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Fang W, Liu S. New 99mTc Radiotracers for Myocardial Perfusion Imaging by SPECT. Curr Radiopharm 2019; 12:171-186. [PMID: 30727939 DOI: 10.2174/1874471012666190206102214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 01/04/2019] [Accepted: 01/08/2019] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Myocardial Perfusion Imaging (MPI) with radiotracers is an integral component in evaluation of the patients with known or suspected coronary artery diseases (CAD). 99mTc-Sestamibi and 99mTc-Tetrofosmin are commercial radiopharmaceuticals for MPI by single photon-emission computed tomography (SPECT). Despite their widespread clinical applications, they do not meet the requirements of an ideal perfusion imaging agent due to their inability to linearly track the regional myocardial blood flow rate at >2.5 mL/min/g. With tremendous development of CZT-based SPECT cameras over the past several years, the nuclear cardiology community has been calling for better perfusion radiotracers with improved extraction and biodistribution properties. METHODS This review will summarize recent research efforts on new cationic and neutral 99mTc radiotracers for SPECT MPI. The goal of these efforts is to develop a 99mTc radiotracer that can be used to detect perfusion defects at rest or under stress, determine the regional myocardial blood flow, and measure the perfusion and left ventricular function. RESULTS The advantage of cationic radiotracers (e.g. 99mTc-Sestamibi) is their long myocardial retention because of the positive molecular charge and fast liver clearance kinetics. 99mTc-Teboroxime derivatives have a high initial heart uptake (high first-pass extraction fraction) due to their neutrality. 99mTc- 3SPboroxime is the most promising radiotracer for future clinical translation considering its initial heart uptake, myocardial retention time, liver clearance kinetics, heart/liver ratios and SPECT image quality. CONCLUSION 99mTc-3SPboroximine is an excellent example of perfusion radiotracers, the heart uptake of which is largely relies on the regional blood flow. It is possible to use 99mTc-3SPboroximine for detection of perfusion defect(s), accurate quantification and determination of regional blood flow rate. Development of such a 99mTc radiotracer is of great clinical benefit for accurate diagnosis of CAD and assessing the risk of future hard events (e.g. heart attack and sudden death) in cardiac patients.
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Affiliation(s)
- Wei Fang
- Department of Nuclear Medicine, Fuwai Hospital, the National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, No.167 North Lishi Road, Xicheng District, Beijing, China
| | - Shuang Liu
- School of Health Sciences, Purdue University, Beijing, IN 47907, United States
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Zhao ZQ, Liu M, Fang W, Liu S. Sulfonyl-Containing Boronate Caps for Optimization of Biological Properties of 99mTc(III) Radiotracers [99mTcCl(CDO)(CDOH)2B-R] (CDOH2 = Cyclohexanedione Dioxime). J Med Chem 2017; 61:319-328. [PMID: 29186661 DOI: 10.1021/acs.jmedchem.7b01412] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Zuo-Quan Zhao
- Department of
Nuclear Medicine, Fuwai Hospital, National Center for Cardiovascular
Diseases, Chinese Academy of Medical Sciences, and Peking Union Medical
College, No.167 North Lishi Road, Xicheng District, Beijing 100037, China
| | - Min Liu
- School
of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Wei Fang
- Department of
Nuclear Medicine, Fuwai Hospital, National Center for Cardiovascular
Diseases, Chinese Academy of Medical Sciences, and Peking Union Medical
College, No.167 North Lishi Road, Xicheng District, Beijing 100037, China
| | - Shuang Liu
- School
of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
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Liu M, Liu S. 99mTc-3Cboroxime: a novel 99mTc(iii) complex [99mTcCl(CDO)(CDOH)2B-3C] (CDOH2 = cyclohexanedione dioxime; 3C-B(OH)2 = 3-(carbamoylphenyl)boronic acid) with high heart uptake and long myocardial retention. Dalton Trans 2017; 46:14509-14518. [DOI: 10.1039/c7dt01292f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, we found that 99mTc-3Cboroxime has the myocardial retention longer than that of 99mTc-Teboroxime, and its heart washout kinetics follows a regressive linear relationship over the 60 min period.
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Affiliation(s)
- Min Liu
- Department of Radiation Medicine and Protection
- Medical College
- Soochow University
- China
- School of Health Sciences
| | - Shuang Liu
- School of Health Sciences
- Purdue University
- USA
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Liu M, Zheng Y, Avcibasi U, Liu S. Novel 99mTc(III)-azide complexes [ 99mTc(N 3)(CDO)(CDOH) 2B-R] (CDOH 2=cyclohexanedione dioxime) as potential radiotracers for heart imaging. Nucl Med Biol 2016; 43:732-741. [PMID: 27632344 DOI: 10.1016/j.nucmedbio.2016.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 05/02/2016] [Indexed: 10/21/2022]
Abstract
INTRODUCTION In this study, novel 99mTc(III)-azide complexes [99mTc(N3)(CDO)(CDOH)2B-R] (99mTc-ISboroxime-N3: R=IS; 99mTc-MPboroxime-N3: R=MP; 99mTc-PAboroxime-N3: R=PA; 99mTc-PYboroxime-N3: R=PY; and 99mTc-Uboroxime-N3: R=5U) were evaluated as heart imaging agents. METHODS Complexes [99mTc(N3)(CDO)(CDOH)2B-R] (R=IS, MP, PA, PY and 5U) were prepared by ligand exchange between NaN3 and [99mTcCl(CDO)(CDOH)2B-R]. Biodistribution and imaging studies were carried out in Sprague-Dawley rats. Image quantification was performed to compare their initial heart uptake and myocardial retention. RESULTS 99mTc-ISboroxime-N3, 99mTc-PYboroxime-N3 and 99mTc-Uboroxime-N3 were prepared with high RCP (93-98%) while the RCP of 99mTc-MPboroxime-N3 and 99mTc-PAboroxime-N3 was 80-85%. The myocardial retention curves of 99mTc-ISboroxime-N3, 99mTc-PYboroxime-N3 and 99mTc-Uboroxime-N3 were best fitted to the bi-exponential decay function. The half-time of the fast component was 1.6±0.4min for 99mTc-ISboroxime-N3, 0.7±0.1min for 99mTc-PYboroxime-N3 and 0.9±0.4min for 99mTc-Uboroxime-N3. The 2-min heart uptake from biodistribution studies followed the ranking order of 99mTc-ISboroxime-N3 (3.60±0.68%ID/g)>99mTc-PYboroxime-N3 (2.35±0.37%ID/g)≫99mTc-Uboroxime-N3 (1.29±0.06%ID/g). 99mTc-ISboroxime-N3 had the highest 2-min heart uptake among 99mTc radiotracers revaluated in SD rats. High quality SPECT images were obtained with the right and left ventricular walls being clearly delineated. The best image acquisition window was 0-5min for 99mTc-ISboroxime-N3. CONCLUSION Both azide coligand and boronate caps had significant impact on the heart uptake and myocardial retention of complexes [99mTc(N3)(CDO)(CDOH)2B-R]. Among the radiotracers evaluated in SD rats, 99mTc-ISboroxime-N3 has the highest initial heart uptake with the heart retention comparable to that of 99mTc-Teboroxime. 99mTc-ISboroxime-N3 is a promising alternative to 99mTc-Teboroxime for SPECT MPI.
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Affiliation(s)
- Min Liu
- Department of Radiation Medicine and Protection, Medical College, Soochow University, China; School of Health Sciences, Purdue University, IN, 47907, USA
| | - Yumin Zheng
- Department of Nuclear Medicine, China-Japan Friendship Hospital, Beijing, 100037, China
| | - Ugur Avcibasi
- School of Health Sciences, Purdue University, IN, 47907, USA; Department of Chemistry, Faculty of Arts and Science, Celal Bayar University, 45040, Yunusemre/Manisa, Turkey
| | - Shuang Liu
- School of Health Sciences, Purdue University, IN, 47907, USA.
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Liu M, Fang W, Liu S. Novel 99mTc(III) Complexes [99mTcCl(CDO)(CDOH)2B–R] (CDOH2 = Cyclohexanedione Dioxime) Useful as Radiotracers for Heart Imaging. Bioconjug Chem 2016; 27:2770-2779. [DOI: 10.1021/acs.bioconjchem.6b00552] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Min Liu
- Department
of Radiation Medicine and Protection, Medical College, Soochow University, China
- School
of Health Sciences, Purdue University, Indiana 47907, United States
| | - Wei Fang
- Department
of Nuclear Medicine, Fuwai Hospital, the National Center for Cardiovascular
Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shuang Liu
- School
of Health Sciences, Purdue University, Indiana 47907, United States
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Ben-Haim S, Kennedy J, Keidar Z. Novel Cadmium Zinc Telluride Devices for Myocardial Perfusion Imaging—Technological Aspects and Clinical Applications. Semin Nucl Med 2016; 46:273-85. [DOI: 10.1053/j.semnuclmed.2016.01.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Redgate S, Barber DC, Fenner JW, Al-Mohammad A, Taylor JC, Hanney MB, Tindale WB. A study to quantify the effect of patient motion and develop methods to detect and correct for motion during myocardial perfusion imaging on a CZT solid-state dedicated cardiac camera. J Nucl Cardiol 2016; 23:514-26. [PMID: 26684196 DOI: 10.1007/s12350-015-0314-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 09/29/2015] [Indexed: 12/15/2022]
Abstract
BACKGROUND Due to differences in the design and acquisition parameters on the solid-state CZT cardiac camera the effect of patient motion may vary compared to Anger cameras. This study evaluates the effect of motion, two new methods of three-dimensional (3D) motion detection and a method of motion correction. METHOD Phantom acquisitions were offset in the X, Y, and Z directions and combined to simulate different types of motion. Motion artifacts were identified using the total perfusion defect and blinded visual interpretation. Motion was detected by registering planar and reconstructed 30 second images, and corrected by summing the aligned reconstructed images. Validation was performed on phantom data. These techniques were then applied to 40 patient studies. RESULTS Motion ≥10 mm and ≥60 seconds in duration introduced significant artifacts. There was no significant difference (P = .258) between the two methods of motion detection. Motion correction removed artifacts from 9/10 phantom simulations. Superior-inferior motion ≥8 mm was measured on 10% of patient studies, and 5% were affected by motion. Motion in the lateral and anterior-posterior directions was <8 mm. CONCLUSION Superior-inferior patient motion artifacts have been identified on myocardial perfusion images acquired on a CZT camera. Routine QC to identify studies with significant motion is recommended.
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Affiliation(s)
- Shelley Redgate
- Nuclear Medicine Department, Sheffield Teaching Hospitals NHS Foundation Trust, I-Floor, Royal Hallamshire Hospital, Glossop Rd, Sheffield, S10 2JF, United Kingdom.
- Medical Physics Group (Cardiovascular Science), University of Sheffield, Sheffield, United Kingdom.
| | - David C Barber
- Medical Physics Group (Cardiovascular Science), University of Sheffield, Sheffield, United Kingdom
| | - John W Fenner
- Medical Physics Group (Cardiovascular Science), University of Sheffield, Sheffield, United Kingdom
| | - Abdallah Al-Mohammad
- Cardiology Department, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom
| | - Jonathon C Taylor
- Nuclear Medicine Department, Sheffield Teaching Hospitals NHS Foundation Trust, I-Floor, Royal Hallamshire Hospital, Glossop Rd, Sheffield, S10 2JF, United Kingdom
| | - Michael B Hanney
- Nuclear Medicine Department, Sheffield Teaching Hospitals NHS Foundation Trust, I-Floor, Royal Hallamshire Hospital, Glossop Rd, Sheffield, S10 2JF, United Kingdom
| | - Wendy B Tindale
- Nuclear Medicine Department, Sheffield Teaching Hospitals NHS Foundation Trust, I-Floor, Royal Hallamshire Hospital, Glossop Rd, Sheffield, S10 2JF, United Kingdom
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Liu S. Radiolabeled Cyclic RGD Peptide Bioconjugates as Radiotracers Targeting Multiple Integrins. Bioconjug Chem 2015; 26:1413-38. [PMID: 26193072 DOI: 10.1021/acs.bioconjchem.5b00327] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Angiogenesis is a requirement for tumor growth and metastasis. The angiogenic process depends on vascular endothelial cell migration and invasion, and is regulated by various cell adhesion receptors. Integrins are such a family of receptors that facilitate the cellular adhesion to and migration on extracellular matrix proteins in the intercellular spaces and basement membranes. Among 24 members of the integrin family, αvβ3 is studied most extensively for its role in tumor angiogenesis and metastasis. The αvβ3 is expressed at relatively low levels on epithelial cells and mature endothelial cells, but it is highly expressed on the activated endothelial cells of tumor neovasculature and some tumor cells. This restricted expression makes αvβ3 an excellent target to develop antiangiogenic drugs and diagnostic molecular imaging probes. Since αvβ3 is a receptor for extracellular matrix proteins with one or more RGD tripeptide sequence, many radiolabeled cyclic RGD peptides have been evaluated as "αvβ3-targeted" radiotracers for tumor imaging over the past decade. This article will use the dimeric and tetrameric cyclic RGD peptides developed in our laboratories as examples to illustrate basic principles for development of αvβ3-targeted radiotracers. It will focus on different approaches to maximize the radiotracer tumor uptake and tumor/background ratios. This article will also discuss some important assays for preclinical evaluations of integrin-targeted radiotracers. In general, multimerization of cyclic RGD peptides increases their integrin binding affinity and the tumor uptake and retention times of their radiotracers. Regardless of their multiplicity, the capability of cyclic RGD peptides to bind other integrins (namely, αvβ5, α5β1, α6β4, α4β1, and αvβ6) is expected to enhance the radiotracer tumor uptake due to the increased integrin population. The results from preclinical and clinical studies clearly show that radiolabeled cyclic RGD peptides (such as (99m)Tc-3P-RGD2, (18)F-Alfatide-I, and (18)F-Alfatide-II) are useful as the molecular imaging probes for early cancer detection and noninvasive monitoring of the tumor response to antiangiogenic therapy.
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Affiliation(s)
- Shuang Liu
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
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9
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Yang Y, Zheng Y, Tomaselli E, Fang W, Liu S. Impact of Boronate Capping Groups on Biological Characteristics of Novel99mTc(III) Complexes [99mTcCl(CDO)(CDOH)2B-R] (CDOH2= Cyclohexanedione Dioxime). Bioconjug Chem 2015; 26:316-28. [PMID: 25585053 DOI: 10.1021/bc500583k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yong Yang
- Department of Nuclear Medicine, Cardiovascular Institute & Fu Wai Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100037, China
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907, United States
| | - Yumin Zheng
- Department of Nuclear Medicine, China-Japan Friendship Hospital, Beijing 100029, China
| | - Elena Tomaselli
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907, United States
| | - Wei Fang
- Department of Nuclear Medicine, Cardiovascular Institute & Fu Wai Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100037, China
| | - Shuang Liu
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907, United States
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Zheng Y, Ji S, Tomaselli E, Ernest C, Freiji T, Liu S. Effect of co-ligands on chemical and biological properties of (99m)Tc(III) complexes [(99m)Tc(L)(CDO)(CDOH)2BMe] (L=Cl, F, SCN and N3; CDOH2=cyclohexanedione dioxime). Nucl Med Biol 2014; 41:813-24. [PMID: 25169135 PMCID: PMC4381195 DOI: 10.1016/j.nucmedbio.2014.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 07/19/2014] [Indexed: 11/17/2022]
Abstract
INTRODUCTION (99m)Tc-Teboroxime ([(99m)TcCl(CDO)(CDOH)2BMe]) is a member of the BATO (boronic acid adducts of technetium dioximes) class of (99m)Tc(III) complexes. This study sought to explore the impact of co-ligands on solution stability, heart uptake and myocardial retention of [(99m)Tc(L)(CDO)(CDOH)2BMe] ((99m)Tc-Teboroxime: L=Cl; (99m)Tc-Teboroxime(F): L=F; (99m)Tc-Teboroxime(SCN): L=SCN; and (99m)Tc-Teboroxime(N3): L=N3). METHODS Radiotracers (99m)Tc-Teboroxime(L) (L=F, SCN and N3) were prepared by reacting (99m)Tc-Teboroxime with NaF, NaSCN and NaN3, respectively. Biodistribution and imaging studies were carried out in Sprague-Dawley rats. Image quantification was performed to compare their heart retention and liver clearance kinetics. RESULTS Complexes (99m)Tc-Teboroxime(L) (L=F, SCN and N3) were prepared in high yield with high radiochemical purity. All new radiotracers were stable for >6h in the kit matrix. In its HPLC chromatogram, (99m)Tc-Teboroxime showed one peak at ~15.5 min, which was shorter than that of (99m)Tc-Teboroxime(F) (~16.4 min). There were two peaks for (99m)Tc-Teboroxime(SCN) at 16.5 and 18.3 min. (99m)Tc-Teboroxime(N3) appeared as a single peak at 18.4 min. Their heart retention and liver clearance curves were best fitted to the bi-exponential decay function. The half-times of fast/slow components were 1.6±0.4/60.7±8.9 min for (99m)Tc-Teboroxime, 0.8±0.2/101.7±20.7 min for (99m)Tc-Teboroxime(F), 1.2±0.3/84.8±16.6 min for (99m)Tc-Teboroxime(SCN), and 2.9±0.9/51.6±5.0 min for (99m)Tc-Teboroxime(N3). The 2-min heart uptake followed the order of (99m)Tc-Teboroxime (3.00±0.37%ID/g)>(99m)Tc-Teboroxime(N3) (2.66±0.01 %ID/g)≈(99m)Tc-Sestamibi (2.55±0.46 %ID/g)>(99m)TcN-MPO (2.38±0.15 %ID/g). (99m)Tc-Teboroxime remains the best in first-pass extraction. The best image acquisition window is 0-5 min for (99m)Tc-Teboroximine and 0-15 min for (99m)Tc-Teboroximine(N3). CONCLUSION Co-ligands had significant impact on the heart uptake and myocardial retention of complexes [(99m)Tc(L)(CDO)(CDOH)2BMe] (L=Cl, F, SCN and N3). Future studies should be directed towards minimizing the liver uptake and radioactivity accumulation in the blood vessels while maintaining their high heart uptake.
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Affiliation(s)
- Yumin Zheng
- School of Health Sciences, Purdue University, IN 47907, USA; Department of Nuclear Medicine, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Shundong Ji
- School of Health Sciences, Purdue University, IN 47907, USA
| | | | - Carley Ernest
- School of Health Sciences, Purdue University, IN 47907, USA
| | - Tom Freiji
- School of Health Sciences, Purdue University, IN 47907, USA
| | - Shuang Liu
- School of Health Sciences, Purdue University, IN 47907, USA.
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Zheng Y, Ji S, Tomaselli E, Liu S. Development of kit formulations for (99m) TcN-MPO: a cationic radiotracer for myocardial perfusion imaging. J Labelled Comp Radiopharm 2014; 57:584-92. [PMID: 25070025 DOI: 10.1002/jlcr.3221] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 06/30/2014] [Accepted: 07/03/2014] [Indexed: 11/11/2022]
Abstract
The objective of this study was to develop a kit formulation for [(99m) TcN(mpo)(PNP5)](+) (MPO = 2-mercaptopyridine oxide), ((99m) TcN-MPO) to support its clinical evaluations as a SPECT radiotracer. Radiolabeling studies were performed using three different formulations (two-vial formulation and single-vial formulations with/without SnCl2 ) to explore the factors influencing radiochemical purity (RCP) of (99m) TcN-MPO. We found that the most important factor affecting the RCP of (99m) TcN-MPO was the purity of PNP5. (99m) TcN-MPO was prepared >98% RCP (n = 20) using the two-vial formulation. For single-vial formulations with/without SnCl2 , β-cyclodextrin (β-CD) is particularly useful as a stabilizer for PNP5. The RCP of (99m) TcN-MPO was 95-98% using β-CD, but its RCP was only 90-93% with γ-cyclodextrin (γ-CD). It seems that PNP5 fits better into the inner cavity of β-CD, which forms more stable inclusion complex than γ-CD in the single-vial formulations. The results from biodistribution and imaging studies in Sprague-Dawley rats clearly demonstrated biological equivalence of three different formulations. Single photon-emission computed tomography data suggested that high quality images could be obtained at 0-30-min post-injection without significant interference from the liver radioactivity. Considering the ease for (99m) Tc-labeling and high RCP of (99m) TcN-MPO, the non-SnCl2 single-vial formulation is an attractive choice for future clinical studies.
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Affiliation(s)
- Yumin Zheng
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, USA; Department of Nuclear Medicine, China-Japan Friendship Hospital, Beijing, 100029, China
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Du Y, Bhattacharya M, Frey EC. Simultaneous Tc-99m/I-123 dual-radionuclide myocardial perfusion/innervation imaging using Siemens IQ-SPECT with SMARTZOOM collimator. Phys Med Biol 2014; 59:2813-28. [PMID: 24819280 PMCID: PMC4142679 DOI: 10.1088/0031-9155/59/11/2813] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Simultaneous dual-radionuclide myocardial perfusion/innervation SPECT imaging can provide important information about the mismatch between scar tissue and denervated regions. The Siemens IQ-SPECT system developed for cardiac imaging uses a multifocal SMARTZOOM collimator to achieve a four-fold sensitivity for the cardiac region, compared to a typical parallel-hole low-energy high-resolution collimator, but without the data truncation that can result with conventional converging-beam collimators. The increased sensitivity allows shorter image acquisition times or reduced patient dose, making IQ-SPECT ideal for simultaneous dual-radionuclide SPECT, where reduced administrated activity is desirable in order to reduce patient radiation exposure. However, crosstalk is a major factor affecting the image quality in dual-radionuclide imaging. In this work we developed a model-based method that can estimate and compensate for the crosstalk in IQ-SPECT data. The crosstalk model takes into account interactions in the object and collimator-detector system. Scatter in the object was modeled using the effective source scatter estimation technique (ESSE), previously developed to model scatter with parallel-hole collimators. The geometric collimator-detector response was analytically modeled in the IQ-SPECT projector. The estimated crosstalk was then compensated for in an iterative reconstruction process. The new method was validated with data from both Monte Carlo simulations and physical phantom experiments. The results showed that the estimated crosstalk was in good agreement with simulated and measured results. After model-based compensation the images from simultaneous dual-radionuclide acquisitions were similar in quality to those from single-radionuclide acquisitions that did not have crosstalk contamination. The proposed model-based method can be used to improve simultaneous dual-radionuclide images acquired using IQ-SPECT. This work also demonstrates that ESSE scatter modeling can be applied to non-parallel-beam projection geometries.
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Affiliation(s)
- Yong Du
- Department of Radiology, Johns Hopkins University, 601 N Caroline Street, JOHC 4263, Baltimore, MD 21287, USA
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13
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Kennedy JA, Israel O, Frenkel A. 3D iteratively reconstructed spatial resolution map and sensitivity characterization of a dedicated cardiac SPECT camera. J Nucl Cardiol 2014; 21:443-52. [PMID: 24429938 DOI: 10.1007/s12350-013-9851-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Revised: 12/22/2013] [Indexed: 11/24/2022]
Abstract
BACKGROUND A solid-state cadmium zinc telluride (CZT) SPECT device provides ultrafast myocardial perfusion imaging (MPI) with a spherical field-of-view (FOV). This study aims at determining the spatial resolution and sensitivity throughout this FOV as a guide for patient positioning. METHODS AND RESULTS For this CZT camera (Discovery 570c, GE Healthcare), the iteratively reconstructed spatial resolution along 3 Cartesian axes was compared (average resolution 6.9 ± 1.0 mm full-width at half-maximum) using a 2 dimensional array of point sources in air which was aligned with a transverse plane shifted throughout the FOV. Sensitivity was plotted in the central transverse slice and axially in locations comparable to the placement of the heart in 266 rest/stress cardiac studies (M 78, age 63 ± 13 years). The average sensitivity was 0.46 ± 0.19 kc/s/MBq with a transverse gradient of 0.039 ± 0.001 kc/s/MBq/cm (8.9% of the sensitivity per cm). Reconstructed relative activity was uniform (uniformity <9%) and count rate was linear (R = 0.999) over 3 orders of magnitude. CONCLUSIONS The CZT SPECT camera offers good resolution, sensitivity, and uniformity, and provides linearity in count rate. A gradient of >8%/cm in sensitivity justifies the crucial role of patient positioning with the heart closest to the detector.
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Affiliation(s)
- John A Kennedy
- Department of Nuclear Medicine, Rambam Health Care Campus, P.O. Box 9602, 31096, Haifa, Israel,
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15
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Wells RG, Marvin B, Kovalski G, Ruddy TD. Planar radionuclide angiography with a dedicated cardiac SPECT camera. J Nucl Cardiol 2013; 20:358-66. [PMID: 23436136 DOI: 10.1007/s12350-013-9674-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 01/08/2013] [Indexed: 11/25/2022]
Abstract
BACKGROUND We compared a dedicated cardiac camera with a traditional system for left ventricular (LV) functional measurements using gated blood-pool imaging. METHODS 24-frame gated planar images were obtained from 48 patients in an LAO orientation for 6M counts/view on a standard gamma camera. Immediately thereafter, 24-frame ECG-gated data were obtained for 8 minutes on a dedicated cardiac SPECT camera. The gated SPECT image volumes were iteratively reconstructed and then transferred offline. In-house software was used to reproject the images into a 24-frame gated planar format. Both the original and the reprojected gated planar datasets were analyzed using semiautomated software to determine ejection fraction (EF), ventricular volume (end diastolic volume, EDV), peak ejection rate (PER), and peak filling rate (PFR). RESULTS The difference in EF values averaged 0.4% ± 4.4%. The correlation in EF was r ≥ 0.94 (P < .01) with a linear regression slope of 0.98. Correlation of the EDV was r ≥ 0.86 (P < .01), but the volumes from the dedicated cardiac camera were smaller (linear regression slope was 0.6). Correlation of PFR and PER were r = 0.91 and r ≥ 0.83, respectively (P < .01 for both). CONCLUSIONS Reprojection of 24-frame gated blood-pool SPECT images is an effective means of obtaining LV functional measurements with a dedicated cardiac SPECT camera using standard 2D-planar analysis tools.
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Affiliation(s)
- R Glenn Wells
- Cardiology, University of Ottawa, Ottawa, ON, Canada.
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Verger A, Djaballah W, Fourquet N, Rouzet F, Koehl G, Imbert L, Poussier S, Fay R, Roch V, Le Guludec D, Karcher G, Marie PY. Comparison between stress myocardial perfusion SPECT recorded with cadmium-zinc-telluride and Anger cameras in various study protocols. Eur J Nucl Med Mol Imaging 2012. [DOI: 10.1007/s00259-012-2292-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Imbert L, Poussier S, Franken PR, Songy B, Verger A, Morel O, Wolf D, Noel A, Karcher G, Marie PY. Compared Performance of High-Sensitivity Cameras Dedicated to Myocardial Perfusion SPECT: A Comprehensive Analysis of Phantom and Human Images. J Nucl Med 2012; 53:1897-903. [DOI: 10.2967/jnumed.112.107417] [Citation(s) in RCA: 191] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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