Design and performance of a prototype whole-body PET/CT scanner with fiber-optic readout

Worstell, W.; Adler, Steven; Domigan, Paul; Johnson, O. E.; Kudrolli, Haris; Lazuka, David; Monteverde, P.; Nevin, John; Rohatgi, Rajat; Romanov, L.; Starsja, S.

doi:10.1109/nssmic.2004.1466389

Cited by 10 publications

(5 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since the WLS fibers readout the signals over row or column, that can reduce the number of photosensors. Accordingly, this approach is advantaged to build large-ring systems, and applied to develop a whole-body clinical PET/CT scanner, although the signals from WLS fibers at present are used to improve detector identification and energy resolution (compared with block detector design), rather than to acquire DOI information [51]. For acceptable performance, however, it is critical to maximize collection of light photons from the ends of the fibers and to minimize the optical crosstalk between adjacent fibers [52].…”

Section: Continuous Doi Measurement By Dual-ended Readout Detectorsmentioning

confidence: 99%

Positron emission tomography (PET) detectors with depth-of- interaction (DOI) capability

2011

View full text Add to dashboard Cite

Because positron emission tomography (PET) provides biochemical information in vivo with the sensitivity at the sub-pico-molar level, pre-clinical research using PET plays an important role in biological and pharmaceutical sciences. However, small animal imaging by PET has been challenging with respect to spatial resolution and sensitivity due to the small volume of the imaging objects. A DOI-encoding technique allows for pre-clinical PET to simultaneously achieve high spatial resolution and high sensitivity. Thus many DOI-encoding methods have been proposed. In this paper we describe why DOI measurements are important, what is required in DOI-encoding designs, and how to extract DOI information in scintillator-based DOI detectors. Recently, there has been a growing interest in DOI measurements for TOF PET detectors to correct time walk as a function of DOI position. Thus, the DOI-encoding method with a high time performance suitable for TOF detectors is now required. The requirements to improve the time resolution in DOI detectors are discussed as well.Keywords Positron emission tomography (PET), Depth of interaction (DOI), Multi-layer detector, Dual-ended readout, Single-ended readout THE IMPORTANCE OF DOI MEASUREMENT Simultaneous improvement in spatial resolution and sensitivityThe PET is an important pre-clinical imaging technique because PET provides biochemical information down to the sub-pico-molar level in vivo [1]. Thus, the development of pre-clinical PET scanners has been actively promoted. The major focus of the development is to obtain a similar quality in small animal images as human images, while the size of the imaging subject decreases and the amount of radiopharmaceutical injected into the small animals is limitedTo obtain a similar level of detail and SNR in mouse images as human images, spatial resolution and sensitivity should be increased. That is why many PET instrument researchers have been attempting for the pre-clinical PET to simultaneously achieve high spatial resolution and high sensitivity. The pre-clinical PET systems therefore have been designed by using very long and narrow crystals with small diameter ring geometry. However, such system structures cause the parallax error to become lager when providing no depth-of-interaction (DOI) information within crystals (general PETs can measure no DOI information), and bring the degradation of the radial resolution in the peripheral field of view (FOV). That is because the reconstruction algorithm, when drawing a line of response (LOR) without DOI information, usually assigns the interaction positions over all depths within a crystal to a single position (i.e. the center position on the front of the interacted crystals).

show abstract

Section: Continuous Doi Measurement By Dual-ended Readout Detectorsmentioning

confidence: 99%

Positron emission tomography (PET) detectors with depth-of- interaction (DOI) capability

2011

View full text Add to dashboard Cite

show abstract

“…Many DOI-encoding detectors have been developed for preclinical and organ-specific PET scanners. These PET scanners demand high spatial resolution and sensitivity mainly because of the small size of the imaging targets (Karp and Daube-Withespoon 1987, Worstell et al 2004, Murayama et al 1998, Levin 2000, Shao et al 2000, Liu et al 2001, Zhang et al 2002, Tsuda et al 2004, Yang et al 2006, Braem et al 2007, Du et al 2007, Jung et al 2007, Hong et al 2008, Ito et al 2010a, Vandenbroucke et al 2010, Freifelder and Karp 1997, Muehllehner 1976.…”

Section: Introductionmentioning

confidence: 99%

Continuous depth-of-interaction measurement in a single-layer pixelated crystal array using a single-ended readout

Ito

Lee

2013

Phys. Med. Biol.

View full text Add to dashboard Cite

We propose a depth-of-interaction (DOI)-encoding method to extract continuous DOI information using a single-layer scintillation crystal array with single-ended readout for cost-effective high-resolution positron emission tomography (PET). DOI information is estimated by different light dispersions along the x- and y-directions tailored by the geometric shape of reflectors around the crystals. The detector module comprised a 22 × 22 array of unpolished LGSO crystals (2.0 × 2.0 × 20 mm(3)). A multi-anode photomultiplier tube with 64 anodes measured light dispersion in the crystal array. Gain non-uniformity of each anode was corrected by an analogue gain compensation circuit. DOI information was determined from peaks in the x and y anode-signal distributions normalized by the total energy of the distribution. Average DOI resolution (full width at half maximum, FWHM) over all crystals and depths was estimated to be 4.2 mm. Average energy resolution from the 2 to 18 mm DOI positions was 11.3% ± 0.79%, with 13% difference in photo-peak positions. Average time resolutions (FWHM) were 320-356 ps. Energy, time and DOI resolutions were uniform over all crystal positions except at the array's edge. This DOI-PET detector shows promise for applications that require high resolution and sensitivity at low cost.

show abstract

“…The direct MC-PMT read-out could improve the crystal encoding and timing, and the fiber read-out would be used only for DOI information. Worstell et al (2004) have successfully developed a whole-body clinical scanner using a similar approach with a very bright scintillator (CsI(Na)) and relatively large crystals (3.75 × 7.5 × 36 mm 3 ). In terms of the numbers of channels and number of PMT elements, this approach is not as efficient as that proposed here; however, it would lead to improved event positioning, energy and timing resolution.…”

Section: Discussionmentioning

confidence: 99%

Comparison of four depth-encoding PET detector modules with wavelength shifting (WLS) and optical fiber read-out

Du¹,

Yang²,

Cherry³

2008

Phys. Med. Biol.

View full text Add to dashboard Cite

We propose detectors for a laboratory positron emission tomography scanner specific for mouse imaging that utilizes fewer detectors and channels of electronics compared with existing designs. The detectors are based on lutetium oxyorthosilicate arrays, read out by orthogonal optical fibers placed on the top and bottom of the arrays. Depth of interaction (DOI) information is obtained from the ratio of the signals at either end of the array. Four different detector modules were evaluated, using different reflector materials and two types of optical fibers (wavelength shifting (WLS) fibers and clear optical fibers). The modules were compared in terms of flood histograms, energy resolution, DOI resolution and timing resolution. Energy resolution for single crystals at one irradiation depth was around 65% full-width half-maximum (FWHM). A DOI resolution of approximately 6 mm was obtained for the modules. Timing resolution was in the range of 5.1-7.8 ns. An array assembled in the laboratory and coupled with WLS fibers had the best DOI resolution; the same array with clear fibers had the best timing resolution and a commercially manufactured array and coupled with WLS fibers had the best energy resolution.

show abstract

Design and performance of a prototype whole-body PET/CT scanner with fiber-optic readout

Cited by 10 publications

References 5 publications

Positron emission tomography (PET) detectors with depth-of- interaction (DOI) capability

Positron emission tomography (PET) detectors with depth-of- interaction (DOI) capability

Continuous depth-of-interaction measurement in a single-layer pixelated crystal array using a single-ended readout

Comparison of four depth-encoding PET detector modules with wavelength shifting (WLS) and optical fiber read-out

Contact Info

Product

Resources

About