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3. Need for Objective Task-based Evaluation of Deep Learning-Based Denoising Methods: A Study in the Context of Myocardial Perfusion SPECT

Author

Yu, Zitong, Rahman, Md Ashequr, Laforest, Richard, Schindler, Thomas H., Gropler, Robert J., Wahl, Richard L., Siegel, Barry A., and Jha, Abhinav K.

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition, Computer Science - Machine Learning, Physics - Medical Physics
Abstract

Artificial intelligence-based methods have generated substantial interest in nuclear medicine. An area of significant interest has been using deep-learning (DL)-based approaches for denoising images acquired with lower doses, shorter acquisition times, or both. Objective evaluation of these approaches is essential for clinical application. DL-based approaches for denoising nuclear-medicine images have typically been evaluated using fidelity-based figures of merit (FoMs) such as RMSE and SSIM. However, these images are acquired for clinical tasks and thus should be evaluated based on their performance in these tasks. Our objectives were to (1) investigate whether evaluation with these FoMs is consistent with objective clinical-task-based evaluation; (2) provide a theoretical analysis for determining the impact of denoising on signal-detection tasks; (3) demonstrate the utility of virtual clinical trials (VCTs) to evaluate DL-based methods. A VCT to evaluate a DL-based method for denoising myocardial perfusion SPECT (MPS) images was conducted. The impact of DL-based denoising was evaluated using fidelity-based FoMs and AUC, which quantified performance on detecting perfusion defects in MPS images as obtained using a model observer with anthropomorphic channels. Based on fidelity-based FoMs, denoising using the considered DL-based method led to significantly superior performance. However, based on ROC analysis, denoising did not improve, and in fact, often degraded detection-task performance. The results motivate the need for objective task-based evaluation of DL-based denoising approaches. Further, this study shows how VCTs provide a mechanism to conduct such evaluations using VCTs. Finally, our theoretical treatment reveals insights into the reasons for the limited performance of the denoising approach.

Published
2023

5. Atlas for reporting PET myocardial perfusion imaging and myocardial blood flow in clinical practice: an information statement from the American Society of Nuclear Cardiology

Author

Chareonthaitawee, Panithaya, Bateman, Timothy M., Beanlands, Rob S., Berman, Daniel S., Calnon, Dennis A., Di Carli, Marcelo F., Heller, Gary V., Murthy, Venkatesh L., Patel, Krishna K., Schindler, Thomas H., Taqueti, Viviany R., Wiefels, Christiane C., and Al-Mallah, Mouaz H.

Published
2023
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11. Myocardial Perfusion PET for the Detection and Reporting of Coronary Microvascular Dysfunction: A JACC: Cardiovascular Imaging Expert Panel Statement

Author

Schindler, Thomas H., Fearon, William F., Pelletier-Galarneau, Matthieu, Ambrosio, Giuseppe, Sechtem, Udo, Ruddy, Terrence D., Patel, Krishna K., Bhatt, Deepak L., Bateman, Timothy M., Gewirtz, Henry, Shirani, Jamshid, Knuuti, Juhani, Gropler, Robert J., Chareonthaitawee, Panithaya, Slart, Riemer H.J.A., Windecker, Stephan, Kaufmann, Philipp A., Abraham, Maria R., Taqueti, Viviany R., Ford, Thomas J., Camici, Paolo G., Schelbert, Heinrich R., and Dilsizian, Vasken

Published
2023
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14. Stress Myocardial Blood Flow Heterogeneity Is a Positron Emission Tomography Biomarker of Ventricular Arrhythmias in Patients With Hypertrophic Cardiomyopathy

Author

Lu, Dai-Yin, Yalçin, Hulya, Yalçin, Fatih, Zhao, Min, Sivalokanathan, Sanjay, Valenta, Ines, Tahari, Abdel, Pomper, Martin G, Abraham, Theodore P, Schindler, Thomas H, and Abraham, M Roselle

Subjects
Cardiovascular, Clinical Research, Biomedical Imaging, Heart Disease, 4.1 Discovery and preclinical testing of markers and technologies, Detection, screening and diagnosis, 4.2 Evaluation of markers and technologies, Academic Medical Centers, Adult, Aged, Baltimore, Biomarkers, Cardiomyopathy, Hypertrophic, Cohort Studies, Death, Sudden, Cardiac, Disease Progression, Female, Humans, Kaplan-Meier Estimate, Male, Middle Aged, Myocardial Perfusion Imaging, Positron Emission Tomography Computed Tomography, Positron-Emission Tomography, Prognosis, Proportional Hazards Models, ROC Curve, Registries, Retrospective Studies, Risk Assessment, Stroke Volume, Survival Analysis, Tachycardia, Ventricular, Cardiorespiratory Medicine and Haematology, Cardiovascular System & Hematology
Abstract

Patients with hypertrophic cardiomyopathy (HC) are at increased risk of sudden cardiac death. Abnormalities in myocardial blood flow (MBF) detected by positron emission tomography (PET) are common in HC, but a PET marker that identifies patients at risk of sudden cardiac death is lacking. We hypothesized that disparities in regional myocardial perfusion detected by PET would identify patients with HC at risk of ventricular arrhythmias. To test this hypothesis, we quantified global and regional MBFs by 13NH3-PET at rest and at stress, and developed a heterogeneity index to assess MBF heterogeneity in 133 symptomatic patients with HC. The MBF heterogeneity index was computed by dividing the highest by the lowest regional MBF value, at rest and after vasodilator stress, in each patient. High stress MBF heterogeneity was defined as an index of ≧1.85. Patients with HC were stratified by the presence or the absence of ventricular arrhythmias, defined as sustained ventricular tachycardia (VT) and/or nonsustained VT, during follow-up. We found that global and regional MBFs at rest and stress were similar in patients with HC with or without ventricular arrhythmias. Variability in regional stress MBF was observed in both groups, but the stress MBF heterogeneity index was significantly higher in patients with HC who developed ventricular arrhythmias (1.82 ± 0.77 vs 1.49 ± 0.25, p

Published
2018

18. PET clinical study of novel antipsychotic LB-102 demonstrates unexpectedly prolonged dopamine receptor target engagement

Author

Wong, Dean F., Chand, Ganesh B., Caito, Nicole, Eramo, Anna, Grattan, Vincent T., Hixon, Mark S., Nicol, Ginger, Lessie, Erin, Prensky, Zachary, Kuwabara, Hiroto, Tian, Lucy, Valenta, Ines, Schindler, Thomas H., Gründer, Gerhard, and Vaino, Andrew R.

Abstract

Regulation of dopamine activity has important clinical consequences, most notably in schizophrenia. LB-102, N-methyl amisulpride, is a novel dopamine D2/3/5-HT7inhibitor being developed as a treatment for schizophrenia and other psychiatric disorders. The characteristic that is common to all current antipsychotics is their engagement of D2dopamine receptors. The goal of this study was to measure the dopamine receptor occupancy of orally administered LB-102 at three different doses (50, 75, and 100 mg as single doses and 50 and 100 mg as multiple doses) and at different timepoints in healthy volunteers using positron emission tomography (PET) with 11C raclopride as a radiotracer. Results of this study (NCT04588129) showed that steady-state once daily oral dosing of 50 mg LB-102 afforded striatal dopamine occupancy (RO) in the desired 60–80% range consistently over the course of 24 h. Contrary to the often observed relationship between RO vs plasma concentrations, maximum dopamine RO significantly lagged maximum plasma concentration and showed little variability under steady state conditions. A similar phenomenon has recently been reported with a non-racemic version of amisulpride [1]. LB-102 was generally safe and well-tolerated at all doses. Results of this study were used to inform dosing in a subsequent Phase 2 clinical study in schizophrenia patients.

Published
2024
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26. Total-Body PET/CT Applications in Cardiovascular Diseases: A Perspective Document of the SNMMI Cardiovascular Council

Author

Slart, Riemer H.J.A., primary, Bengel, Frank M., additional, Akincioglu, Cigdem, additional, Bourque, Jamieson M., additional, Chen, Wengen, additional, Dweck, Marc R., additional, Hacker, Marcus, additional, Malhotra, Saurabh, additional, Miller, Edward J., additional, Pelletier-Galarneau, Matthieu, additional, Packard, René R.S., additional, Schindler, Thomas H., additional, Weinberg, Richard L., additional, Saraste, Antti, additional, and Slomka, Piotr J., additional

Published
2024
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27. Early diagnosis and management of cardiac amyloidosis: A clinical perspective.

Author

Bellofatto, Ilaria Anna, Schindler, Thomas H., Portincasa, Piero, Carbone, Federico, Canepa, Marco, Liberale, Luca, and Montecucco, Fabrizio

Subjects
*CARDIAC amyloidosis, *EARLY diagnosis, *CARDIAC magnetic resonance imaging
Abstract

This article provides information on the diagnosis and management of cardiac amyloidosis (CA), a condition characterized by abnormal protein deposits in the heart tissue. CA can be caused by two main types of amyloidosis: light chain (AL) and transthyretin (ATTR) amyloidosis. The article highlights the challenges in diagnosing CA due to its varied symptoms and involvement of multiple organs. It suggests that internal medicine physicians, experienced in managing multisystemic disorders, can play a crucial role in early detection and treatment. The article discusses the latest guidelines, including the use of Tafamidis and Patisiran as treatment options, and emphasizes the importance of imaging techniques for diagnosis. It also emphasizes the need for a multidisciplinary approach and ongoing support for CA patients. [Extracted from the article]

Published
2024
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28. PET-determined myocardial perfusion and flow in coronary artery disease characterization.

Author

Valenta, Ines and Schindler, Thomas H.

Subjects
CORONARY arterial radiography, ANGINA pectoris, LEFT heart ventricle, PREDICTIVE tests, MYOCARDIAL ischemia, CORONARY circulation, POSITRON emission tomography, PERFUSION imaging, CORONARY artery disease, PERFUSION, LEFT ventricular dysfunction
Abstract

Positron emission tomography (PET) myocardial perfusion imaging in conjunction with tracer-kinetic modeling enables the concurrent assessment of myocardial perfusion and regional myocardial blood flow (MBF) of the left ventricle in absolute terms in milliliters per gram per minute (mL/g/min). The non-invasive quantification of MBF during pharmacologically induced hyperemia, at rest, and corresponding myocardial flow reserve (MFR) opens a new avenue for the identification and characterization of classical or endogen type of coronary microvascular dysfunction (CMD) as functional substrate for microvascular angina in patients with non-obstructive coronary artery disease (CAD) and/or no CAD at all. Further, PET-MBF quantification expands the scope of conventional myocardial perfusion imaging from the identification of advanced, and flow-limiting, epicardial CAD to early stages of atherosclerosis and/or CMD. Adding MBF assessment to myocardial perfusion may also reliably unravel diffuse ischemia owing to significant left main stenosis and/or multivessel CAD, commonly confirmed by peak stress transient ischemic cavity dilation of the left ventricle during maximal vasomotor stress compared to rest on gated PET images. Owing to high spatial and contrast resolution in conjunction with photon-attenuation free myocardial perfusion PET images, PET is preferentially used for CAD detection in advanced obesity and women with pronounced breast habitus. With increasing clinical use of cardiac PET perfusion and MBF assessment, individualized, and image-guided cardiovascular treatment decisions in CAD patients is likely to ensue, while its translation into improved cardiovascular outcome remains to be investigated. [ABSTRACT FROM AUTHOR]

Published
2024
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38. Myocardial Perfusion PET for the Detection and Reporting of Coronary Microvascular Dysfunction: A JACC: Cardiovascular Imaging Expert Panel Statement

Author

Schindler, Thomas H, Fearon, William F, Pelletier-Galarneau, Matthieu, Ambrosio, Giuseppe, Sechtem, Udo, Ruddy, Terrence D, Patel, Krishna K, Bhatt, Deepak L, Bateman, Timothy M, Gewirtz, Henry, Shirani, Jamshid, Knuuti, Juhani, Gropler, Robert J, Chareonthaitawee, Panithaya, Slart, Riemer H J A, Windecker, Stephan, Kaufmann, Philipp A, Abraham, Maria R, Taqueti, Viviany R, Ford, Thomas J, Camici, Paolo G, Schelbert, Heinrich R, Dilsizian, Vasken, University of Zurich, and Schindler, Thomas H

Subjects
2741 Radiology, Nuclear Medicine and Imaging, 610 Medicine & health, 10181 Clinic for Nuclear Medicine, 2705 Cardiology and Cardiovascular Medicine
Published
2023

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