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Mirshahvalad SA, Farag A, Thiessen J, Wong R, Veit-Haibach P. Current Applications of PET/MR: Part I: Technical Basics and Preclinical/Clinical Applications. Can Assoc Radiol J 2024; 75:815-825. [PMID: 38813998 DOI: 10.1177/08465371241255903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024] Open
Abstract
Positron emission tomography/magnetic resonance (PET/MR) imaging has gone through major hardware improvements in recent years, making it a reliable state-of-the-art hybrid modality in clinical practice. At the same time, image reconstruction, attenuation correction, and motion correction algorithms have significantly evolved to provide high-quality images. Part I of the current review discusses technical basics, pre-clinical applications, and clinical applications of PET/MR in radiation oncology and head and neck imaging. PET/MR offers a broad range of advantages in preclinical and clinical imaging. In the preclinic, small and large animal-dedicated devices were developed, making PET/MR capable of delivering new insight into animal models in diseases and facilitating the development of methods that inform clinical PET/MR. Regarding PET/MR's clinical applications in radiation medicine, PET and MR already play crucial roles in the radiotherapy process. Their combination is particularly significant as it can provide molecular and morphological characteristics that are not achievable with other modalities. In addition, the integration of PET/MR information for therapy planning with linear accelerators is expected to provide potentially unique biomarkers for treatment guidance. Furthermore, in clinical applications in the head and neck region, it has been shown that PET/MR can be an accurate modality in head and neck malignancies for staging and resectability assessment. Also, it can play a crucial role in diagnosing residual or recurrent diseases, reliably distinguishing from oedema and fibrosis. PET/MR can furthermore help with tumour characterization and patient prognostication. Lastly, in head and neck carcinoma of unknown origin, PET/MR, with its diagnostic potential, may obviate multiple imaging sessions in the near future.
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Affiliation(s)
- Seyed Ali Mirshahvalad
- University Medical Imaging Toronto, Toronto Joint Department Medical Imaging, University Health Network, Sinai Health System, Women's College Hospital, University of Toronto, Toronto, ON, Canada
- Department of Medical Imaging, University of Toronto, Toronto, ON, Canada
| | - Adam Farag
- University Medical Imaging Toronto, Toronto Joint Department Medical Imaging, University Health Network, Sinai Health System, Women's College Hospital, University of Toronto, Toronto, ON, Canada
| | - Jonathan Thiessen
- Imaging Program, Lawson Health Research Institute, London, ON, Canada
- Medical Biophysics, Medical Imaging, Western University, London, ON, Canada
| | - Rebecca Wong
- Department of Radiation Oncology, Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Patrick Veit-Haibach
- University Medical Imaging Toronto, Toronto Joint Department Medical Imaging, University Health Network, Sinai Health System, Women's College Hospital, University of Toronto, Toronto, ON, Canada
- Department of Medical Imaging, University of Toronto, Toronto, ON, Canada
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Wilk B, Smailovic H, Sullivan R, Sistermans ER, Butler J, Jago H, Kovacs M, Wisenberg G, Thiessen JD, Prato FS. Myocardial glucose suppression may interfere with the detection of inflammatory cells with FDG-PET as suggested in a canine model of myocardial infarction. EJNMMI Res 2023; 13:90. [PMID: 37823919 PMCID: PMC10570261 DOI: 10.1186/s13550-023-01040-y] [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: 04/05/2023] [Accepted: 10/04/2023] [Indexed: 10/13/2023] Open
Abstract
BACKGROUND After myocardial infarction, fibrosis and an ongoing dysregulated inflammatory response have been shown to lead to adverse cardiac remodeling. FDG PET is an imaging modality sensitive to inflammation as long as suppression protocols are observed while gadolinium enhanced MRI can be used to determine extracellular volume (ECV), a measure of fibrosis. In patients, glucose suppression is achieved variously through a high fat diet, fasting and injection of heparin. To emulate this process in canines, a heparin injection and lipid infusion are used, leading to similar fatty acids in the blood. The aim of this study was to examine the effect of glucose suppression on the uptake of FDG in the infarcted myocardial tissue and also on the determination of ECV in both the infarcted tissue and in the myocardium remote to the zone of infarction during a long constant infusion of FDG and Gd-DTPA. RESULTS Extracellular volume was affected neither by suppression nor the length of the constant infusion in remote and infarcted tissue. Metabolic rate of glucose in infarcted tissue decreased during and after suppression of glucose uptake by lipid infusion and heparin injection. An increase in fibrosis and inflammatory cells was found in the center of the infarct as compared to remote tissue. CONCLUSION The decrease in the metabolic rate of glucose in the infarcted tissue suggests that inflammatory cells may be affected by glucose suppression through heparin injection and lipid infusion.
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Affiliation(s)
- Benjamin Wilk
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada.
- Medical Biophysics, Western University, London, ON, Canada.
| | - Haris Smailovic
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON, Canada
| | - Rebecca Sullivan
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON, Canada
| | - Erik R Sistermans
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
| | - John Butler
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
| | - Hannah Jago
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
| | - Michael Kovacs
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON, Canada
| | - Gerald Wisenberg
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON, Canada
- MyHealth Centre, Arva, ON, Canada
| | - Jonathan D Thiessen
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON, Canada
| | - Frank S Prato
- Department of Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Medical Biophysics, Western University, London, ON, Canada
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Murphy J, AlJaroudi WA, Hage FG. Review of cardiovascular imaging in the Journal of Nuclear Cardiology 2022: positron emission tomography, computed tomography, and magnetic resonance. J Nucl Cardiol 2023; 30:941-954. [PMID: 37204688 DOI: 10.1007/s12350-023-03283-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 04/17/2023] [Indexed: 05/20/2023]
Abstract
In 2022, the Journal of Nuclear Cardiology® published many excellent original research articles and editorials focusing on imaging in patients with cardiovascular disease. In this review of 2022, we summarize a selection of articles to provide a concise recap of major advancements in the field. In the first part of this 2-part series, we addressed publications pertaining to single-photon emission computed tomography. In this second part, we focus on positron emission tomography, cardiac computed tomography, and cardiac magnetic resonance. We specifically review advances in imaging of non-ischemic cardiomyopathy, cardio-oncology, infectious disease cardiac manifestations, atrial fibrillation, detection and prognostication of atherosclerosis, and technical improvements in the field. We hope that this review will be useful to readers as a reminder to articles they have seen during the year as well as ones they have missed.
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Affiliation(s)
- John Murphy
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - 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, GSB 446, 1900 University BLVD, Birmingham, AL, 35294, USA.
- Section of Cardiology, Birmingham Veterans Affairs Medical Center, Birmingham, AL, USA.
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Chau OW, Islam A, Lock M, Yu E, Dinniwell R, Yaremko B, Brackstone M, Pavlosky W, Butler J, Biernaski H, Graf C, Wisenberg G, Prato FS, Gaede S. PET/MRI Assessment of Acute Cardiac Inflammation 1 Month After Left-Sided Breast Cancer Radiation Therapy. J Nucl Med Technol 2023; 51:133-139. [PMID: 37192822 DOI: 10.2967/jnmt.122.264960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 03/30/2023] [Indexed: 05/18/2023] Open
Abstract
Our purpose was to investigate the utility of 18F-FDG PET/MRI and serial blood work to detect early inflammatory responses and cardiac functionality changes at 1 mo after radiation therapy (RT) in patients with left-sided breast cancer. Methods: Fifteen left-sided breast cancer patients who enrolled in the RICT-BREAST study underwent cardiac PET/MRI at baseline and 1 mo after standard RT. Eleven patients received deep-inspiration breath-hold RT, whereas the others received free-breathing RT. A list-mode 18F-FDG PET scan with glucose suppression was acquired. Myocardial inflammation was quantified by the change in 18F-FDG SUVmean (based on body weight) and analyzed on the basis of the myocardial tissue associated with the left anterior descending, left circumflex, or right coronary artery territories. MRI assessments, including left ventricular functional and extracellular volumes (ECVs), were extracted from T1 (before and during a constant infusion of gadolinium) and cine images, respectively, acquired simultaneously during the PET acquisition. Cardiac injury and inflammation biomarker measurements of high-sensitivity troponin T, high-sensitivity C-reactive protein, and erythrocyte sedimentation rate were measured at the 1-mo follow-up and compared with preirradiation values. Results: At the 1-mo follow-up, a significant increase (10%) in myocardial SUVmean in left anterior descending segments (P = 0.04) and ECVs in slices at the apex (6%) and base (5%) was detected (P ≤ 0.02). Further, a significant reduction in left ventricular stroke volume (-7%) was seen (P < 0.02). No significant changes in any circulating biomarkers were seen at follow-up. Conclusion: Myocardial 18F-FDG uptake and functional MRI, including stroke volume and ECVs, were sensitive to changes at 1 mo after breast cancer RT, with findings suggesting an acute cardiac inflammatory response to RT.
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Affiliation(s)
- Oi Wai Chau
- London Regional Cancer Program, London, Ontario, Canada;
- Western University, London, Ontario, Canada
| | - Ali Islam
- Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada; and
| | - Michael Lock
- London Regional Cancer Program, London, Ontario, Canada
- Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
| | - Edward Yu
- London Regional Cancer Program, London, Ontario, Canada
- Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
| | - Robert Dinniwell
- London Regional Cancer Program, London, Ontario, Canada
- Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
| | - Brian Yaremko
- London Regional Cancer Program, London, Ontario, Canada
- Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
| | - Muriel Brackstone
- Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada; and
- London Health Sciences Centre, London, Ontario, Canada
| | - William Pavlosky
- Lawson Health Research Institute, London, Ontario, Canada; and
- London Health Sciences Centre, London, Ontario, Canada
| | - John Butler
- Lawson Health Research Institute, London, Ontario, Canada; and
| | | | - Chantelle Graf
- Lawson Health Research Institute, London, Ontario, Canada; and
| | - Gerald Wisenberg
- Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada; and
- London Health Sciences Centre, London, Ontario, Canada
| | - Frank S Prato
- Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada; and
| | - Stewart Gaede
- London Regional Cancer Program, London, Ontario, Canada
- Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada; and
- London Health Sciences Centre, London, Ontario, Canada
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Xi XY, Liu Z, Wang LF, Yang MF. Prognostic value of cardiac inflammation in ST-segment elevation myocardial infarction: A 18F-fluorodeoxyglucose PET/CT study. J Nucl Cardiol 2022; 29:3018-3027. [PMID: 34773185 DOI: 10.1007/s12350-021-02858-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 10/24/2021] [Indexed: 01/18/2023]
Abstract
BACKGROUND 18F-fluorodeoxyglucose (FDG) imaging is used to detect cardiac inflammation and predict functional outcome in acute myocardial infarction (MI). However, data on the correlation of post-MI acute cardiac inflammation evaluated by 18F-FDG imaging and major adverse cardiac events (MACE) are limited. Therefore, we sought to explore the prognostic value of cardiac 18F-FDG imaging in patients with acute ST-segment elevation MI (STEMI). METHODS Thirty-six patients with STEMI underwent 18F-FDG positron emission tomography/computed tomography (PET/CT) 5 days after primary percutaneous coronary intervention. 18F-FDG activity in infarcted and remote regions, as well as peri-coronary adipose tissue (PCAT), were measured and expressed as the maximum standardized uptake value (SUVmax). Patients were followed to determine the occurrence of MACE. RESULTS The infarcted myocardium had a higher 18F-FDG intensity than the remote area. Moreover, the PCAT of culprit coronary arteries showed a higher 18F-FDG uptake than that of non-culprit arteries. Multivariate Cox regression analysis showed that increased SUVmax of PCAT [HR 5.198; 95% CI (1.058, 25.537), P = .042] was independently associated with a higher risk of MACE. CONCLUSIONS Enhanced PCAT activity after acute MI is related to the occurrence of MACE, and 18F-FDG PET/CT plays a promising role in providing prognostic information in patients with STEMI.
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Affiliation(s)
- Xiao-Ying Xi
- Department of Nuclear Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Ze Liu
- Department of Cardiology, Peking University Third Hospital Yanqing Hospital, Beijing, 102100, China
| | - Le-Feng Wang
- Center of Cardiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China.
| | - Min-Fu Yang
- Department of Nuclear Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China.
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Wilk B, Smailovic H, Wisenberg G, Sykes J, Butler J, Kovacs M, Thiessen JD, Prato FS. Tracking the progress of inflammation with PET/MRI in a canine model of myocardial infarction. J Nucl Cardiol 2022; 29:1315-1325. [PMID: 33462785 DOI: 10.1007/s12350-020-02487-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 11/28/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND Following myocardial infarction, tissue undergoes pathophysiological changes involving inflammation and scar tissue formation. However, little is known about the pathophysiology and prognostic significance of any corresponding changes in remote myocardium. The aim of this study was to investigate the potential application of a combined constant infusion of 18F-FDG and Gd-DTPA to quantitate inflammation and extracellular volume (ECV) from 3 to 40 days after myocardial infarction. METHODS Eight canine subjects were imaged at multiple time points following induction of an MI with a 60-minute concurrent constant infusion of Gd-DTPA and 18F-FDG using a hybrid PET/MRI scanner. RESULTS There was a significant increase in ECV in remote myocardium on day 14 post-MI (P = .034) and day 21 (P = .021) compared to the baseline. ECV was significantly elevated in the infarcted myocardium compared to remote myocardium at all time points post-MI (days 3, 7, 14, 21, and 40) (P < .001) while glucose uptake was also increased within the infarct on days 3, 7, 14, and 21 but not 40. CONCLUSIONS The significant increase in ECV in remote tissue may be due to an ongoing inflammatory process in the early weeks post-infarct.
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Affiliation(s)
- B Wilk
- Lawson Health Research Institute, London, Canada.
- Department of Medical Biophysics, Western University, London, Canada.
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada.
| | - H Smailovic
- Lawson Health Research Institute, London, Canada
- Department of Medical Imaging, Western University, London, Canada
| | - G Wisenberg
- Lawson Health Research Institute, London, Canada
- MyHealth Centre, Arva, Canada
| | - J Sykes
- Lawson Health Research Institute, London, Canada
| | - J Butler
- Lawson Health Research Institute, London, Canada
| | - M Kovacs
- Lawson Health Research Institute, London, Canada
- Department of Medical Biophysics, Western University, London, Canada
- Department of Medical Imaging, Western University, London, Canada
| | - J D Thiessen
- Lawson Health Research Institute, London, Canada
- Department of Medical Biophysics, Western University, London, Canada
- Department of Medical Imaging, Western University, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
| | - F S Prato
- Lawson Health Research Institute, London, Canada
- Department of Medical Biophysics, Western University, London, Canada
- Department of Medical Imaging, Western University, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
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