Detector development for microPET II

A 1 μl resolution PET scanner for small animal imaging

A. Chatziioannou, Y. C. Tai, N. Doshi, Simon R Cherry

Research output: Contribution to journalArticle

110 Citations (Scopus)

Abstract

We are currently developing a small animal positron emission tomography (PET) scanner with a design goal of 1 microlitre (1 mm3) image resolution. The detectors consist of a 12 × 12 array of 1 × 1 × 10 mm lutetium oxyorthosilicate (LSO) scintillator crystals coupled to a 64-channel photomultiplier tube (PMT) via 5 cm long optical fibre bundles. The optical fibre connection allows a high detector packing fraction despite the dead space surrounding the active region of the PMT. Optical fibre bundles made from different types of glass were tested for light transmission, and also their effects on crystal identification and energy resolution, and compared to direct coupling of the LSO arrays to the PMTs. We also investigated the effects of extramural absorber (EMA) in the fibre bundles. Based on these results, fibre bundles manufactured from F2 glass were selected. We built three pairs of prototype detectors (directly coupled LSO array, fibre bundle without EMA and fibre bundle with EMA) and measured flood histograms, energy resolution, intrinsic spatial resolution and timing resolution. The results demonstrated an intrinsic spatial resolution (FWHM) of 1.12 mm (directly coupled), 1.23 mm (fibre bundle without EMA coupling) and 1.27 mm (fibre bundle with EMA coupling) using an approximately 500 μm diameter Na-22 point source. Using a 330 μm outer diameter steel needle line source filled with F-18, spatial resolution for the detector with the EMA optical fibre bundle improved to 1.05 mm. The respective timing and energy FWHM values were 1.96 ns, 21% (directly coupled), 2.20 ns, 23% (fibre bundle without EMA) and 2.99 ns, 30% (fibre bundle with EMA). The peak-to-valley ratio in the flood histograms was better with EMA (5:1) compared to the optical fibre bundle without EMA (2.5:1), due to the decreased optical cross-talk. In comparison to the detectors used in our current generation microPET scanner, these detectors substantially improve on the spatial resolution, preserve the timing resolution and provide adequate energy resolution for a modern high-resolution animal PET tomograph.

Original languageEnglish (US)
Pages (from-to)2899-2910
Number of pages12
JournalPhysics in Medicine and Biology
Volume46
Issue number11
DOIs
StatePublished - 2001

Fingerprint

Optical Fibers
Positron emission tomography
Positron-Emission Tomography
scanners
bundles
animals
positrons
Animals
tomography
absorbers
Detectors
Imaging techniques
Fibers
detectors
Optical fibers
fibers
Glass
optical fibers
Photomultipliers
spatial resolution

ASJC Scopus subject areas

  • Biomedical Engineering
  • Physics and Astronomy (miscellaneous)
  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology

Cite this

Detector development for microPET II : A 1 μl resolution PET scanner for small animal imaging. / Chatziioannou, A.; Tai, Y. C.; Doshi, N.; Cherry, Simon R.

In: Physics in Medicine and Biology, Vol. 46, No. 11, 2001, p. 2899-2910.

Research output: Contribution to journalArticle

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