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Velo AF, Fan P, Xie H, Chen X, Boutagy N, Feher A, Sinusas AJ, Ljungberg M, Liu C. 99mTc/ 123I Dual-Radionuclide Correction for Self-Scatter, Down-Scatter, and Tailing Effect for a CZT SPECT with Varying Tracer Distributions. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2023; 7:839-850. [PMID: 38745858 PMCID: PMC11090119 DOI: 10.1109/trpms.2023.3297443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
SPECT systems distinguish radionuclides by using multiple energy windows. For CZT detectors, the energy spectrum has a low energy tail leading to additional crosstalk between the radionuclides. Previous work developed models to correct the scatter and crosstalk for CZT-based dedicated cardiac systems with similar 99mTc/123I tracer distributions. These models estimate the primary and scatter components by solving a set of equations employing the MLEM approach. A penalty term is applied to ensure convergence. The present work estimates the penalty term for any 99mTc/123I activity level. An iterative approach incorporating Monte Carlo into the iterative image reconstruction loops was developed to estimate the penalty terms. We used SIMIND and XCAT phantoms in this study. Distribution of tracers in the myocardial tissue and blood pool were varied to simulate a dynamic acquisition. Evaluations of the estimated and the real penalty terms were performed using simulations and large animal data. The myocardium to blood pool ratio was calculated using ROIs in the myocardial tissue and the blood pool for quantitative analysis. All corrected images yielded a good agreement with the gold standard images. In conclusion, we developed a CZT crosstalk correction method for quantitative imaging of 99mTc/123I activity levels by dynamically estimating the penalty terms.
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Affiliation(s)
- Alexandre F Velo
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06510 USA
| | - Peng Fan
- Beijing Institute of Spacecraft System Engineering, Beijing, China
| | - Huidong Xie
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06510 USA
| | - Xiongchao Chen
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06510 USA
| | - Nabil Boutagy
- Department of Internal Medicine (Cardiology), Yale University, New Haven, CT 06510 USA
| | - Attila Feher
- Department of Internal Medicine (Cardiology), Yale University, New Haven, CT 06510 USA
| | - Albert J Sinusas
- Department of Internal Medicine (Cardiology), Yale University, New Haven, CT 06510 USA
| | | | - Chi Liu
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06510 USA
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2
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Wetzl M, Sanders JC, Kuwert T, Ritt P. Effect of reduced photon count levels and choice of normal data on semi-automated image assessment in cardiac SPECT. J Nucl Cardiol 2020; 27:1469-1482. [PMID: 29654444 DOI: 10.1007/s12350-018-1272-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 03/19/2018] [Indexed: 10/17/2022]
Abstract
BACKGROUND The SMARTZOOM multifocal collimator from Siemens Healthcare was developed to improve the γ-photon sensitivity in myocardial perfusion imaging without truncating the field of view. As part of the IQ-SPECT package, it may be used to reduce radiopharmaceutical dose to patients, as well as acquisition time. The aim of this study was twofold: (1) to evaluate the influence of dose reduction in semi-automated MPI scoring, with focus on different strategies for the choice of normal data (count-matched, full-count), and (2) to evaluate the effect of dose reduction afforded by Siemens' IQ-SPECT package. METHODS 50 patients underwent Tc-99m-sestamibi one-day stress/rest SPECT/CT. Multiple levels of count reduction were generated using binomial thinning. Using Corridor 4DM, summed stress score (SSS) was calculated using either count-matched or full-count normal data. Studies were classified as low-risk (SSS < 4) or intermediate/high-risk (SSS ≥ 4). RESULTS Count reduction using count-matched normal data increases false-normal rate and decreases sensitivity. With full-count normal data, count reduction increases false-hypoperfusion rate, leading to decreased specificity. Altogether, rate of reclassification was significant at roughly 67% dose and below. CONCLUSION Significant bias results from count level of normal data relative to actual patient data. Compared to standard LEHR, IQ-SPECT should allow for significant dose reduction.
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Affiliation(s)
- Matthias Wetzl
- Clinic of Nuclear Medicine, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Ulmenweg 18, 91054, Erlangen, Germany
| | - James C Sanders
- Clinic of Nuclear Medicine, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Ulmenweg 18, 91054, Erlangen, Germany
- Pattern Recognition Lab, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Torsten Kuwert
- Clinic of Nuclear Medicine, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Ulmenweg 18, 91054, Erlangen, Germany
| | - Philipp Ritt
- Clinic of Nuclear Medicine, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Ulmenweg 18, 91054, Erlangen, Germany.
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Dietze MMA, Kunnen B, Stella M, de Jong HWAM. Monte Carlo-based scatter correction for the SMARTZOOM collimator. EJNMMI Phys 2020; 7:49. [PMID: 32700063 PMCID: PMC7376766 DOI: 10.1186/s40658-020-00318-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 07/07/2020] [Indexed: 11/10/2022] Open
Abstract
Background Myocardial perfusion imaging is a commonly performed SPECT protocol and hence it would be beneficial if its scan duration could be shortened. For traditional gamma cameras, two developments have separately shown to allow for a shortened scan duration: (i) reconstructing with Monte Carlo-based scatter correction instead of dual-energy window scatter correction and (ii) acquiring projections with the SMARTZOOM collimator instead of a parallel-hole collimator. This study investigates which reduction in scan duration can be achieved when both methods are combined in a single system. Results The SMARTZOOM collimator was implemented in a Monte Carlo-based reconstruction package and the implementation was validated through image quality phantom experiments. The potential for scan duration reduction was evaluated with a phantom configuration that is realistic for myocardial perfusion imaging. The original reconstruction quality was achieved in 76 ± 8% of the original scan duration when switching from dual-energy window scatter correction to Monte Carlo-based scatter correction. The original reconstruction quality was achieved in 56 ± 13% of the original scan duration when switching from the parallel-hole to the SMARTZOOM collimator. After combining both methods in a single system, the original reconstruction quality was achieved in 34 ± 7% of the original scan duration. Conclusions Monte Carlo-based scatter correction combined with the SMARTZOOM collimator can further decrease the scan duration in myocardial perfusion imaging.
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Affiliation(s)
- Martijn M A Dietze
- Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, P.O. Box 85500, 3508, GA, Utrecht, The Netherlands. .,Image Sciences Institute, University Medical Center Utrecht, Utrecht University, P.O. Box 85500, 3508, GA, Utrecht, The Netherlands.
| | - Britt Kunnen
- Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, P.O. Box 85500, 3508, GA, Utrecht, The Netherlands.,Image Sciences Institute, University Medical Center Utrecht, Utrecht University, P.O. Box 85500, 3508, GA, Utrecht, The Netherlands
| | - Martina Stella
- Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, P.O. Box 85500, 3508, GA, Utrecht, The Netherlands
| | - Hugo W A M de Jong
- Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, P.O. Box 85500, 3508, GA, Utrecht, The Netherlands.,Image Sciences Institute, University Medical Center Utrecht, Utrecht University, P.O. Box 85500, 3508, GA, Utrecht, The Netherlands
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Abstract
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.
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Affiliation(s)
- Jing Wu
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, United States of America
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Esquinas PL, Rodríguez-Rodríguez C, Esposito TVF, Harboe J, Bergamo M, Celler A, Saatchi K, Sossi V, Häfeli UO. Dual SPECT imaging of 111In and 67Ga to simultaneously determine in vivo the pharmacokinetics of different radiopharmaceuticals: a quantitative tool in pre-clinical research. ACTA ACUST UNITED AC 2018; 63:235029. [DOI: 10.1088/1361-6560/aaef63] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Characteristics of iodine-123 IQ-SPECT/CT imaging compared with conventional SPECT/CT. Ann Nucl Med 2018; 33:103-111. [PMID: 30324427 DOI: 10.1007/s12149-018-1310-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 10/08/2018] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Although the utility of IQ-SPECT imaging using 99mTc and 201Tl myocardial perfusion SPECT has been reported, 123I-labeled myocardial SPECT has not been fully evaluated. We determined the characteristics and utility of 123I IQ-SPECT imaging compared with conventional SPECT (C-SPECT). METHODS Two myocardial phantom patterns were used to simulate normal myocardium and myocardial infarction. SPECT acquisition was performed using a hybrid dual-head SPECT/CT system equipped with a SMARTZOOM collimator for IQ-SPECT or a low-medium energy general purpose collimator for C-SPECT. Projection data were reconstructed using ordered subset expectation maximization with depth-dependent 3-dimensional resolution recovery for C-SPECT and ordered subset conjugate gradient minimizer method for IQ-SPECT. Three types of myocardial image were created; namely, no correction (NC), with attenuation correction (AC), and with both attenuation and scatter corrections (ACSC). Five observers visually scored the homogeneity of normal myocardium and defect severity of the myocardium with inferior defects by a five-point scale: homogeneity scores (5 = homogeneous to 1 = inhomogeneous) and defect scores (5 = excellent to 1 = poor). We also created a 17-segment polar map and quantitatively assessed segmental %uptake using a myocardial phantom with normal findings and defects. RESULTS The average visual homogeneity scores of the IQ-SPECT with NC and ACSC were significantly higher than that of C-SPECT, whereas the average visual defect scores of IQ-SPECT with AC and ACSC were significantly lower. The %uptake of all segments for IQ-SPECT with NC was significantly higher than that of C-SPECT. Furthermore, the subtraction of %uptake for C-SPECT and IQ-SPECT was the largest in inferior wall, which was approximately 10.1%, 14.7% and 14.4% for NC, AC and ACSC, respectively. The median % uptake values of the inferior wall with defect areas for C-SPECT and IQ-SPECT were 46.9% and 50.7% with NC, 59.8% and 69.2% with AC, and 54.7% and 66.5% with ACSC, respectively. CONCLUSION 123I IQ-SPECT imaging significantly improved the attenuation artifact compared with C-SPECT imaging. Although the defect detectability of IQ-SPECT was inferior to that of C-SPECT, 123I IQ-SPECT images with NC and ACSC met the criteria for defect detectability. Use of 123I IQ-SPECT is suitable for routine examinations.
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Marcassa C, Zoccarato O. Dual-isotope cardiac SPECT: the Twin Peaks Saga in nuclear cardiology. J Nucl Cardiol 2018; 25:1705-1707. [PMID: 28452005 DOI: 10.1007/s12350-017-0900-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 04/06/2017] [Indexed: 10/19/2022]
Affiliation(s)
- C Marcassa
- Department of Cardiology, ICS Maugeri, Institute for Clinical Care and Research (IRCCS), Scientific Institute of Veruno, Novara, Italy.
| | - O Zoccarato
- Department of Nuclear Medicine, ICS Maugeri, Institute for Clinical Care and Research (IRCCS), Scientific Institute of Veruno, Novara, Italy
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D'estanque E, Hedon C, Lattuca B, Bourdon A, Benkiran M, Verd A, Roubille F, Mariano-Goulart D. Optimization of a simultaneous dual-isotope 201Tl/ 123I-MIBG myocardial SPECT imaging protocol with a CZT camera for trigger zone assessment after myocardial infarction for routine clinical settings: Are delayed acquisition and scatter correction necessary? J Nucl Cardiol 2017; 24:1361-1369. [PMID: 27225516 DOI: 10.1007/s12350-016-0524-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 04/11/2016] [Indexed: 01/08/2023]
Abstract
BACKGROUND Dual-isotope 201Tl/123I-MIBG SPECT can assess trigger zones (dysfunctions in the autonomic nervous system located in areas of viable myocardium) that are substrate for ventricular arrhythmias after STEMI. This study evaluated the necessity of delayed acquisition and scatter correction for dual-isotope 201Tl/123I-MIBG SPECT studies with a CZT camera to identify trigger zones after revascularization in patients with STEMI in routine clinical settings. METHODS Sixty-nine patients were prospectively enrolled after revascularization to undergo 201Tl/123I-MIBG SPECT using a CZT camera (Discovery NM 530c, GE). The first acquisition was a single thallium study (before MIBG administration); the second and the third were early and late dual-isotope studies. We compared the scatter-uncorrected and scatter-corrected (TEW method) thallium studies with the results of magnetic resonance imaging or transthoracic echography (reference standard) to diagnose myocardial necrosis. RESULTS Summed rest scores (SRS) were significantly higher in the delayed MIBG studies than the early MIBG studies. SRS and necrosis surface were significantly higher in the delayed thallium studies with scatter correction than without scatter correction, leading to less trigger zone diagnosis for the scatter-corrected studies. Compared with the scatter-uncorrected studies, the late thallium scatter-corrected studies provided the best diagnostic values for myocardial necrosis assessment. CONCLUSIONS Delayed acquisitions and scatter-corrected dual-isotope 201Tl/123I-MIBG SPECT acquisitions provide an improved evaluation of trigger zones in routine clinical settings after revascularization for STEMI.
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Affiliation(s)
- Emmanuel D'estanque
- Nuclear Medicine Department, Montpellier University Hospital, 371, Avenue du Doyen Gaston Giraud, 34295, Montpellier Cedex 5, France.
| | - Christophe Hedon
- Cardiology Department, Montpellier University Hospital, Montpellier, France
- U1046 INSERM, UMR9214 CNRS, Montpellier University Hospital, Montpellier, France
| | - Benoît Lattuca
- Cardiology Department, Montpellier University Hospital, Montpellier, France
| | - Aurélie Bourdon
- Nuclear Medicine Department, Montpellier University Hospital, 371, Avenue du Doyen Gaston Giraud, 34295, Montpellier Cedex 5, France
| | - Meriem Benkiran
- Nuclear Medicine Department, Montpellier University Hospital, 371, Avenue du Doyen Gaston Giraud, 34295, Montpellier Cedex 5, France
| | - Aurélie Verd
- Nuclear Medicine Department, Montpellier University Hospital, 371, Avenue du Doyen Gaston Giraud, 34295, Montpellier Cedex 5, France
| | - François Roubille
- Cardiology Department, Montpellier University Hospital, Montpellier, France
- U1046 INSERM, UMR9214 CNRS, Montpellier University Hospital, Montpellier, France
| | - Denis Mariano-Goulart
- Nuclear Medicine Department, Montpellier University Hospital, 371, Avenue du Doyen Gaston Giraud, 34295, Montpellier Cedex 5, France
- U1046 INSERM, UMR9214 CNRS, Montpellier University Hospital, Montpellier, France
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Assante R, Acampa W. Dual isotope and multidetector camera: The best choices for a specific end-point. J Nucl Cardiol 2017; 24:1370-1373. [PMID: 27197817 DOI: 10.1007/s12350-016-0520-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 04/12/2016] [Indexed: 01/08/2023]
Affiliation(s)
- Roberta Assante
- Department of Advanced Biomedical Sciences, University Federico II, Via Pansini 5, 80131, Naples, Italy
| | - Wanda Acampa
- Department of Advanced Biomedical Sciences, University Federico II, Via Pansini 5, 80131, Naples, Italy.
- Institute of Biostructure and Bioimaging, National Council of Research, Naples, Italy.
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Simultaneous Tc-99m and I-123 dual-radionuclide imaging with a solid-state detector-based brain-SPECT system and energy-based scatter correction. EJNMMI Phys 2016; 3:10. [PMID: 27357946 PMCID: PMC4927533 DOI: 10.1186/s40658-016-0147-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 06/09/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A brain single-photon emission computed tomography (SPECT) system using cadmium telluride (CdTe) solid-state detectors was previously developed. This CdTe-SPECT system is suitable for simultaneous dual-radionuclide imaging due to its fine energy resolution (6.6 %). However, the problems of down-scatter and low-energy tail due to the spectral characteristics of a pixelated solid-state detector should be addressed. The objective of this work was to develop a system for simultaneous Tc-99m and I-123 brain studies and evaluate its accuracy. METHODS A scatter correction method using five energy windows (FiveEWs) was developed. The windows are Tc-lower, Tc-main, shared sub-window of Tc-upper and I-lower, I-main, and I-upper. This FiveEW method uses pre-measured responses for primary gamma rays from each radionuclide to compensate for the overestimation of scatter by the triple-energy window method that is used. Two phantom experiments and a healthy volunteer experiment were conducted using the CdTe-SPECT system. A cylindrical phantom and a six-compartment phantom with five different mixtures of Tc-99m and I-123 and a cold one were scanned. The quantitative accuracy was evaluated using 18 regions of interest for each phantom. In the volunteer study, five healthy volunteers were injected with Tc-99m human serum albumin diethylene triamine pentaacetic acid (HSA-D) and scanned (single acquisition). They were then injected with I-123 N-isopropyl-4-iodoamphetamine hydrochloride (IMP) and scanned again (dual acquisition). The counts of the Tc-99m images for the single and dual acquisitions were compared. RESULTS In the cylindrical phantom experiments, the percentage difference (PD) between the single and dual acquisitions was 5.7 ± 4.0 % (mean ± standard deviation). In the six-compartment phantom experiment, the PDs between measured and injected activity for Tc-99m and I-123 were 14.4 ± 11.0 and 2.3 ± 1.8 %, respectively. In the volunteer study, the PD between the single and dual acquisitions was 4.5 ± 3.4 %. CONCLUSIONS This CdTe-SPECT system using the FiveEW method can provide accurate simultaneous dual-radionuclide imaging. A solid-state detector SPECT system using the FiveEW method will permit quantitative simultaneous Tc-99m and I-123 study to become clinically applicable.
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Tanaka H, Takahashi T, Kozono N, Tanakamaru Y, Ohashi N, Yasunobu Y, Tanaka K, Okada T, Kaseda S, Nakanishi T, Kihara Y. Prediction of Flow-Limiting Fractional Flow Reserve in Patients With Stable Coronary Artery Disease Based on Quantitative Myocardial Perfusion Imaging. Am J Cardiol 2016; 117:1417-26. [PMID: 26970815 DOI: 10.1016/j.amjcard.2016.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 02/08/2016] [Accepted: 02/08/2016] [Indexed: 11/29/2022]
Abstract
Although fractional flow reserve (FFR) and myocardial perfusion imaging (MPI) findings fundamentally differ, several cohort studies have revealed that these findings correlate. Here, we investigated whether flow-limiting FFR could be predicted from adenosine stress thallium-201 MPI with single-photon emission computed tomography (SPECT) findings derived from 84 consecutive, prospectively identified patients with stable coronary artery disease and 212 diseased vessels. Among them, FFR was measured in 136 diseased vessels (64%). The findings were compared with regional perfusion abnormalities including stress total perfusion defect (TPD) - rest TPD determined using quantitative perfusion single-photon emission computed tomography software. The FFR inversely correlated the most accurately with stress TPD - rest TPD (r = -0.552, p <0.001). Predictors of major vessels of interest comprising FFR <0.80, included stress TPD - rest TPD, the transient ischemic dilation ratio, left ventricular ejection fraction at rest and beta blockers for left anterior descending artery (LAD) regions, and stress TPD - rest TPD, left ventricular mass, left ventricular ejection fraction at rest, right coronary artery lesions, the transient ischemic dilation ratio, and age for non-LAD regions. The diagnostic accuracy of formulas to predict major vessels of interest with FFR <0.80 was high (sensitivity, specificity and accuracy for LAD and non-LAD: 84%, 87% and 86%, and 75%, 93% and 87%, respectively). In conclusion, although somewhat limited by a sample size and a single-center design, flow-limiting FFR could be predicted from MPI findings with a defined probability. A cohort study might validate our results and provide a novel adjunctive tool with which to diagnose functionally significant coronary artery disease from MPI findings.
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Affiliation(s)
- Haruki Tanaka
- Department of Cardiology, Miyoshi Central Hospital, Miyoshi City, Hiroshima, Japan.
| | - Teruyuki Takahashi
- Department of Radiology, Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital, Hiroshima, Japan
| | - Nami Kozono
- Department of Medical Information Management, Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital, Hiroshima, Japan
| | - Yoshiki Tanakamaru
- Department of Radiology, Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital, Hiroshima, Japan
| | - Norihiko Ohashi
- Department of Cardiology, Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital, Hiroshima, Japan
| | - Yuji Yasunobu
- Department of Cardiology, Miyoshi Medical Association Hospital, Miyoshi City, Hiroshima, Japan
| | - Koichi Tanaka
- Department of Cardiology, Miyoshi Central Hospital, Miyoshi City, Hiroshima, Japan
| | - Takenori Okada
- Department of Cardiology, Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital, Hiroshima, Japan
| | - Shunichi Kaseda
- Department of Cardiology, Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital, Hiroshima, Japan
| | - Toshio Nakanishi
- Department of Cardiology, Miyoshi Central Hospital, Miyoshi City, Hiroshima, Japan
| | - Yasuki Kihara
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
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Matsuo S, Nakajima K, Onoguchi M, Wakabayash H, Okuda K, Kinuya S. Nuclear myocardial perfusion imaging using thallium-201 with a novel multifocal collimator SPECT/CT: IQ-SPECT versus conventional protocols in normal subjects. Ann Nucl Med 2015; 29:452-9. [PMID: 25821018 DOI: 10.1007/s12149-015-0965-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 03/19/2015] [Indexed: 11/26/2022]
Abstract
OBJECTIVE A novel multifocal collimator, IQ-SPECT (Siemens) consists of SMARTZOOM, cardio-centric and 3D iterative SPECT reconstruction and makes it possible to perform MPI scans in a short time. The aims are to delineate the normal uptake in thallium-201 ((201)Tl) SPECT in each acquisition method and to compare the distribution between new and conventional protocol, especially in patients with normal imaging. METHODS Forty patients (eight women, mean age of 75 years) who underwent myocardial perfusion imaging were included in the study. All patients underwent one-day protocol perfusion scan after an adenosine-stress test and at rest after administering (201)Tl and showed normal results. Acquisition was performed on a Symbia T6 equipped with a conventional dual-headed gamma camera system (Siemens ECAM) and with a multifocal SMARTZOOM collimator. Imaging was performed with a conventional system followed by IQ-SPECT/computed tomography (CT). Reconstruction was performed with or without X-ray CT-derived attenuation correction (AC). Two nuclear physicians blinded to clinical information interpreted all myocardial perfusion images. A semi-quantitative myocardial perfusion was analyzed by a 17-segment model with a 5-point visual scoring. The uptake of each segment was measured and left ventricular functions were analyzed by QPS software. RESULTS IQ-SPECT provided good or excellent image quality. The quality of IQ-SPECT images without AC was similar to those of conventional LEHR study. Mid-inferior defect score (0.3 ± 0.5) in the conventional LEHR study was increased significantly in IQ-SPECT with AC (0 ± 0). IQ-SPECT with AC improved the mid-inferior decreased perfusion shown in conventional images. The apical tracer count in IQ-SPECT with AC was decreased compared to that in LEHR (0.1 ± 0.3 vs. 0.5 ± 0.7, p < 0.05). The left ventricular ejection fraction from IQ-SPECT was significantly higher than that from the LEHR collimator (p = 0.0009). CONCLUSION The images of IQ-SPECT acquired in a short time are equivalent to that of conventional LEHR. The results indicated that the IQ-SPECT system with AC is capable of correcting inferior artifacts with high image quality.
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Affiliation(s)
- Shinro Matsuo
- Department of Nuclear Medicine, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, 920-8641, Japan,
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Takahashi T, Tanaka H, Kozono N, Tanakamaru Y, Idei N, Ohashi N, Ohtsubo H, Okada T, Yasunobu Y, Kaseda S. Characteristics of images of angiographically proven normal coronary arteries acquired by adenosine-stress thallium-201 myocardial perfusion SPECT/CT-IQ[Symbol: see text]SPECT with CT attenuation correction changed stepwise. Ann Nucl Med 2014; 29:256-67. [PMID: 25472779 DOI: 10.1007/s12149-014-0935-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 11/20/2014] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Although several studies have shown the diagnostic and prognostic value of CT-based attenuation correction (AC) of single photon emission computed tomography (SPECT) images for diagnosing coronary artery disease (CAD), this issue remains a matter of debate. To clarify the characteristics of CT-AC SPECT images that might potentially improve diagnostic performance, we analyzed images acquired using adenosine-stress thallium-201 myocardial perfusion SPECT/CT equipped with IQ[Symbol: see text]SPECT (SPECT/CT-IQ[Symbol: see text]SPECT) from patients with angiographically proven normal coronary arteries after changing the CT attenuation correction (CT-AC) in a stepwise manner. METHODS We enrolled 72 patients (Male 36, Female 36) with normal coronary arteries according to findings of invasive coronary angiography or CT-angiography within three months after a SPECT/CT study. Projection images were reconstructed at CT-AC values of (-), 40, 60, 80 and 100 % using a CT number conversion program according to our definition and analyzed using polar maps according to sex. RESULTS CT attenuation corrected segments were located from the mid- and apical-inferior spread through the mid- and apical-septal regions and finally to the basal-anterior and basal- and mid-lateral regions in males, and from the mid-inferior region through the mid-septal and mid-anterior, and mid-lateral regions in females as the CT-AC values increased. Segments with maximal mean counts shifted from the apical-anterior to mid-anterolateral region under both stress and rest conditions in males, whereas such segments shifted from the apical-septal to the mid-anteroseptal region under both stress and rest conditions in females. CONCLUSIONS We clarified which part of the myocardium and to which degree CT-AC affects it in adenosine-stress thallium-201 myocardial perfusion SPECT/CT-IQ[Symbol: see text]SPECT images by changing the CT-AC value stepwise. We also identified sex-specific shifts of segments with maximal mean counts that changed as CT-AC values increased.
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Affiliation(s)
- Teruyuki Takahashi
- Department of Radiology, Hiroshima Red Cross Hospital and Atomic-bomb Survivors Hospital, Hiroshima, Japan
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