THE OCCURRENCE OF FALSE-POSITIVE TC-99M SESTAMIBI BULLS EYE DEFECTS IN DIFFERENT REFERENCE DATABASES - A STUDY OF AN AGE-STRATIFIED AND GENDER-STRATIFIED HEALTHY POPULATION

Myocardial perfusion single-photon emission tomographic (SPET) imaging has been shown to be sensitive in the detection of coronary artery di sease (CAD), whereas its specificity has been suboptimal. The aim of t he present study was to study the frequency of abnormal bull's eye per fusion defects in a large age-stratified group of healthy subjects und ergoing myocardial SPET assessed by comparison with two existing comme rcially available reference databases. One hundred and twenty-eight he althy volunteers (76 males and 52 females) with a less than 5% likelih ood of CAD underwent rest and exercise technetium-99m sestamibi SPET. The false-positive response rate, defined as a significant reversible defect, was 12% when compared to the CEqual database and 29% when comp ared to the Cedars-Sinai database. With the CEqual program, rest defec ts occurred in 12% of the subjects. Defects occurred more often in wom en than in men, but the difference did not attain statistical signific ance. Significant defects were most frequent in the inferior wall and in women in the anterior wall as well. The distribution of defects was independent of age. Our results suggest that the specificity of Tc-99 m-sestamibi myocardial SPET using commercially available reference fil es is suboptimal. The risk of obtaining a false-positive test result i n subjects undergoing Tc-99m-sestamibi myocardial SPET with a very low likelihood of CAD was higher than anticipated. With both reference fi res false-positive test results were most frequency observed in the in ferior wall. Our data suggest that commercial reference files for myoc ardial SPET need to be optimised, and should be used with caution. The use of attenuation correction may prove to be a major step forward.