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


Myocardial perfusion imaging has become an effective clinical tool for diagnosing Coronary Artery Disease (CAD), risk stratifying of patients after infarction, assessing myocardial viability and planning therapy and is usually performed with the patient in the supine position. It is, however, recognized that the diaphragmatic attenuation of the inferior wall and the breast attenuation of the anterior wall in females, has an impact on the test specificity. Planar acquisition, prone imaging, ECG gating and image quantitation constitute overcome soft tissue attenuation. In the presence of an inferior wall perfusion defect in the stress supine study, positional change (prone imaging) is a low cost, effective and clinically validated technique to overcome soft tissue attenuation artifacts including both diaphragmatic and breast attenuation artifact and helps in accurate diagnosis of coronary artery disease. The purpose of this study is initially to confirm the impact of the supine and prone approaches on attenuation artifacts. Additionally, we investigated its role in reducing subsequent rest imaging and unnecessary referrals to coronary arteriography, aiming to d ecrease investigation and hospital waiting time, patient discomfort and also radiation exposure.