title: Timing of the hepatic arterial phase at Gd-EOB-DTPA-enhanced hepatic dynamic MRI: comparison of the test-injection and the fixed-time delay method.
abstract: OBJECTIVE
  To compare the fixed-time- and the test-injection method with respect to the image quality of hypervascular hepatocellular carcinoma (HCC) and the adequacy of timing of the hepatic arterial phase (HAP) in Gd-EOB-DTPA (EOB) enhanced MRI.
  
  
  METHODS
  We studied 63 patients with computed tomography (CT) -proven hypervascular HCC: 30 (group 1) were scanned HAP using the fixed-time delay method (protocol 1); in the other 33 (group 2), we applied the test-injection method (protocol 2). We compared the protocols with respect with tumor-to-liver contrast (TLC), contrast-to-noise-ratio (CNR), and relative enhancement of the liver and tumor (REL , RET ) during HAP. Two radiologists compared the adequacy of HAP, image contrast, image noise, and overall image quality.
  
  
  RESULTS
  Under protocol 2, TLC, CNR, and REL and RET of hypervascular HCC were significantly higher (P < 0.01). The proportion of optimal HAP was significantly higher for protocol 2 than protocol 1 (P < 0.01). The visual score of the image contrast and the overall image quality were significantly higher in group 2 than group 1 (P = 0.02 and P = 0.01, respectively).
  
  
  CONCLUSIONS
  At EOB-enhanced hepatic dynamic MRI, the test-injection method yielded better image quality of hypervascular HCC and improved adequacy of timing of HAP.
authors.affiliation: Department of Diagnostic Radiology, Amakusa Regional Medical Center, Kumamoto, Japan. shinichi1025jp@yahoo.co.jp
authors.forename: Shinichi
authors.initials: S
authors.lastname: Nakamura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakaura
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kidoh
authors.forename: Daisuke
authors.initials: D
authors.lastname: Utsunomiya
authors.forename: Yasuro
authors.initials: Y
authors.lastname: Doi
authors.forename: Kazunori
authors.initials: K
authors.lastname: Harada
authors.forename: Shozaburou
authors.initials: S
authors.lastname: Uemura
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000150:complications / Q000473:pathology*; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006499:Hepatic Artery / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007269:Injections, Intra-Arterial; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000150:complications / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000209:etiology / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: Gd-EOB-DTPA; hepatic arterial phase; hepatic dynamic MRI; hepatocellular carcinoma; test-injection method