title: Dynamic enhancement of upper abdominal organs in normal volunteers with MRI and effects of contrast dose reduction.
abstract: BACKGROUND
  To quantify enhancement parameters of the upper abdominal organs over time during magnetic resonance (MR) examinations and to evaluate the effect of a dose reduction of contrast medium on these parameters.
  
  
  METHODS
  Ten volunteers underwent two separate dynamic enhanced MR examinations with 0.1 and 0.075 mmol/kg of contrast medium, respectively. Breath-hold gradient-echo T1-weighted images were acquired every second for 118 s followed by delayed images. The percentages of enhancement, the time to maximum enhancement, and the area under the time-versus-enhancement curve were calculated for each organ.
  
  
  RESULTS
  The mean times to maximum percentage of enhancement were less than 25 s for the pancreas, kidneys, and spleen and 50 s for the liver. The mean values of maximum percentage of enhancement for the standard/reduced doses were 72%/62% (pancreas), 165%/155% (kidneys), 114%/87% (spleen), and 67%/53% (liver). This difference was significant when liver enhancement was considered (p = 0.02). In addition, when the areas under the time-versus-enhancement curves were compared, the difference between the standard dose and reduced dose was significant for all organs tested (p < 0.05).
  
  
  CONCLUSIONS
  Dynamic scanning of the upper abdomen should start early after contrast injection. Injection parameters should be standardized to capture arterial and venous enhancements in liver examinations. A 25% dose reduction did not significantly affect peak enhancement (except for the liver) but did significantly reduce overall enhancement.
authors.affiliation: Department of Diagnostic Radiology, Montreal General Hospital, McGill University, 1650 Cedar Avenue, Montreal, Quebec H3G 1A4, Canada.
authors.forename: E E
authors.initials: EE
authors.lastname: Coche
authors.forename: P M
authors.initials: PM
authors.lastname: Bret
authors.forename: C
authors.initials: C
authors.lastname: Reinhold
mesh_terms: D000328:Adult; D019540:Area Under Curve; D003287:Contrast Media / Q000008:administration & dosage* / Q000493:pharmacokinetics; D019786:Gadolinium DTPA / Q000008:administration & dosage* / Q000493:pharmacokinetics; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007275:Injections, Intravenous; D007668:Kidney / Q000033:anatomy & histology*; D008099:Liver / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000033:anatomy & histology*; D012815:Signal Processing, Computer-Assisted; D013154:Spleen / Q000033:anatomy & histology*; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA