Document Type : Original Article
Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
Departments of Radiology, Tabriz University of Medical Sciences, Tabriz, Iran
Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Departments of Medical Physics, Tabriz University of Medical Sciences, Tabriz, Iran
Introduction: Myocardial perfusion SPECTby 99mTc-Sestamibi and 99mTc-Tetrofosmin radiopharmaceuticals usually presents a false significant increase in the radiotracer uptake in the inferior myocardium due to the uptake in organs such as liver, bowel, stomach and biliary system. The present study evaluated a suitable Slit angle for differentiating extra-cardiac activities by Slit Slat collimation.
Methods: The Siemens E.CAM gamma camera equipped with a Low Energy High Resolution (LEHR) collimator was simulated with the Simulating Medical Imaging Nuclear Detectors (SIMIND) Monte Carlo program. Following the verification of the simulation, a Slit Slat collimator was simulated for SPECT imaging of a NURBS-based Cardiac Torso (NCAT) phantom with different Slit angels ranged from 0 to 30 degrees. The reconstructed images were qualitatively assessed with blinded observer method by three nuclear medicine specialists.
Results:The improved differentiation of the bowel activity from the cardiac was obtained by a Slit-Slat collimator with the Slit angle of 7 degree. While for gastric activity differentiation an angle of 15 degree for the Slit was useful.
Conclusion: The results showed that Slit Slat collimation with 7 and 15 Slit angle provide a suitable differentiation of the bowel and gastric activities from the cardia, respectively.