Object: 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.
Materials and 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.
Conclusion: 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.