A prototype coded aperture detector for small animal SPECT

Meikle, Steven R.; Kench, Peter; Weisenberger, A.G.; Wojcik, R.; Smith, Mark F.; Majewski, S.; Eberl, Stefan; Fulton, Roger; Rosenfeld, Anatoly B.; Fulham, Michael

doi:10.1109/tns.2002.803802

Cited by 112 publications

(49 citation statements)

References 13 publications

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“…Data were acquired for 40 seconds per projection at 9˚ increments over 360˚ and reconstructed using 5 iterations and 5 subsets of 3D OS-EM. The 3D multipinhole OS-EM algorithm is described in previous reports [7,8]. A Gaussian function was fitted to radial and tangential count profiles of each of the reconstructed point sources.…”

Section: B Tomographic Performance Two 99mmentioning

confidence: 99%

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Performance evaluation of a multipinhole small animal SPECT system

Meikle

Kench

Wojcik

et al. 2003

2003 IEEE Nuclear Science Symposium. Conference Record (IEEE Cat. No.03CH37515)

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Abstract-We have designed and constructed a small animal SPECT system based on compact, high resolution detectors and multipinhole apertures. The scanner is currently configured with two detectors mounted on a rotating gantry. Each detector comprises a NaI(Tl) crystal array (1x1x5 mm elements), a 12 cm diameter position-sensitive photomultiplier tube (Hamamatsu R3292) and a tungsten aperture with 1 or more pinholes. In this study, we performed phantom experiments to characterise the planar and tomographic performance of the scanner. Intrinsic resolution measured with a highly collimated 99m Tc point source stepped across the detector face was 1.0±0.1 mm FWHM and 2.9±0.1 mm FWTM. Energy resolution at 140 keV varied from 14% FWHM for central crystals to 19% for edge crystals and was 20% FWHM for the whole detector normalised spectrum. Intrinsic uniformity for the central field of view was 2.4% differential and 3.8% integral. Reconstructed spatial resolution was 1.2 mm FWHM at the centre of the field of view and 1.2, 1.7 mm FWHM (radial, tangential) at 10 mm off-axis, using typical geometric parameters for mouse and rat brain imaging. Reconstructed images of a micro deluxe hot rod phantom demonstrate the high resolution of the system and indicate similar resolution and improved signal-to-noise is obtained with a 2 pinhole aperture compared with a single pinhole. We conclude that the performance characteristics of this system make it suitable for high resolution imaging of small laboratory animals.

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Section: B Tomographic Performance Two 99mmentioning

confidence: 99%

“…We are developing a dedicated small animal SPECT system based on compact high resolution detectors [7,8]. Collimation with multipinhole apertures is also being investigated by our group and by Schramm et al to devise optimal approaches for improving the detection efficiency of small animal SPECT [9,10].…”

Section: Introductionmentioning

confidence: 99%

Performance evaluation of a multipinhole small animal SPECT system

Meikle

Kench

Wojcik

et al. 2003

2003 IEEE Nuclear Science Symposium. Conference Record (IEEE Cat. No.03CH37515)

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“…In a study on a similar aspect, a stationary system dedicated to the imaging of small animals with non-multiplexed projections was proposed [9]. This system, showing sub millimeter details of tracer uptake, allows assessment of tracer dynamics in the organs of the living mouse.…”

Section: Introductionmentioning

confidence: 99%

Design and Development of a High Performance Pinhole Array Dual Head SPECT Using Monte Carlo Simulation

Rahman¹

2015

IJIEE

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Abstract-The Purpose of this study is to investigate the performance of a dual head SPECT system having an array of pinholes as a collimator. Several analytical methods are used to evaluate the performance of the given pinhole array detector module design. Monte Carlo simulation studies using Geant4 Application for Tomographic Emission (GATE) validate the performance of this novel dual head SPECT where a cylindrical water phantom is imaged. We are proposing a pinhole array detector module with 48mm by 48mm of active area behind an array of 100 pinholes laid out in a 10 by 10 lattice. This configuration allows high detection efficiency and excellent sensitivity in SPECT imaging. The system is based on a pixelated array of NaI crystals (100 × 100 × 10mm elements) coupled with an array of position sensitive photomultiplier tubes (PSPMTs). The basic characteristics of this system were evaluated with pinhole apertures of 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm and 3mm respectively. A conventional filtered back projection algorithm was used to reconstruct the images. Performance evaluation of this system indicates that high quality images can be obtained for in vivo imaging.Index Terms-Dual head SPECT, SPECT instrumentation, pinhole SPECT and GATE. I. INTRODUCTIONIn the past several years, SPECT has developed significantly and is now considered to be an imperative modality in the nuclear emission field. SPECT is a physiological imaging tool that is commonly used for visualizing or measuring the function of specific organs. There are definite advantages for improved SPECT devices [1]. Higher sensitivity and resolution are necessary for small animal imaging than for human imaging to achieve a level of anatomic detail that is comparable to human studies. Dedicated small animal imaging systems are being developed in several modalities. In spite of the requirement for higher spatial resolution, SPECT is most often based on the Anger camera principle: a collimator is placed in front of a NaI (Tl) scintillation crystal associated with a set of photomultipliers. Conventional collimators used for SPECT imaging cannot provide better detection efficiency and result in poor image quality. SPECT is a rapidly changing field, and the past several years have produced new developments in both hardware technology and image processing algorithms [2]. At the component level, there have been improvements in scintillators and photon transducers as well as in the greater availability of semiconductor technology. The current Manuscript received September 10, 2014; revised November 25, 2014 state-of-the-art of SPECT has been developing from many fronts and there is still scope to see improvements in instrumentation and innovative image reconstruction algorithms. Despite the readily available isotopes, unlike PET, SPECT suffers from low detection efficiency and low resolution; therefore, many investigations have focused on increasing its sensitivity without degrading spatial resolution [3]- [5]. A pinhole approach for SPECT is envisaged for superior spa...

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“…2, the method (which is described in detail in [3]) is to determine the coordinates of each pinhole focal point and its corresponding mirror point in the fixed (unrotated) reference frame as ( ) φ τ φ…”

Section: B Image Reconstructionmentioning

confidence: 99%

“…These applications and advances in instrumentation are applicable to positron emitters and single photon emitters. PET is able to image a wide range of We have previously demonstrated the feasibility of using a multi-pinhole array as an encoding aperture, together with compact high resolution pixelated gamma detectors [2,3]. This results in substantially increased detection efficiency compared with conventional SPECT systems while maintaining high spatial resolution.…”

Section: Introductionmentioning

confidence: 99%

CoALA-SPECT: a coded aperture laboratory animal SPECT system for pre clinical imaging

Meikle

Wojcik

Weisenberger

et al.

2002 IEEE Nuclear Science Symposium Conference Record

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Abstract-We have previously demonstrated the potential of multi-pinhole coded apertures when used in conjunction with compact pixelated detectors for high resolution, high sensitivity small animal SPECT. We are now constructing a prototype SPECT system with three such detectors mounted on a rotating gantry. Each detector comprises a 12 cm diameter circular array of NaI(Tl) crystals, each 1x1x5 mm 3 on a 1.25 mm pitch. Each crystal array is coupled to a Hamamatsu R3292 12.7 cm diameter PS-PMT. Signals from the three detectors are read out by a custom subtractive resistive circuit and multiplexed. Data are acquired by a National Instruments PCI-6110E board running on a Macintosh dual processor G4 computer under Kmax software control. Images are reconstructed using a 3D iterative MAP-EM algorithm based on a multi-pinhole forward and back projector. The trade-off between contrast and variance was studied by simulation for a number of multipinhole configurations. We also performed initial planar imaging studies on one of the detectors. Our results indicate that spatial resolution approaching 1 mm full width at half maximum (FWHM) can be achieved with a single pinhole aperture, while improved contrast and variance may result from using optimized multi-pinhole apertures.

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A prototype coded aperture detector for small animal SPECT

Cited by 112 publications

References 13 publications

Performance evaluation of a multipinhole small animal SPECT system

Performance evaluation of a multipinhole small animal SPECT system

Design and Development of a High Performance Pinhole Array Dual Head SPECT Using Monte Carlo Simulation

CoALA-SPECT: a coded aperture laboratory animal SPECT system for pre clinical imaging

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