title: Evaluation of diffusion weighted imaging of magnetic resonance imaging in small focal hepatic lesions: a quantitative study in 56 cases.
abstract: BACKGROUND
  Diffusion-weighted imaging (DWI) as a new technique of magnetic resonance imaging (MRI) is used to detect focal hepatic lesions. This study was designed to evaluate the significance of DWI to differentiate focal hepatic lesions less than 3 cm in diameter by the quantitation of apparent diffusion coefficient (ADC) values.
  
  
  METHODS
  DWI using 1.5T MRI scanner unit was performed with a spin-echo single-shot echo planar imaging (EPI) in 56 cases of small focal hepatic lesions, including hepatocellular carcinoma (11), hepatic metastatic tumor (15), hepatic cavernous hemangioma (14), and hepatic cyst (16). The ADC values of these lesions were calculated respectively. The ratios of the ADC values of lesion/liver in hepatocellular carcinomas and hepatic metastatic tumors were also estimated.
  
  
  RESULTS
  The mean ADC values (mm2/s) were (0.93+/-0.06) x 10(-3) in hepatocellular carcinomas, (1.09+/-0.18) x 10(-3) in hepatic metastatic tumors, (1.95+/-0.38) x 10(-3) in hepatic cavernous hemangiomas, and (3.18+/-0.33) x 10(-3) in hepatic cysts. The ratios of ADC values of lesion/liver were 0.90+/-0.06 and 1.15+/-0.14 in hepatocellular carcinoma and hepatic metastatic tumors respectively, which were significantly different (P < 0.05).
  
  
  CONCLUSIONS
  The measurement of ADC values and the ratios of ADC values of lesion/liver are helpful in MR diagnosis and differentiation of focal hepatic lesions.
authors.affiliation: Imaging Center, Affiliated Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China. quanxianyue@163.com
authors.forename: Xian-Yue
authors.initials: XY
authors.lastname: Quan
authors.forename: Xi-Jie
authors.initials: XJ
authors.lastname: Sun
authors.forename: Zhi-Jian
authors.initials: ZJ
authors.lastname: Yu
authors.forename: Ming
authors.initials: M
authors.lastname: Tang
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis*; D003560:Cysts / Q000175:diagnosis*; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000592:standards; D005260:Female; D006392:Hemangioma, Cavernous / Q000175:diagnosis*; D006801:Humans; D008107:Liver Diseases / Q000175:diagnosis*; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary; D008297:Male; D008875:Middle Aged