Development of an Optical Fiber-Based MR Compatible Gamma Camera for SPECT/MRI Systems

作者：Yamamoto Seiichi^*; Watabe Tadashi; Kanai Yasukazu; Watabe Hiroshi; Hatazawa Jun

来源：IEEE Transactions on Nuclear Science, 2015, 62(1): 76-81.

DOI：10.1109/TNS.2014.2387432

• Gamma camera
• MRI
• optical fiber
• SPECT

Optical fiber is a promising material for integrated positron emission tomography (PET) and magnetic resonance imaging (MRI) PET/ MRI systems. Because its material is plastic, it has no interference betweenMRI. However, it is unclear whether this material can also be used for a single photon emission tomography (SPECT)/MRI system. For this purpose, we developed an optical fiber-based block detector for a SPECT/MRI system and tested its performance by combining mm (YSO) pixels into a block and was coupled it to an optical fiber image guide that used was 0.5-mm in diameter with 80-cm long double clad fibers. The image guide had mm rectangular input and an equal size output. The input of the optical fiber-based image guide was bent at 90 degrees, aotomultiplier tube (HQE-PSPMT). The parallel hole, 7-mm-thick collimator made of tungsten plastic was mounted on a YSO block. The diameter of the collimator holes was 0.8 mm which was positioned one-to-one coupled to the YSO pixels. We evaluated the intrinsic and system performances. We resolved most of the YSO pixels in a two-dimensional histogram for Co-57 gamma photons (122-keV) with an average peak-to-value ratio of 1.5. The energy resolution was 38% full-width at half-maximum (FWHM). The system resolution was 1.7-mm FWHM, 1.5 mm from the collimator surface, and the sensitivity was 0.06%. Images of a Co-57 point source could be successfully obtained inside 0.3 T MRI without serious interference. We concnd the output was optically coupled to a 1-in square high quantum efficiency position sensitive phlude that the developed optical fiber-based YSO block detector is promising for SPECT/MRI systems.

• 出版日期2015-2