What is the most precise test to diagnose coronary artery blockage?
Currently, the most widely accepted "gold standard" test for examing the coronary arteries is angiography. This entails inserting a catheter (like a wire) in the femoral artery of the patient (near the groin) and advancing it through the artery back to the heart and eventually into the coronary arteries. Once the catheter is in place, a form of dye is injected into the arteries while a physician (usually interventional cardiologist) examines the flow of the dye under X-ray. Any blockages obstructing the flow of dye (which is in the blood) will be visualized.
Along with angiography, the most advanced CT scanners (computed tomography) are also extremely precise. With this test, dye is injected intravenously (no catheters involved) and the patient is moved through the CT scanner. Very clear pictures of the coronary arteries can be obtained in this manner. Patients with kidney disease are not candidates for this procedure because the intravenous dye can cause kidney problems in already damaged kidneys.