Ultra-high-resolution brain SPECT imaging: simulation results

Rogulski, M.M.; Barber, H. Bradford; Barrett, Harrison H.; Shoemaker, R. L.; Woolfenden, James M.

doi:10.1109/23.256722

Cited by 89 publications

(39 citation statements)

References 7 publications

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“…In other words, the area density of resolution elements must be high. If this is achieved, then many "mini-gamma cameras" can be employed to obtain stationary SPECT (no moving parts) at relatively low cost in materials 10 . By using the standard Anger cameras with relatively large resolution elements, it is impractical to conceive of more than six LFOV (~400 x 560 mm 2 ) cameras surrounding the patient in a relatively bulky system design and large patient-to-pinhole distances.…”

Section: Minificationmentioning

confidence: 99%

Advantages of semiconductor CZT for medical imaging

et al. 2007

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Cadmium zinc telluride (CdZnTe, or CZT) is a room-temperature semiconductor radiation detector that has been developed in recent years for a variety of applications. CZT has been investigated for many potential uses in medical imaging, especially in the field of single photon emission computed tomography (SPECT). CZT can also be used in positron emission tomography (PET) as well as photon-counting and integration-mode x-ray radiography and computed tomography (CT). The principal advantages of CZT are 1) direct conversion of x-ray or gamma-ray energy into electron-hole pairs; 2) energy resolution; 3) high spatial resolution and hence high space-bandwidth product; 4) room temperature operation, stable performance, high density, and small volume; 5) depth-of-interaction (DOI) available through signal processing. These advantages will be described in detail with examples from our own CZT systems. The ability to operate at room temperature, combined with DOI and very small pixels, make the use of multiple, stationary CZT 'mini-gamma cameras" a realistic alternative to today's large Anger-type cameras that require motion to obtain tomographic sampling. The compatibility of CZT with Magnetic Resonance Imaging (MRI)-fields is demonstrated for a new type of multi-modality medical imaging, namely SPECT/MRI. For pre-clinical (i.e., laboratory animal) imaging, the advantages of CZT lie in spatial and energy resolution, small volume, automated quality control, and the potential for DOI for parallax removal in pinhole imaging. For clinical imaging, the imaging of radiographically dense breasts with CZT enables scatter rejection and hence improved contrast. Examples of clinical breast images with a dual-head CZT system are shown.

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Section: Minificationmentioning

confidence: 99%

Advantages of semiconductor CZT for medical imaging

et al. 2007

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“…At present these ultra-high resolutions are obtained using traditional gamma cameras, by employing the principle of pinhole magnification. For future improvements of small animal SPECT imaging, gamma cameras with better spatial resolution and significant energy discrimination are essential [8][9][10][11]. Compact, high-resolution gamma cameras using EM-CCDs in combination with micro-columnar CsI(TI) scintillators [12] are being developed by many research groups [13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Depth-of-interaction detection and correction with a multi-scale algorithm in CCD based gamma cameras

Korevaar

Heemskerk

Goorden

et al. 2008

2008 IEEE Nuclear Science Symposium Conference Record

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Gamma cameras based on Charge Coupled Devices (CCDs) and micro-columnar CsI scintillators can reach high spatial resolutions. However, the gamma interaction probability of these scintillators is low (typically <30% at 141 keV) due to the limited thickness of presently available micro-columnar scintillators. Continuous scintillators can improve the interaction probability but suffer from increased light spread compared to columnar scintillators. In addition, for both types of scintillators gamma photons incident at an oblique angle reduce the spatial resolution due to the variable depth of interaction (DOl). To improve spatial resolution and spectral characteristics of these detectors, we have developed a fast analytic scintillation detection algorithm that makes use of a depth-dependent light spread model and as a result is able to determine the DOl in the scintillator. This algorithm, performing multi-scale frame analysis, was tested for an Electron Multiplying CCD (EM-CCD) optically coupled to CsI(TI) scintillators of different thicknesses.For a 2.6 mm thick scintillator a spatial resolution of 148 J.1m Full Width Half Maximum (FWHM) was obtained with an energy resolution of 46% FWHM for gamma photons incident perpendicularly (interaction probability 61 % at 141 keY). The multi-scale algorithm improves the spatial resolution up to 11 %, and the energy resolution up to 36 % compared to a previously implemented algorithm that did not model the depth-dependent light spread. In addition, the multi-scale algorithm can accurately approximate DOl. As a result, degradation of the spatial resolution due to the variable DOl for gamma photons incident at a 47 0 angle was improved from 2600 Jlm to 508 Jlm FWHM for a 3 mm thick scintillator. We conclude that the multi-scale algorithm significantly improves CCD based gamma cameras as can be applied in future SPECT systems.

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“…One of the few ways to enable all three attributes to be improved at once is by increasing the number of effective detector pixels. [14, 15]…”

Section: Introductionmentioning

confidence: 99%

Molecular imaging in the College of Optical Sciences: an overview of two decades of instrumentation development

et al. 2014

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During the past two decades, researchers at the University of Arizona’s Center for Gamma-Ray Imaging (CGRI) have explored a variety of approaches to gamma-ray detection, including scintillation cameras, solid-state detectors, and hybrids such as the intensified Quantum Imaging Device (iQID) configuration where a scintillator is followed by optical gain and a fast CCD or CMOS camera. We have combined these detectors with a variety of collimation schemes, including single and multiple pinholes, parallel-hole collimators, synthetic apertures, and anamorphic crossed slits, to build a large number of preclinical molecular-imaging systems that perform Single-Photon Emission Computed Tomography (SPECT), Positron Emission Tomography (PET), and X-Ray Computed Tomography (CT). In this paper, we discuss the themes and methods we have developed over the years to record and fully use the information content carried by every detected gamma-ray photon.

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Ultra-high-resolution brain SPECT imaging: simulation results

Cited by 89 publications

References 7 publications

Advantages of semiconductor CZT for medical imaging

Advantages of semiconductor CZT for medical imaging

Depth-of-interaction detection and correction with a multi-scale algorithm in CCD based gamma cameras

Molecular imaging in the College of Optical Sciences: an overview of two decades of instrumentation development

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