Publications by authors named "Matthieu Pelletier-Galarneau"

56 Publications

Incremental Value of FDG-PET in the Evaluation of Cardiac Masses.

Curr Cardiol Rep 2021 06 3;23(7):78. Epub 2021 Jun 3.

Department of Medical Imaging, Montreal Heart Institute, 5000 Bélanger, Montreal, Quebec, H1T1C8, Canada.

Purpose Of Review: This study aims to review the various roles and evidence underlying the use of fluorodeoxyglucose (FDG) PET/CT and PET/MR for the assessment of cardiac masses.

Recent Findings: The role of FDG-PET for the evaluation of cardiac masses continues to evolve. Studies have shown that FDG-PET is particularly well-suited for differentiating malignant from benign cardiac lesions based on their metabolic activity. Furthermore, FDG-PET is uniquely positioned to investigate patients with cardiac mass as most malignant cardiac lesions are metastasis. Finally, FDG-PET enables staging of patients with primary malignant cardiac tumor, identification of potential biopsy site, and planning of radiotherapy. FDG-PET is a complementary tool for the evaluation of patients with cardiac mass and can help differentiate benign from malignant lesions, as well as provide whole-body staging.
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http://dx.doi.org/10.1007/s11886-021-01509-zDOI Listing
June 2021

Quantification of Myocardial Mitochondrial Membrane Potential Using PET.

Curr Cardiol Rep 2021 05 10;23(6):70. Epub 2021 May 10.

Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, 125 Nashua St., Boston, MA, 02114, USA.

Purpose Of Review: To present a method enabling in vivo quantification of tissue membrane potential (ΔΨ), a proxy of mitochondrial membrane potential (ΔΨ), to review the origin and role of ΔΨ, and to highlight potential applications of myocardial ΔΨ imaging.

Recent Findings: Radiolabelled lipophilic cations have been used for decades to measure ΔΨ in vitro. Using similar compounds labeled with positron emitters and appropriate compartment modeling, this technique now allows in vivo quantification of ΔΨ with positron emission tomography. Studies have confirmed the feasibility of measuring myocardial ΔΨ in both animals and humans. In addition, ΔΨ showed very low variability among healthy subjects, suggesting that this method could allow detection of relatively small pathological changes. In vivo assessment of myocardial ΔΨ provides a new tool to study the pathophysiology of cardiovascular diseases and has the potential to serve as a new biomarker to assess disease stage, prognosis, and response to therapy.
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http://dx.doi.org/10.1007/s11886-021-01500-8DOI Listing
May 2021

Rubidium-82 Positron Emission Tomography with Intravenous Ergonovine to Diagnose Vasospastic Angina.

Can J Cardiol 2021 Mar 31. Epub 2021 Mar 31.

Montreal Heart Institute, Montréal, Canada.

The gold standard to diagnose vasospastic angina is intracoronary reactivity testing which is performed selectively at dedicated centers. Non-invasive imaging with single-photon emission computerized tomography (SPECT) or echocardiography do not enable accurate localization of spasm or quantification of change in myocardial perfusion in response to an abnormal vasoreactivity. Rubidium-82 positron emission tomography myocardial perfusion imaging (Rb PET-MPI) with intravenous ergonovine was used to diagnose refractory vasospastic angina in a patient with a complex ischemic syndrome, recent coronary stenting and persistent atypical angina despite maximal-tolerable doses of guideline-directed medical therapy.
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http://dx.doi.org/10.1016/j.cjca.2021.03.020DOI Listing
March 2021

Assessing cardiovascular infection and inflammation with FDG-PET.

Am J Nucl Med Mol Imaging 2021 15;11(1):46-58. Epub 2021 Feb 15.

Department of Medical Imaging, Montreal Heart Institute Montreal, Quebec, Canada.

FDG-PET has been shown to be a useful imaging modality for the assessment of cardiovascular infection and inflammatory pathologies. However, interpretation of these studies can be challenging in light of the variability of physiological myocardial uptake and, occasionally, interpreter's lack of familiarity with the typical findings present in cardiac pathologies. In this article, we review established and emerging applications for cardiovascular infection and inflammation imaging with FDG-PET and present typical examples of representative pathologies.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7936252PMC
February 2021

Assessment of myocardial inflammation post-infarct with PET/MRI: Getting into the nitty-gritty.

J Nucl Cardiol 2021 Feb 24. Epub 2021 Feb 24.

Department of Medical Imaging, Institut de Cardiologie de Montréal, Montreal, Canada.

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http://dx.doi.org/10.1007/s12350-021-02558-1DOI Listing
February 2021

FLT-PET for the assessment of systemic sarcoidosis including cardiac and CNS involvement: a prospective study with comparison to FDG-PET.

EJNMMI Res 2020 Dec 10;10(1):154. Epub 2020 Dec 10.

Arrhythmia Service, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, 40 Ruskin Street - Room H 1285, Ottawa, ON, K1Y 4W7, Canada.

Background: 2-deoxy-2-[18F]fluoro-D-glucose's (FDG) biodistribution limits the evaluation of cardiac sarcoidosis (CS) and neurosarcoidosis (NS). While protocols for cardiac suppression exist, they can be inconvenient for patients and lead to incomplete cardiac suppression in many cases. Furthermore, FDG PET is limited in the detection of neurosarcoidosis due to an inability to suppress high level of physiological uptake within the brain. 3'-deoxy-3'-[F]fluorothymidine (FLT) has been shown to accumulate in sarcoidosis lesions and this tracer lacks significant physiological myocardial and brain uptake, suggesting that this tracer may be useful for the assessment of sarcoidosis, including CS and NS, without the need for patient preparation. This prospective pilot study examined the performance of FLT vs FDG PET for systemic sarcoidosis, including cardiac and neural involvement.

Materials And Methods: Fourteen subjects with sarcoidosis were prospectively recruited and imaged with FDG- and FLT-PET. Two blinded, experienced readers independently reviewed the FLT-PET and FDG-PET images. Lesion distribution was compared between FLT and FDG. Agreement between FLT- and FDG-PET was determined using Cohen's kappa and the intra-class correlation coefficient. Inter-observer variability of FLT and FDG-PET was assessed.

Results: Twelve subjects had CS as per Heart Rhythm Society criteria and 1 had NS. FLT-PET was positive in 12 (86%), and FDG-PET in 11 (79%), with cardiac uptake present in 6 (50%) and 7 (58%) of subjects with CS, respectively. The subject with NS demonstrated uptake on both FLT and FDG-PET, with more lesions on FLT. There were no significant differences in the anatomical distribution of lesions between FLT and FDG. SUVs were significantly (p < 0.001) higher for FDG than FLT (5.8 ± 3.0 vs 2.3 ± 1.1, respectively), but not (p = 0.90) after adjusting for blood pool activity (2.8 ± 1.4 vs 2.8 ± 1.1, respectively). Agreement between FLT- and FDG-PET was good to excellent for the diagnosis of sarcoidosis, lung involvement, CS, and NS (κ = 0.76, 0.69, 0.86, and 1.0, respectively). Inter-observer agreement for FLT was excellent for diagnosing sarcoidosis, CS and NS (κ = 0.81, 0.85, and 1.0, respectively) and comparable to that of FDG.

Conclusions: FLT-PET may be useful for the assessment of systemic sarcoidosis, as well as cardiac and neural involvement.
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http://dx.doi.org/10.1186/s13550-020-00742-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7728930PMC
December 2020

Sinus Tarsi Syndrome on Bone Scintigraphy With SPECT/CT: Spectrum of Findings.

Clin Nucl Med 2021 Feb;46(2):e103-e105

Abstract: Sinus tarsi syndrome is a common cause of hindfoot pain in adults; however, diagnosis on planar bone scintigraphy can be challenging. We present 3 cases of sinus tarsi syndrome, review the spectrum of imaging findings associated with sinus tarsi syndrome, and show the key role that SPECT/CT can play in its diagnosis.
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http://dx.doi.org/10.1097/RLU.0000000000003396DOI Listing
February 2021

Comparison of 18F-sodium fluoride positron emission tomography imaging and 99mTc-pyrophosphate in cardiac amyloidosis.

J Nucl Cardiol 2020 Nov 4. Epub 2020 Nov 4.

Department of Medical Imaging, Institut de Cardiologie de Montréal, Montréal, Canada.

Background: Pyrophosphate (PYP) scintigraphy provides high diagnostic accuracy for the detection of transthyretin (ATTR) cardiac amyloidosis (CA). There has recently been emerging interest in using 18F-sodium fluoride (NaF) for this application, yet its sensitivity has never been directly compared to that of PYP, the current molecular gold standard METHODS: Twelve subjects with ATTR-CA and 5 controls referred for PYP-SPECT were prospectively enrolled. 18F-NaF PET/CT scans were performed at 1 and 3 hours. Qualitative and quantitative analyses of the images were performed, and the sensitivity of 18F-NaF PET/CT and PYP-SPECT were compared RESULTS: Visual interpretation of NaF PET/CT yielded a sensitivity of 0.25 (95% CI 0.089 to 0.53) for the detection of ATTR-CA, which is significantly inferior to that of PYP-SPECT/CT (100%, P = .016). Visual interpretation at 3 hours yielded a similar sensitivity of 0.30 (95% CI 0.11 to 0.60, P  = 1.00). There were no false-positive NaF PET studies. Mean target-to-background ratio (TBRmean) at 1h did not differ significantly (P = .21) in ATTR-CA subjects (0.83 ± 0.15) compared to controls (0.72 ± 0.15). Receiver operating characteristic (ROC) analysis yielded an area under the curve (AUC) of 0.69 ± 0.16 (95% CI 0.37 to 1.00, P = .23).

Conclusion: With qualitative and quantitative analyses, sensitivity of NaF PET/CT is significantly inferior to that of PYP-SPECT for the diagnosis of ATTR-CA.
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http://dx.doi.org/10.1007/s12350-020-02425-5DOI Listing
November 2020

The Utility of SPECT/CT in Diagnosing Haglund Syndrome With Bone Scintigraphy.

Clin Nucl Med 2021 Jan;46(1):45-46

Haglund syndrome-the combination of Haglund's deformity, retrocalcaneal bursitis, and achilles tendinopathy-is a common cause of hind foot pain in adults; however, diagnosis on planar scintigraphy can be challenging. We present a case of Haglund syndrome and show the key role that SPECT/CT can play in its diagnosis.
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http://dx.doi.org/10.1097/RLU.0000000000003346DOI Listing
January 2021

In vivo quantitative mapping of human mitochondrial cardiac membrane potential: a feasibility study.

Eur J Nucl Med Mol Imaging 2021 02 27;48(2):414-420. Epub 2020 Jul 27.

Department of Radiology, Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, 125 Nashua Street, #6604, Boston, MA, 02114, USA.

Purpose: Alteration in mitochondrial membrane potential (ΔΨ) is an important feature of many pathologic processes, including heart failure, cardiotoxicity, ventricular arrhythmia, and myocardial hypertrophy. We present the first in vivo, non-invasive, assessment of regional ΔΨ in the myocardium of normal human subjects.

Methods: Thirteen healthy subjects were imaged using [F]-triphenylphosphonium ([F]TPP+) on a PET/MR scanner. The imaging protocol consisted of a bolus injection of 300 MBq followed by a 120-min infusion of 0.6 MBq/min. A 60 min, dynamic PET acquisition was started 1 h after bolus injection. The extracellular space fraction (f) was simultaneously measured using MR T1-mapping images acquired at baseline and 15 min after gadolinium injection with correction for the subject's hematocrit level. Serial venous blood samples were obtained to calculate the plasma tracer concentration. The tissue membrane potential (ΔΨ), a proxy of ΔΨ, was calculated from the myocardial tracer concentration at secular equilibrium, blood concentration, and fECS measurements using a model based on the Nernst equation.

Results: In 13 healthy subjects, average tissue membrane potential (ΔΨ), representing the sum of cellular membrane potential (ΔΨ) and ΔΨ, was - 160.7 ± 3.7 mV, in excellent agreement with previous in vitro assessment.

Conclusion: In vivo quantification of the mitochondrial function has the potential to provide new diagnostic and prognostic information for several cardiac diseases as well as allowing therapy monitoring. This feasibility study lays the foundation for further investigations to assess these potential roles. Clinical trial identifier: NCT03265431.
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http://dx.doi.org/10.1007/s00259-020-04878-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7839097PMC
February 2021

Detection of Native and Prosthetic Valve Endocarditis: Incremental Attributes of Functional FDG PET/CT over Morphologic Imaging.

Curr Cardiol Rep 2020 07 9;22(9):93. Epub 2020 Jul 9.

Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.

Purpose Of Review: The clinical and incremental value of functional imaging with F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) for the diagnosis and management of patients with suspected native and prosthetic valve infective endocarditis (IE).

Recent Findings: The diagnosis of IE is challenging because of the highly variable clinical presentations, especially in the case of prosthetic valve endocarditis (PVE). FDG PET/CT has been shown to play an important role for the diagnosis of PVE as a major Duke criterion. Whether FDG PET/CT could play a similar role in patients with suspected native valve endocarditis (NVE) is less well established. It is increasingly recognized that IE is a multisystem disorder, and identification of extra-cardiac manifestations on whole-body FDG PET/CT impacts management and prognosis of patients with IE. Finally, FDG PET/CT provides incremental prognostic value over other clinical and para-clinical parameters, enabling prediction of in-hospital mortality, IE recurrence, hospitalization, and new onset heart failure and embolic events. FDG PET/CT plays a key role in the investigation of patients with suspected IE, enabling detection of valvular infection and extra-cardiac manifestations of the infection which has important prognostic implications.
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http://dx.doi.org/10.1007/s11886-020-01334-wDOI Listing
July 2020

Vascular graft infection: Improving diagnosis with functional imaging.

J Nucl Cardiol 2020 Jul 8. Epub 2020 Jul 8.

Department of Medical Imaging, Centre Hospitalier de l'Université de Montréal, Montreal, Canada.

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http://dx.doi.org/10.1007/s12350-020-02269-zDOI Listing
July 2020

In vivo quantification of mitochondrial membrane potential.

Nature 2020 Jul 8;583(7815):E17-E18. Epub 2020 Jul 8.

Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.

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http://dx.doi.org/10.1038/s41586-020-2366-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7357846PMC
July 2020

Imaging of Mitochondrial Depolarization of Myocardium With Positron Emission Tomography and a Proton Gradient Uncoupler.

Front Physiol 2020 15;11:491. Epub 2020 May 15.

Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.

Background: We recently reported a method using positron emission tomography (PET) and the tracer F-labeled tetraphenylphosphonium (F-TPP) for mapping the tissue (i.e., cellular plus mitochondrial) membrane potential (ΔΨ) in the myocardium. The purpose of this work is to provide additional experimental evidence that our methods can be used to observe transient changes in the volume of distribution for F-TPP and mitochondrial membrane potential (ΔΨ).

Methods: We tested these hypotheses by measuring decreases of F-TPP concentration elicited when a proton gradient uncoupler, BAM15, is administered by intracoronary infusion during PET scanning. BAM15 is the first proton gradient uncoupler shown to affect the mitochondrial membrane without affecting the cellular membrane potential. Preliminary dose response experiments were conducted in two pigs to determine the concentration of BAM15 infusate necessary to perturb the F-TPP concentration. More definitive experiments were performed in two additional pigs, in which we administered an intravenous bolus plus infusion of F-TPP to reach secular equilibrium followed by an intracoronary infusion of BAM15.

Results: Intracoronary BAM15 infusion led to a clear decrease in F-TPP concentration, falling to a lower level, and then recovering. A second BAM15 infusion reduced the F-TPP level in a similar fashion. We observed a maximum depolarization of 10 mV as a result of the BAM15 infusion.

Summary: This work provides evidence that the total membrane potential measured with F-TPP PET is sensitive to temporal changes in mitochondrial membrane potential.
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http://dx.doi.org/10.3389/fphys.2020.00491DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7243673PMC
May 2020

Tc-99m-pyrophosphate scintigraphy for the diagnosis of ATTR cardiac amyloidosis: Comparison of quantitative and semi-quantitative approaches.

J Nucl Cardiol 2020 10 31;27(5):1808-1815. Epub 2020 May 31.

Department of Medical Imaging, Institut de Cardiologie de Montreal, 5000, Bélanger, Montreal, QC, H1T1C8, Canada.

Background: ATTR cardiac amyloidosis (CA) can be diagnosed with Tc-99m-PYP scintigraphy. There are two recommended interpretative approaches: the quantitative heart-to-contralateral lung ratio (H/CL) at 1 hour and the semi-quantitative visual system at 3 hours. This study's aim was to compare both approaches and to apply the semi-quantitative method at 1 hour.

Methods: Tc-99m-PYP scans of 122 consecutive subjects were reviewed using both approaches. On 1 hour planar images, regions of interest were drawn over the heart and contralateral chest to determine H/CL. Myocardial uptake was graded on 1 and 3 hour SPECT images according to the semi-quantitative method. Concordance was examined using kappa statistics.

Results: 31, 10, and 81 studies were positive, negative, and equivocal, respectively, for ATTR-CA using the H/CL approach. Using the grading system, 35, 77, and 10 scans were positive, negative, and equivocal, respectively. The quantitative approach led to a significantly higher proportion of equivocal studies compared to the semi-quantitative approach (P < .0001). These approaches yielded discordant results in 2 subjects; biopsy results were concordant with SPECT grade. 1 and 3 hour SPECT grades provided concordant result in 99% of cases.

Conclusions: The H/CL approach resulted in a high proportion of equivocal studies. Using SPECT imaging, the semi-quantitative approach minimized this proportion and showed high concordance at 1 and 3 hours.
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http://dx.doi.org/10.1007/s12350-020-02205-1DOI Listing
October 2020

Comparison of myocardial blood flow and flow reserve with dobutamine and dipyridamole stress using rubidium-82 positron emission tomography.

J Nucl Cardiol 2021 02 24;28(1):34-45. Epub 2020 May 24.

University of Ottawa Heart Institute, University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada.

Background: The objective of this study was to compare the hyperemic myocardial blood flow (MBF) and myocardial flow reserve (MFR) obtained with dobutamine to those of dipyridamole in patients referred for myocardial perfusion imaging (MPI) using Rb positron emission tomography.

Methods: One hundred and fifty-six patients who underwent a Rb PET MPI study with dobutamine stress were included. A matching cohort of patients who underwent a Rb PET MPI study with dipyridamole stress was created, accounting for sex, age, history of coronary artery disease (CAD), prior revascularization, CAD risk factors, body mass index, and MPI interpretation.

Results: Global rest MBF (median [interquartile range] 0.84 [0.64-1.00] vs 0.69 [0.59-0.85]), stress MBF (2.36 [1.73-3.08] vs 1.66 [1.25-2.06]), MFR (2.75 [2.19-3.64] vs 2.29 [1.78-2.84]), and corrected MFR (2.85 [2.14-3.64] vs 2.20 [1.65-2.75]) were all significantly higher (P < 0.0001) in the dobutamine cohort compared to the dipyridamole cohort.

Conclusion: The results of this study suggest that dobutamine produces higher MBF compared to dipyridamole in a representative population referred to nuclear cardiology laboratories.
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http://dx.doi.org/10.1007/s12350-020-02186-1DOI Listing
February 2021

[F]FDG-PET CT for the evaluation of native valve endocarditis.

J Nucl Cardiol 2020 Mar 16. Epub 2020 Mar 16.

Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, USA.

Background: We examined the use of [F]FDG-PET/CT for the diagnosis of native valve endocarditis (NVE).

Methods: PET/CT images in patients with suspected NVE were retrospectively reviewed independently by two experienced physicians blinded to all clinical information. The gold standard consisted of surgical findings, when available, or the modified Duke criteria.

Results: Fifty four subjects were included, 31 (57%) with a diagnosis of NVE. [F]FDG-PET/CT correctly identified 21/31 (67.7%) subjects, yielding a sensitivity and specificity of 68% (95% CI 49-83%) and 100% (95% CI 85-100%), respectively. The sensitivity and specificity of the modified Duke criteria were 48% and 74%, respectively. Positive and negative predictive values of PET were 100% (95% CI 84-100%) and 70% (95% CI 51-84%), respectively. Modifying the Duke criteria to include [F]FDG-PET positivity as a major criterion increased sensitivity to 77% without affecting specificity and led to the correct reclassification of 8/18 (44.4%) subjects from Possible IE to Definite IE.

Conclusion: The addition of a positive [F]FDG-PET/CT as a major criterion in the modified Duke Criteria improved performance of the criteria for the diagnosis of NVE, particularly in those subjects with Possible IE.
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http://dx.doi.org/10.1007/s12350-020-02092-6DOI Listing
March 2020

Revisiting the relevance of the 3-month safety period in the evaluation of prosthetic valve endocarditis with FDG-PET/CT.

J Nucl Cardiol 2020 Feb 13. Epub 2020 Feb 13.

Department of Medical Imaging, Institut de Cardiologie de Montréal, Montréal, Canada.

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http://dx.doi.org/10.1007/s12350-020-02070-yDOI Listing
February 2020

Microvascular Angina Diagnosed by Absolute PET Myocardial Blood Flow Quantification.

Curr Cardiol Rep 2020 Jan 28;22(2). Epub 2020 Jan 28.

Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.

Purpose Of Review: The aim of this review is to provide an update on the use of positron emission tomography (PET) with myocardial blood flow (MBF) quantification for the diagnosis and management of patients with microvascular disease.

Recent Findings: It is now recognized that a large proportion of patients with classical angina and non-obstructive epicardial disease are suffering from microvascular angina. Microvascular angina shares several key features with epicardial coronary disease, including many risk factors. Clinical criteria for the diagnosis of microvascular angina were recently proposed and PET imaging is called to play a central role in evaluation of these patients. Indeed, PET allows non-invasive measurements of MBF and flow reserve, which are altered in microvascular dysfunction. Furthermore, PET with flow quantification provides independent prognostic information and has the potential to monitor response to therapy in microvascular disease. PET with MBF quantification allows detection of microvascular dysfunction and plays a key role in the investigation of patients with suspected microvascular angina.
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http://dx.doi.org/10.1007/s11886-020-1261-2DOI Listing
January 2020

Preclinical Validation of a Single-Scan Rest/Stress Imaging Technique for N-Ammonia Positron Emission Tomography Cardiac Perfusion Studies.

Circ Cardiovasc Imaging 2020 01 21;13(1):e009407. Epub 2020 Jan 21.

Department of Radiology, Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston (N.J.G., M.P.-G., D.W.W., J.L.G., M.D.N., G.E.F., N.M.A.).

Background: We previously proposed a technique for quantitative measurement of rest and stress absolute myocardial blood flow (MBF) using a 2-injection single-scan imaging session. Recently, we validated the method in a pig model for the long-lived radiotracer F-Flurpiridaz with adenosine as a pharmacological stressor. The aim of the present work is to validate our technique for NH.

Methods: Nine studies were performed in 6 pigs; 5 studies were done in the native state and 4 after infarction of the left anterior descending artery. Each study consisted of 3 dynamic scans: a 2-injection rest-rest single-scan acquisition (scan A), a 2-injection rest/stress single-scan acquisition (scan B), and a conventional 1-injection stress acquisition (scan C). Variable doses of adenosine combined with dobutamine were administered to induce a wide range of MBF. The 2-injection single-scan measurements were fitted with our nonstationary kinetic model (MGH2). In 4 studies, NH injections were paired with microsphere injections. MBF estimates obtained with our method were compared with those obtained with the standard method and with microspheres. We used a model-based method to generate separate rest and stress perfusion images.

Results: In the absence of stress (scan A), the MBF values estimated by MGH2 were nearly the same for the 2-radiotracer injections (mean difference: 0.067±0.070 mL·min·cc, limits of agreement: [-0.070 to 0.204] mL·min·cc), showing good repeatability. Bland-Altman analyses demonstrated very good agreement with the conventional method for both rest (mean difference: -0.034±0.035 mL·min·cc, limits of agreement: [-0.103 to 0.035] mL·min·cc) and stress (mean difference: 0.057±0.361 mL·min·cc, limits of agreement: [-0.651 to 0.765] mL·min·cc) MBF measurements. Positron emission tomography and microsphere MBF measurements correlated closely. Very good quality perfusion images were obtained.

Conclusions: This study provides in vivo validation of our single-scan rest-stress method for NH measurements. The NH rest/stress myocardial perfusion imaging procedure can be compressed into a single positron emission tomography scan session lasting less than 15 minutes.
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http://dx.doi.org/10.1161/CIRCIMAGING.119.009407DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7205554PMC
January 2020

Reverse redistribution on Rb-82: Does the mechanism of stress play a role?

World J Nucl Med 2019 Oct-Dec;18(4):420-423. Epub 2019 Dec 18.

Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard University, Boston, Massachusetts, United States.

We present a case of reverse redistribution in a patient imaged with Rb-82 positron-emitting tomography. The patient was imaged twice in rapid succession using pharmacological stress - once with dipyridamole and once with dobutamine. The patient demonstrated reverse redistribution after dipyridamole but not after dobutamine administration. We speculate on the relationship between the pharmacological stressing agent and the presence of reverse redistribution.
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http://dx.doi.org/10.4103/wjnm.WJNM_100_18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6945350PMC
December 2019

A big step towards clinical implementation of myocardial blood flow quantification with CZT SPECT.

J Nucl Cardiol 2019 Sep 18. Epub 2019 Sep 18.

Division of Cardiology, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada.

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http://dx.doi.org/10.1007/s12350-019-01894-7DOI Listing
September 2019

Utility of FDG-PET/CT for the Detection and Characterization of Sternal Wound Infection Following Sternotomy.

Nucl Med Mol Imaging 2019 Aug 14;53(4):253-262. Epub 2019 Jun 14.

1Department of Medical Imaging, Institut de cardiologie de Montréal, Montreal, Quebec, Canada.

Purpose: FDG-PET/CT has the potential to play an important role in the diagnosis of sternal wound infections (SWI). The purpose of this study was to analyze the diagnostic accuracy of FDG-PET/CT for SWI in patients following sternotomy.

Methods: We performed a single-center, retrospective analysis of patients who had undergone median sternotomy and FDG-PET/CT imaging. The gold standard consisted of positive bacterial culture and/or the presence of purulent material at surgery. Qualitative patterns of sternal FDG uptake, SUV, and associated CT findings were determined, and an imaging scoring system was developed. The diagnostic performances were studied in both the recent (≤ 6 months between sternotomy and imaging) and remote surgery phase (> 6 months).

Results: A total of 40 subjects were identified with 11 confirmed SWI cases. Consensus interpretation was associated with a sensitivity of 91% and specificity of 97%. Combination of uptake patterns yielded an AUC of 0.96 while use of SUVmax yielded an AUC of 0.82.

Conclusions: Results suggest that FDG-PET/CT may be useful for the diagnosis of SWI with optimal diagnostic accuracy achieved by identifying specific patterns of uptake. SUV can be helpful in assessing subjects with remote surgery, but its use is limited in the context of recent surgery. Further studies are required to confirm these results.
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http://dx.doi.org/10.1007/s13139-019-00599-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6694333PMC
August 2019

Editorial commentary: Potential for personalized imaging with new radiotracers and cardiac PET.

Trends Cardiovasc Med 2020 01 7;30(1):20-21. Epub 2019 May 7.

Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, Canada. Electronic address:

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http://dx.doi.org/10.1016/j.tcm.2019.04.010DOI Listing
January 2020

The potential of regional myocardial blood flow measurement with SPECT.

J Nucl Cardiol 2021 02 30;28(1):260-262. Epub 2019 Apr 30.

Division of Cardiology, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada.

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http://dx.doi.org/10.1007/s12350-019-01727-7DOI Listing
February 2021

The potential for PET-guided revascularization of coronary artery disease.

Eur J Nucl Med Mol Imaging 2019 06 2;46(6):1218-1221. Epub 2019 Apr 2.

Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada.

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http://dx.doi.org/10.1007/s00259-019-04316-5DOI Listing
June 2019

PET/CT for Diagnosis and Management of Large-Vessel Vasculitis.

Curr Cardiol Rep 2019 03 18;21(5):34. Epub 2019 Mar 18.

Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada.

Purpose Of Review: This review aims to discuss the use of fluorodeoxyglucose (FDG) positron emission tomography (PET/CT) for diagnosis and management of patients with large-vessel vasculitis (LVV).

Recent Findings: Incidence of LVV is likely underestimated, in part due to its non-specific symptoms. Nevertheless, early diagnosis of LVV is essential to initiate timely therapy in order to prevent vascular complications, such as stenoses and aneurysms. FDG PET/CT imaging has the ability to detect LVV during the acute phase, prior to edema and other vascular structural changes, with its high sensitivity for inflammatory activity. FDG PET/CT was shown to be a powerful prognostic marker by allowing identification of patients at risk of vascular complications. Additionally, preliminary data support the use of FDG PET/CT to follow therapy efficacy. FDG PET/CT allows early detection of inflammation, before morphological and irreversible vascular changes can be observed, allowing prompt diagnosis and treatment of LVV.
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http://dx.doi.org/10.1007/s11886-019-1122-zDOI Listing
March 2019

Examining the sensitivity of 18F-NaF PET for the imaging of cardiac amyloidosis.

J Nucl Cardiol 2021 02 4;28(1):209-218. Epub 2019 Mar 4.

Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard University, Boston, MA, USA.

Background: Conventional nuclear imaging with bone-seeking radiopharmaceuticals has been shown to be a sensitive test for the detection of transthyretin cardiac amyloidosis (ATTR); however, to date, few data exist on the utility of F-sodium fluoride (NaF) positron emission tomography (PET) in subjects with cardiac amyloidosis (CA).

Methods: Myocardial perfusion imaging and cardiac F-NaF PET/CT of 7 subjects with ATTR, four with light-chain CA (AL), and four controls were retrospectively reviewed. Qualitative interpretation and quantitative analyses with average left ventricular standardized uptake values (SUV) and target-to-background ratios (TBR) were performed.

Results: Average TBR was significantly increased in subjects with ATTR (0.98 ± 0.09) compared to AL (0.85 ± 0.08, P = .026) and CTL (0.82 ± 0.07, P = .020), while SUV was not (P = .14). Receiver-operator characteristic (ROC) analysis yielded an area under the curve (AUC) of 0.91, with a sensitivity/specificity of 75%/100% for TBR using a cutoff value of 0.89 for the diagnosis of ATTR. Qualitative interpretation resulted in a sensitivity/specificity of 57%/100% for ATTR.

Conclusions: While F-NaF PET/CT demonstrates good diagnostic accuracy for ATTR, particularly when using quantitative analysis, the low TBR values observed in ATTR indicate poor myocardial signal. F-NaF PET/CT is not yet ready for clinical use in CA until further comparison studies are performed with Tc-DPD/PYP.
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http://dx.doi.org/10.1007/s12350-019-01675-2DOI Listing
February 2021
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