Role of Prone SPECT Myocardial Perfusion Imaging in Patients with Equivocal or Abnormal Supine Myocardial Perfusion SPECT

Abstract

Abstract Introduction: Combined supine-prone myocardial perfusion SPECT (MPS) has been shown to reduce attenuation artifact in comparison to supine-only MPS in mixed gender populations with varying risk for coronary artery disease. The aim of this study is to determine whether the additional prone MPS has an advantage over the supine only MPS in determining the diagnostic value of myocardial perfusion SPECT inpatient with known and unknown coronary artery disease. Material& Methods: This prospective study was performed on 93 patients, divided into two major groups patients with known coronary artery disease and without known coronary artery disease. The duration of this study was 06 months including 03 months for clinical follow up. All patients who were assessed using standard stress supine protocol in addition to stress prone includedwho were observed either inferior, anterior or antero-septal wall perfusion defect in the stress supinestudy and they were underwent stress prone using coronary angiography as gold standard evaluating coronary artery disease. Results: Total n=93 patients were enrolled in this prospective study and divided into two main categories. Group I (n=29) included 31% of study population with known coronary artery disease and Group II (n=64) comprises of 69% of study population with no prior history of coronary artery disease. Prone imaging correctly revealed defect improvement in 72 (77%) patients (72/93) with perfusion defects in anterior and inferior wall. Chi-Square (Pearson) test was applied for statistical analysis which revealed p value of “0.005”. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of prone stress MPS in Group-I was calculated as 92%, 80%, 96%, 67% &90% while in Group-I these values were 86%, 81%, 80%, 87% and 83.3% respectively. The combined sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of prone stress was 89.5%, 81%, 89.5%, 81% & 86.4%. Conclusion: It is concluded that the addition of prone MPS with supine MPS overcomes soft tissue attenuation artifact hence decreases the false positive rates and preventing unnecessary further investigations and improves diagnostic accuracy.