The aim of this study was to evaluate the effect of cardiac output (CO) on aortic peak enhancement using protocols with different contrast material (CM) injection durations.
We used a flow phantom that simulated the human circulatory system. Contrast material was injected at a rate of 4.0 mL/s for a period of 2.5, 5, 10, 15, or 20 seconds for a CO of 2.8, 4.2, and 5.6 L/min. Single-level serial computed tomography scans of the simulated aorta were acquired after the start of CM delivery, and aortic peak enhancement was recorded under the different injection protocols.
Under a long injection duration protocol (20 seconds), a decrease in CO increased aortic peak enhancement proportionally (CO of 2.8 L/min, 420 Hounsfield units [HU]; CO of 4.2 L/min, 365 HU; CO of 5.6 L/min, 291 HU). However, this effect was decreased under shorter injection duration protocols (5, 10, and 15 seconds); under the shortest (2.5-second) injection duration protocol, a decrease in CO resulted in a decrease in aortic peak enhancement (CO of 2.8 L/min, 36 HU; CO of 4.2 L/min, 51 HU; CO of 5.6 L/min, 55 HU).
The magnitude of the effect of CO on aortic peak enhancement depends on the CM injection duration.
From the Departments of *Diagnostic Radiology and †Medical Physics, Kumamoto University, Kumamoto; and ‡Department of Diagnostic Radiology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Received for publication July 15, 2016; accepted August 27, 2016.
Correspondence to: Masafumi Kidoh, MD, Faculty of Life Sciences, Department of Diagnostic Radiology, Kumamoto University, 1-1-1, Honjo, Kumamoto 860-8556, Japan (e-mail: firstname.lastname@example.org).
The authors declare no conflict of interest.