@misc{oai:repo.qst.go.jp:00069916,
 author = {Inubushi, Masayuki and Shidahara, Miho and Murai, Chika and Tsuji, Atsushi and Koizumi, Mitsuru and Kanno, Iwao and Saga, Tsuneo and 犬伏 正幸 and 志田原 美保 and 村井 知佳 and 辻 厚至 and 小泉 満 and 菅野 巖 and 佐賀 恒夫},
 month = {Oct},
 note = {Purpose: From the viewpoint of practical use, we evaluated the basic performance of a commercial high-resolution small animal SPECT system FX(SPECT/CT) (Gamma Medica-Ideas, CA) In our system, a single-pinhole or 5-hole collimator, which consists of 1mm diameter apertures, can be mounted on a 12 x 12cm NaI(Tl) scintillation detector.
Methods: For evaluation of spatial resolution, sensitivity and effective FOV, a line source, a point source and a cylindrical phantom (1.6cm diameter) filled with 99mTcO4- solution were scanned with various rotation of radius (ROR) from 2.5cm to 8.0cm. The sensitivity, E [cps/MBq], using a point source located at the center of rotation was calculated by the division of measured total counts in the projection and its known activity. For resolution FWHM was calculated by fitting the line source image with Gaussian function. The axial length of cylindrical phantom, which preserve less than 10% bias compared with averaged counts in 1cm diam. circular region of interest (ROI) at the central slice, was regarded as effective FOV.
Results: The relationship between sensitivity (y) and ROR (x) was y = 175.9x^(-1.97), y = 1641x^(-2.04) for single- and 5-hole collimator, respectively. The relationship between resolution (y) and ROR (x) was y = 0.13x+0.49, y = 0.19x+0.29, respectively. Effective FOV (y) of single-hole collimator (y = 1.2x-1.3) resulted in quite different from that of 5-hole collimator (y = 0.42x-0.45) due to the amount of overlapping in projection data.
Conclusions: We evaluated the basic performance of the pinhole SPECT system, which did not depend only on detector system but also on ROR and the type of collimator. For its practical use, therefore, physical setting such as ROR and collimator should be carefully optimized for research purposes., Annual Congress of the European Association of Nuclear Medicine 2009},
 title = {Practical performance evaluation of a commercial small animal SPECT system with a single-pinhole or 5-hole collimator},
 year = {2009}
}