Assessment of using physical shield for reducing the subdiaphragmatic artifact in MPI SPECT: simulation and clinical study

Abstract

Subdiaphragmatic activity contributes to inferior wall artifacts in 99mTc MPI SPECT. Imaging in the prone position has been suggested as a method to overcome this problem. The aim of this study was to evaluate the impact of using a physical shield in supine position image for reducing this artifact and compare the achieved clinical and stimulation result with the result of the prone position. In this study, simulation projections of NCAT phantom were produced by SimSET. For clinical study, a total of 32 patients who underwent single-day 99mTc-sestamibi stress/rest SPECT were enrolled in the study. All patients had routine ECG-gated, supine along with a physical shield, and prone position SPECT imaging. Summed stress score (SSS) obtained by Oasis hardware and three nuclear medicine physicians have been present to compare the results of physical shield and prone position for simulation and clinical study. The simulation results showed there is no difference between the result of using physical shield and prone imaging. The SSS for the supine along with a physical shield, and prone, were 6.06 ± 3.64, and 5.1 ± 3.7, respectively (P = 0.001). Three physicians had selected supine images against prone. Statistical analysis demonstrated that there is no statistically significant difference between the mean SSS of supine with a physical shield and mean SSS of prone studies (α = 0.05). Technetium-99m MPI in the patient with physical shield has the same result and, in some cases, provides greater diagnostic accuracy than prone imaging; moreover, it provides an inexpensive, comfortable approach for old people to overcome subdiaphragmatic artifact.