[Optimal timing of contrast enhancement in coronary CT angiography using the Bolus-tracking method].
Negative product value for coronary artery disease is 98% to 99%. Therefore, the number of unnecessary cardiac catheterization procedures is reduced as the usefulness of CT systems for examination of the coronary arteries improves. In the bolus-tracking method, in which an ROI is placed in the ascending aorta to trigger scanning, scanning may not be performed at the optimal time of contrast enhancement depending on the patient. In addition to identifying the causes of this problem, we have developed a new method in which ROIs are placed in the right ventricle and left atrium to trigger scanning when the concentrations of contrast medium in the right ventricle and left atrium become equal. The two methods were then compared and evaluated. In the scan method, in which an ROI is placed in the ascending aorta, the reason for non-optimal scan timing is considered to be that the time required for contrast medium injected via an antecubital vein to reach the heart varies depending on the individual patient(approximately 3 times the variation of our method)followed by a delay of approximately 5 seconds between the scan trigger time and the actual scan start time. In the scan method in which scanning is triggered when the concentrations of contrast medium in the right ventricle and left atrium become equal, scanning can be performed at the time of peak enhancement regardless of differences in the time required for the injected contrast medium to reach the target region or differences in the injection rate, demonstrating the usefulness of this method.
Kitai
Takaaki
T
Department of Radiology, Maizuru Kyosai Hospital, Japan.
Ogawa
Takesi
T
Noguti
Jun
J
Hara
Muneyosi
M
Otuka
Hitosi
H
Yamamoto
Fumiaki
F
Kawakami
Satosi
S
Yamada
Hiroki
H
D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta; D001835:Body Weight; D002302:Cardiac Output; D003287:Contrast Media / Q000008:administration & dosage* / Q000493:pharmacokinetics; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006325:Heart Atria / Q000378:metabolism; D006352:Heart Ventricles / Q000378:metabolism; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media