Authors:
R. Bugalho
1
;
B. Carriço
1
;
C. S. Ferreira
1
;
M. Ferreira
1
;
R. Moura
2
;
C. Ortigão
2
;
J. Pinheiro
1
;
P. Rodrigues
1
;
J. C. Silva
1
;
A. Trindade
2
and
J. Varela
3
Affiliations:
1
IP - Laboratório de Instrumentação e Física Experimental de Partículas, Portugal
;
2
LIP - Laboratório de Instrumentação e Física Experimental de Partículas, Portugal
;
3
LIP - Laboratório de Instrumentação e Física Experimental de Partículas, IST- Instituto Superior Técnico, Portugal
Keyword(s):
Avalanche photodiode, Dark current, Gain, Positron emission mammography, Quality control.
Related
Ontology
Subjects/Areas/Topics:
Biomedical Engineering
;
Biomedical Equipment
;
Biomedical Instrumentation
;
Biomedical Instruments and Devices
;
Biomedical Sensors
;
Embedded Signal Processing
;
Emerging Technologies
;
Telecommunications
;
Wireless and Mobile Technologies
;
Wireless Information Networks and Systems
Abstract:
A high-resolution Positron Emission Tomography (PET) scanner prototype, named Clear-PEM, was developed by the Portuguese PET Consortium in the framework of the Crystal Clear Collaboration (CCC). This scanner is a PET prototype dedicated for breast cancer imaging mammography, based on a novel readout scheme constituted by fine-pitch scintillator crystals, avalanche photodiodes (APD), low-noise high-gain frontend amplifiers and a reconfigurable FPGA-based electronics readout system. The Clear-PEM scanner is designed to exam both the breast and the auxiliary lymph node areas, aiming at the detection of tumours down to 2 mm in diameter. The prototype has two planar detector heads, each composed of 96 detector modules. Each detector module is composed of a matrix of 32 identical 2x2x20 mm3 LYSO:Ce scintillator crystals, read at both ends by Hamamatsu S8550 APD arrays (4x8) for Depth-of-Interaction (DOI) capability. The APD arrays were characterized through the measurement of gain and dark
current as a function of bias voltage, under controlled conditions. A set of 984 APD arrays followed a well defined quality control (QC) protocol, aiming at the rejection of arrays not complying with the defined specifications. From the total of 984, only 1 (0.1%) was rejected, reassuring the trust in these detectors for prototype assembly and future applications.
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