title: 64-section multidetector CT of the upper abdomen: optimization of a saline chaser injection protocol for improved vascular and parenchymal contrast enhancement.
abstract: OBJECTIVE
  To prospectively investigate the effect of varying the injection flow rates of a saline chaser on vascular and parenchymal contrast enhancement during abdominal MDCT.
  
  
  METHODS
  100 consecutive patients were randomly assigned to four injection protocols. A fixed dose of contrast medium was administered followed by no saline (Protocol A) or 50 mL of saline at 2, 4, or 8 mL/s (Protocols B, C, and D). Peak, time-to-peak, and duration of 90% peak enhancement were determined for aorta, pancreas, and liver.
  
  
  RESULTS
  Aortic peak enhancement was significantly higher for Protocol D (369.5 HU) compared with Protocols A and B (332.9 HU and 326.0 HU, respectively; P < 0.05). Pancreatic peak enhancement was significantly higher for Protocols C and D (110.6 HU and 110.9 HU, respectively) compared to Protocol A (92.5 HU; P < 0.05). Aortic and pancreatic time-to-peak enhancement occurred significantly later for Protocol D compared with Protocol A (42.8 s vs. 36.1 s [P < 0.001] and 49.7 s vs. 45.3 s [P = 0.003]).
  
  
  CONCLUSIONS
  Injecting a saline chaser at high flow rates yields significantly higher peak aortic and pancreatic enhancement, with a slight longer time-to-peak enhancement.
authors.affiliation: Department of Radiology, Duke University Medical Center, Erwin Road, Durham, NC 27710, USA. danielemarin2@gmail.com
authors.forename: Daniele
authors.initials: D
authors.lastname: Marin
authors.forename: Rendon C
authors.initials: RC
authors.lastname: Nelson
authors.forename: Antonino
authors.initials: A
authors.lastname: Guerrisi
authors.forename: Huiman
authors.initials: H
authors.lastname: Barnhart
authors.forename: Sebastian T
authors.initials: ST
authors.lastname: Schindera
authors.forename: Roberto
authors.initials: R
authors.lastname: Passariello
authors.forename: Carlo
authors.initials: C
authors.lastname: Catalano
mesh_terms: D034841:Abdominal Cavity / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging; D016009:Chi-Square Distribution; D003287:Contrast Media; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D016014:Linear Models; D008099:Liver / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000000981:diagnostic imaging; D011446:Prospective Studies; D011856:Radiographic Image Enhancement / Q000379:methods*; D012016:Reference Values; D012680:Sensitivity and Specificity; D012965:Sodium Chloride / Q000494:pharmacology*; D036542:Tomography, Spiral Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D012965:Sodium Chloride