Optimization of a large-area detector-block based on SiPM and pixelated LYSO crystal arrays

• Published in: Physica medica Vol. 42; pp. 19 - 27
• Main Authors: Calva-Coraza, E., Alva-Sánchez, H., Murrieta-Rodríguez, T., Martínez-Dávalos, A., Rodríguez-Villafuerte, M.
• Format: Journal Article
• Language: English
• Published: Italy Elsevier Ltd 01.10.2017
• Subjects: Calibration; Cesium Radioisotopes; Detector characterization; Equipment Design; Fluorine Radioisotopes; LYSO; Mammography - instrumentation; Positron emission mammography; Positron-Emission Tomography - instrumentation; Scintillation Counting - instrumentation; Silicon; Silicon photomultipliers; LYSO; Positron emission mammography; Detector characterization; Silicon photomultipliers
• ISSN: 1120-1797; 1724-191X
• DOI: 10.1016/j.ejmp.2017.08.003

•SensL ArrayC-60035-64PSiPM with 40×40 LYSO array is proposed as large area detector.•16-ch readout board (row & column) with COG algorithms for position encoding.•Crystal maps show good uniformity and energy resolution with minimum distortion.•Detector modules show excellent performance at room temperature. We present the performance evaluation of a large-area detector module based on the ArrayC-60035-64P, an 8×8 array of tileable, 7.2mm pitch, silicon photomultipliers (SiPM) by SensL, covering a total area of 57.4mm×57.4mm. We characterized the ArrayC-60035-64P, operating at room temperature, using LYSO pixelated crystal arrays of different pitch sizes (1.075, 1.430, 1.683, 2.080 and 2.280mm) to determine the resolvable crystal size. After an optimization process, a 7mm thick coupling light guide was used for all crystal pitches. To identify the interaction position a 16-channel (8 columns, 8 rows) symmetric charge division (SCD) readout board together with a center-of-gravity algorithm was used. Based on this, we assembled the detector modules using a 40×40 LYSO, 1.43mm pitch array, covering the total detector area. Calibration was performed using a 137Cs source resulting in excellent crystal maps with minor geometric distortion, a mean 4.1 peak-to-valley ratio and 9.6% mean energy resolution for 662keV photons in the central region. The resolvability index was calculated in the x and y directions with values under 0.42 in all cases. We show that these large area SiPM arrays, combined with a 16-channel SCD readout board, can offer high spatial resolution, without processing a big number of signals, attaining excellent energy resolution and detector uniformity.