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Zelt JGE, Mielniczuk LM, Orlandi C, Robinson S, Hadizad T, Walter O, Garrard L, Beanlands RSB, deKemp RA. PET imaging of sympathetic innervation with [ 18F]Flurobenguan vs [ 11C]mHED in a patient with ischemic cardiomyopathy. J Nucl Cardiol 2019; 26:2151-2153. [PMID: 30456496 DOI: 10.1007/s12350-018-01527-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 11/07/2018] [Indexed: 11/24/2022]
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Renaud JM, Wu KY, Gardner K, Aung M, Beanlands RSB, deKemp RA. Saline-push improves rubidium-82 PET image quality. J Nucl Cardiol 2019; 26:1869-1874. [PMID: 29589206 PMCID: PMC6908549 DOI: 10.1007/s12350-018-1261-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 03/16/2018] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Rubidium-82 (82Rb) PET is used widely for myocardial perfusion imaging. The purpose of this study was to investigate if an additional saline-push following the 82Rb elution improves PET image quality. METHODS 82Rb PET scans were acquired with and without 26 mL saline-push in six patients as part of a clinical quality improvement program. Dynamic images were analyzed to measure the total activity delivered to the superior vena cava (SVC) and retained in the left ventricle (LV) myocardium. Tracer uptake images were used to measure blood background coefficient-of-variation (COV), myocardium-to-blood signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) to assess image quality. RESULTS Similar eluted activity was measured with/without the saline-push (830 vs 795 MBq; P = 0.24). The activity delivered to the heart and retained in the myocardium was consistently increased more than twofold (SVC: + 114% and LV: + 104%; P < 0.001) with the saline-push. Image quality was improved in all patients, with lower background noise (COV: - 19%), higher SNR (+ 24%) and CNR (+ 27%) (all P ≤ 0.01). CONCLUSIONS The saline-push used to flush 82Rb activity out of the infuser tubing, patient injection and intravenous access lines consistently increased the activity delivered to the heart by twofold. This technique is recommended to maximize image quality with 82Rb PET.
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Bami K, Tewari S, Guirguis F, Garrard L, Guo A, Hossain A, Ruddy TD, Beanlands RSB, deKemp RA, Chow BJW, Dwivedi G. Prognostic utility of splenic response ratio in dipyridamole PET myocardial perfusion imaging. J Nucl Cardiol 2019; 26:1888-1897. [PMID: 29651739 DOI: 10.1007/s12350-018-1269-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 03/13/2018] [Indexed: 11/26/2022]
Abstract
BACKGROUND Cardiac magnetic resonance perfusion studies with adenosine stress have shown that splenic response can identify patients with inadequate pharmacologic stress. We investigate the incremental prognostic impact of splenic response ratio (SRR) in patients with normal Rubidium (Rb)-82 PET myocardial perfusion imaging (MPI). METHODS Consecutive patients undergoing dipyridamole Rb-82 PET MPI for the evaluation of coronary artery disease were screened. Spleen and liver Rb-82 activity was measured and the SRR was calculated: SRR = (Spleen stress/Liver stress)/(Spleen rest/Liver rest). Major adverse cardiac events (MACE) were determined at 1 year of follow-up in patients with normal summed stress score and normal summed difference score. RESULTS Of the 839 patients screened, the spleen was visualized in 703 (84%) of scans. There was significantly higher MACE observed in splenic non-responders vs splenic responders in both the normal SSS (7.8% vs 2.9%, P = .027) and the normal SDS groups (7.4% vs 2.2%, P = .014). In multivariate analysis in patients with normal SDS, splenic response was a significant, independent predictor of MACE (HR 2.97, 95% CI 1.10 to 8.04, P = .033). CONCLUSIONS SRR is a novel imaging metric to identify patients with sub-maximal vasodilator stress and an incremental prognostic marker in patients with normal SDS and SSS (Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT01128023).
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Thorn SL, Barlow SC, Feher A, Stacy MR, Doviak H, Jacobs J, Zellars K, Renaud JM, Klein R, deKemp RA, Khakoo AY, Lee T, Spinale FG, Sinusas AJ. Application of Hybrid Matrix Metalloproteinase-Targeted and Dynamic 201Tl Single-Photon Emission Computed Tomography/Computed Tomography Imaging for Evaluation of Early Post-Myocardial Infarction Remodeling. Circ Cardiovasc Imaging 2019; 12:e009055. [PMID: 31707811 PMCID: PMC7250243 DOI: 10.1161/circimaging.119.009055] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The induction of matrix metalloproteinases (MMPs) and reduction in tissue inhibitors of MMPs (TIMPs) plays a role in ischemia/reperfusion (I/R) injury post-myocardial infarction (MI) and subsequent left ventricular remodeling. We developed a hybrid dual isotope single-photon emission computed tomography/computed tomography approach for noninvasive evaluation of regional myocardial MMP activation with 99mTc-RP805 and dynamic 201Tl for determination of myocardial blood flow, to quantify the effects of intracoronary delivery of recombinant TIMP-3 (rTIMP-3) on I/R injury. METHODS Studies were performed in control pigs (n=5) and pigs following 90-minute balloon occlusion-induced ischemia/reperfusion (I/R) of left anterior descending artery (n=9). Before reperfusion, pigs with I/R were randomly assigned to intracoronary infusion of rTIMP-3 (1.0 mg/kg; n=5) or saline (n=4). Three days post-I/R, dual isotope imaging was performed with 99mTc-RP805 and 201Tl along with contrast cineCT to assess left ventricular function. RESULTS The ischemic to nonischemic ratio of 99mTc-RP805 was significantly increased following I/R in saline group (4.03±1.40), and this ratio was significantly reduced with rTIMP-3 treatment (2.22±0.57; P=0.03). This reduction in MMP activity in the MI-rTIMP-3 treatment group was associated with an improvement in relative MI region myocardial blood flow compared with the MI-saline group and improved myocardial strain in the MI region. CONCLUSIONS We have established a novel hybrid single-photon emission computed tomography/computed tomography imaging approach for the quantitative assessment of regional MMP activation, myocardial blood flow, and cardiac function post-I/R that can be used to evaluate therapeutic interventions such as intracoronary delivery of rTIMP-3 for reduction of I/R injury in the early phases of post-MI remodeling.
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Erthal F, Hossain A, Dorbala S, Shaw LJ, Di Carli MF, Merhige ME, Williams BA, Veledar E, Min JK, Berman DS, deKemp RA, Beanlands RSB, Chow BJW. Is There an Age When Myocardial Perfusion Imaging May No Longer Be Prognostically Useful? Circ Cardiovasc Imaging 2019; 11:e007322. [PMID: 30012824 DOI: 10.1161/circimaging.117.007322] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 05/23/2018] [Indexed: 11/16/2022]
Abstract
BACKGROUND Heart disease continues to be the leading cause of death, and the prevalence of coronary artery disease is expected to increase as the population ages. It is important to understand the clinical utility of medical tests, or its lack thereof, in the aging population. The objective of this study was to understand the incremental prognostic value of positron emission tomographic (PET) myocardial perfusion imaging in the elderly (≥85 years of age). METHODS AND RESULTS A total of 3343 patients enrolled in a multicenter observational PET registry were analyzed. Participants were initially divided into 3 age categories: 65 to 74.9, 75 to 84.9, and ≥85 years of age and followed for all-cause death. Median follow-up time was 3 years. Of the total patient population, 248 patients (49% men) were ≥85 years old. When compared with younger patients, individuals ≥85 years had a higher prevalence of hypertension (79%) and a lower incidence of dyslipidemia (54%) and diabetes mellitus (24%). On multivariable analysis, %left ventricular stress defect and %left ventricular ischemia were predictors of patient outcome for those <85 years of age but was not statistically significant in those ≥85 years of age. The prognostic value of PET (%left ventricular stress defect and %left ventricular ischemia) appeared to decrease with advancing age. CONCLUSIONS The elderly is a high-risk population irrespective of PET myocardial perfusion imaging results, and incremental prognostic value of PET myocardial perfusion imaging appears to wane in those ≥85 years of age. Although PET myocardial perfusion imaging may be diagnostically useful in the elderly, its prognostic value in this population requires further evaluation.
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Wu KY, Timmerman NP, McPhedran R, Hossain A, Beanlands RSB, Chong AY, deKemp RA. Differential association of diabetes mellitus and female sex with impaired myocardial flow reserve across the spectrum of epicardial coronary disease. Eur Heart J Cardiovasc Imaging 2019; 21:576-584. [DOI: 10.1093/ehjci/jez163] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Indexed: 12/14/2022] Open
Abstract
Abstract
Aims
Diabetes mellitus (DM) affects the macro- and microvasculature, leading to impairment in coronary vascular reactivity. Microvascular dysfunction is more prevalent in females compared to males, leading to increased cardiovascular risk in women. The purpose of this study was to quantify the association between diabetes and female sex on myocardial flow reserve (MFR) across the spectrum of epicardial coronary artery disease (CAD).
Methods and results
In 222 patients with known or suspected CAD (63.7 ± 10.7 years, 66 females, 85 with diabetes) who had rubidium-82 positron emission tomography (PET) and invasive coronary angiography within 6 months, a multiple linear regression model was developed to predict MFR based on clinical risk factors and imaging results across a spectrum of regional epicardial disease. A significant interaction effect suggested that impairment of MFR is accelerated in diabetics with increasing severity of epicardial disease. Furthermore, female sex (−13%), decade of age (−6%), ischaemia on electrocardiogram (−10%), resting rate-pressure product (−3%), and rest end-diastolic volume (−0.2%) were associated with reductions in MFR independent of the combined extent and severity of epicardial disease.
Conclusion
In the presence of significant obstructive epicardial disease, MFR decreases more rapidly in patients with DM compared to those without. Additional patient demographics and risk factors such as female sex and older age, and stress PET functional parameters should also be considered in the clinical interpretation of MFR. This has implications for the diagnosis and management of CAD patients with these and other risk factors for microvascular disease.
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deKemp RA, Wells RG, Ruddy TD. SPECT quantification of myocardial blood flow: A journey of a thousand miles begins with a single step (Lao Tzu, Chinese philosopher, 604-531 BC). J Nucl Cardiol 2019; 26:772-774. [PMID: 29071671 DOI: 10.1007/s12350-017-1106-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 10/11/2017] [Indexed: 11/30/2022]
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Pfau D, Thorn SL, Zhang J, Mikush N, Renaud JM, Klein R, deKemp RA, Wu X, Hu X, Sinusas AJ, Young LH, Tirziu D. Angiotensin Receptor Neprilysin Inhibitor Attenuates Myocardial Remodeling and Improves Infarct Perfusion in Experimental Heart Failure. Sci Rep 2019; 9:5791. [PMID: 30962467 PMCID: PMC6453892 DOI: 10.1038/s41598-019-42113-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/19/2019] [Indexed: 12/11/2022] Open
Abstract
Angiotensin receptor blocker-neprilysin inhibitor (ARNi) therapy improves the prognosis of heart failure patients. However, the mechanisms remain unclear. This study investigated the biological effects of ARNi with neprilysin inhibitor sacubitril and angiotensin receptor blocker valsartan on myocardial remodeling and cardiac perfusion in experimental heart failure (HF) after myocardial infarction (MI). Male Lewis rats (10-weeks old) with confirmed HF were randomized one-week post-MI to treatment with vehicle (water), sacubitril/valsartan or valsartan, as comparator group, for either 1 or 5 weeks. Sacubitril/valsartan for 1-week limited LV contractile dysfunction vs. vehicle and both sacubitril/valsartan and valsartan attenuated progressive LV dilation after 1 and 5 weeks treatment. After 5 weeks, both sacubitril/valsartan and valsartan reduced CTGF expression in the remote myocardium, although only sacubitril/valsartan prevented interstitial fibrosis. In the border zone, sacubitril/valsartan and valsartan reduced hypertrophic markers, but only sacubitril/valsartan reduced cardiomyocyte size and increased VEGFA expression. In the infarct, sacubitril/valsartan induced an early uptake of 99mTc-NC100692 (a radiotracer of angiogenesis) and improved perfusion, as determined by 201Tl microSPECT/CT imaging. In conclusion, ARNi improved global LV function, limited remodeling in the remote and border zones, and increased perfusion to the infarct. Sacubitril/valsartan had more consistent effects than valsartan on LV remodeling in experimental HF.
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Wells RG, deKemp RA. Does time-of-flight improve image quality in the heart? J Nucl Cardiol 2019; 26:413-416. [PMID: 28718075 DOI: 10.1007/s12350-017-0992-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 06/29/2017] [Indexed: 10/19/2022]
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Hunter CRRN, Klein R, Alessio AM, deKemp RA. Patient body motion correction for dynamic cardiac PET-CT by attenuation-emission alignment according to projection consistency conditions. Med Phys 2019; 46:1697-1706. [PMID: 30710381 DOI: 10.1002/mp.13419] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 11/09/2022] Open
Abstract
INTRODUCTION Patient body motion is known to cause large deviations in the determination of myocardial blood flow (MBF) with errors exceeding 300%. Accurate correction for patient whole-body motion is still a largely unsolved problem in cardiac positron emission tomography (PET) imaging. OBJECTIVE This study evaluated the efficacy of using Natterer's formulation of the Helgason-Ludwig consistency conditions on the two-dimensional Radon transform to align computed tomography to PET projection data in multiple time frames of a dynamic sequence for the purpose of frame-by-frame correction of rigid whole-body motion. METHODS The correction algorithm was evaluated with digital NCAT phantoms using realistic noise added by the analytical simulator. Count rates used in the simulation were derived from clinical patient data. In addition, a proof of concept test using measured data with a cardiac torso phantom was conducted. RESULTS Motion correction resulted in significant improvement in the accuracy of MBF estimates, especially for high count-rate acquisitions. Maximum errors for 2 cm of motion dropped from 325% to 25% and from 250% to 25% using global and regional partial-volume correction, respectively. Median MBF errors dropped from 33% to 4.5% and 27% to 3.8%, respectively. Importantly, the correction algorithm performed equally well to compensate for body motion in both early and late time frames. CONCLUSION Cardiac PET-CT data used for attenuation correction (CTAC) alignment using projection consistency conditions was effective for reducing errors in MBF measurements due to simulated patient motion, and can be integrated into the image reconstruction workflow.
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Harnett DT, Hazra S, Maze R, Mc Ardle BA, Alenazy A, Simard T, Henry E, Dwivedi G, Glover C, deKemp RA, Davies RA, Ruddy TD, Chow BJW, Beanlands RS, Hibbert B. Clinical performance of Rb-82 myocardial perfusion PET and Tc-99m-based SPECT in patients with extreme obesity. J Nucl Cardiol 2019; 26:275-283. [PMID: 28357812 DOI: 10.1007/s12350-017-0855-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 03/12/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND We evaluated the performance of stress imaging with technetium-99m-labeled tetrofosmin single-photon emission computed tomography (SPECT) and rubidium-82 positron emission tomography (PET) in patients with extreme obesity, defined as body mass index ≥40 kg/m2. METHODS We identified patients with extreme obesity who underwent angiography in our center and either stress SPECT or PET within the previous six months. Cohorts of patients with extreme obesity and a <5% pretest likelihood of CAD who underwent SPECT (N = 25) or PET (N = 25) were also included. RESULTS In total, 108 patients who underwent SPECT (N = 57) or PET (N = 51) were identified. Scan interpretation was classified as definitely normal or abnormal in 83.3% of PET and 60.5% of SPECT scans, respectively (P < .01). PET demonstrated higher diagnostic accuracy and normalcy rate. PET was found to have higher specificity for the pooled cohort. Similar findings were observed using stenosis cut-offs of ≥50% and ≥70%. CONCLUSIONS In patients with extreme obesity, PET enabled more definitive scan interpretation with less artifact compared to SPECT. PET provided higher diagnostic accuracy and specificity in the detection of obstructive coronary artery disease.
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El-Sherif O, Xhaferllari I, Sykes J, Butler J, deKemp RA, Renaud J, Yin H, Wilk B, Sullivan R, Pickering JG, Battista J, Wisenberg G, Prato FS, Gaede S. [ 18F]FDG cardiac PET imaging in a canine model of radiation-induced cardiovascular disease associated with breast cancer radiotherapy. Am J Physiol Heart Circ Physiol 2018; 316:H586-H595. [PMID: 30575441 DOI: 10.1152/ajpheart.00273.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Radiotherapy for the treatment of left-sided breast cancer increases the long-term risk of cardiovascular disease. The purpose of the present study was to noninvasively image the progression of radiation-induced cardiac inflammation in a large animal model using a hybrid PET and MRI system. Five canines were imaged using [18F]fluorodeoxyglucose PET to assess changes in myocardial inflammation. All animals were imaged at baseline, 1 wk, and 1, 3, 6, and 12 mo after focused cardiac external beam irradiation with image guidance. Radiation was delivered in a single fraction. The linear quadratic model was used to convert a typical multifractionated heart dose to a corrected single-fraction biologically equivalent dose. Immunohistochemistry was performed on excised left ventricular tissue samples from all five irradiated canines and one nonirradiated control canine to confirm the presence of inflammation. The mean doses delivered to the entire heart, left ventricle, left anterior descending artery, and left circumflex artery were 1.7 ± 0.2, 2.7 ± 0.2, 5.5 ± 0.9, and 1.1 ± 0.4 Gy, respectively. FDG standard uptake values remained persistently elevated compared with baseline (1.1 ± 0.03 vs. 2.6 ± 0.19, P < 0.05). The presence of myocardial inflammation was confirmed histologically and correlated with myocardial dose. This study suggests a global inflammatory response that is persistent up to 12 mo postirradiation. Inflammation PET imaging should be considered in future clinical studies to monitor the early changes in cardiac function that may play a role in the ultimate development of radiation-induced cardiac toxicity. NEW & NOTEWORTHY Using advanced cardiac PET imaging, we have shown the spatial and quantitative relationship between radiation dose deposition and temporal changes in inflammation. We have shown that the progression of radiation-induced cardiac inflammation is immediate and does not subside for up to 1 yr after radiation. Results are presented in a large animal model that closely resembles the size and vessel architecture of humans. The proposed imaging protocol can be easily replicated for clinical use.
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Wu KY, Dinculescu V, Renaud JM, Chen SY, Burwash IG, Mielniczuk LM, Beanlands RSB, deKemp RA. Repeatable and reproducible measurements of myocardial oxidative metabolism, blood flow and external efficiency using 11C-acetate PET. J Nucl Cardiol 2018; 25:1912-1925. [PMID: 29453603 DOI: 10.1007/s12350-018-1206-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 11/30/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND Non-invasive approaches to investigate myocardial efficiency can help track the progression of heart failure (HF). This study evaluates the repeatability and reproducibility of 11C-acetate positron emission tomography (PET) imaging of oxidative metabolism. METHODS AND RESULTS Dynamic 11C-acetate PET scans were performed at baseline and followup (47 ± 22 days apart) in 20 patients with stable HF with reduced ejection fraction. Two observers blinded to patients' clinical data used FlowQuant® to evaluate test-retest repeatability, as well as intra- and inter-observer reproducibility of 11C-acetate tracer uptake and clearance rates, for the measurement of myocardial oxygen consumption (MVO2), myocardial external efficiency (MEE), work metabolic index (WMI), and myocardial blood flow. Reproducibility and repeatability were evaluated using intra-class-correlation (ICC) and Bland-Altman coefficient-of-repeatability (CR). Test-retest correlations and repeatability were better for MEE and WMI compared to MVO2. All intra- and inter-observer correlations were excellent (ICC = 0.95-0.99) and the reproducibility values (CR = 3%-6%) were significantly lower than the test-retest repeatability values (22%-54%, P < 0.001). Repeatability was improved for all parameters using a newer PET-computed tomography (CT) scanner compared to older PET-only instrumentation. CONCLUSION 11C-acetate PET measurements of WMI and MEE exhibited excellent test-retest repeatability and operator reproducibility. Newer PET-CT scanners may be preferred for longitudinal tracking of cardiac efficiency.
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Murthy VL, Bateman TM, Beanlands RS, Berman DS, Borges-Neto S, Chareonthaitawee P, Cerqueira MD, deKemp RA, DePuey EG, Dilsizian V, Dorbala S, Ficaro EP, Garcia EV, Gewirtz H, Heller GV, Lewin HC, Malhotra S, Mann A, Ruddy TD, Schindler TH, Schwartz RG, Slomka PJ, Soman P, Di Carli MF. Correction to: Clinical Quantification of Myocardial Blood Flow Using PET: Joint Position Paper of the SNMMI Cardiovascular Council and the ASNC. J Nucl Cardiol 2018; 25:2189-2190. [PMID: 29637524 DOI: 10.1007/s12350-018-1259-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The above position statement originally published containing errors in the author metadata; specifically, the Expert Content Reviewers-Andrew Einstein, Raymond Russell and James R. Corbett-were tagged as full authors of the paper. The article metadata has now been corrected to remove Drs. Einstein, Russell and Corbett from the author line, and the PubMed record has been updated accordingly.
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deKemp RA, Wells RG, Beanlands RSB. Lesion contrast recovery for partial-volume averaging: Quantitative correction or qualitative enhancement? J Nucl Cardiol 2018; 25:1757-1759. [PMID: 28364189 DOI: 10.1007/s12350-017-0869-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 03/21/2017] [Indexed: 11/29/2022]
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Wang T, Wu KY, Miner RC, Renaud JM, Beanlands RSB, deKemp RA. Reproducible quantification of cardiac sympathetic innervation using graphical modeling of carbon-11-meta-hydroxyephedrine kinetics with dynamic PET-CT imaging. EJNMMI Res 2018; 8:63. [PMID: 30030665 PMCID: PMC6054601 DOI: 10.1186/s13550-018-0421-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 07/02/2018] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Graphical methods of radiotracer kinetic modeling in PET are ideal for parametric imaging and data quality assurance but can suffer from noise bias. This study compared the Logan and Multilinear Analysis-1 (MA1) graphical models to the standard one-tissue-compartment (1TC) model, including correction for partial-volume effects, in dynamic PET-CT studies of myocardial sympathetic innervation in the left ventricle (LV) using [11C]HED. METHODS Test and retest [11C]HED PET imaging (47 ± 22 days apart) was performed in 18 subjects with heart failure symptoms. Myocardial tissue volume of distribution (VT) was estimated using Logan and MA1 graphical methods and compared to the 1TC standard model values using intraclass correlation (ICC) and Bland-Altman analysis of the non-parametric reproducibility coefficient (NPC). RESULTS A modeling start-time of t* = 5 min gave the best fit for both Logan and MA1 (R2 = 0.95) methods. Logan slightly underestimated VT relative to 1TC (p = 0.002), whereas MA1 did not (p = 0.96). Both the MA1 and Logan models exhibited good-to-excellent agreement with the 1TC (MA1-1TC ICC = 0.96; Logan-1TC ICC = 0.93) with no significant differences in NPC between the two comparisons (p = 0.92). All methods exhibited good-to-excellent test-retest repeatability with no significant differences in NPC (p = 0.57). CONCLUSIONS Logan and MA1 models exhibited similar agreement and variability compared to the 1TC for modeling of [11C]HED kinetics. Using t* = 5 min and partial-volume correction produced accurate estimates of VT as an index of myocardial sympathetic innervation.
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Cocker MS, Spence JD, Hammond R, deKemp RA, Lum C, Wells G, Bernick J, Hill A, Nagpal S, Stotts G, Alturkustani M, Adeeko A, Yerofeyeva Y, Rayner K, Peterson J, Khan AR, Naidas AC, Garrard L, Yaffe MJ, Leung E, Prato FS, Tardif JC, Beanlands RSB. [18F]-Fluorodeoxyglucose PET/CT imaging as a marker of carotid plaque inflammation: Comparison to immunohistology and relationship to acuity of events. Int J Cardiol 2018; 271:378-386. [PMID: 30007487 DOI: 10.1016/j.ijcard.2018.05.057] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 05/02/2018] [Accepted: 05/17/2018] [Indexed: 11/19/2022]
Abstract
BACKGROUND [18F]-fluorodeoxyglucose (18FDG) uptake imaged with positron emission tomography (PET) and computed tomography (CT) may serve as a biomarker of plaque inflammation. This study evaluated the relationship between carotid plaque 18FDG uptake and a) intraplaque expression of macrophage and macrophage-like cellular CD68 immunohistology; b) intraplaque inflammatory burden using leukocyte-sensitive CD45 immunohistology; c) symptomatic patient presentation; d) time from last cerebrovascular event. METHODS 54 patients scheduled for carotid endarterectomy underwent 18FDG PET/CT imaging. Maximum 18FDG uptake (SUVmax) and tissue-to-blood ratio (TBRmax) was measured for carotid plaques. Quantitative immunohistological analysis of macrophage-like cell expression (CD68) and leukocyte content (CD45) was performed. RESULTS 18FDG uptake was related to CD68 macrophage expression (TBRmax: r = 0.51, p < 0.001), and total-plaque leukocyte CD45 expression (TBRmax: r = 0.632, p = 0.009, p < 0.001). 18FDG TBRmax uptake in carotid plaque associated with patient symptoms was greater than asymptomatic plaque (3.58 ± 1.01 vs. 3.13 ± 1.10, p = 0.008). 18FDG uptake differed between an acuity threshold of <90 days and >90 days (SUVmax:3.15 ± 0.87 vs. 2.52 ± 0.45, p = 0.015). CONCLUSIONS In this CAIN cohort, 18FDG uptake imaged with PET/CT serves a surrogate marker of intraplaque inflammatory macrophage, macrophage-like cell and leukocyte burden. 18FDG uptake is greater in plaque associated with patient symptoms and those with recent cerebrovascular events. Future studies are needed to relate 18FDG uptake and disease progression.
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Klein R, Ocneanu A, Renaud JM, Ziadi MC, Beanlands RSB, deKemp RA. Consistent tracer administration profile improves test-retest repeatability of myocardial blood flow quantification with 82Rb dynamic PET imaging. J Nucl Cardiol 2018; 25:929-941. [PMID: 27804067 PMCID: PMC5966478 DOI: 10.1007/s12350-016-0698-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Quantification of myocardial blood flow (MBF) and stress/rest flow reserve is used increasingly to diagnose multi-vessel coronary artery disease and micro-vascular disease with PET imaging. However, variability in the measurements may limit physician confidence to direct revascularization therapies based on specific threshold values. This study evaluated the effects of rubidium-82 (82Rb) tracer injection profile using a constant-activity-rate (CA) vs a constant-flow-rate (CF) infusion to improve test-retest repeatability of MBF measurements. METHOD 22 participants underwent single-session 82Rb dynamic PET imaging during rest and dipyridamole stress using one of 2 test-retest infusion protocols: CA-CA (n = 12) or CA-CF (n = 10). MBF was quantified using a single-tissue-compartment model (1TCM) and a simplified retention model (SRM). Non-parametric test-retest repeatability coefficients (RPCnp) were compared between groups. Myocardium-to-blood contrast and signal-to-noise ratios of the late uptake images (2 to 6 minutes) were also compared to evaluate standard myocardial perfusion image (MPI) quality. RESULTS MBF values in the CA-CA group were more repeatable (smaller RPCnp) than the CA-CF group using the 1TCM at rest alone, rest and stress combined, and stress/rest reserve (21% vs 36%, 16% vs 19%, and 20% vs 27%, P < 0.05, respectively), and using the SRM at Rest and Stress alone, Rest and Stress combined, and stress/rest reserve (21% vs 38%, 15% vs 25%, 22% vs 38%, and 23% vs 49%, P < 0.05, respectively). In terms of image quality, myocardium-to-blood contrast and signal-to-noise ratios were not significantly different between groups. CONCLUSIONS Constant-activity-rate 'square-wave' infusion of 82Rb produces more repeatable tracer injection profiles and decreases the test-retest variability of MBF measurements, when compared to a constant-flow-rate 'bolus' administration of 82Rb, especially with SRM, and without compromising standard MPI quality.
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Juneau D, Ruddy TD, Beanlands RSB, deKemp RA. False-positive 13N-ammonia positron emission tomography perfusion scan caused by misalignment of adjacent lung activity during attenuation correction. J Nucl Cardiol 2018; 25:1056-1058. [PMID: 28452006 DOI: 10.1007/s12350-017-0891-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 03/31/2017] [Indexed: 10/19/2022]
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Chih S, Chong AY, Erthal F, deKemp RA, Davies RA, Stadnick E, So DY, Overgaard C, Wells G, Mielniczuk LM, Beanlands RS. PET Assessment of Epicardial Intimal Disease and Microvascular Dysfunction in Cardiac Allograft Vasculopathy. J Am Coll Cardiol 2018; 71:1444-1456. [DOI: 10.1016/j.jacc.2018.01.062] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 12/30/2017] [Accepted: 01/19/2018] [Indexed: 11/17/2022]
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Murthy VL, Bateman TM, Beanlands RS, Berman DS, Borges-Neto S, Chareonthaitawee P, Cerqueira MD, deKemp RA, DePuey EG, Dilsizian V, Dorbala S, Ficaro EP, Garcia EV, Gewirtz H, Heller GV, Lewin HC, Malhotra S, Mann A, Ruddy TD, Schindler TH, Schwartz RG, Slomka PJ, Soman P, Di Carli MF, Einstein A, Russell R, Corbett JR. Clinical Quantification of Myocardial Blood Flow Using PET: Joint Position Paper of the SNMMI Cardiovascular Council and the ASNC. J Nucl Cardiol 2018; 25:269-297. [PMID: 29243073 DOI: 10.1007/s12350-017-1110-x] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Juneau D, deKemp RA, Beanlands RSB. Reporting myocardial flow reserve with PET. Ready or not, here it is! But walk before you fly! J Nucl Cardiol 2018; 25:164-168. [PMID: 29058114 DOI: 10.1007/s12350-017-1087-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 01/26/2023]
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Murthy VL, Bateman TM, Beanlands RS, Berman DS, Borges-Neto S, Chareonthaitawee P, Cerqueira MD, deKemp RA, DePuey EG, Dilsizian V, Dorbala S, Ficaro EP, Garcia EV, Gewirtz H, Heller GV, Lewin HC, Malhotra S, Mann A, Ruddy TD, Schindler TH, Schwartz RG, Slomka PJ, Soman P, Di Carli MF. Clinical Quantification of Myocardial Blood Flow Using PET: Joint Position Paper of the SNMMI Cardiovascular Council and the ASNC. J Nucl Med 2017; 59:273-293. [PMID: 29242396 DOI: 10.2967/jnumed.117.201368] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 09/11/2017] [Indexed: 12/30/2022] Open
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Drozd K, Ahmadi A, Deng Y, Jiang B, Petryk J, Thorn S, Stewart D, Beanlands R, deKemp RA, DaSilva JN, Mielniczuk LM. Effects of an endothelin receptor antagonist, Macitentan, on right ventricular substrate utilization and function in a Sugen 5416/hypoxia rat model of severe pulmonary arterial hypertension. J Nucl Cardiol 2017; 24:1979-1989. [PMID: 27688036 DOI: 10.1007/s12350-016-0663-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 07/25/2016] [Indexed: 10/20/2022]
Abstract
BACKGROUND Altered myocardial energy metabolism has been linked to worsening of RV function in pulmonary arterial hypertension (PAH). The aim of this study was to evaluate RV glucose and fatty acid metabolism in vivo in a rat model of PAH using positron emission tomography (PET) and investigate the effects of Macitentan on RV substrate utilization. METHODS PAH was induced in male Sprague-Dawley rats by a single subcutaneous injection of Sugen 5416 (20 mg/kg) followed by 3 weeks of hypoxia (10% oxygen). At week 5 post-injection, the PAH rats were randomized to Macitentan (30 mg/kg daily) treatment or no treatment. Substrate utilization was serially assessed 5 and 8 weeks post-injection with 2-[18F]fluoro-2-deoxyglucose (FDG) and 14(R,S)-[18F]fluoro-6-thia-heptadecanoic acid (FTHA) PET for glucose and fatty acid metabolism respectively and correlated with in vivo functional measurements. RESULTS PAH induction resulted in a 2.5-fold increase in RV FDG uptake (standardized uptake value (SUV) of normal control: 1.6 ± 0.4, week 5: 4.1 ± 1.9, week 8: 4.0 ± 1.6, P < 0.05 for all groups vs. control). RV FTHA showed twofold increased uptake at week 5 (SUV control: 1.50 ± 0.39, week 5: 3.06 ± 1.10, P = 0.03). Macitentan significantly decreased RV FDG uptake at 8 weeks (SUV: 2.5 ± 0.9, P = 0.04), associated with improved RV ejection fraction and reduced RV systolic pressure, while FTHA uptake was maintained. CONCLUSION PAH is associated with metabolic changes in the RV, characterized by a marked increase in FDG and FTHA uptake. Macitentan treatment reduced PAH severity and was associated with a decrease in RV FDG uptake and improved RV function.
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Klein R, Ocneanu A, deKemp RA. Time-frame sampling for 82Rb PET flow quantification: Towards standardization of clinical protocols. J Nucl Cardiol 2017; 24:1530-1534. [PMID: 28687966 DOI: 10.1007/s12350-017-0981-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 05/30/2017] [Indexed: 12/26/2022]
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