title: Hepatic cavernous hemangiomas: relationship between speed of intratumoral enhancement during dynamic MRI and apparent diffusion coefficient on diffusion-weighted imaging.
abstract: OBJECTIVE
  To investigate the relationships between the apparent diffusion coefficients (ADCs) on diffusion-weighted imaging (DWI) and the speed of contrast-enhancement in hepatic hemangiomas.
  
  
  METHODS
  Sixty-nine hepatic hemangiomas (≥ 1 cm) were evaluated with DWI, by using multiple b values (b = 50, 400, 800 s/mm(2)), followed by a gadolinium-enhanced dynamic MRI. The lesions were classified into three groups, according to the speed of contrast-enhancement on the portal phase. ADCs were measured on the ADC map automatically, and were calculated by using the two different b values (mADC(50-400) with b values = 50 and 400; mADC(400-800) with b values = 400 and 800 s/mm(2)).
  
  
  RESULTS
  The mean ADCs (× 10(-3) mm(2)/s) were significantly higher in the rapid group (1.9 ± 0.44) than in the intermediate (1.7 ± 0.35, p = 0.046) or the slow groups (1.4 ± 0.34, p = 0.002). There were significant differences between the rapid and the slow groups in mADC(50-400) (2.12 vs. 1.48; p = 0.008) and mADC(400-800) (1.68 vs. 1.22, p = 0.010), and between the rapid and the intermediate groups in mADC(50-400) (2.12 vs. 1.79, p = 0.049). Comparing mADC(50-400) with mADC(400-800), there was a significant difference only in the rapid group (p = 0.001).
  
  
  CONCLUSIONS
  Higher ADCs of rapidly-enhancing hemangiomas may be related to richer intralesional vascular perfusion. Also, the restricted diffusion may be attributed to the difference of structural characteristics of hemangioma.
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul 135-720, Korea.
authors.forename: Se Jin
authors.initials: SJ
authors.lastname: Nam
authors.forename: Kae Young
authors.initials: KY
authors.lastname: Park
authors.forename: Jeong-Sik
authors.initials: JS
authors.lastname: Yu
authors.forename: Jae-Joon
authors.initials: JJ
authors.lastname: Chung
authors.forename: Joo Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Ki Whang
authors.initials: KW
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D019786:Gadolinium DTPA; D006392:Hemangioma, Cavernous / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: Diffusion-weighted MR imaging; Hemangioma; Liver, MR; Liver, neoplasms