Optimization of contrast material administration for electrocardiogram-gated computed tomographic angiography of the chest.
OBJECTIVE
Electrocardiogram-gated computed tomographic angiography is increasingly used in the differential diagnosis of acute chest pain. We studied the optimal timing of contrast material injection using a test bolus and a bolus-tracking technique.


METHODS
Thirty patients were prospectively included in the study. Volume and flow of high concentration contrast material were adapted to body weight. The scan delay was determined using either a test bolus or a bolus-tracking technique. Attenuation profiles of the different vascular districts were measured to evaluate the timing techniques.


RESULTS
In all the patients except for one, an adequate and homogeneous contrast enhancement of more than 200 Hounsfield units (HU) was achieved (285 +/- 45 HU) in the different vascular districts. The pulmonary transit time in the test bolus group was 7 seconds (range, 4-11 seconds). Differences and variability of pulmonary and aortic enhancement were small in both groups (13 +/- 48 HU vs -9 +/- 21 HU), with differences of less than 70 HU over the craniocaudal range and very small intraindividual differences between pulmonary attenuation and systemic attenuation.


CONCLUSIONS
Contrast administration regimens for electrocardiogramgated computed tomographic angiography of the chest can be optimized using the bolus-tracking method in the ascending aorta, with a short delay after trigger. Body weight adaptation of volume and injection rate of the contrast material results in a reliable simultaneous opacification of the pulmonary and systemic vasculature.
Johnson
Thorsten R C
TR
Department of Clinical Radiology, Medical Clinic I, University of Munich-Grosshadern Campus, Marchioninistrasse, Munich, Germany. thorsten.johnson@med.uni-muenchen.de
Nikolaou
Konstantin
K
Wintersperger
Bernd J
BJ
Fink
Christian
C
Rist
Carsten
C
Leber
Alexander W
AW
Knez
Andreas
A
Reiser
Maximilian F
MF
Becker
Christoph R
CR
D000368:Aged; D000369:Aged, 80 and over; D001027:Aortography / Q000379:methods; D001835:Body Weight; D002637:Chest Pain / Q000209:etiology; D003287:Contrast Media / Q000008:administration & dosage*; D017023:Coronary Angiography / Q000379:methods*; D003327:Coronary Disease / Q000175:diagnosis*; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007472:Iohexol / Q000008:administration & dosage / Q000031:analogs & derivatives; D008171:Lung Diseases / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D007472:Iohexol; C038192:iopromide