Prone Imaging in Cardiac SPECT

A. To reduce inferior and inferolateral wall attenuation artifacts caused by the diaphragm

Prone imaging is performed by placing the patient face-down, which causes the diaphragm and abdominal contents to fall away from the inferior wall of the heart due to gravity. This reduces the diaphragmatic attenuation that commonly creates artifactual inferior wall perfusion defects on supine imaging. An inferior wall defect that DISAPPEARS on prone imaging is almost certainly a diaphragmatic attenuation artifact. An inferior wall defect that PERSISTS on both supine and prone images is more likely to represent true RCA territory ischemia or infarction. Prone imaging is particularly useful when CT attenuation correction is not available.