title: Differentiating Hemangioblastomas from Brain Metastases Using Diffusion-Weighted Imaging and Dynamic Susceptibility Contrast-Enhanced Perfusion-Weighted MR Imaging.
abstract: OBJECTIVE
  On DWI and DSC-PWI, hemangioblastomas and brain metastases may exhibit different signal intensities depending on their cellularity and angiogenesis. The purpose of this study was to evaluate whether a hemangioblastoma can be differentiated from a single brain metastasis with DWI and DSC-PWI.
  
  
  METHODS
  We retrospectively reviewed DWI, DSC-PWI, and conventional MR imaging of 21 patients with hemangioblastomas and 30 patients with a single brain metastasis. Variables of minimum ADC and relative ADC were acquired by DWI and the parameter of relative maximum CBV, by DSC-PWI. Minimum ADC, relative ADC, and relative maximum CBV values were compared between hemangioblastomas and brain metastases by using the nonparametric Mann-Whitney test. The sensitivity, specificity, positive and negative predictive values, accuracy, and the area under the receiver operating characteristic curve were determined.
  
  
  RESULTS
  Both the minimum ADC values and relative ADC ratios were significantly higher in hemangioblastomas compared with brain metastases (P< .001 for both minimum ADC values and relative ADC ratios). The same was true for the relative maximum CBV ratio (P< .002). The threshold value of ≥6.59 for relative maximum CBV provided sensitivity, specificity, and accuracy of 95.24%, 53.33%, and 70.59%, respectively, for differentiating hemangioblastomas from brain metastases. Compared with relative maximum CBV, relative ADC had high sensitivity (95.24%), specificity (96.67%), and accuracy (96.08%) using the threshold value of ≥1.54. The optimal threshold value for minimum ADC was ≥1.1 × 10-3mm2/s.
  
  
  CONCLUSIONS
  DWI and DSC-PWI are helpful in the characterization and differentiation of hemangioblastomas from brain metastases. DWI appears to be the most efficient MR imaging technique for providing a distinct differentiation of the 2 tumor types.
authors.affiliation: From the Department of Radiology, First Affiliated Hospital of Fujian Medical University, Fuzhou, P.R. China.
authors.forename: D
authors.identifier: http://orcid.org/0000-0002-0143-659X
authors.initials: D
authors.lastname: She
authors.affiliation: From the Department of Radiology, First Affiliated Hospital of Fujian Medical University, Fuzhou, P.R. China.
authors.forename: X
authors.identifier: http://orcid.org/0000-0001-8899-7199
authors.initials: X
authors.lastname: Yang
authors.affiliation: From the Department of Radiology, First Affiliated Hospital of Fujian Medical University, Fuzhou, P.R. China.
authors.forename: Z
authors.identifier: http://orcid.org/0000-0002-2104-4681
authors.initials: Z
authors.lastname: Xing
authors.affiliation: From the Department of Radiology, First Affiliated Hospital of Fujian Medical University, Fuzhou, P.R. China. dairongcao@163.com.
authors.forename: D
authors.identifier: http://orcid.org/0000-0002-0051-3143
authors.initials: D
authors.lastname: Cao