The Usefulness of Dipyridamole 99mTc-MIBI Myocardial Scintigraphy in the Detection of Coronary Artery Disease

ABSTRACT

Though exercise T1-201 myocardial perfusion-scintigraphy is an important test in the diagnosis and evaluation of coronary artery disease, this test is limited in cases with poor physical conditions and unstable angina and the physical characteristics of thallium are not ideal for nuclear imaging of the myocardium. Recently, technetium-99m-labelled agent(99mTc-MIBI) has been developed to improved the quality of imaging and for easy usage in myocardial perfusion scan. Therefore, we performed dipyridamole 99mTc-MIBI myocardial scintigraphy and coronary angiography on 25 subjects who were suspeced to have coronary artery disease and the results obtanined were as follows ; 1) The overall diagnostic sensitivity of dipyridamole 99mTc-MIBI perfusion scintigraphy was 73.4%, while specificity was 66.7%. 2) Per vessel sensitivity for coronary artery disease diagnosis by the test was 71.4% and a per vessel specificity for coronary artery disease was 95.7%. 3) In all 75 coronary arteries, LAD had a sensitivity of 66.7%(10/15) and a specificity of 100%(10/10); RCA had a sensitivity of 75%(6/8) and a specificity of 82.4%(14/17); LCX had a sensitivity of 60%(3/5) and a specificity of 100%(20/20). 4) After infusion of dipyridamole, the most frequent adverse effect was chest pain which was seen in 8 cases(32%). The headache was seen in 7 cases(28%). Most of the symptoms were mild in severity and subsided spontaneously but 3 subjects were severe enough to require intravenous administration of aminophylline. In conclusion, dipyridamole 99m2011-06-17Tc-MIBI myocardial perfusion scintigraphy is a useful and safe test for diagnosis of coronary artery disease.