Clinical validation of SPECT attenuation correction using x-ray computed tomography-derived attenuation maps: multicenter clinical trial with angiographic correlation.

Background: Nonuniform attenuation artifacts cause suboptimal specificity of stress single photon emission computed tomography (SPECT) myocardial perfusion images. In phantoms, normal subjects, and patients suspected of having coronary artery disease (CAD), we evaluated a new hybrid attenuation correction (AC) system that combines x-ray computed tomography (CT) with conventional stress SPECT imaging.

Methods And Results: The effect of CT-based AC was evaluated in phantoms by assessing homogeneity of normal cardiac inserts.

Acute beta-blockade reduces the extent and severity of myocardial perfusion defects with dipyridamole Tc-99m sestamibi SPECT imaging.

Objectives: The goal of this study was to examine the effect of acute beta-blockade on dipyridamole Tc-99m sestamibi myocardial perfusion imaging (DMPI).

Background: Studies suggest that antianginal drugs may reduce the presence and severity of myocardial perfusion defects with dipyridamole stress. However, there are no data regarding specific drugs.