A new apparatus for brain imaging: four-head rotating gamma camera single-photon emission computed tomograph

The development of a new rotating gamma camera SPECT device for imaging the brain was undertaken with the objective of achieving the highest full volume imaging spatial and temporal resolution performance. For this purpose, four rectangular gamma camera detectors were arranged as close to the head as possible, and united in a block to insure detector head registration and alignment as well as to enable rotation stability at high speeds. Phantom and clinical studies performed demonstrated 42 sequential, 4-mm thick transaxial images acquired in one scan and with sufficient volume to permit the entire cerebrum and cerebellum to be imaged with high sensitivity. The central field of view reconstructed spatial resolution measured 7.0 mm full width of half maximum utilizing the high-resolution collimator, and tomographic images of arbitrary planes including sagittal and coronal demonstrated equally high resolution. The high sensitivity and high speed rotational acquisition capability of the device permits dynamic SPECT studies to be carried out in the analysis of rapidly varying radiotracer concentrations.