Correlation of Morphological and Functional Cardiac Images: Fusion of Myocardial Perfusion SPECT and CT Angiography

Objectives: The current study evaluates the value of cardiac hybrid imaging (CHI), performed by the fusion of functional and anatomic cardiac images, in the detection of hemodynamically significant coronary stenosis in cases with multiple coronary stenosis. Methods: A total of 36 patients (10 female, 26 male) in whom ischemia or infarction was detected on gated myocardial perfusion single photon emission computed tomography (gMPS) and multiple coronary stenosis were concomitantly detected on coronary computed tomography angiography (CCTA) and undergone invasive coronary angiography (ICA) was included in this study. Statistical analyses were performed using SPSS 22 Windows software. McNemar test was applied to show concordance between coronary CT angiography, ICA and CHI in the detection of anatomically or hemodynamically significant stenosis in three major coronary arteries. Comparison results of coronary arteries responsible for perfusion defects on CHI and gMPS are presented as percentages (%). Results: There was total accordance between coronary arteries leading to perfusion defects detected by gMPS and CHI in 50% of patients. It was observed a partial accordance in 36.1% of the patients. Additionally, it was also detected perfusion defects originated from side branches in 25% of the patients. Between results of CCTA and ICA, no statistically significant difference was noted in the detection of anatomically significant stenoses in the left main coronary artery, left anterior descending artery (LAD), left circumflex artery (LCx) and right coronary artery (RCA) (p=1.000, 0.070, 0.549, and 1.000, respectively). In addition, no statistically significant difference was found in the detection of anatomically and hemodynamically significant stenoses in LAD, LCx and RCA by CCTA and CHI (p=0.344, 0.629, and 0.219, respectively). No statistically significant difference was observed in the detection of anatomically and hemodynamically significant stenoses in LAD, LCx and RCA by ICA and CHI (p=0.804, 1.000, and 0.344, respectively). Conclusion: It is possible to detect hemodynamically significant coronary stenosis directly by CHI modality in patients with multiple coronary stenosis, wide perfusion defects.