Technetium pyrophosphate uptake in transthyretin cardiac amyloidosis: Associations with echocardiographic disease severity and outcomes.

Background: Quantitative uptake of Technetium 99 m-pyrophosphate (TcPYP) is sensitive and specific for diagnosing transthyretin cardiac amyloidosis (ATTR). We sought to examine the association between TcPYP uptake intensity and echocardiographic measures of disease severity and clinical outcomes.

Methods And Results: A retrospective analysis was performed of 75 patients who underwent TcPYP scintigraphy.

Impact of Time-of-Flight Reconstruction on Cardiac PET Images of Obese Patients.

Purpose: The benefit of time-of-flight (TOF) information in PET oncology studies is well established, demonstrating improved signal-to-noise ratio and enhanced lesion detection. In cardiac PET studies, tracer distribution and study interpretation differ substantially from oncology PET, and the benefit of TOF is less established. We investigate the impact of TOF on reconstructed myocardial distribution in Rb PET perfusion studies of obese patients, for whom TOF would have most significant impact.

Transmission Imaging in Lymphoscintigraphy with a 153Gd Flood Source.

Unlabelled: Lymphoscintigraphy uses intradermal or interstitial injections of (99m)Tc-labeled tracers to produce images of focal lymph nodes. Because there is little or no anatomic information in the (99m)Tc images, a (57)Co flood source is sometimes used to provide transmission data along with the emission data. The anatomic shadow from the transmission scan generally improves interpretation and surgical planning.

Outcome of cardiac sarcoidosis after radiofrequency ablation and placement of AICD- A propensity matched analysis.

Background: Cardiac Sarcoidosis (CS) can lead to life-threatening ventricular dysrhythmias and sudden death. Immunosuppressive medications, radiofrequency ablation (RFA), and implantable cardioverter defibrillators (ICD) have been utilized to manage ventricular dysrhythmias but their benefits remain poorly defined.

Objective: The aim of this study is to assess the durability of RFA in CS population and to determine outcome predictors after RFA.

Do myocardial PET-MR and PET-CT FDG images provide comparable information?

Introduction: Although positron emission tomography PET-MR imaging is emerging into clinical practice, many aspects of this imaging technique such as attenuation correction have yet to be validated for myocardial imaging. Thus, it is uncertain whether PET-MR FDG images provide clinical information which is comparable to PET-CT FDG images. The study goal was to systematically compare relative myocardial FDG concentrations obtained from cardiac PET-MR images to those derived from same day PET-CT images.

Predictive value of exercise myocardial perfusion imaging in the Medicare population: the impact of the ability to exercise.

Background: Although the prognostic value of quantitative single photon emission computed tomography myocardial perfusion imaging (MPI) with exercise and pharmacologic stress is well established, the prognostic and management value in the Medicare age population is less clear.

Methods: The prospectively populated Cleveland Clinic nuclear cardiology database was used to identify 5,994 consecutive pateints, age >65 years [1,664 (28%) exercise MPI, mean age 72.4±5.

Identification of therapeutic benefit from revascularization in patients with left ventricular systolic dysfunction: inducible ischemia versus hibernating myocardium.

Background: Although the recent surgical treatment of ischemic heart failure substudy reported that revascularization of viable myocardium did not improve survival, these results were limited by the viability imaging technique used and the lack of inducible ischemia information. We examined the relative impact of stress-rest rubidium-82/F-18 fluorodeoxyglucose positron emission tomography identified ischemia, scar, and hibernating myocardium on the survival benefit associated with revascularization in patients with systolic dysfunction.

Methods And Results: The extent of perfusion defects and metabolism-perfusion mismatch was measured with an automated quantitative method in 648 consecutive patients (age, 65±12 years; 23% women; mean left ventricular ejection fraction, 31±12%) undergoing positron emission tomography.

Predictors and incremental prognostic value of left ventricular mechanical dyssynchrony response during stress-gated positron emission tomography in patients with ischemic cardiomyopathy.

Objectives: The study sought to investigate whether there is stress-induced worsening of left ventricular mechanical dyssynchrony (LVMD) in patients with ischemic cardiomyopathy (ICM), determine the predictors of LVMD response (LVMDR) and its incremental prognostic value.

Background: The effect of stress physiology on LVMD in patients with ICM has not been adequately evaluated, and the prognostic value of abnormal LVMDR beyond traditional predictors of mortality remains uncertain.

Methods: 489 consecutive patients with ICM, LV ejection fraction (EF) <35% undergoing rest/stress Rb-82 gated PET were evaluated.

Effect of stress testing on left ventricular mechanical synchrony by phase analysis of gated positron emission tomography in patients with normal myocardial perfusion.

Purpose: There are limited data on whether differences exist in left ventricular (LV) mechanical dyssynchrony indices derived from stress versus rest gated positron emission tomography (PET) in patients with normal myocardial perfusion imaging (MPI).

Methods: Stress/rest (82)Rb gated PET was performed in consecutive patients with normal MPI between 2006 and 2010. Patients were divided into two groups: group 1 [LV ejection fraction (EF) ≥ 55% and QRS < 120 ms] and group 2 (LVEF ≤35%).

Ischemic changes on rubidium-82 positron emission tomography imaging are associated with left ventricular functional and volumetric change independent of metabolic properties and echocardiographic functional variables in ischemic cardiomyopathy.

Positron emission tomography (PET) imaging allows identification of stress-induced ischemia and myocardial viability in patients with ischemic cardiomyopathy. We assessed the left ventricular (LV) functional response to vasodilator stress in patients with advanced ischemic cardiomyopathy undergoing pharmacologic stress (PET) perfusion and metabolic imaging. Additionally, we aimed to determine if mitral regurgitation (MR), right ventricular (RV) dysfunction and diastolic function influenced the observed LV responses to pharmacologic stress.

Lessons from regadenoson and low-level treadmill/regadenoson myocardial perfusion imaging: initial clinical experience in 1263 patients.

Background: Regadenoson is a pharmacologic stress agent, which was recently approved for stress myocardial perfusion imaging (MPI). Aside from the initial protocol-driven studies, clinical experience with this stress agent is limited. Furthermore, low-level treadmill testing in a large population with regadenoson has not previously been evaluated.

SPECT/CT imaging: clinical utility of an emerging technology.

Single-photon emission computed tomography (SPECT) has been a mainstay of nuclear medicine practice for several decades. More recently, combining the functional imaging available with SPECT and the anatomic imaging of computed tomography (CT) has gained more acceptance and proved useful in many clinical situations. Most vendors now offer integrated SPECT/CT systems that can perform both functions on one gantry and provide fused functional and anatomic data in a single imaging session.

Preliminary data on the diagnostic accuracy of rubidium-82 cardiac PET perfusion imaging for the evaluation of ischemia in a pediatric population.

Evaluation of myocardial perfusion is sometimes necessary in children with congenital heart disease or acquired coronary artery abnormalities. Limited information is available regarding the clinical utility of myocardial perfusion imaging in children. PET imaging with rubidium-82 may provide a convenient clinical means of assessing regional circulatory compromise in pediatric patients with small hearts, due to its improved spatial resolution.

PET and PET/CT imaging: what clinicians need to know.

Positron emission tomography (PET), once the sole province of academic medical centers, is rapidly being adopted in daily clinical practice in community hospitals and outpatient centers. It can be especially useful in oncology, cardiology, and neurology. We provide an overview of the fundamentals of PET and PET with computed tomography (PET/CT) and discuss their current clinical utility.

A knowledge-based method for reducing attenuation artefacts caused by cardiac appliances in myocardial PET/CT.

Attenuation artefacts due to implanted cardiac defibrillator leads have previously been shown to adversely impact cardiac PET/CT imaging. In this study, the severity of the problem is characterized, and an image-based method is described which reduces the resulting artefact in PET. Automatic implantable cardioverter defibrillator (AICD) leads cause a moving-metal artefact in the CT sections from which the PET attenuation correction factors (ACFs) are derived.

Myocardial perfusion reserve in adults with cyanotic congenital heart disease.

In patients with cyanotic congenital heart disease (CCHD), a right-to-left shunt results in systemic hypoxemia. Systemic hypoxemia incites a compensatory erythrocytosis, which increases whole blood viscosity. We considered that these changes might adversely influence myocardial perfusion in CCHD patients.