PET imaging using a triple-head gamma camera.

Interest in clinical fluorodeoxyglucose (FDG) imaging with multiple-head gamma cameras is growing. To improve sensitivity, triple-head coincidence imaging has been proposed. We report our initial experiences with a triple-head coincidence gamma camera with 19 mm sodium iodide crystal thickness. Several positron emission tomography-image quality parameters were evaluated using a Carlson and line source phantom. The system sensitivity with two-dimensional axial shields was 830 cps kBq-1 ml-1 and maximum noise equivalent count rate 1900 cps for an 18F-activity of 50 MBq. The imaging resolution was in central axial 7.0 mm and in central transaxial 7.6 mm, respectively. The average scatter fraction in scattered media was 29%. Clinical brain, heart and whole body images studies with [18F]FDG were acquired and they show good correlation with the phantom image quality. As a conclusion, triple-head coincidence gamma camera provides relatively high-count rate imaging with good contrast and resolution.