title: Patient-specific time to peak abdominal organ enhancement varies with time to peak aortic enhancement at MR imaging.
abstract: OBJECTIVE
  To retrospectively evaluate the relationship between the times to peak enhancement of the liver, pancreas, and jejunum with respect to the time to peak aortic enhancement at magnetic resonance (MR) imaging.
  
  
  METHODS
  The committee on human research approved this study and waived written informed consent. This study was HIPAA compliant. The study retrospectively identified 141 patients (63 men, 78 women; mean age, 57 years) who underwent abdominal MR imaging by using a test bolus that was monitored approximately every second for 2 minutes with a spoiled gradient-echo T1 transverse section through the upper abdomen. The times to peak enhancement of the aorta, liver, pancreas, and jejunum were recorded and correlated with the time to peak aortic enhancement, age, and sex by means of univariate and multivariate linear regression analyses.
  
  
  RESULTS
  The mean time to peak aortic enhancement was 21.1 seconds (range, 8.7-41.8 seconds). The times to peak enhancement of the liver, pancreas, and jejunum were positively and linearly correlated with the time to peak aortic enhancement (r = 0.69, 0.86, and 0.80, respectively, all P < .001) and were 3.39, 1.64, and 2.04 times longer than the time to peak aortic enhancement, respectively. Age, sex, and history of heart disease did not give additional predictive information for determining the time to peak visceral enhancement.
  
  
  CONCLUSIONS
  The times to peak enhancement of the liver, pancreas, and jejunum are linearly related to that of the aorta. These results could potentially allow tailored patient- and organ-specific scan delay optimization at contrast material-enhanced MR image evaluation.
authors.affiliation: Department of Radiology, University of California-San Francisco, 505 Parnassus Ave, Box 0628, C-324C, San Francisco, CA 94143-0628, USA.
authors.forename: Lisa L
authors.initials: LL
authors.lastname: Chu
authors.forename: Bonnie N
authors.initials: BN
authors.lastname: Joe
authors.forename: Antonio C A
authors.initials: AC
authors.lastname: Westphalen
authors.forename: Emily M
authors.initials: EM
authors.lastname: Webb
authors.forename: Fergus V
authors.initials: FV
authors.lastname: Coakley
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Yeh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000473:pathology*; D002648:Child; D005260:Female; D006801:Humans; D007583:Jejunum / Q000473:pathology*; D008099:Liver / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000473:pathology*; D012189:Retrospective Studies; D013997:Time Factors