Cardiac Molecular Imaging
Molecular imaging enables the visualization and interrogation of specific biologic targets and pathways that precede or underlie changes in morphology, physiology, and function of the heart. Accordingly, it aims at identifying precursors or early stages of cardiac disease, and it may facilitate monitoring and guidance of novel, increasingly specific and versatile cardiovascular therapies. Although SPECT and PET imaging of myocardial metabolism and autonomic innervation are already embedded in clinical practice, various additional targets, probes, and techniques are under development. These techniques hold promise to become...
Source: Seminars in Nuclear Medicine - September 1, 2014 Category: Radiology Authors: Tim Wollenweber, Frank M. Bengel Source Type: research
Cardiac Hot Spot Imaging With 18FDG
Myocardial perfusion imaging is the mainstay of nuclear cardiovascular imaging. It has been in extensive clinical use for well over 35 years for diagnosing, risk-stratification, and long-term follow-up of patients with suspected or known coronary artery disease. A unique strength of nuclear imaging is its ability to provide a repertoire of tools for imaging metabolic and biochemical processes, receptor and transporter function, inflammation, and gene expression at molecular and cellular levels in intact organisms, under a wide variety of physiological conditions. With this approach, only selective myocardium with targeted ...
Source: Seminars in Nuclear Medicine - September 1, 2014 Category: Radiology Authors: Diwakar Jain, Zuo-Xiang He, Vikram Lele Source Type: research
Myocardial Viability: It is Still Alive
Heart failure presents a significant problem in industrialized countries, with a high prevalence, morbidity, and mortality, where it is most frequently caused by coronary artery disease. Revascularization in patients with symptomatic heart failure has been associated with improved cardiovascular outcomes. Predictors of outcome benefit from revascularization include the presence and extent of hibernating myocardium, ischemia, scar, left ventricular ejection fraction, and renal function. Viability is useful in directing the management of patients with ischemic cardiomyopathy. It is especially useful in those with the highest...
Source: Seminars in Nuclear Medicine - September 1, 2014 Category: Radiology Authors: Siok P. Lim, Brian A. Mc Ardle, Rob S. Beanlands, Renee C. Hessian Source Type: research
Cardiac PET Perfusion: Prognosis, Risk Stratification, and Clinical Management
Myocardial perfusion imaging (MPI) with PET has expanded significantly over the past decade. With the wider availability of PET scanners and the routine use of quantitative blood flow imaging, the clinical use of PET MPI is expected to increase further. PET MPI is a powerful tool to identify risk, to quantify risk, and to guide therapy in patients with known or suspected coronary artery disease. A large body of evidence supports the prognostic value of PET MPI and ejection fraction in intermediate- to high-risk subjects, in women, in obese individuals, and in post-coronary artery bypass grafting individuals. A normal perfu...
Source: Seminars in Nuclear Medicine - September 1, 2014 Category: Radiology Authors: Sharmila Dorbala, Marcelo F. Di Carli Source Type: research
Cardiac PET Perfusion Tracers: Current Status and Future Directions
PET myocardial perfusion imaging (MPI) is increasingly being used for noninvasive detection and evaluation of coronary artery disease. However, the widespread use of PET MPI has been limited by the shortcomings of the current PET perfusion tracers. The availability of these tracers is limited by the need for an onsite (15O water and 13N ammonia) or nearby (13N ammonia) cyclotron or commitment to costly generators (82Rb). Owing to the short half-lives, such as 76 seconds for 82Rb, 2.06 minutes for 15O water, and 9.96 minutes for 13N ammonia, their use in conjunction with treadmill exercise stress testing is either not possi...
Source: Seminars in Nuclear Medicine - September 1, 2014 Category: Radiology Authors: Jamshid Maddahi, René R.S. Packard Source Type: research
Letter From the Guest Editor: Update in Cardiovascular Nuclear Medicine (Part II)
This is Part 2 of an update in Cardiovascular Nuclear Medicine, focusing here on cardiac PET. The issue opens with a comprehensive review by Drs Maddahi and Packard on the state of PET perfusion tracers. While clinical PET perfusion is currently limited to 82Rb and 13NH3, newer agents under investigation, such as 18F flurpiridaz, promise to make PET more widely accessible and to produce images that are even better than those with current tracers. The clinical utility of perfusion PET has been extensively investigated by the team at the Brigham and Women׳s Hospital, with the superb review by Drs Dorbala and DiCarli demonst...
Source: Seminars in Nuclear Medicine - September 1, 2014 Category: Radiology Authors: Mark I. Travin Source Type: research
Letter From the Editors
The predominant application of PET is in the field of oncology. However, we should not forget that cardiac studies were the earliest approved PET techniques and that they have made an ever-increasing impact in clinical medicine since that time. Clearly, 18F-FDG, the primary PET agent, has a role in myocardial viability, and it has also been used increasingly in the diagnosis of cardiac sarcoidosis. (Source: Seminars in Nuclear Medicine)
Source: Seminars in Nuclear Medicine - September 1, 2014 Category: Radiology Authors: Leonard M. Freeman, M. Donald Blaufox Source Type: research
Clinical Decision Making With Myocardial Perfusion Imaging in Patients With Known or Suspected Coronary Artery Disease
Myocardial perfusion imaging (MPI) to diagnose coronary artery disease (CAD) is best performed in patients with intermediate pretest likelihood of disease; unfortunately, pretest likelihood is often overestimated, resulting in the inappropriate use of perfusion imaging. A good functional capacity often predicts low risk, and MPI for diagnosing CAD should be reserved for individuals with poor exercise capacity, abnormal resting electrocardiography, or an intermediate or high probability of CAD. With respect to anatomy-based testing, coronary CT angiography has a good negative predictive value, but stenosis severity correlat...
Source: Seminars in Nuclear Medicine - June 19, 2014 Category: Radiology Authors: Paul Cremer, Rory Hachamovitch, Balaji Tamarappoo Source Type: research
Left Ventricular Dyssynchrony Assessment Using Myocardial Single-Photon Emission CT
Myocardial SPECT using standard procedure for perfusion imaging and phase analysis is a novel approach to left ventricular dyssynchrony assessment. Preliminary data suggest excellent repeatability and potential utility for guiding cardiac resynchronization therapy and elucidating mechanisms. (Source: Seminars in Nuclear Medicine)
Source: Seminars in Nuclear Medicine - June 19, 2014 Category: Radiology Authors: Prem Soman, Ji Chen Source Type: research
Cardiac Radionuclide Imaging to Assess Patients With Heart Failure
Heart failure (HF) is a major problem, with a high prevalence, morbidity, mortality, and cost, and is expected to become more widespread. Radionuclide imaging currently plays an important role in evaluating these patients, with much potential for increased utility. Myocardial perfusion imaging (MPI) with radiotracers is commonly used to differentiate an ischemic from a nonischemic etiology of HF and cardiomyopathy. In some instances, MPI effectively distinguishes among these, but often, standard MPI is deficient in that a nonischemic cardiomyopathy can have focal defects in tracer uptake and coronary artery disease with gl...
Source: Seminars in Nuclear Medicine - June 19, 2014 Category: Radiology Authors: Mark I. Travin Source Type: research
Quantitative Assessment of Myocardial Blood Flow—Clinical and Research Applications
Myocardial perfusion imaging with SPECT/CT or with PET/CT is a mainstay in clinical practice for the diagnostic assessment of downstream, flow-limiting effects of epicardial lesions during hyperemic flows and for risk stratification of patients with known or suspected coronary artery disease (CAD). In patients with multivessel CAD, the relative distribution of radiotracer uptake in the left ventricular myocardium during stress and rest accurately identifies flow-limiting epicardial lesions or the most advanced, so called culprit, lesion. Often, less severe obstructive CAD lesions may go undetected or underdiagnosed. The co...
Source: Seminars in Nuclear Medicine - June 19, 2014 Category: Radiology Authors: Thomas H. Schindler, Alessandra Quercioli, Ines Valenta, Giuseppe Ambrosio, Richard L. Wahl, Vasken Dilsizian Source Type: research
Advances in Cardiac Processing Software
New software methods that incorporate iterative reconstruction, resolution recovery, and noise compensation now provide the ability to maintain or improve myocardial perfusion SPECT image quality with conventional sodium iodide cameras. Despite lower image counting statistics associated with significantly decreased injected radiopharmaceutical doses or shortened acquisition times or both, image quality is preserved or even improved compared with conventional processing methods. The ability to prescribe a desired myocardial count density by preselecting a SPECT acquisition time now avoids additional patient radiation exposu...
Source: Seminars in Nuclear Medicine - June 19, 2014 Category: Radiology Authors: Ernest Gordon DePuey Source Type: research
New Cardiac Cameras: Single-Photon Emission CT and PET
Nuclear cardiology instrumentation has evolved significantly in the recent years. Concerns about radiation dose and long acquisition times have propelled developments of dedicated high-efficiency cardiac SPECT scanners. Novel collimator designs, such as multipinhole or locally focusing collimators arranged in geometries that are optimized for cardiac imaging, have been implemented to enhance photon-detection sensitivity. Some of these new SPECT scanners use solid-state photon detectors instead of photomultipliers to improve image quality and to reduce the scanner footprint. These new SPECT devices allow dramatic up to 7-fo...
Source: Seminars in Nuclear Medicine - June 19, 2014 Category: Radiology Authors: Piotr J. Slomka, Daniel S. Berman, Guido Germano Source Type: research
Letter from the Guest Editor: Update in Cardiovascular Nuclear Medicine
There have been many advances in the field of cardiovascular nuclear imaging since the most recent review of the topic in Seminars in Nuclear Medicine almost 10 years ago in January 2005. The assortment of articles by leaders in the field in this part 1 issue and in the part 2 issue coming in September provides in-depth descriptions of SPECT, PET, and hybrid imaging technological advancements related to acquiring and processing cardiac images using current standard and potential new radiotracers, better understood and expanded clinical applications in patients with a variety of heart conditions that include not only corona...
Source: Seminars in Nuclear Medicine - June 19, 2014 Category: Radiology Authors: Mark I. Travin Source Type: research
Letter From the Editors
Following its introduction into routine nuclear cardiology in the mid-1970, myocardial perfusion imaging (MPI) witnessed great growth and popularity for 3 decades. Starting with thallium-201 planar imaging and progressing to SPECT imaging with Tc-99m sestamibi, MPI has added a powerful imaging tool for detecting both the presence and extent of coronary artery disease. As our knowledge increased and technologic advances flourished, it became possible to obtain additional information concerning risk assessment and prognosis. From 2000-2006, the use of MPI increased by 41%. However, for a variety of reasons, this trend has re...
Source: Seminars in Nuclear Medicine - June 19, 2014 Category: Radiology Authors: Leonard M. Freeman, M. Donald Blaufox Source Type: research
