title: Radial MRI during free breathing in contrast-enhanced hepatobiliary phase imaging.
abstract: BACKGROUND
  Use of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) for diagnosis of hepatic tumors has been previously reported. Fat-saturated 3D T1-weighted gradient echo sequence (TIGRE) imaging using a breath-hold technique is usually used for dynamic studies and hepatobiliary phase Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI). In cases where the patient has difficulty holding their breath, this scanning method can be difficult.
  
  
  OBJECTIVE
  To investigate the usefulness of a fat-saturated T1-weighted spin-echo (SE) sequence using a radial read-out (radial acquisition regime-SE, RADAR-SE) during free breathing for hepatobiliary phase Gd-EOB-DTPA-enhanced MRI.
  
  
  METHODS
  Images were acquired at 1.5 T. First, a phantom with diluted Gd-EOB-DTPA was scanned using the TIGRE sequence and the RADAR-SE sequence. Contrast ratios of the sequences were compared. Next, the hepatobiliary phase was imaged in 62 patients using the TIGRE sequence with breath-hold and the RADAR-SE during free breathing. Qualitative and quantitative evaluations were compared.
  
  
  RESULTS
  In the phantom study, RADAR-SE had a higher contrast ratio than TIGRE. In the clinical study, artifacts were more conspicuous in RADAR-SE compared to TIGRE images in the qualitative evaluation. However, RADAR-SE images were equal to or better than TIGRE images in patients who had difficulty holding their breath. The signal intensity ratio of the liver was statistically higher using RADAR-SE than TIGRE.
  
  
  CONCLUSIONS
  RADAR-SE can be useful for hepatobiliary phase Gd-EOB-DTPA-enhanced MRI in patients who have difficulty holding their breath.
authors.affiliation: Department of Radiology, Toho University Ohashi Medical Center, Tokyo, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Gomi
authors.forename: Masahashi
authors.initials: M
authors.lastname: Nagamoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Akiko
authors.initials: A
authors.lastname: Tabata
authors.forename: Mikiko
authors.initials: M
authors.lastname: Iwasaki
authors.forename: Minako
authors.initials: M
authors.lastname: Ooka
authors.forename: Nozomu
authors.initials: N
authors.lastname: Murata
authors.forename: Mika
authors.initials: M
authors.lastname: Tsunoo
authors.forename: Yuo
authors.initials: Y
authors.lastname: Iizuka
authors.forename: Ehiichi
authors.initials: E
authors.lastname: Kohda
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Shiraga
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D012119:Respiration; D059629:Signal-To-Noise Ratio
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: Abdomen; MR imaging; liver; radial scan