Development of a miniature scintillation camera using an NaI(Tl) scintillator and PSPMT for scintimammography.
We have developed a small scintillation camera dedicated to breast imaging and have evaluated the performance of the system. In order to increase the limited field of view (FOV) determined by the size of a position-sensitive photomultiplier tube (PSPMT), the imaging characteristics of a diverging hole collimator (DHC) were also investigated. The small scintillation camera system consists of an NaI(Tl) crystal (60 mm x 60 mm x 6 mm) coupled to a Hamamatsu R3941 PSPMT, a resistor chain circuit, preamplifiers, nuclear instrument modules, an analogue to digital converter and a PC for control and display. The intrinsic energy resolution of the system was 12.9% FWHM at 140 keV. The spatial resolution was measured using a line-slit mask and 99mTc point sources and was 3.1 mm FWHM. The intrinsic sensitivity of the system was approximately 162 counts/s kBq(-1). The DHC made it possible to image a larger FOV (75 x 75 mm2 at the surface of collimator) than a parallel-hole collimator (60 x 60 mm2). The system sensitivity obtained using the DHC gradually decreased with distance (3% at 1 cm, 6% at 2 cm and 9% at 3 cm). The results demonstrate that the system developed in this study could be utilized clinically to image malignant breast tumours. A DHC can be employed to expand the FOV of the system confined by the size of PSPMT with a modest compromise in the performance of the system.
Kim
J H
JH
Department of Nuclear Medicine, Samsung Medical Center, Seoul, Korea.
Choi
Y
Y
Joo
K S
KS
Sihn
B S
BS
Chong
J W
JW
Kim
S E
SE
Lee
K H
KH
Choe
Y S
YS
Kim
B T
BT
D001943:Breast Neoplasms / Q000175:diagnosis; D005260:Female; D015902:Gamma Cameras; D006801:Humans; D008327:Mammography / Q000295:instrumentation* / Q000379:methods*; D012680:Sensitivity and Specificity; D012974:Sodium Iodide / Q000737:chemistry; D012984:Software
D012974:Sodium Iodide