title: Test bolus measurement: effects of the respiratory position on bolus arrival time and signal-intensity-time curve quality.
abstract: OBJECTIVE
  The aim of our study is to determine if the respiratory position (free breathing, end expiration) influences bolus arrival time (BAT) or the quality of the SI-time curve in the test bolus measurement.
  
  
  METHODS
  We examined 150 consecutive patients in free breathing and end expiration with 1 mL contrast media (CM) and a flow of 3 mL/s with MRI. The BAT in the aorta and the quality of the SI-time curve were determined.
  
  
  RESULTS
  In 13/300 measurements BAT could not be determined because of poor quality of the SI-time curve (two free breathing, 11 end expiration). Mean BAT was 21 s in both respiratory positions. In 13/137 (9%) there was a difference in BAT in end expiration and free breathing of more than 5 s without a tendency towards elongation or shortening of BAT due to the respiratory command (RC). Quality of the SI-time curve was significantly better in the second of both measurements independently of the respiratory position and in free breathing compared to end expiration.
  
  
  CONCLUSIONS
  Test bolus examinations may differ in an individual patient of more than 5 s without a tendency towards elongation or shortening due to the RC. SI-time curve quality is negatively influenced by the RC.
authors.affiliation: Department of Radiology, University od Erlangen, Maximiliansplatz 1, Erlangen, Germany. rolf.janka@idr.imed.uni-erlangen.de
authors.forename: Rolf
authors.initials: R
authors.lastname: Janka
authors.forename: Marius
authors.initials: M
authors.lastname: Rudy
authors.forename: Rudy
authors.initials: R
authors.lastname: Marius
authors.forename: Michael
authors.initials: M
authors.lastname: Lell
authors.forename: Lell
authors.initials: L
authors.lastname: Michael
authors.forename: Michael
authors.initials: M
authors.lastname: Uder
authors.forename: Uder
authors.initials: U
authors.lastname: Michael
authors.forename: Werner
authors.initials: W
authors.lastname: Bautz
authors.forename: Bautz
authors.initials: B
authors.lastname: Werner
authors.forename: Evelyn
authors.initials: E
authors.lastname: Wenkel
authors.forename: Wenkel
authors.initials: W
authors.lastname: Evelyn
mesh_terms: D000368:Aged; D045853:Exhalation / Q000502:physiology*; D005260:Female; D006801:Humans; D001239:Inhalation / Q000502:physiology*; D008099:Liver / Q000033:anatomy & histology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011187:Posture; D015656:Respiratory Mechanics; D013131:Spine / Q000033:anatomy & histology