Development of thyroid diagnostic equipment using semiconductor detector

Abstract

Current commercial gamma-ray imaging system are general purpose device designed to support a diagnosis for thyroid cancer. These generally require a reasonably large detector plate and the ability to image the thyroid. Recently, new applications of gamma-ray imaging system have emerged which place different demands on gamma-ray imaging system instrumentation, requiring high spatial resolution and sensitivity, in particular for imaging small volumes. These emerging applications, a large plate is not only not required but also limits the performance that can be achieved when imaging small volumes. Significant research has been undertaken in the development of read out schemes of scintillator crystal configurations in an attempt to improve the spatial resolution of gamma-ray imaging system. Silicon Photomultiplier (SiPM) detectors are attractive candidates for the replacement of Photomultiplier in nuclear imaging. Provide high gain with low voltage and fast response. We are developing a new gamma-ray imaging system detection module with depth of interaction capability. Pixilated scintillation crystals read out by SiPM 4×4 arrays form the basis of the new module. This article concentrates on comparison of the some kind of scintillator performance of the SiPM. In particular we are interested in measuring and quantitative improvement of the detector efficiency, linearity, and energy resolution of the SiPM based detector. Initial characterization of prototype detector consisting of a 4 × 4 SiPM array coupled to either the front surface of a 3mm × 3mm × 15mm × 16pics LYSO crystal. The readout system include SensL preamplifier circuit, anger logic circuit, Notice Scintillate ADC(FADC) and collect & analysis data software root. The parameters that have been measured are: detector efficiency, linearity, and energy resolution. Best energy resolution was experimentally measured 11% for 511keV and spatial resolutions <; 3mm (22Na, 1uCi).