Helical CT of aorta after endoluminal stent-graft therapy: value of biphasic acquisition.
OBJECTIVE
We report our prospective study evaluating biphasic helical CT of the aorta after endoluminal stent-graft placement.


METHODS
Biphasic helical CT scans in 95 patients with abdominal and thoracic aortic aneurysms who had undergone endoluminal stent-graft placement were reviewed. After a test bolus injection of 15 ml of contrast media at a rate of 3.5 ml/sec for the measurement of the optimal start delay, the aorta was scanned using the following parameters: collimation of 5 mm, table speed of 7 mm per rotation, tube rotation time of 0.75 sec, 120 kV, and 295 mA. A delayed helical CT scan was obtained 15 sec after the initial acquisition using the same parameters.


RESULTS
Biphasic helical CT scans showed perigraft leakage in 45 (47%) of 95 patients. Leakage was shown only on arterial phase CT in eight patients and only on the delayed scans in three patients. In two patients, leakage shown on the delayed acquisition was retrospectively seen on the first scan. Leakage and outflow vessels were most visible on the arterial phase acquisition in 17 patients and on the second acquisition in six patients. Overall, biphasic acquisition was superior to arterial phase acquisition alone in 15 (16%) of 95 patients.


CONCLUSIONS
The diagnostic value of biphasic helical CT is superior to arterial phase acquisition alone for the evaluation of the aorta after endoluminal stent-graft therapy.
Golzarian
J
J
Department of Radiology, Erasme Hospital, University of Brussels, Belgium.
Dussaussois
L
L
Abada
H T
HT
Gevenois
P A
PA
Van Gansbeke
D
D
Ferreira
J
J
Struyven
J
J
D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging* / Q000601:surgery; D017545:Aortic Aneurysm, Thoracic / Q000000981:diagnostic imaging* / Q000601:surgery; D019917:Blood Vessel Prosthesis Implantation; D005119:Extravasation of Diagnostic and Therapeutic Materials / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000601:surgery; D012086:Reoperation; D015607:Stents; D014057:Tomography, X-Ray Computed