TY - JOUR
T1 - An instantaneous photomultiplier tube gain-tuning method for PET or gamma camera detectors using an LED network
AU - Li, Hongdi
AU - Liu, Yaqiang
AU - Xing, Tao
AU - Wang, Yu
AU - Uribe, Jorge
AU - Baghaei, Hossain
AU - Xie, Shuping
AU - Kim, Soonseok
AU - Ramirez, Rocio
AU - Wong, Wai Hoi
N1 - Funding Information:
Manuscript received November 10, 2003; revised June 29, 2005. This work was supported in part by the NIH-CA58980 PHS Grant, NIH-CA61880 PHS Grant, NIH-CA76246 PHS Grant, NIH-CA58980S PHS Grant, NIH-EB01481 PHS Grant, NIH-EB00217 PHS Grant, NIH-EB01038 PHS Grant, U.S. Army-Breast Cancer Research Grant, Texas ARP/ATP Grant 003657-0058-2001.
PY - 2005/10
Y1 - 2005/10
N2 - A photomultiplier tube (PMT) gain can change with many environmental factors, such as room temperature, patient load, short-term or long-term radiation exposure, and time. Unbalanced PMT gains degrade the image resolution and quality in a positron emission tomography (PET) camera or a gamma camera. This paper presented a new method to instantaneously recover the original manufacture PMT gain setting using a blue light-emitting diode (LED) network. Each LED shines directly into the center of a scintillation crystal block from the PMT side, and the light is collected by the surrounding PMTs. The gain tuning is done by changing the gains of these surrounding PMTs or their following amplifiers to have the same signal output. An LED has well-known problems of large light-yield varieties and is very sensitive to temperature. To overcome these problems, the light outputs of two neighboring LEDs are aligned first by a shared PMT. Each LED flashes at 250-KHz pulse rate, the data acquisition for the gain tuning can be finished within a very short time so the LED temperature effect can be ignored. The amount of LED light output is set as close as possible to the amount of scintillation light by programming the width or height of the pulses; therefore, the same electronics can be used for data acquisition and tuning. We estimated a 12 module PET camera with 924 PMTs in a PMT-quadrant-sharing design can be tuned in 1 min.
AB - A photomultiplier tube (PMT) gain can change with many environmental factors, such as room temperature, patient load, short-term or long-term radiation exposure, and time. Unbalanced PMT gains degrade the image resolution and quality in a positron emission tomography (PET) camera or a gamma camera. This paper presented a new method to instantaneously recover the original manufacture PMT gain setting using a blue light-emitting diode (LED) network. Each LED shines directly into the center of a scintillation crystal block from the PMT side, and the light is collected by the surrounding PMTs. The gain tuning is done by changing the gains of these surrounding PMTs or their following amplifiers to have the same signal output. An LED has well-known problems of large light-yield varieties and is very sensitive to temperature. To overcome these problems, the light outputs of two neighboring LEDs are aligned first by a shared PMT. Each LED flashes at 250-KHz pulse rate, the data acquisition for the gain tuning can be finished within a very short time so the LED temperature effect can be ignored. The amount of LED light output is set as close as possible to the amount of scintillation light by programming the width or height of the pulses; therefore, the same electronics can be used for data acquisition and tuning. We estimated a 12 module PET camera with 924 PMTs in a PMT-quadrant-sharing design can be tuned in 1 min.
KW - Calibration
KW - Light-emitting diode (LED)
KW - Photo-multiplier tube (PMT)
KW - Positron emission tomography (PET)
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U2 - 10.1109/TNS.2005.858233
DO - 10.1109/TNS.2005.858233
M3 - Article
AN - SCOPUS:29144491488
SN - 0018-9499
VL - 52
SP - 1295
EP - 1299
JO - IEEE Transactions on Nuclear Science
JF - IEEE Transactions on Nuclear Science
IS - 5 I
ER -