Development of a flexible optical fiber based high resolution integrated PET/MRI system
- Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi 461-8673 (Japan)
Purpose: The simultaneous measurement of PET and magnetic resonance imaging (MRI) is an emerging field for molecular imaging research. Although optical fiber based PET/MRI systems have advantages on less interference between PET and MRI, there is a drawback in reducing the scintillation light due to the fiber. To reduce the problem, the authors newly developed flexible optical fiber bundle based block detectors and employed them for a high resolution integrated PET/MRI system. Methods: The flexible optical fiber bundle used 0.5 mm diameter, 80 cm long double clad fibers which have dual 12 mm Multiplication-Sign 24 mm rectangular inputs and a single 24 mm Multiplication-Sign 24 mm rectangular output. In the input surface, LGSO scintillators of 0.025 mol.% (decay time: {approx}31 ns: 0.9 mm Multiplication-Sign 1.3 mm Multiplication-Sign 5 mm) and 0.75 mol.% (decay time: {approx}46 ns: 0.9 mm Multiplication-Sign 1.3 mm Multiplication-Sign 6 mm) were optically coupled in depth direction to form depth-of-interaction detector, arranged in 11 Multiplication-Sign 13 matrix and optically coupled to the fiber bundle. The two inputs of the bundle are bent for 90 Degree-Sign , bound to one, and are optically coupled to a Hamamatsu 1-in. square position sensitive photomultiplier tube. Results: Light loss due to the fiber bundle could be reduced and the performance of the block detectors was improved. Eight optical fiber based block detectors (16 LGSO blocks) were arranged in a 56 mm diameter ring to form a PET system. Spatial resolution and sensitivity were 1.2 mm full-width at half-maximum and 1.2% at the central field-of-view, respectively. Sensitivity change was less than 1% for 2 Degree-Sign C temperature changes. This PET system was integrated with a 0.3 T permanent magnet MRI system which has 17 cm diameter hole at the yoke area for insertion of the PET detector ring. There was no observable interference between PET and MRI. Simultaneous imaging of PET and MRI was successfully performed for small animal studies. Conclusions: The authors confirmed that the developed high resolution PET/MRI system is promising for molecular imaging research.
- OSTI ID:
- 22099076
- Journal Information:
- Medical Physics, Vol. 39, Issue 11; Other Information: (c) 2012 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
- Country of Publication:
- United States
- Language:
- English
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