Computed tomographic coronary angiography: experience at Baylor University Medical Center/Baylor Jack and Jane Hamilton Heart and Vascular Hospital

Scoring system for predicting saphenous vein graft patency in coronary artery bypass grafting

The initial and long-term benefits of coronary artery bypass grafting depend upon maintaining the coronary blood flow supplied by the graft. In order to devise a scoring system for predicting graft patency, we evaluated presumptive correlations between saphenous vein graft patency and the characteristics of saphenous veins that were used as conduits in coronary revascularization.We prospectively evaluated 1,000 saphenous vein segments that were implanted in 403 consecutive patients who underwent on-pump coronary artery bypass grafting at our hospital from January 2006 through February 2009. Branches, varicosity, diameter, and wall thickness were evaluated, and a scoring system was created in order to obtain a value for each characteristic. The patients were postoperatively monitored for 1 year, and graft patency was then evaluated with the use of 64-slice multidetector computed tomography.Lesions were found in 12.3% of the grafts. All of the evaluated characteristics of the grafts had a significant correlation with saphenous vein graft flow (P <0.0001). Using the venous characteristics in our statistical analysis, we devised a formula to obtain a score (range, 4-12) to predict the patency of each graft. A cutoff score of 7 yielded 87.8% sensitivity and 82.8% specificity.Our scoring system has good prognostic value. We believe that it can assist surgeons in choosing the most appropriate conduit and target vessel for coronary artery bypass grafting, especially in high-risk patients who are particularly dependent on blood flow through saphenous vein grafts.

Sixty-four–slice multidetector computed tomography: the future of ED cardiac care

Multidetector computed tomography (MDCT) imaging, a technological advance over traditional CT, is a promising possible alternative to cardiac catheterization for evaluating patients with chest pain in the emergency department (ED). In comparison with traditional CT, MDCT offers increased spatial and temporal resolution that allows reliable visualization of the coronary arteries. In addition, a "triple scan," which includes evaluation for pulmonary embolism and thoracic aortic dissection, can be incorporated into a single study. This test will enable emergency physicians to rapidly evaluate patients for life-threatening illnesses and may allow safer and earlier discharges of many patients with chest pain in comparison with a traditional rule-out protocol. In this article, we will highlight the technological advances of MDCT imaging, review the literature on coronary angiography via MDCT, and discuss the future of this technology as it relates to the ED.

Localizing calcifications in cardiac CT data sets using a new vessel segmentation approach

The new generation of multislice computed tomography (CT) scanners allows for the acquisition of high-resolution images of the heart. Based on that image data, the heart can be analyzed in a noninvasive way-improving the diagnosis of cardiovascular malfunctions on one hand, and the planning of an eventually necessary intervention on the other. One important parameter for the evaluation of the severity of a coronary artery disease is the number and localization of calcifications (hard plaques). This work presents a method for localizing these calcifications by employing a newly developed vessel segmentation approach. This extraction technique has been developed for, and tested with, contrast-enhanced CT data sets of the heart. The algorithm provides enough information to compute the vessel diameter along the extracted segment. An approach for automatically detecting calcified regions that combines diameter information and gray value analysis is presented. In addition, specially adapted methods for the visualization of these analysis results are described.

Use of multislice computed tomographic coronary angiography for the diagnosis of anomalous coronary arteries

The accurate diagnosis of anomalous coronary arteries by invasive angiography is limited by the inability to define the anatomic course in relation to surrounding structures. Computed tomographic coronary angiography has recently emerged as a noninvasive method to visualize the coronary arteries. Multislice computed tomography with up to 64 detector arrays, along with 3-dimensional rendering, has further improved the temporal and spatial resolution of noninvasive coronary imaging. In this series of cases, the investigators describe their institution's experience with computed tomographic coronary angiography as a complement to invasive coronary angiography in determining the origin and course of different anomalous coronary arteries in 16 patients. With the aid of 3-dimensional volume rendering, 6 anomalous right coronary arteries, 4 anomalous left circumflex coronary arteries, 4 single coronary arteries, and 2 anomalous left main coronary arteries were all clearly defined with regard to their origin and course. It is proposed that computed tomographic coronary angiography is the diagnostic test of choice in the evaluation of such anomalies.