Effect of different saline chaser volumes and flow rates on intravascular contrast enhancement in CT using a circulation phantom.
OBJECTIVE
To evaluate the influence of different saline chaser volumes and different saline chaser flow rates on the intravascular contrast enhancement in MDCT.


METHODS
In a physiological flow phantom contrast medium (120 ml, 300 mgI/ml, Ultravist 300) was administered at a flow rate of 6 ml/s followed by different saline chaser volumes (0, 30, 60 and 90 ml) at the same injection rate or followed by a 30-ml saline chaser at different injection rates (2, 4, 6 and 8 ml/s). Serial CT-scans at a level covering the pulmonary artery, the ascending and the descending aorta replica were obtained. Time-enhancement curves were computed and both pulmonary and aortic peak enhancement and peak time were determined.


RESULTS
Compared to contrast medium injection without a saline chaser the pushing with a saline chaser (30, 60, and 90 ml) resulted in a statistically significant increased pulmonary peak enhancement (all p=0.008) and prolonged peak time (p=0.032, p=0.024 and p=0.008, respectively). Highest aortic peak enhancement values were detected for a saline chaser volume of 30 ml. A saline chaser flow rate of 8 ml/s resulted in the highest pulmonary peak enhancement values compared to flow rates of 2, 4 and 6 ml/s (all p=0.008). Aortic peak enhancement showed the highest values for a flow rate of 6 ml/s.


CONCLUSIONS
A saline chaser volume of 30 ml and an injection rate of 6 ml/s are sufficient to best improve vascular contrast enhancement in the pulmonary artery and the aorta in MDCT.
Behrendt
Florian F
FF
Department of Diagnostic and Interventional Radiology, University Hospital (RWTH) Aachen, Pauwelsstrasse, Aachen, Germany. behrendt@rad.rwth-aachen.de
Bruners
Philipp
P
Keil
Sebastian
S
Plumhans
Cedric
C
Mahnken
Andreas H
AH
Das
Marco
M
Ackermann
Diana
D
Günther
Rolf W
RW
Mühlenbruch
Georg
G
D001013:Aorta, Thoracic / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000008:administration & dosage*; D006801:Humans; D007267:Injections; D007472:Iohexol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D019047:Phantoms, Imaging; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D012965:Sodium Chloride / Q000008:administration & dosage*; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D007472:Iohexol; D012965:Sodium Chloride; C038192:iopromide