Performance improvement of small gamma camera using NaI(Tl) plate and position sensitive photo-multiplier tubes.
The purpose of this study was to improve the performance of a small gamma camera, utilizing a NaI(Tl) plate and a 5" position sensitive PMT. We attempted to build a NaI(Tl) plate crystal system which retained all its advantages, while at the same time integrating some of the advantages inherent in an array-type scintillation crystal system. Flood images were obtained with a lead hole mask, and position mapping was performed by detecting hole positions in the flood image. Energy calibration was performed using the energy spectra obtained from each hole position. Flood correction was performed using a uniformity correction table containing the relative efficiency of each image element. The spatial resolution was improved about 16% after correction at the centre field of view. Resolution deterioration at the outer field of view (OFOV) was considerably ameliorated, from 6.7 mm to 3.2 mm after correction. The sensitivity at the OFOV was also increased after correction, from 0.7 cps microCi(-1) to 2.0 cps microCi(-1). The correction also improved uniformity, from 5.2% to 2.1%, and linearity, from 0.5 mm to 0 mm. The results of this study indicate that the revised correction method can be employed to considerably improve the performance of a small gamma camera using a NaI(Tl) plate-type crystal. This method also provides high spatial resolution and linearity, like array-type crystals do, while retaining the specific advantages of plate-type crystals.
Jeong
Myung Hwan
MH
Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Kangnam-Ku, Seoul, 135-710, Korea.
Choi
Yong
Y
Chung
Yong Hyun
YH
Song
Tae Yong
TY
Jung
Jin Ho
JH
Hong
Key Jo
KJ
Min
Byung Jun
BJ
Choe
Yearn Seong
YS
Lee
Kyung-Han
KH
Kim
Byung-Tae
BT
D004582:Electronics, Medical; D004867:Equipment Design; D019544:Equipment Failure Analysis; D015902:Gamma Cameras; D007089:Image Enhancement / Q000295:instrumentation*; D049268:Positron-Emission Tomography / Q000295:instrumentation*; D011877:Radionuclide Imaging / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012974:Sodium Iodide / Q000528:radiation effects*; D014159:Transducers
D012974:Sodium Iodide