Improved uniformity of aortic enhancement with customized contrast medium injection protocols at CT angiography.
OBJECTIVE
To compare the uniformity of aortoiliac opacification obtained from uniphasic contrast medium injections versus individualized biphasic injections at computed tomographic (CT) angiography.


METHODS
Thirty-two patients with an abdominal aortic aneurysm underwent CT angiography. In 16 patients (group 1), 120 mL of contrast material was administered at a flow rate of 4 mL/sec. In the other 16 patients (group 2), biphasic injection protocols were computed by using mathematic deconvolution of each patient's time-attenuation response to a standardized test injection. Attenuation uniformity was quantified as the "plateau deviation" of enhancement values, which were calculated as the SD of the time-contiguous attenuation values observed during the 30-second scanning period.


RESULTS
Group 2 patients received between 77 and 165 mL (mean, 115 mL) of contrast medium. Initial flow rates ranged from 4.1 to 10.0 mL/sec (mean, 6.8 mL/sec) for the first 4-6 seconds; continuing flow rates ranged from 2.0 to 4.8 mL/sec (mean, 3.1 mL/sec) for the remaining 24-26 seconds. The plateau deviation was significantly smaller in group 2 patients (19 HU) versus group 1 patients (38 HU, P <.001).


CONCLUSIONS
At CT angiography, tailored biphasic injections led to more uniform aortoiliac enhancement, compared with standard uniphasic injections of contrast medium.
Fleischmann
D
D
Department of Radiology, University of Vienna, AKH, Währinger Gürtel 18-20, A-1090, Austria. dominik.fleischmann@univie.ac.at
Rubin
G D
GD
Bankier
A A
AA
Hittmair
K
K
D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging; D001027:Aortography / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging; D007275:Injections, Intravenous / Q000379:methods; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011856:Radiographic Image Enhancement / Q000379:methods*; D012212:Rheology; D013997:Time Factors; D014057:Tomography, X-Ray Computed
D003287:Contrast Media