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Kaimoto Y, Fukushima K, Kanaya K, Asanuma M, Aoba K, Yamamoto A, Nakao R, Kaneko K, Nagao M, Chida K. Optimization of Intraventricular Radioactive Concentration for 13N ammonia PET with Time-of-Flight Scanner: Simplified Phantom Study with Noise Equivalent Count Rate Analysis. ANNALS OF NUCLEAR CARDIOLOGY 2023; 9:33-39. [PMID: 38058574 PMCID: PMC10696149 DOI: 10.17996/anc.23-00178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/02/2023] [Accepted: 02/09/2023] [Indexed: 12/08/2023]
Abstract
Background: Myocardial blood flow quantification (MBF) is one of the distinctive features for cardiac positron emission tomography. The MBF calculation is mostly obtained by estimating the input function from the time activity curve in dynamic scan. However, there is a substantial risk of count-loss because the high radioactivity pass through the left ventricular (LV) cavity within a short period. We aimed to determine the optimal intraventricular activity using the noise equivalent count rate (NECR) analysis with simplified phantom model. Methods: Positron emission tomography computed tomography scanner with LYSO crystal and time of flight was used for phantom study. 150 MBq/mL of 13N was filled in 10 mL of syringe, placed in neck phantom to imitate end-systolic small LV. 3D list-mode acquisition was repeatedly performed along radioactive decay. Net true and random count rate were calculated and compared to the theoretical activity in the syringe. NECR curve analysis was used to determine the optimal radioactive concentration. Result: The attenuation curves showed good correlation to the theoretical activity between 20 to 370, and 370 to 740 MBq (r2=1.0 ± 0.0001, p<0.0001; r2=0.99 ± 0.0001, p<0.0001 for 20 to 370, and 370 to 740, respectively), while did not over 740 MBq (p=0.62). NECR analysis revealed that the peak rate was at 2.9 Mcps, there at the true counts were significantly suppressed. The optimal radioactive concentration was determined as 36 MBq/mL. Conclusion: Simulative analysis for high-dose of 13N using the phantom imitating small LV confirmed that the risk of count-loss was increased. The result can be useful information in assessing the feasibility of MBF quantification in clinical routine.
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Affiliation(s)
- Yoko Kaimoto
- Department of Radiological service, Tokyo Woman's Medical University, Tokyo, Japan
- Department of Health Sciences, Graduate School of Medicine, Tohoku University, Miyagi, Japan
| | - Kenji Fukushima
- Department of Radiology and Nuclear Medicine, Fukushima Medical University, Fukushima, Japan
| | - Kazuko Kanaya
- Department of Radiological service, Tokyo Woman's Medical University, Tokyo, Japan
| | - Masayasu Asanuma
- Department of Radiological service, Tokyo Woman's Medical University, Tokyo, Japan
| | - Kaoru Aoba
- Department of Radiological service, Tokyo Woman's Medical University, Tokyo, Japan
| | - Atsushi Yamamoto
- Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women's Medical University, Tokyo, Japan
- Department of Cardiology, Tokyo Women's Medical University, Tokyo, Japan
| | - Risako Nakao
- Department of Cardiology, Tokyo Women's Medical University, Tokyo, Japan
| | - Koichiro Kaneko
- Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women's Medical University, Tokyo, Japan
| | - Michinobu Nagao
- Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women's Medical University, Tokyo, Japan
| | - Koichi Chida
- Department of Health Sciences, Graduate School of Medicine, Tohoku University, Miyagi, Japan
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Bober RM, Milani RV, Kachur SM, Morin DP. Assessment of resting myocardial blood flow in regions of known transmural scar to confirm accuracy and precision of 3D cardiac positron emission tomography. EJNMMI Res 2023; 13:87. [PMID: 37752344 PMCID: PMC10522549 DOI: 10.1186/s13550-023-01037-7] [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] [Received: 04/13/2023] [Accepted: 09/20/2023] [Indexed: 09/28/2023] Open
Abstract
BACKGROUND Composite invasive and non-invasive data consistently demonstrate that resting myocardial blood flow (rMBF) in regions of known transmural myocardial scar (TMS) converge on a value of ~ 0.30 mL/min/g or lower. This value has been confirmed using the 3 most common myocardial perfusion agents (13N, 15O-H2O and 82Rb) incorporating various kinetic models on older 2D positron emission tomography (PET) systems. Thus, rMBF in regions of TMS can serve as a reference "truth" to evaluate low-end accuracy of various PET systems and software packages (SWPs). Using 82Rb on a contemporary 3D-PET-CT system, we sought to determine whether currently available SWP can accurately and precisely measure rMBF in regions of known TMS. RESULTS Median rMBF (in mL/min/g) and COV in regions of TMS were 0.71 [IQR 0.52-1.02] and 0.16 with 4DM; 0.41 [0.34-0.54] and 0.10 with 4DM-FVD; 0.66 [0.51-0.85] and 0.11 with Cedars; 0.51 [0.43-0.61] and 0.08 with Emory-Votaw; 0.37 [0.30-0.42], 0.07 with Emory-Ottawa, and 0.26 [0.23-0.32], COV 0.07 with HeartSee. CONCLUSIONS SWPs varied widely in low end accuracy based on measurement of rMBF in regions of known TMS. 3D PET using 82Rb and HeartSee software accurately (0.26 mL/min/g, consistent with established values) and precisely (COV = 0.07) quantified rMBF in regions of TMS. The Emory-Ottawa software yielded the next-best accuracy (0.37 mL/min/g), though rMBF was higher than established gold-standard values in ~ 5% of the resting scans. 4DM, 4DM-FDV, Cedars and Emory-Votaw SWP consistently resulted values higher than the established gold standard (0.71, 0.41, 0.66, 0.51 mL/min/g, respectively), with higher interscan variability (0.16, 0.11, 0.11, and 0.09, respectively). TRIAL REGISTRATION clinicaltrial.gov, NCT05286593, Registered December 28, 2021, https://clinicaltrials.gov/ct2/show/NCT05286593 .
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Affiliation(s)
- Robert M Bober
- Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, Ochsner Health, 1514 Jefferson Highway, New Orleans, LA, 70121-2483, USA.
- Ochsner Clinical School, Queensland University School of Medicine, New Orleans, LA, USA.
| | - Richard V Milani
- Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, Ochsner Health, 1514 Jefferson Highway, New Orleans, LA, 70121-2483, USA
- Ochsner Clinical School, Queensland University School of Medicine, New Orleans, LA, USA
| | - Sergey M Kachur
- Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, Ochsner Health, 1514 Jefferson Highway, New Orleans, LA, 70121-2483, USA
| | - Daniel P Morin
- Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, Ochsner Health, 1514 Jefferson Highway, New Orleans, LA, 70121-2483, USA
- Ochsner Clinical School, Queensland University School of Medicine, New Orleans, LA, USA
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Carroll L, Enger SA. Simulation of a novel, non-invasive radiation detector to measure the arterial input function for dynamic positron emission tomography. Med Phys 2023; 50:1647-1659. [PMID: 36250522 DOI: 10.1002/mp.16055] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 09/14/2022] [Accepted: 10/04/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Dynamic positron emission tomography (dPET) is a nuclear medicine imaging technique providing functional images for organs of interest with applications in oncology, cardiology, and drug discovery. This technique requires the acquisition of the time-course arterial plasma activity concentration, called the arterial input function (AIF), which is conventionally acquired via arterial blood sampling. PURPOSE The aim of this study was to (A) optimize the geometry for a novel and cost efficient non-invasive detector called NID designed to measure the AIF for dPET scans through Monte Carlo simulations and (B) develop a clinical data analysis chain to successfully separate the arterial component of a simulated AIF signal from the venous component. METHODS The NID was optimized by using an in-house Geant4-based software package. The sensitive volume of the NID consists of a band of 10 cm long and 1 mm in diameter scintillating fibers placed over a wrist phantom. The phantom was simulated as a cylinder, 10 cm long and 6.413 cm in diameter comprised of polyethylene with two holes placed through it to simulate the patient's radial artery and vein. This phantom design was chosen to match the wrist phantom used in our previous proof of concept work. Two geometries were simulated with different arrangements of scintillating fibers. The first design used a single layer of 64 fibers. The second used two layers, an inner layer with 29 fibers and an outer layer with 30 fibers. Four positron emitting radioisotopes were simulated: 18 F, 11 C, 15 O, and 68 Ga with 100 million simulated decay events per run. The total and intrinsic efficiencies of both designs were calculated as well as the full width half maximum (FWHM) of the signal. In addition, contribution by the annihilation photons versus positrons to the signal was investigated. The results obtained from the two simulated detector models were compared. A clinical data analysis chain using an expectation maximization maximum likelihood algorithm was tested. This analysis chain will be used to separate arterial counts from the total signal. RESULTS The second NID design with two layers of scintillating fibers had a higher efficiency for all simulations with a maximum increase of 17% total efficiency for 11 C simulation. All simulations had a significant annihilation photon contribution. The signal for 18 F and 11 C was almost entirely due to photons. The clinical data analysis chain was within 1% of the true value for 434 out of 440 trials. Further experimental studies to validate these simulations will be required. CONCLUSIONS The design of the NID was optimized and its efficiency increased through Monte Carlo simulations. A clinical data analysis chain was successfully developed to separate the arterial component of an AIF signal from the venous component. The simulations show that the NID can be used to accurately measure the AIF non-invasively for dPET scans.
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Affiliation(s)
- Liam Carroll
- Medical Physics Unit, Department of Oncology, Faculty of Medicine, McGill University, Montréal, Quebec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - Shirin A Enger
- Medical Physics Unit, Department of Oncology, Faculty of Medicine, McGill University, Montréal, Quebec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
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4
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de Winter RW, Jukema RA, van Diemen PA, Schumacher SP, Driessen RS, Stuijfzand WJ, Everaars H, Bom MJ, van Rossum AC, van de Ven PM, Verouden NJ, Nap A, Raijmakers PG, Danad I, Knaapen P. The impact of coronary revascularization on vessel-specific coronary flow capacity and long-term outcomes: a serial [15O]H2O positron emission tomography perfusion imaging study. Eur Heart J Cardiovasc Imaging 2022; 23:743-752. [PMID: 34878102 PMCID: PMC9159743 DOI: 10.1093/ehjci/jeab263] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 11/25/2021] [Indexed: 11/12/2022] Open
Abstract
AIMS Coronary flow capacity (CFC) integrates quantitative hyperaemic myocardial blood flow (hMBF) and coronary flow reserve (CFR) to comprehensively assess physiological severity of coronary artery disease (CAD). This study evaluated the effects of revascularization on CFC as assessed by serial [15O]H2O positron emission tomography (PET) perfusion imaging. METHODS AND RESULTS A total of 314 patients with stable CAD underwent [15O]H2O PET imaging at baseline and after myocardial revascularization to assess changes in hMBF, CFR, and CFC in 415 revascularized vessels. Using thresholds for ischaemia and normal perfusion, vessels were stratified in five CFC categories: myocardial steal, severely reduced CFC, moderately reduced CFC, minimally reduced CFC, and normal flow. Additionally, the association between CFC increase and the composite endpoint of death and non-fatal myocardial infarction (MI) was studied. Vessel-specific CFC improved after revascularization (P < 0.01). Furthermore, baseline CFC was an independent predictor of CFC increase (P < 0.01). The largest changes in ΔhMBF (0.90 ± 0.74, 0.93 ± 0.65, 0.79 ± 0.74, 0.48 ± 0.61, and 0.29 ± 0.66 mL/min/g) and ΔCFR (1.01 ± 0.88, 0.99 ± 0.69, 0.87 ± 0.88, 0.66 ± 0.91, and -0.01 ± 1.06) were observed in vessels with lower baseline CFC (P < 0.01 for both). During a median follow-up of 3.5 (95% CI 3.1-3.9) years, an increase in CFC was independently associated with lower rates of death and non-fatal MI (HR 0.43, 95% CI 0.19-0.98, P = 0.04). CONCLUSION Successful revascularization results in an increase in CFC. Furthermore, baseline CFC was an independent predictor of change in hMBF, CFR, and subsequently CFC. In addition, an increase in CFC was associated with a favourable outcome in terms of death and non-fatal MI.
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Affiliation(s)
- Ruben W de Winter
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Ruurt A Jukema
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Pepijn A van Diemen
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Stefan P Schumacher
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Roel S Driessen
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Wynand J Stuijfzand
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Henk Everaars
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Michiel J Bom
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Albert C van Rossum
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Peter M van de Ven
- Department of Epidemiology & Data Science, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Niels J Verouden
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Alexander Nap
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Pieter G Raijmakers
- Department of Radiology, Nuclear Medicine & PET Research, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Ibrahim Danad
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Paul Knaapen
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
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Rubidium-82 PET/CT myocardial perfusion imaging. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00091-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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AlJaroudi WA, Hage FG. Review of cardiovascular imaging in the Journal of Nuclear Cardiology 2020: positron emission tomography, computed tomography, and magnetic resonance. J Nucl Cardiol 2021; 28:2100-2111. [PMID: 34105040 PMCID: PMC8186871 DOI: 10.1007/s12350-021-02685-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 05/19/2021] [Indexed: 11/13/2022]
Abstract
Although the year 2020 was different from other years in many respects, the Journal of Nuclear Cardiology published excellent articles pertaining to imaging in patients with cardiovascular disease due to the dedication of the investigators in our field all over the world. In this review, we will summarize a selection of these articles to provide a concise review of the main advancements that have recently occurred in the field and provide the reader with an opportunity to review a wide selection of articles. We will focus on publications dealing with positron emission tomography, computed tomography, and magnetic resonance and hope that you will find this review helpful.
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Affiliation(s)
- Wael A AlJaroudi
- Division of Cardiovascular Medicine, Augusta University, Augusta, GA, USA
| | - Fadi G Hage
- Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Lyons Harrison Research Building 306, 1900 University BLVD, Birmingham, AL, 35294, USA.
- Section of Cardiology, Birmingham Veterans Affairs Medical Center, Birmingham, AL, USA.
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7
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Bober R. Decay Correction for Quantitative Myocardial PET Perfusion in Established PET Scanners: A Potentially Overlooked Source of Errors. J Nucl Med Technol 2021; 49:344-349. [PMID: 34330807 DOI: 10.2967/jnmt.121.262320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/05/2021] [Indexed: 11/16/2022] Open
Abstract
Quantitative myocardial PET perfusion requires decay correction (DC) of the dynamic datasets to ensure that measured activity reflects true physiology and not radiotracer decay or frame duration. DC is typically performed by the PET camera system, and the exact algorithm is buried within the settings and assumed to be correct for quantitative perfusion data. For quantitative myocardial perfusion, sequential dynamic images should be decay-corrected to the activity at the midpoint of the first scan in the sequence. However, there are different DC algorithms that can be implemented depending on the needs and expertise of the laboratory. As such, before quantitative myocardial perfusion is performed, the DC technique of a camera system should be tested.
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Affiliation(s)
- Robert Bober
- John Ochsner Heart and Vascular Institute, Department of Cardiovascular Diseases, and Ochsner Clinical School, Queensland University School of Medicine, New Orleans, Louisiana
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8
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Nye JA, Piccinelli M, Hwang D, David Cooke C, Paeng JC, Lee JM, Cho SG, Folks R, Bom HS, Koo BK, Garcia EV. Dynamic cardiac PET motion correction using 3D normalized gradient fields in patients and phantom simulations. Med Phys 2021; 48:5072-5084. [PMID: 34174095 DOI: 10.1002/mp.15059] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/06/2021] [Accepted: 06/09/2021] [Indexed: 11/09/2022] Open
Abstract
This work expands on the implementation of three-dimensional (3D) normalized gradient fields to correct for whole-body motion and cardiac creep in [N-13]-ammonia patient studies and evaluates its accuracy using a dynamic phantom simulation model. METHODS A full rigid-body algorithm was developed using 3D normalized gradient fields including a multi-resolution step and sampling off the voxel grid to reduce interpolation artifacts. Optimization was performed using a weighted similarity metric that accounts for opposing gradients between images of blood pool and perfused tissue without the need for segmentation. Forty-three retrospective dynamic [N-13]-ammonia PET/CT rest/adenosine-stress patient studies were motion corrected and the mean motion parameters plotted at each frame time point. Motion correction accuracy was assessed using a comprehensive dynamic XCAT simulation incorporating published physiologic parameters of the heart's trajectory following adenosine infusion as well as corrupted attenuation correction commonly observed in clinical studies. Accuracy of the algorithm was assessed objectively by comparing the errors between isosurfaces and centers of mass of the motion corrected XCAT simulations. RESULTS In the patient studies, the overall mean cranial-to-caudal translation was 7 mm at stress over the duration of the adenosine infusion. Noninvasive clinical measures of relative flow reserve and myocardial flow reserve were highly correlated with their invasive analogues. Motion correction accuracy assessed with the XCAT simulations showed an error of <1 mm in late perfusion frames that broadened gradually to <3 mm in earlier frames containing blood pool. CONCLUSION This work demonstrates that patients undergoing [N-13]-ammonia dynamic PET/CT exhibit a large cranial-to-caudal translation related to cardiac creep primarily at stress and to a lesser extent at rest, which can be accurately corrected by optimizing their 3D normalized gradient fields. Our approach provides a solution to the challenging condition where the image intensity and its gradients are opposed without the need for segmentation and remains robust in the presence of PET-CT mismatch.
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Affiliation(s)
- Jonathon A Nye
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, USA
| | - Marina Piccinelli
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, USA
| | - Doyeon Hwang
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, Korea
| | - Charles David Cooke
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, USA
| | - Jin Chul Paeng
- Department of Nuclear Medicine, Seoul National University Hospital, Seoul, Korea
| | - Joo Myung Lee
- Samsung Medical Center, Heart Vascular Stroke Institute, Seoul, Korea
| | - Sang-Geon Cho
- Department of Nuclear Medicine, Chonnam National University Hospital, Gwangju, Korea
| | - Russell Folks
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, USA
| | - Hee-Seung Bom
- Department of Nuclear Medicine, Chonnam National University Hospital, Gwangju, Korea
| | - Bon-Kwon Koo
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, Korea
| | - Ernest V Garcia
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, USA
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Abstract
Positron emission tomography and/or computed tomography (PET/CT) MPI is a powerful imaging modality for the assessment of cardiovascular diseases. It offers several advantages over single-photon emission computed tomography (SPECT) MPI including robust attenuation correction and absolute quantification of radiotracer activity. PET MPI has a large evidence base and is the only clinical tool to evaluate coronary microvascular dysfunction. In addition, the clinical use and evidence base for 2-deoxy-2-[18F]fluoro-D-g1ucose (18F-FDG) cardiac PET imaging for inflammation and metabolism imaging is rising exponentially. In order to gain from the advances of this sophisticated quantitative technique, a high-quality scan is critical. It is important for readers to recognize a poor-quality scan, identify artifacts contributing to the poor image quality, and understand how to correct them prior to reporting the results. In this review, we will discuss some normal variants and pitfalls in cardiac PET/CT radionuclide MPI, myocardial viability, and inflammation imaging.
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Affiliation(s)
- Vasvi Singh
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; Midwest Heart and Vascular Specialists, HCA Midwest Health, Kansas City, MO
| | - Sharmila Dorbala
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.
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10
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Bober RM, Milani RV, Krim SR, Morin DP. PET Stress Testing with Coronary Flow Capacity in the Evaluation of Patients with Coronary Artery Disease and Left Ventricular Dysfunction: Rethinking the Current Paradigm. Curr Cardiol Rep 2021; 23:50. [PMID: 33761005 PMCID: PMC7990801 DOI: 10.1007/s11886-021-01478-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/17/2021] [Indexed: 11/03/2022]
Abstract
PURPOSE OF REVIEW Cardiomyopathy with underlying left ventricular (LV) dysfunction is a heterogenous group of disorders that may be present with, and/or secondary to, coronary artery disease (CAD). The purpose of this review is to demonstrate, via case illustrations, the benefits offered by cardiac positron-emission tomography (PET) stress testing with coronary flow capacity (CFC) in the evaluation and treatment of patients with left ventricular (LV) dysfunction and CAD. RECENT FINDINGS CFC, a metric that is increasing in prominence, represents the integration of several absolute perfusion metrics into clinical strata of CAD severity. Our prior work has demonstrated improvement in regional perfusion metrics as a result of revascularization to territories with severe reduction in CFC. Conversely, when CFC is adequate, there is no change in regional perfusion metrics following revascularization, despite angiographically severe stenosis. Furthermore, Gould et al. demonstrated decreased rates of myocardial infarction and death following revascularization of myocardium with severely reduced CFC, with no clinical benefit observed following revascularization of patients with preserved CFC. In a series of cases, we present pre-revascularization and post-revascularization PET scans with perfusion metrics in patients with LV dysfunction and CAD. In these examples, we demonstrate improvement in LV function and perfusion metrics following revascularization only in cases where baseline CFC is severely reduced. PET with CFC offers unique guidance regarding revascularization in patients with reduced LV function and CAD.
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Affiliation(s)
- Robert M. Bober
- Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, 1514 Jefferson Highway, New Orleans, LA 70121-2483 USA
- Ochsner Clinical School, Queensland University School of Medicine, New Orleans, LA USA
| | - Richard V. Milani
- Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, 1514 Jefferson Highway, New Orleans, LA 70121-2483 USA
- Ochsner Clinical School, Queensland University School of Medicine, New Orleans, LA USA
| | - Selim R. Krim
- Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, 1514 Jefferson Highway, New Orleans, LA 70121-2483 USA
- Ochsner Clinical School, Queensland University School of Medicine, New Orleans, LA USA
| | - Daniel P. Morin
- Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, 1514 Jefferson Highway, New Orleans, LA 70121-2483 USA
- Ochsner Clinical School, Queensland University School of Medicine, New Orleans, LA USA
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Gould KL, Bui L, Kitkungvan D, Patel MB. Reliability and Reproducibility of Absolute Myocardial Blood Flow: Does It Depend on the PET/CT Technology, the Vasodilator, and/or the Software? Curr Cardiol Rep 2021; 23:12. [PMID: 33483794 PMCID: PMC7822783 DOI: 10.1007/s11886-021-01449-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/08/2021] [Indexed: 11/01/2022]
Abstract
PURPOSE OF REVIEW The COURAGE and ISCHEMIA trials showed no reduced mortality after revascularization compared to medical treatment. Is this lack of benefit due to revascularization having no benefit regardless of CAD severity or to suboptimal patient selection due to non-quantitative cardiac imaging? RECENT FINDINGS Comprehensive, integrated, myocardial perfusion quantified by regional pixel distribution of coronary flow capacity (CFC) is the final common expression of objective CAD severity for which revascularization reduces mortality. Current lack of revascularization benefit derives from narrow thinking focused on measuring one isolated aspect of coronary characteristics, such as angiogram stenosis, its fractional flow reserve (FFR), anatomic FFR simulations, relative stress imaging, absolute stress ml/min/g or coronary flow reserve (CFR) alone, or even more narrowly on global CFR or fixed regions of interest in assumed coronary artery distributions, or in arbitrary 17 segments on bull's-eye displays, rather than regional pixel distribution of perfusion metrics as they actually are in an individual. Comprehensive integration of all quantitative perfusion metrics per regional pixel into coronary flow capacity guides artery-specific interventions for reduced mortality in non-acute CAD but requires addressing the methodologic questions in the title.
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Affiliation(s)
- K. Lance Gould
- Weatherhead PET Center For Preventing and Reversing Atherosclerosis, Division of Cardiology, Department of Medicine, McGovern Medial Medical School, University of Texas, and Memorial Hermann Hospital, Houston, TX USA
- Weatherhead PET Center For Preventing and Reversing Atherosclerosis, McGovern Medical School, University of Texas Health Science Center at Houston, 6431 Fannin St., Room MSB 4.256, Houston, TX 77030 USA
| | - Linh Bui
- Division of Cardiology, McGovern Medical School, Houston, TX USA
| | - Danai Kitkungvan
- Division of Cardiology, McGovern Medical School, Houston, TX USA
| | - Monica B. Patel
- Division of Cardiology, McGovern Medical School, Houston, TX USA
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Johnson GB, Harms HJ, Johnson DR, Jacobson MS. PET Imaging of Tumor Perfusion: A Potential Cancer Biomarker? Semin Nucl Med 2020; 50:549-561. [PMID: 33059824 DOI: 10.1053/j.semnuclmed.2020.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Perfusion, as measured by imaging, is considered a standard of care biomarker for the evaluation of many tumors. Measurements of tumor perfusion may be used in a number of ways, including improving the visual detection of lesions, differentiating malignant from benign findings, assessing aggressiveness of tumors, identifying ischemia and by extension hypoxia within tumors, and assessing treatment response. While most clinical perfusion imaging is currently performed with CT or MR, a number of methods for PET imaging of tumor perfusion have been described. The inert PET radiotracer 15O-water PET represents the recognized gold standard for absolute quantification of tissue perfusion in both normal tissue and a variety of pathological conditions including cancer. Other cancer PET perfusion imaging strategies include the use of radiotracers with high first-pass uptake, analogous to those used in cardiac perfusion PET. This strategy produces more visually pleasing high-contrast images that provide relative rather than absolute perfusion quantification. Lastly, multiple timepoint imaging of PET tracers such as 18F-FDG, are not specifically optimized for perfusion, but have advantages related to availability, convenience, and reimbursement. Multiple obstacles have thus far blocked the routine use of PET imaging for tumor perfusion, including tracer production and distribution, image processing, patient body coverage, clinical validation, regulatory approval and reimbursement, and finally feasible clinical workflows. Fortunately, these obstacles are being overcome, especially within larger imaging centers, opening the door for PET imaging of tumor perfusion to become standard clinical practice. In the foreseeable future, it is possible that whole-body PET perfusion imaging with 15O-water will be able to be performed in a single imaging session concurrent with standard PET imaging techniques such as 18F-FDG-PET. This approach could establish an efficient clinical workflow. The resultant ability to measure absolute tumor blood flow in combination with glycolysis will provide important complementary information to inform prognosis and clinical decisions.
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Affiliation(s)
- Geoffrey B Johnson
- Department of Radiology, Mayo Clinic, Rochester, MNDepartment of Neurology, Mayo Clinic, Rochester, MN; Department of Immunology, Mayo Clinic, Rochester, MN.
| | - Hendrik J Harms
- Department of Surgical Sciences, Nuclear Medicine, PET and Radiology, Uppsala University, Uppsala Sweden
| | - Derek R Johnson
- Department of Radiology, Mayo Clinic, Rochester, MNDepartment of Neurology, Mayo Clinic, Rochester, MN
| | - Mark S Jacobson
- Department of Radiology, Mayo Clinic, Rochester, MNDepartment of Neurology, Mayo Clinic, Rochester, MN
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