کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8167061 | 1526244 | 2018 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
A phoswich detector design for improved spatial sampling in PET
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
ابزار دقیق
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Block detector designs, utilizing a pixelated scintillator array coupled to a photosensor array in a light-sharing design, are commonly used for positron emission tomography (PET) imaging applications. In practice, the spatial sampling of these designs is limited by the crystal pitch, which must be large enough for individual crystals to be resolved in the detector flood image. Replacing the conventional 2D scintillator array with an array of phoswich elements, each consisting of an optically coupled side-by-side scintillator pair, may improve spatial sampling in one direction of the array without requiring resolving smaller crystal elements. To test the feasibility of this design, a 4Ã4 phoswich array was constructed, with each phoswich element consisting of two optically coupled, 3.17Ã1.58Ã10mm3 LSO crystals co-doped with cerium and calcium. The amount of calcium doping was varied to create a 'fast' LSO crystal with decay time of 32.9 ns and a 'slow' LSO crystal with decay time of 41.2 ns. Using a Hamamatsu R8900U-00-C12 position-sensitive photomultiplier tube (PS-PMT) and a CAEN V1720 250 MS/s waveform digitizer, we were able to show effective discrimination of the fast and slow LSO crystals in the phoswich array. Although a side-by-side phoswich array is feasible, reflections at the crystal boundary due to a mismatch between the refractive index of the optical adhesive (n=1.5) and LSO (n=1.82) caused it to behave optically as an 8Ã4 array rather than a 4Ã4 array. Direct coupling of each phoswich element to individual photodetector elements may be necessary with the current phoswich array design. Alternatively, in order to implement this phoswich design with a conventional light sharing PET block detector, a high refractive index optical adhesive is necessary to closely match the refractive index of LSO.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment - Volume 882, 21 February 2018, Pages 124-128
Journal: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment - Volume 882, 21 February 2018, Pages 124-128
نویسندگان
Jonathan D. Thiessen, Merry A. Koschan, Charles L. Melcher, Fang Meng, Graham Schellenberg, Andrew L. Goertzen,