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Christina
authors.initials: C
authors.lastname: Tsien
authors.affiliation: Department of Neurosurgery, University of Michigan Health System, Ann Arbor, Michigan.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Heth
authors.affiliation: Department of Diagnostic Radiology, Clinical Sciences Lund, Lund University, Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden.
authors.forename: Pia C
authors.initials: PC
authors.lastname: Sundgren
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy / Q000379:methods; D001921:Brain / Q000473:pathology / Q000528:radiation effects*; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy; D000071937:Cerebral Blood Volume / Q000502:physiology; D003287:Contrast Media; D003937:Diagnosis, Differential; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005625:Frontal Lobe / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D020360:Neoadjuvant Therapy / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D055420:Perfusion Imaging / Q000379:methods*; D011832:Radiation Injuries / Q000000981:diagnostic imaging*; D066127:White Matter / Q000000981:diagnostic imaging; D055815:Young Adult
chemical_list: D003287:Contrast Media
keywords: Magnetic resonance perfusion imaging; brain neoplasm; brain tumor; diffusion tensor imaging; radiation necrosis