Comparison of resting intracoronary particulate imaging and stress thallium-201 studies.

Stress thallium-201 and resting dual intracoronary particulate imaging were evaluated in 120 patients who underwent coronary angiography. Forty of 42 patients without significant coronary disease had normal stress images and 41 had normal rest studies. Eighty-three stress perfusion defects were identified in 61 of 78 patients with coronary artery disease. At rest, 39 of these defects were resolved or improved, whereas 44 remained unchanged. The angiographic presence of collateral vessels and radionuclide evidence of blood flow distribution through them could not always be correlated as 36 angiographic collateral vessels had no regional distribution flow patterns with either method. Particulate studies demonstrated myocardial flow distribution through 25 angiographic collateral vessels and further identified seven collateralized areas not seen angiographically. The resting particulate images additionally defined flow distribution patterns in 15 instances in which the angiogram indicated two potential sources of blood supply.