title: Intracranial hemangiopericytoma: MR imaging findings and diagnostic usefulness of minimum ADC values.
abstract: OBJECTIVE
  To describe the clinical and magnetic resonance (MR) imaging features of primary intracranial hemangiopericytoma (HPC), and to assess the usefulness of minimum apparent diffusion coefficient (MinADC) value of HPC in the differential diagnosis from meningioma.
  
  
  METHODS
  From 2004 to 2010, fifteen patients with primary intracranial HPC were included. The clinical data, conventional MR findings (n = 15), and diffusion weighted image (DWI) features (n = 10) were retrospectively analyzed. MinADC value of the HPCs (n = 10) was measured on ADC map and was compared with that of meningiomas (n = 37).
  
  
  RESULTS
  In 15 cases of HPC, isointense signal was detected on both T1-weighted images (T1WI) and T2-weighted images (T2WI) in 11 cases, and heterogeneous signal was demonstrated in 4 cases. Isointensity (n = 9) and iso- and slight hyperintensity (n = 1) were shown on DWI. The mean MinADC value of HPC [(1.116 ± 0.127) × 10(-3) mm(2) /s] was significantly higher than that of meningioma [(0.875 ± 0.104) × 10(-3) mm(2) /s] (P < 0.01). For the differentiation between HPC and meningioma, the critical cutoff MinADC value was 0.991 × 10(-3) mm(2) /s, which provided the best combination of sensitivity (88.9%) and specificity (82.4%).
  
  
  CONCLUSIONS
  MinADC value may be an useful tool for the differentiation between HPC and meningioma.
authors: Department of Radiology, People's Liberation Army General Hospital, China.
authors: Gang
authors: G
authors: Liu
authors: Zhi-Ye
authors: ZY
authors: Chen
authors: Lin
authors: L
authors: Ma
authors: Xin
authors: X
authors: Lou
authors: Shi-Jun
authors: SJ
authors: Li
authors: Yu-Lin
authors: YL
authors: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D001932:Brain Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology*; D008579:Meningioma / Q000473:pathology*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: ROC curve; apparent diffusion coefficient (ADC); hemangiopericytoma; magnetic resonance imaging; value