Contribution of prone position to the evaluation of inferior wall attenuation in myocardial perfusion spect study

The nuclear cardiologic methods are gradually used in addition to classical diagnostic methods in patients with coronary artery diseases. Myocardial perfusion scintigraphy is a non-invasive method that can be used for the diagnosis of ischemic heart disease. It can also be used for the evaluation of the size of ischemic damage, myocardial damage at perioperative period and for the follow-up of the by-pass and balloon angioplasty operations. Besides it can be used for the evaluation of myocardial viability.Our purpose is to estimate the contribution of prone imaging to the evaluation of inferior wall attenuation artifacts which can be constitute by the liver or diaphragm, especially in male patients. We performed myocardial perfusion SPECT imaging to 20 female and 40 male patients. Images were acquired in a 180° always beginning in the 45° right anterior oblique position and finishing 45° left posterior oblique position for both supine and prone. With the reconstruction of the raw data, short axis, vertical long axis and horizontal long axis images were acquired. Polar maps generated from the short axis slices were used to calculate the average regional activity. We compared the visual evaluation of left ventricular activity and also the results of the polar map which were obtained from supine and prone imaging. Inferior wall values in the male patients showed statistically significant alteration (prone: 66.5±5.74, supine:59.1±6, p < 0.05). Other walls didn?t show significant alteration.In conclusion, prone images will decrease rate of suspicious or false interpretations especially in inferior wall of male patients. In myocardial perfusion scanning, especially male patients should be also imaged in prone position to minimize artifactual inferior wall defects and to improve accuracy.Keywords: Myocardial perfusion scintigraphy, inferior wall, attenuation, prone position.