TY - JOUR
T1 - Dual APD array readout of LSO crystals
T2 - Optimization of crystal surface treatment
AU - Shao, Y.
AU - Meadors, K.
AU - Silverman, R. W.
AU - Farrell, R.
AU - Cirignano, L.
AU - Grazioso, R.
AU - Shah, K. S.
AU - Cherry, S. R.
N1 - Funding Information:
Manuscript received July 2, 2001; revised November 5, 2001. This work was supported by the NIH SBIR under Grant 2R44CA78100-02 and the Department of Energy under Contract DE-FC03-87-ER60615. Y. Shao is with GE Corporate R&D, Niskayuna, NY 12309 USA. K. Meadors and R. W. Silverman are with the Crump Institute for Molecular Imaging, Department of Molecular and Medical Pharmacology UCLA School of Medicine, Los Angeles, CA 95616 USA. R. Farrell, L. Cirignano, R. Grazioso, and K. S. Shah are with the Radiation Monitoring Devices, Inc., Watertown, MA 02172 USA. S. R. Cherry is with the Department of Biomedical Engineering, University of California, Davis, Davis, CA 95616 USA (e-mail: srcherry@ucdavis.edu). Publisher Item Identifier S 0018-9499(02)06203-2.
PY - 2002/6
Y1 - 2002/6
N2 - We are developing a compact positron emission tomography (PET) detector module with a depth of interaction capability (DOI) based on a lutetium oxyorthosilicate (LSO) scintillator array coupled at both ends by avalanche photodiode (APD) arrays. This leads to a detector with high sensitivity that can provide high and uniform image resolution. We report studies on improving the DOI resolution by optimizing the crystal surface treatment. Six 2 × 2 × 20 mm LSO crystals were treated with different surface finishes along their length: raw saw-cut, polished optical finish, and chemically etched by hot anhydrous phosphoric acid (H3PO4) with etching times varying from 1 to 5 min. The ratio of the signals from the two APD arrays was used to measure DOI, and the sum of the signals to measure the total light output. Crystals finished by chemical etching for 2-3 min gave the best overall detector performance, with DOI resolutions ranging from 3.1 to 3.9 mm for events above a 150-keV threshold and uniform light output for different DOI positions. The energy resolution ranged between 14% and 18%. This detector design appears promising for PET applications requiring very high resolution and high sensitivity, for example, in small animal imaging and human breast imaging.
AB - We are developing a compact positron emission tomography (PET) detector module with a depth of interaction capability (DOI) based on a lutetium oxyorthosilicate (LSO) scintillator array coupled at both ends by avalanche photodiode (APD) arrays. This leads to a detector with high sensitivity that can provide high and uniform image resolution. We report studies on improving the DOI resolution by optimizing the crystal surface treatment. Six 2 × 2 × 20 mm LSO crystals were treated with different surface finishes along their length: raw saw-cut, polished optical finish, and chemically etched by hot anhydrous phosphoric acid (H3PO4) with etching times varying from 1 to 5 min. The ratio of the signals from the two APD arrays was used to measure DOI, and the sum of the signals to measure the total light output. Crystals finished by chemical etching for 2-3 min gave the best overall detector performance, with DOI resolutions ranging from 3.1 to 3.9 mm for events above a 150-keV threshold and uniform light output for different DOI positions. The energy resolution ranged between 14% and 18%. This detector design appears promising for PET applications requiring very high resolution and high sensitivity, for example, in small animal imaging and human breast imaging.
KW - Avalanche photodiodes
KW - Depth of interaction
KW - Positron emission tomography (PET)
KW - Scintillation detector
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U2 - 10.1109/TNS.2002.1039544
DO - 10.1109/TNS.2002.1039544
M3 - Article
AN - SCOPUS:0036624298
SN - 0018-9499
VL - 49 I
SP - 649
EP - 654
JO - IEEE Transactions on Nuclear Science
JF - IEEE Transactions on Nuclear Science
IS - 3
ER -