Korean J Thorac Cardiovasc Surg.
1999 Aug;32(8):693-701.
Noninvasive Evaluation of Coronary Artery Bypass Graft Patency by
Electron Beam Tomography
- Affiliations
-
- 1Department of Diagnostic Radiology, Yonsei University, College of Medicine.
- 2Cardiovascular Surgery in Yonsei Cardiovascualr Center, Yonsei University,
College of Medicine, Seoul, Korea.
Abstract
-
Recently non-invasive diagnostic imaging replaced the invasive catheter angiography in the
diagnosis of vascular disease. Catheter methods are now almost confined to the purpose of
intervention. Coronary artery or coronary artery bypass graft still needs catheter technique
because of small diameter and the cardiac motion. The last challenge for radiologists in this
domain is to obtain a non-invasive imaging. Electron beam tomography(EBT) for high temporal
resolution is able to obtain a coronary arteriogram or coronary artery bypass graft (CABG),
of which CABG imaging is quite useful for the evaluation of patency. In our experience as well
as others, the accuracy of EBT angiogram in evaluating CABG patency revealed that the accuracy
of patency of saphenous vein grafts(SVG) is high due to relatively wide lumen, short and
straight course and less influence from cardiac motion. The sensitivity and specificity
of patency of SVGs were 92%, 97% respectively in the prospective evaluat on and 100% each
in the retrospective evaluation. A false positive and a false negative case are rudimentary
errors in the initial learing period. In contrast the analysis of left internal mammary
artery(LIMA) graft was difficult due to the inherent small size and the adjacent surgical
clips provoking beam-hardening artifact; therefore, the method of combining 3 dimensional
reconstruction and flow mode study was important in improving the accuracy of LIMA patency.
The sensitivity and specificity of LIMA patency were 100% and 80% in both prospective and
retrospective evaluation. Therefore, EBT angiography is an accurate non-invasive diagnostic
modality for evaluating the patency of CABG, particularly in SVGs. The accuracy can be
improved with the improvement of the EBT and the development of the image reconstruction
software.