[Effect of attenuation correction and scatter compensation on the 99mTc-MIBI myocardial perfusion spect in patients without coronary artery disease].

OBJECTIVE

Attenuation correction (AC) and scatter compensation (SC) techniques are recent developments of myocardial perfusion SPECT. Our aim was to evaluate the effect of AC + SC on the myocardial distribution of 99mTc-MIBI in a population without coronary artery disease.

MATERIAL AND METHODS

A multiarray of Gd-153 linear sources was used for simultaneous transmission/emission 99mTc-MIBI myocardial perfusion SPECT in 27 patients without coronary artery disease. A visual analysis and polar map quantification was performed. Changes between non-corrected (NC) and corrected (AC + SC) studies were compared.

RESULTS

AC + SC produced an increase in liver activity and better visualization of the right ventricle. Intestinal activity increased in six patients. Myocardial homogeneity was increased by AC + SC. No differences by gender were observed after AC + SC. In females AC + SC led to a decrease of uptake in the anterior wall, apex and apical segments of the lateral wall and septum, and an increase in the inferior wall. In males AC + SC caused an increase of uptake in the inferior wall and in the basal segments of septum and a decrease of uptake in apex and apical segments of anterior and lateral walls. AC + SC generated false defects in the anterior wall of five patients.

CONCLUSIONS

Our results show the usefulness of AC + SC for compensating the interferences produced by attenuation on the myocardial distribution of 99mTc-MIBI. Because AC + SC may introduce false defects, it must not be applied to normal perfused myocardium.