title: Comparison of diffusion-weighted imaging between high and standard b-values for primary central nervous system lymphoma.
abstract: OBJECTIVE
  To investigate the utility of diffusion-weighted (DW) magnetic resonance imaging (MRI) with a high b-value (b = 3000 s/mm(2)) compared with standard b-value (b = 1000 s/mm(2)) DW imaging in patients with primary central nervous system lymphoma (PCNSL).
  
  
  METHODS
  High and standard b-value (b = 3000 and 1000 s/mm(2), respectively) DW images were acquired in 15 patients with PCNSL. The number and location of the lesions were assessed. MRI signal intensities (SIs), signal-to-noise ratios (SNRs), contrast-to-noise ratios (CNRs), contrast ratios (CRs), and apparent diffusion coefficients (ADCs) of the lesions and normal parenchyma were measured.
  
  
  RESULTS
  Thirty-two lesions in 15 patients were revealed. Twenty-seven of the lesions were hyperintense at DW MRI with high and standard b-values; high b-value images revealed five additional lesions. Lesions were also more conspicuous at high b-value (b = 3000 s/mm(2)) DW MRI compared to standard b-value images (b = 1000 s/mm(2)). SNR, CNR, and ADC values in lesions and normal parenchyma were lower in the b = 3000 s/mm(2) images compared to the b = 1000 s/mm(2) images (SNR: 250.7 ± 124.7 versus 112.3 ± 68.7; CNR: 83.4 ± 74.7 versus 59.6 ± 60.4, b = 1000 and 3000 s/mm(2), respectively). The CR was significantly greater in the b = 3000 s/mm(2) images compared to the b = 1000 s/mm(2) images (CR: 0.28 ± 0.13 versus 0.18 ± 0.10).
  
  
  CONCLUSIONS
  Although quantitative analyses revealed higher SI, SNR, and CNR values in standard b-value (b = 1000 s/mm(2)) DW images, higher b-value imaging could be beneficial for detecting additional lesions and improving the contrast between lesions and normal tissue in patients with PCNSL.
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Xiamen University, Fujian, China.
authors.forename: H
authors.initials: H
authors.lastname: Han
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Xiamen University, Fujian, China.
authors.forename: C
authors.initials: C
authors.lastname: Han
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Xiamen University, Fujian, China.
authors.forename: S
authors.initials: S
authors.lastname: Huang
authors.affiliation: Department of Neurosurgery, The First Affiliated Hospital of Xiamen University, Fujian, China.
authors.forename: J
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Xiamen University, Fujian, China. Electronic address: zhuangxiongjievip@163.com.
authors.forename: X
authors.initials: X
authors.lastname: Zhuang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016543:Central Nervous System Neoplasms / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio