title: Hepatic arterial phase on gadoxetic acid-enhanced liver MR imaging: a randomized comparison of 0.5 mL/s and 1 mL/s injection rates.
abstract: OBJECTIVE
  To compare gadoxetic acid injection rates of 0.5 mL/s and 1 mL/s for hepatic arterial-phase magnetic resonance (MR) imaging.
  
  
  METHODS
  In this prospective study, 101 consecutive patients with suspected focal liver lesions were included and randomly divided into two groups. Each group underwent dynamic liver MR imaging using a 3.0-T scanner after an intravenous injection of gadoxetic acid at rates of either 0.5 mL/s (n = 50) or 1 mL/s (n = 51). Arterial phase images were analyzed after blinding the injection rates. The signal-to-noise ratios (SNRs) of the liver, aorta, portal vein, hepatic vein, spleen, and pancreas were measured. The contrast-to-noise ratios (CNRs) of the hepatocellular carcinomas (HCC) were calculated. Finally, two experienced radiologists were independently asked to identify, if any, HCCs in the liver on the images and score the image quality in terms of the presence of artifacts and the proper enhancement of the liver, aorta, portal vein, hepatic vein, hepatic artery, spleen, pancreas, and kidney.
  
  
  RESULTS
  The SNRs were not significantly different between the groups (p = 0.233-0.965). The CNRs of the HCCs were not significantly different (p = 0.597). The sensitivity for HCC detection and the image quality scores were not significantly different between the two injection rates (p = 0.082-1.000).
  
  
  CONCLUSIONS
  Image quality and sensitivity for hepatic HCCs of arterial-phase gadoxetic acid-enhanced MR were not significantly improved by reducing the contrast injection rate to 0.5 mL/s compared with 1 mL/s.
authors.affiliation: Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun 519-763, Korea.
authors.forename: Sung Mo
authors.initials: SM
authors.lastname: Kim
authors.affiliation: Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun 519-763, Korea.
authors.forename: Suk Hee
authors.initials: SH
authors.lastname: Heo
authors.affiliation: Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun 519-763, Korea.
authors.forename: Jin Woong
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun 519-763, Korea.
authors.forename: Hyo Soon
authors.initials: HS
authors.lastname: Lim
authors.affiliation: Department of Radiology, Chonnam National University Hospital, Gwangju 501-757, Korea.
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Shin
authors.affiliation: Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun 519-763, Korea.
authors.forename: Yong Yeon
authors.initials: YY
authors.lastname: Jeong
authors.affiliation: Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun 519-763, Korea.
authors.forename: Heoung Keun
authors.initials: HK
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006499:Hepatic Artery; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: Gadoxetic acid; Hepatocellular carcinoma; Injection rate; Magnetic resonance imaging