Multi-pinhole cardiac SPECT performance with hemi-Ellipsoid detectors for two geometries

Kalluri, Kesava S.; Bhusal, Narayan; Shumilov, Dmytro; Könik, Arda; Mukherjee, Joyeeta Mitra; Pretorius, P. Hendrik; Dey, Joyoni

doi:10.1109/nssmic.2015.7582127

Cited by 4 publications

(8 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We adopted the stationary 21‐detector‐pinhole configuration geometry with pinholes described as NPH21b200 in Ref. . Briefly, the 21 detectors collimated with pinholes are distributed on three arcs of a spherical surface (shown in a volume rendering superposed on the NCAT phantom, in Fig.…”

Section: Methodsmentioning

confidence: 97%

“…In this work, we investigate a full system with 21 hemi‐ellipsoid curved detectors (the NPH21b200 system described in Ref. ) using GATE (Geant4 Application for Tomographic Emission) simulations and analyze the performance compared to state‐of‐the‐art clinical systems. The hemi‐ellipsoid detector system is termed ellipsoid system for simplicity here onward.…”

Section: Methodsmentioning

confidence: 99%

“…1(a) in Ref. ). Each detector‐pinhole is separated from the nearest one by at least a 1 cm buffer, the closest point between adjacent units being at the base of the crystal.…”

Section: Methodsmentioning

confidence: 99%

“…A MPH MLEM/OSEM reconstruction algorithm developed by Dey was used to reconstruct the rod‐sources and the NCAT phantom acquired in simulations by GATE. The sampling was voxel based (ray casting‐based regular sampling of each voxel).…”

Section: Methodsmentioning

confidence: 99%

“…Dey previously explored a theoretical hemi‐paraboloid system with analytical forward system acquisition simulation of point‐sources, yielding 2.26 times sensitivity improvement over a base flat‐detector system for equivalent average FWHM. We did a preliminary exploration of the hemi‐ellipsoid detector shape and estimated that further performance improvement is possible compared to a hemi‐paraboloid shape of the same base diameter and height (because of higher magnification in the center over a larger angular sector).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Performance analysis of a high‐sensitivity multi‐pinhole cardiac SPECT system with hemi‐ellipsoid detectors

Bhusal

Dey

et al. 2018

Medical Physics

View full text Add to dashboard Cite

Purpose: Single-photon emission computed tomography (SPECT) is a noninvasive imaging modality, used in myocardial perfusion imaging. The challenges facing the majority of clinical SPECT systems are low sensitivity, poor resolution, and the relatively high radiation dose to the patient. New generation systems (GE Discovery, DSPECT) dedicated to cardiac imaging improve sensitivity by a factor of 5-8. This improvement can be used to decrease acquisition time and/or dose. However, in the case of ultra-low dose (~3 mCi) injections, acquisition times are still significantly long, taking 10-12 min. The purpose of this work is to investigate a new gamma camera design with 21 hemiellipsoid detectors each with a pinhole collimator for cardiac SPECT for further improvement in sensitivity and resolution and reduced patient exposures and imaging times. Methods: To evaluate the resolution of our hemi-ellipsoid system, GATE Monte-Carlo simulations were performed on point-sources, rod-sources, and NCAT phantoms. For average full-width-half-maximum (FWHM) equivalence with base flat-detector, the pinhole-diameter for the curved hemi-ellipsoid detector was found to be 8.68 mm, an operating pinhole-diameter nominally expected to be~3 times more sensitive than state-of-the-art systems. Rod-sources equally spaced within the region of interest were acquired with a 21-detector system and reconstructed with our multi-pinhole (MPH) iterative OSEM algorithm with collimator resolution recovery. The results were compared with the results of a state-of-the-art system (GE Discovery) available in the literature. The system was also evaluated using the mathematical anthropomorphic NCAT (NURBS-based Cardiac Torso; Segars et al. IEEE Trans Nucl Sci. 1999;46:503-506) phantom with a full (clinical)-dose acquisition (25 mCi) for 2 min and an ultra-low dose acquisition of 3 mCi for 5.44 min. The estimated left ventricle (LV) counts were compared with the available literature on a state-of-the-art system (DSPECT). FWHM of the LV wall on MPH-OSEM-reconstructed images with collimator resolution recovery was estimated. Results: On acquired rod-sources, the average resolution (FWHM) after reconstruction with resolution recovery in the entire region of interest (ROI) for cardiac imaging was on the average 4.44 mm (AE2.84), compared to 6.9 mm (AE1 mm) reported for GE Discovery (Kennedy et al., J Nucl Cardiol. 2014:21:443-452). For NCAT studies, improved sensitivity allowed a full-dose (25 mCi) 2-min acquisition (Ell8.68mmFD) which yielded 3.79 M LV counts. This is~3.35 times higher compared to 1.13 M LV counts acquired in 2 min for clinical full dose for state-of-the-art DSPECT. The increased sensitivity also allowed an ultra-low dose acquisition protocol (Ell8.68 mmULD), 3 mCi (eight times less injected dose) in 5.44 min. This ultra-low dose protocol yielded~1.23 M LV counts which was comparable to the full-dose 2-min acquisition for DSPECT. The estimated NCAT average FWHM at the LV wall after 12 iterations of the OSEM reconstruction was 4.95 and 5.66 mm...

show abstract

Section: Methodsmentioning

confidence: 97%

Section: Methodsmentioning

confidence: 99%

“…1(a) in Ref. ). Each detector‐pinhole is separated from the nearest one by at least a 1 cm buffer, the closest point between adjacent units being at the base of the crystal.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Performance analysis of a high‐sensitivity multi‐pinhole cardiac SPECT system with hemi‐ellipsoid detectors

Bhusal

Dey

et al. 2018

Medical Physics

View full text Add to dashboard Cite

show abstract

Recent advances in cardiac SPECT instrumentation and imaging methods

Liu

2019

Phys. Med. Biol.

View full text Add to dashboard Cite

Cardiac SPECT continues to play a critical role in detecting and managing cardiovascular disease, in particularly coronary artery disease (CAD) (Jaarsma et al 2012 J. Am. Coll. Cardiol. 59 1719–28), (Agostini et al 2016 Eur. J. Nucl. Med. Mol. Imaging 43 2423–32). While conventional dual-head SPECT scanners using parallel-hole collimators and scintillation crystals with photomultiplier tubes are still the workhorse of cardiac SPECT, they have the limitations of low photon sensitivity (~130 count s−1 MBq−1), poor image resolution (~15 mm) (Imbert et al 2012 J. Nucl. Med. 53 1897–903), relatively long acquisition time, inefficient use of the detector, high radiation dose, etc. Recently our field observed an exciting growth of new developments of dedicated cardiac scanners and collimators, as well as novel imaging algorithms for quantitative cardiac SPECT. These developments have opened doors to new applications with potential clinical impact, including ultra-low-dose imaging, absolute quantification of myocardial blood flow (MBF) and coronary flow reserve (CFR), multi-radionuclide imaging, and improved image quality as a result of attenuation, scatter, motion, and partial volume corrections (PVCs). In this article, we review the recent advances in cardiac SPECT instrumentation and imaging methods. This review mainly focuses on the most recent developments published since 2012 and points to the future of cardiac SPECT from an imaging physics perspective.

show abstract

The clinical utilities of multi-pinhole single photon emission computed tomography

Ozsahin¹,

Chen²,

Könik³

et al. 2020

Quant Imaging Med Surg

View full text Add to dashboard Cite

Single photon emission computed tomography (SPECT) is an important imaging modality for various applications in nuclear medicine. The use of multi-pinhole (MPH) collimators can provide superior resolution-sensitivity trade-off when imaging small field-of-view compared to conventional parallel-hole and fan-beam collimators. Besides the very successful application in small animal imaging, there has been a resurgence of the use of MPH collimators for clinical cardiac and brain studies, as well as other small fieldof-view applications. This article reviews the basic principles of MPH collimators and introduces currently available and proposed clinical MPH SPECT systems.

show abstract

Multi-pinhole cardiac SPECT performance with hemi-Ellipsoid detectors for two geometries

Cited by 4 publications

References 6 publications

Performance analysis of a high‐sensitivity multi‐pinhole cardiac SPECT system with hemi‐ellipsoid detectors

Performance analysis of a high‐sensitivity multi‐pinhole cardiac SPECT system with hemi‐ellipsoid detectors

Recent advances in cardiac SPECT instrumentation and imaging methods

The clinical utilities of multi-pinhole single photon emission computed tomography

Contact Info

Product

Resources

About