Development of an optical fiber-based MR compatible gamma camera for SPECT/MRI systems

Seiichi Yamamoto, Tadashi Watabe, Yasukazu Kanai, Hiroshi Watabe, Jun Hatazawa

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


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 between MRI. 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 1.2 × 1.2 × 6 mm Y2SiO5 (YSO) pixels into a 15 × 15 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 22 × 22 mm rectangular input and an equal size output. The input of the optical fiber-based image guide was bent at 90 degrees, and the output was optically coupled to a 1-in square high quantum efficiency position sensitive photomultiplier 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 conclude that the developed optical fiber-based YSO block detector is promising for SPECT/MRI systems.

Original languageEnglish
Article number7027243
Pages (from-to)76-81
Number of pages6
JournalIEEE Transactions on Nuclear Science
Issue number1
Publication statusPublished - 2015 Feb 6


  • Gamma camera
  • MRI
  • optical fiber

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering
  • Electrical and Electronic Engineering


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