CT CORONARY ANGIOGRAPHY:
The socio-economic importance of heart disease provides considerable motivation for development of radiologic tools for noninvasive imaging of the coronary arteries. Coronary heart disease is the single largest killer of men and women in the United States with annual cost to the healthcare system averaging 142 billion dollars per year. The recent development and ongoing improvements in ECG-synchronized multidetector row CT have enabled unparalleled noninvasive evaluation of coronary arteries.
25 to 30% of diagnostic cardiac catheterizations are normal and another 30 to 40% find moderate disease that does not warrant stenting or surgery. With a negative predictive value in the range of 97% coronary CTA may eliminate unnecessary catheterizations. There is no risk that a patient with significant stenosis will not be detected by 64 slice CT coronary angiography. Therefore, cardiac CTA is a highly sensitive triage tool for patient's suspected of coronary stenosis, pulmonary embolus and aortic dissection.
Parkview Imaging is proud to have installed the Toshiba 64-slice CT. Its ultrafast speed and dazzling resolution have application for imaging all organ systems, particularly the cardiovascular. It has the power to "freeze" cardiac motion, a revolutionary capability which will result in earlier, noninvasive diagnosis of coronary artery disease.
The scanner is capable of volumetrically aquiring 64, 0.5 mm slices with each 360 degree rotation of the x-ray tube which is achieved in 0.4 seconds. The entire heart can be imaged in 6-8 heart beats. After the scan data is acquired, it is processed on a powerful computer workstation which provides high resolution images using a volume rendering technique.
What can 64-slice Coronary CTA Achieve?
1. Accurately rule out coronary artery stenosis (high negative predictive value).
2. One study provides; coronary calcification score, coronary angiogram, functional analysis (stroke-volume and cardiac output), rules out cardiac anomalies and images heart valves. Within the same study evaluates thoracic aorta and pulmonary arteries.
3. Displays a fifth dimension of time and physiologic motion. Time stops with 64 slice.
4. Provides a big improvement over 16 slice in image quality for coronary artery and graft imaging. Resolution in the range of 0.35 mm competes with catheter angiography and its 3-D capability makes it better than catheter angiography.
5. Decreases the volume of contrast required.
6. Permits earlier diagnosis noninvasively which equals better cardiac patient management. Indications may include;
- Screen high risk patients.
- Evaluate abnormal stress test.
- Evaluate efficacy of drug therapy.
- Evaluate stents and grafts.
- Preop screening.
- Workup heart failure.
- Evaluate myocardial perfusion.
- Plan interventions.
- Rule out cardiac anomalies.
- Workup chest pain to also rule out pulmonary emboli and aortic dissection.
7. It permits the evaluation of plaque morphology-soft, fibrous and calcified.
8. CTA has high patient acceptance because of its speed and ease. There is no arterial puncture, no complications, no hospitalization and much less expense.