Automated data acquisition and analysis for evaluation of PET detector units

In order to quickly evaluate detector units prior to incorporation into a positron emission tomography (PET) scanner, an automated method for measuring the critical characteristics of detector units was developed. The procedure uses annihilation radiation (⁶⁸Ge) to measure timing and energy resolution, count rate uniformity, and position encoding. Several detector units are connected to a multiplexor, allowing sequential data collection from the individual detector units. Data from a detector´s photomultiplier tubes are collected using standard Nuclear Instrumentation Modules (NIMs) electronics, and computer automated measurement and control (CAMAC) analog-to-digital converters and scalers. Acquisition is controlled by a Macintosh computer running LabVIEW. Data are automatically transferred to a Sun workstation for analysis. This system has been used to evaluate several different detector units, including a six by six bismuth germanate (BGO) crystal array mounted on two Hamamatsu Photonics R1548 photomultiplier tubes