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Boschi A, Uccelli L, Marvelli L, Cittanti C, Giganti M, Martini P. Technetium-99m Radiopharmaceuticals for Ideal Myocardial Perfusion Imaging: Lost and Found Opportunities. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27041188. [PMID: 35208982 PMCID: PMC8877792 DOI: 10.3390/molecules27041188] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/06/2022] [Accepted: 02/08/2022] [Indexed: 02/07/2023]
Abstract
The favorable nuclear properties in combination with the rich coordination chemistry make technetium-99m the radioisotope of choice for the development of myocardial perfusion tracers. In the early 1980s, [99mTc]Tc-Sestamibi, [99mTc]Tc-Tetrofosmin, and [99mTc]Tc-Teboroxime were approved as commercial radiopharmaceuticals for myocardial perfusion imaging in nuclear cardiology. Despite its peculiar properties, the clinical use of [99mTc]Tc-Teboroxime was quickly abandoned due to its rapid myocardial washout. Despite their widespread clinical applications, both [99mTc]Tc-Sestamibi and [99mTc]Tc-Tetrofosmin do not meet the requirements of an ideal perfusion imaging agent due to their relatively low first-pass extraction fraction and high liver absorption. An ideal radiotracer for myocardial perfusion imaging should have a high myocardial uptake; a high and stable target-to-background ratio with low uptake in the lungs, liver, stomach during the image acquisition period; a high first-pass myocardial extraction fraction and very rapid blood clearance; and a linear relationship between radiotracer myocardial uptake and coronary blood flow. Although it is difficult to reconcile all these properties in a single tracer, scientific research in the field has always channeled its efforts in the development of molecules that are able to meet the characteristics of ideality as much as possible. This short review summarizes the developments in 99mTc myocardial perfusion tracers, which are able to fulfill hitherto unmet medical needs and serve a large population of patients with heart disease, and underlines their strengths and weaknesses, the lost and found opportunities thanks to the developments of the new ultrafast SPECT technologies.
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Affiliation(s)
- Alessandra Boschi
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via L. Borsari, 46-44121 Ferrara, Italy;
- Correspondence: ; Tel.:+39-0532-455354
| | - Licia Uccelli
- Department of Translational Medicine, University of Ferrara, Via Fossato di Mortara, 70 c/o Viale Eliporto, 46-44121 Ferrara, Italy; (L.U.); (C.C.); (M.G.)
| | - Lorenza Marvelli
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via L. Borsari, 46-44121 Ferrara, Italy;
| | - Corrado Cittanti
- Department of Translational Medicine, University of Ferrara, Via Fossato di Mortara, 70 c/o Viale Eliporto, 46-44121 Ferrara, Italy; (L.U.); (C.C.); (M.G.)
| | - Melchiore Giganti
- Department of Translational Medicine, University of Ferrara, Via Fossato di Mortara, 70 c/o Viale Eliporto, 46-44121 Ferrara, Italy; (L.U.); (C.C.); (M.G.)
| | - Petra Martini
- Department of Environmental and Prevention Sciences, University of Ferrara, Via L. Borsari, 46-44121 Ferrara, Italy;
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Abstract
The knowledge on element 43 (Tc) of the periodic table, built over the years through the contributions given by the close relationship between chemistry and nuclear medicine, allowed the development of new and increasingly effective radiopharmaceuticals useful both as perfusion and target specific imaging agents for SPECT (single photon emission tomography). Among the manifold Tc-compounds, Tc(V) nitrido complexes played a relevant role in the search for new technetium-99m radiopharmaceuticals, providing efficient labeling procedures that can be conveniently exploited for the design and synthesis of agents, also incorporating small organic molecules or peptides having defined structural features. With this work, we present an overview of four decades of research on the chemistry and on the nuclear medicine applications of Tc(V) nitrido complexes.
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Detection of anthracycline-induced cardiotoxicity using perfusion-corrected 99mTc sestamibi SPECT. Sci Rep 2019; 9:216. [PMID: 30659226 PMCID: PMC6338786 DOI: 10.1038/s41598-018-36721-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 11/23/2018] [Indexed: 01/02/2023] Open
Abstract
By the time cardiotoxicity-associated cardiac dysfunction is detectable by echocardiography it is often beyond meaningful intervention. 99mTc-sestamibi is used clinically to image cardiac perfusion by single photon emission computed tomography (SPECT) imaging, but as a lipophilic cation its distribution is also governed by mitochondrial membrane potential (ΔΨm). Correcting scans for variations in perfusion (using a ΔΨm-independent perfusion tracer such as (bis(N-ethoxy-N-ethyldithiocarbamato)nitrido 99mTc(V)) (99mTc-NOET) could allow 99mTc-sestamibi to be repurposed to specifically report on ΔΨm as a readout of evolving cardiotoxicity. Isolated rat hearts were perfused within a γ-detection apparatus to characterize the pharmacokinetics of 99mTc-sestamibi and 99mTc-NOET in response to mitochondrial perturbation by hypoxia, ionophore (CCCP) or doxorubicin. All interventions induced 99mTc-sestamibi washout; hypoxia from 24.9 ± 2.6% ID to 0.4 ± 6.2%, CCCP from 22.8 ± 2.5% ID to −3.5 ± 3.1%, and doxorubicin from 23.0 ± 2.2% ID to 17.8 ± 0.7, p < 0.05. Cardiac 99mTc-NOET retention (34.0 ± 8.0% ID) was unaffected in all cases. Translating to an in vivo rat model, 2 weeks after bolus doxorubicin injection, there was a dose-dependent loss of cardiac 99mTc-sestamibi retention (from 2.3 ± 0.3 to 0.9 ± 0.2 ID/g with 10 mg/kg (p < 0.05)), while 99mTc-NOET retention (0.93 ± 0.16 ID/g) was unaffected. 99mTc-NOET therefore traps in myocardium independently of the mitochondrial perturbations that induce 99mTc-sestamibi washout, demonstrating proof-of-concept for an imaging approach to detect evolving cardiotoxicity.
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Iqbal B, Currie G, Greene L, Kiat H. Novel Radiopharmaceuticals in Cardiovascular Medicine: Present and Future. J Med Imaging Radiat Sci 2014; 45:423-434. [DOI: 10.1016/j.jmir.2014.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 09/03/2014] [Accepted: 09/05/2014] [Indexed: 01/25/2023]
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Tisato F, Bolzati C, Refosco F, Porchia M, Seraglia R, Carta D, Pasqualini R. Insights into the failure of the potential, neutral myocardial imaging agent TcN-NOET: physicochemical identification of by-products and degradation species. Nucl Med Biol 2012; 39:335-46. [DOI: 10.1016/j.nucmedbio.2011.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 09/14/2011] [Accepted: 09/17/2011] [Indexed: 10/14/2022]
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Broisat A, Ruiz M, Goodman NC, Hanrahan SM, Reutter BW, Brennan KM, Janabi M, Schaefer S, Watson DD, Beller GA, VanBrocklin HF, Glover DK. Myocardial uptake of 7'-(Z)-[(123)I]iodorotenone during vasodilator stress in dogs with critical coronary stenoses. Circ Cardiovasc Imaging 2011; 4:685-92. [PMID: 21917783 DOI: 10.1161/circimaging.110.961763] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND There is a well-recognized need for a new generation of single photon emission computed tomography (SPECT) perfusion tracers with improved myocardial extraction over a wide flow range. Radiotracers that target complex I of the mitochondrial electron transport chain have been proposed as a new class of myocardial perfusion imaging agents. 7-(Z)-[(125)I]iodorotenone ((125)I-ZIROT) has demonstrated superior myocardial extraction and retention characteristics in rats and in isolated perfused rabbit hearts. We sought to fully characterize the biodistribution and myocardial extraction versus flow relationship of (123)I-ZIROT in an intact large-animal model. METHODS AND RESULTS The (123)I-ZIROT was administered during adenosine A(2A) agonist-induced hyperemia in 5 anesthetized dogs with critical left anterior descending (LAD) stenoses. When left circumflex (LCx) flow was maximal, (123)I-ZIROT and microspheres were coinjected and the dogs were euthanized 5 minutes later. (123)I-ZIROT biodistribution was evaluated in 2 additional dogs by in vivo planar imaging. At (123)I-ZIROT injection, transmural LAD flow was unchanged from baseline (mean±SEM, 0.90±0.22 versus 0.87±0.11 mL/[min · g]; P=0.92), whereas LCx zone flow increased significantly (mean±SEM, 3.25±0.51 versus 1.00±0.17 mL/[min · g]; P<0.05). Myocardial (123)I-ZIROT extraction tracked regional myocardial flow better than either thallium-201 or (99m)Tc-sestamibi from previous studies using a similar model. Furthermore, the (123)I-ZIROT LAD/LCx activity ratios by ex vivo imaging or well counting (mean±SEM, 0.42±0.08 and 0.45±0.1, respectively) only slightly underestimated the LAD/LCx microsphere flow ratio (0.32±0.09). CONCLUSIONS The ability of (123)I-ZIROT to more linearly track blood flow over a wide range makes it a promising new SPECT myocardial perfusion imaging agent with potential for improved coronary artery disease detection and better quantitative estimation of the severity of flow impairment.
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Affiliation(s)
- Alexis Broisat
- Experimental Cardiology Laboratory, Cardiovascular Division, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA
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Gullberg GT, Reutter BW, Sitek A, Maltz JS, Budinger TF. Dynamic single photon emission computed tomography--basic principles and cardiac applications. Phys Med Biol 2010; 55:R111-91. [PMID: 20858925 PMCID: PMC3306016 DOI: 10.1088/0031-9155/55/20/r01] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The very nature of nuclear medicine, the visual representation of injected radiopharmaceuticals, implies imaging of dynamic processes such as the uptake and wash-out of radiotracers from body organs. For years, nuclear medicine has been touted as the modality of choice for evaluating function in health and disease. This evaluation is greatly enhanced using single photon emission computed tomography (SPECT), which permits three-dimensional (3D) visualization of tracer distributions in the body. However, to fully realize the potential of the technique requires the imaging of in vivo dynamic processes of flow and metabolism. Tissue motion and deformation must also be addressed. Absolute quantification of these dynamic processes in the body has the potential to improve diagnosis. This paper presents a review of advancements toward the realization of the potential of dynamic SPECT imaging and a brief history of the development of the instrumentation. A major portion of the paper is devoted to the review of special data processing methods that have been developed for extracting kinetics from dynamic cardiac SPECT data acquired using rotating detector heads that move as radiopharmaceuticals exchange between biological compartments. Recent developments in multi-resolution spatiotemporal methods enable one to estimate kinetic parameters of compartment models of dynamic processes using data acquired from a single camera head with slow gantry rotation. The estimation of kinetic parameters directly from projection measurements improves bias and variance over the conventional method of first reconstructing 3D dynamic images, generating time-activity curves from selected regions of interest and then estimating the kinetic parameters from the generated time-activity curves. Although the potential applications of SPECT for imaging dynamic processes have not been fully realized in the clinic, it is hoped that this review illuminates the potential of SPECT for dynamic imaging, especially in light of new developments that enable measurement of dynamic processes directly from projection measurements.
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Affiliation(s)
- Grant T Gullberg
- E O Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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Riou LM, Broisat A, Lartizien C, Toufektsian MC, Maitrejean S, Janier M, Vanzetto G, Fagret D, Ghezzi C. Assessment of non-reperfused and reperfused myocardial infarction using diffusible or deposited radiolabelled perfusion imaging agents. Eur J Nucl Med Mol Imaging 2006; 34:330-7. [PMID: 17004095 DOI: 10.1007/s00259-006-0230-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Accepted: 07/17/2006] [Indexed: 12/22/2022]
Abstract
PURPOSE Incomplete microvascular reperfusion is often observed in patients undergoing thrombolytic therapy or angioplasty for acute myocardial infarction and has important prognostic implications. We compared the myocardial uptake of diffusible ((201)Tl) and deposited ((99m)TcN-NOET) perfusion imaging agents in the setting of experimental infarction. METHODS Rats were subjected to permanent coronary occlusion (OCC, n=10) or to 45-min occlusion and reperfusion (REP, n=17). Seven days later, the tracers were co-injected and the animals were euthanised 15 min (all ten rats in the OCC group and 12 rats in the REP group) or 120 min (five rats from the REP group, euthanised at this time point to evaluate any redistribution of the tracers: REP-RED group) afterwards. Infarct size determination and (99m)TcN-NOET/(201)Tl ex vivo imaging were performed. Regional flow and tissue oedema were quantified using radioactive microspheres and (99m)Tc-DTPA, respectively. RESULTS (99m)TcN-NOET and (201)Tl defect magnitudes were similar in OCC animals (0.11+/-0.01 vs 0.13+/-0.01). In REP animals, (201)Tl defect magnitude (0.25+/-0.02) was significantly lower than the magnitude of (99m)TcN-NOET and flow defects (0.14+/-0.03 and 0.17+/-0.01, respectively; p<0.05), despite the lack of (201)Tl redistribution (REP-RED animals). (99m)Tc-DTPA indicated the presence of oedema in the reperfused area. Blood distribution studies showed that, unlike (99m)TcN-NOET, (201)Tl plasma activity was mostly unbound to plasma proteins. CONCLUSION (99m)TcN-NOET and (201)Tl delineated the non-viable area in chronic non-reperfused and reperfused myocardial infarction. The significantly decreased (201)Tl defect in reperfused infarction was likely due to partial diffusion of the tracer from the plasma into the oedema present in the infarcted area. Deposited perfusion tracers might be better suited than diffusible agents for the assessment of regional flow following reperfusion of myocardial infarction.
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Affiliation(s)
- L M Riou
- INSERM, U340 Radiopharmaceutiques Biocliniques; Université de Grenoble, La Tronche, France.
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Jeetley P, Sabharwal NK, Soman P, Kinsey C, Raval U, Bhonsle U, Lahiri A. Comparison between Tc-99m N-NOET and Tl-201 in the assessment of patients with known or suspected coronary artery disease. J Nucl Cardiol 2004; 11:664-72. [PMID: 15592189 DOI: 10.1016/j.nuclcard.2004.05.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND Technetium 99m N-ethoxy-N-ethyl dithiocarbamate (N-NOET) is a new radionuclide tracer for cardiac single photon emission computed tomography (SPECT) imaging. It combines the advantageous properties of a Tc-99m agent with the redistribution characteristics of thallium 201. We directly compared the two agents in patients with known or suspected coronary artery disease. METHODS AND RESULTS Fifty patients underwent treadmill exercise Tc-99m N-NOET and Tl-201 SPECT studies. Images were acquired at stress, redistribution, and reinjection. Segmental analysis was carried out, and direct comparisons were made with corresponding segments. A stress score index was calculated and compared with the degree of lung uptake for each patient. From the 50 patients, 2657 of 2664 exercise, redistribution, and reinjection segments (99%) were interpreted. There was excellent agreement between the two modalities (weighted kappa = 0.83). Of the patients, 24 demonstrated reversible ischemia by Tl-201 SPECT reinjection imaging, of which Tc-99m N-NOET stress-redistribution imaging correctly identified 14 (58%); this improved significantly to 20 patients (83%) ( P = .03) when a reinjection protocol was used. A higher stress score index was seen in those patients with significant lung uptake (lung-heart ratio > or =0.6) after Tc-99m N-NOET stress imaging (1.6 vs 1.3, P = .03). CONCLUSION SPECT imaging with Tc-99m N-NOET is comparable to Tl-201 for the diagnosis of coronary artery disease. Significant lung uptake with stress Tc-99m N-NOET may also indicate the severity of disease.
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Affiliation(s)
- Paramjit Jeetley
- Department of Cardiovascular Medicine, Northwick Park Hospital, Watford Road, Harrow, Middlesex HA2 0HX, UK
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Vanzetto G, Fagret D, Ghezzi C. Tc-99m N-NOET: Chronicle of a unique perfusion imaging agent and a missed opportunity? J Nucl Cardiol 2004; 11:647-50. [PMID: 15592185 DOI: 10.1016/j.nuclcard.2004.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Affiliation(s)
- George A Beller
- Department of Medicine, University of Virginia Health System, Charlottesville, USA
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Beller GA. George Allan Beller, MD: a conversation with the editor. Interview by William Clifford Roberts. Am J Cardiol 2003; 91:203-23. [PMID: 12521636 DOI: 10.1016/s0002-9149(02)03225-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Kailasnath P, Sinusas AJ. Comparison of Tl-201 with Tc-99m-labeled myocardial perfusion agents: technical, physiologic, and clinical issues. J Nucl Cardiol 2001; 8:482-98. [PMID: 11481571 DOI: 10.1067/mnc.2001.115078] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- P Kailasnath
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Conn, USA
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Kailasnath P, Sinusas AJ. Technetium-99m-labeled myocardial perfusion agents: Are they better than thallium-201? Cardiol Rev 2001; 9:160-72. [PMID: 11304401 DOI: 10.1097/00045415-200105000-00009] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/08/2001] [Indexed: 11/25/2022]
Abstract
Currently, thallium-201 (201Tl)- and technetium-99m (99mTc)-labeled tracers are used interchangeably for the detection of coronary artery disease, the assessment of myocardial viability, and risk stratification. This article reviews some of the potential advantages and disadvantages of the 99mTc-labeled tracers relative to 201Tl. The basic myocardial kinetic properties and biodistribution of the commonly used 99mTc-labeled perfusion tracers are compared with those of 201Tl. The clinical value of the 99mTc-labeled perfusion tracers is then compared with that of 201Tl imaging. With regard to imaging physics and radiation safety, the 99mTc-labeled tracers are superior to 201Tl. Cost and tracer availability also may favor 99mTc-labeled perfusion tracers rather than 201Tl imaging. However, the most widely used 99mTc-labeled perfusion tracers currently approved for clinical use-99mTc-sestamibi and 99mTc-tetrofosmin-do not track myocardial flow as well as 201Tl does. This shortcoming of 99mTc-labeled perfusion tracers may reduce the sensitivity of these agents in detecting subcritical coronary artery disease. The most notable new perfusion agent is 99mTc-labeled bis(N-ethoxy, N-ethyl dithiocarbamato) nitrido technetium(v), which is considered to be the 99mTc-labeled equivalent of 201Tl. However, 99mTc-labeled bis(N-ethoxy, N-ethyl dithiocarbamato) nitrido technetium(v) is a neutral compound with kinetic properties that are very different from those of 201Tl. Myocardial perfusion imaging is often conducted in conjunction with exercise or with different pharmacologic stressors, both of which augment regional flow heterogeneity. Each of these stressors has unique effects on the coronary vasculature and influences the behavior of the radiolabeled perfusion agents. The substantial differences in myocardial uptake, clearance kinetics, and biodistribution between each of the 99mTc-labeled perfusion tracers and 201Tl should be considered in the clinical application of perfusion imaging. The myocardial retention of all of the agents is affected by myocardial viability. However, 201Tl demonstrates greater differential clearance from normal and ischemic regions (redistribution), making 201Tl a better agent for assessment of viability, particularly in patients with extremely low flow. In contrast, agents that do not redistribute, such as 99mTc-tetrofosmin, might be better for acute assessment of "risk areas" or of chest pain. Each of the available perfusion tracers has unique advantages and disadvantages that must be considered to ensure its optimal application.
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Affiliation(s)
- P Kailasnath
- Department of Diagnostic Radiology, Yale University School of Medicine, P.O. Box 208042, TE-2, New Haven, CT 06520-8042, USA
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Sinusas AJ. Technetium 99m-N-NOET: although not equivalent to thallium-201, it still offers new opportunities. J Nucl Cardiol 2000; 7:185-8. [PMID: 10796010 DOI: 10.1016/s1071-3581(00)90043-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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