Coronary artery disease (CAD) is the leading cause of mortality and morbidity in the United States and health care costs exceed $100 billion every year. CAD also is responsible for 30% of deaths worldwide. CAD occurs when arteries become blocked and cannot deliver necessary blood flow to downstream regions.
Coronary CT angiography (CTA) and fractional flow reserve (FFR) are two current detection methods for CAD. A CTA is a procedure that attempts to visually identify artery blockages from CT images of a patient’s heart. There can be considerable inter- and intra-observer differences in results due to the subjective nature of CTA scans. An FFR exam is an invasive procedure in which catheters are inserted into the coronary arteries. Pressure measurements are taken proximal and distal to the artery blockage; the ratio of proximal to distal pressure is the artery FFR measurement. FFR readings have a high sensitivity and specificity but can put a patient at risk, especially in the case of a severe blockage or multiple vessel disease.
We are developing a technique to detect a patient’s CAD risk with low dose CT scans. The technique will give a quantitative measurement of the blood delivered to the muscles of the heart (myocardial perfusion). Perfusion measurements have been shown to correlate with FFR measurements and can be performed without the need for an invasive procedure. The developed technique could be completed in as little as two cardiac cycles and therefore expose a patient to less radiation than current techniques.