title: Minimum apparent diffusion coefficients in the evaluation of brain tumors.
abstract: OBJECTIVE
  To determine whether diffusion-weighted imaging by using minimum apparent diffusion coefficient (ADC(min)) values could differentiate various brain tumors including gliomas, metastases, and lymphomas.
  
  
  METHODS
  We examined 65 patients with histologically or clinically diagnosed brain tumors (12 low-grade gliomas, 31 high-grade gliomas, 14 metastatic tumors, and 8 lymphomas) using a 1.5 T MR unit. On diffusion-weighted imaging, the ADC(min) values were measured within the tumors and mean values were evaluated regarding statistical differences between groups.
  
  
  RESULTS
  The ADC(min) values of low-grade gliomas (1.09+/-0.20 x 10(-3)mm(2)/s) were significantly higher (p<.001) than those of other tumors. There were no statistical significant differences between glioblastomas (0.70+/-0.16 mm(2)/s), anaplastic astrocytomas (0.77+/-0.21 mm(2)/s), metastases (0.78+/-0.21 mm(2)/s), and lymphomas. But, lymphomas had lower mean ADC(min) values (0.54+/-0.10mm(2)/s) than high-grade gliomas and metastases.
  
  
  CONCLUSIONS
  The ADC measurements may help to differentiate low-grade gliomas from high-grade gliomas, metastases, and lymphomas. Although there is no statistical difference, lymphomas seem to have marked restriction in diffusion coefficients.
authors.affiliation: Department of Radiology, School of Medicine, Ege University, 35100 Bornova, Izmir, Turkey. okitis@med.ege.edu.tr
authors.forename: Omer
authors.initials: O
authors.lastname: Kitis
authors.forename: Hakan
authors.initials: H
authors.lastname: Altay
authors.forename: Cem
authors.initials: C
authors.lastname: Calli
authors.forename: Nilgun
authors.initials: N
authors.lastname: Yunten
authors.forename: Taner
authors.initials: T
authors.lastname: Akalin
authors.forename: Taskin
authors.initials: T
authors.lastname: Yurtseven
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001932:Brain Neoplasms / Q000473:pathology*; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005910:Glioma / Q000473:pathology; D006801:Humans; D008223:Lymphoma / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000473:pathology