Several attempts have been made in the past at imaging the fetus at 3T as part of the continuous search for increased image signal and better anatomic delineation of the developing fetus. Until now, imaging of the fetus at 3T has been disappointing, with numerous artifacts impeding image analysis. Improved technology now allows imaging of the fetus at greater magnetic strength, while still enco...

Advances in computed tomography have led to continuous improvement in cardiac imaging. Dedicated postprocessing capabilities, faster scan times, and cardiac gating methods reveal details of normal cardiac anatomy and anatomic variants that can mimic pathologic conditions. This article will review normal cardiac anatomy and variants that can mimic disease. Radiologists should be familiar with no...

UNLABELLED A novel PET radiotracer, Flurpiridaz F 18, has undergone phase II clinical trial evaluation as a high-resolution PET cardiac perfusion imaging agent. In a subgroup of patients imaged with this agent, we assessed the feasibility and benefit of simultaneous correction of respiratory and cardiac motion. METHODS In 16 patients, PET imaging was performed on a 4-ring scanner in dual card...

Schneider (1999) recently addressed the question of whether Ca 2 1 sparks arise from the opening of a single ryanodine receptor (RyR) channel or the simultaneous opening of several channels. The discussion highlighted the importance of single RyR channel permeation and gating in the interpretation of Ca 2 1 spark data. The Schneider (1999) perspective inspired us to extend this theoretical disc...

This paper is the first description of a calcium-activated nonspecific cation channel in adult ventricular muscle. We report gating kinetics and ionic selectivity data from experiments performed at the single channel level. Calcium activation is described by a gating model wherein two ions are involved in the reaction. Channel gating exhibited marked voltage dependence. Ionic selectivity experi...

Background An important requirement for successful cardiac MRI is accurate gating. However, obtaining proper Electrocardiogram (ECG) gating inside the MRI is a difficult problem, due to the Magneto-Hydro-Dynamic (MHD) effect, resulting in frequent intermittent gating. The MHD effect generates a voltage due to conductive blood flow perpendicular to B0, and distorts the real ECG. Intermittent gat...

The interaction of antiarrhythmic drugs with ion channels is often described within the context of the modulated receptor hypothesis, which explains the action of drugs by proposing that the binding site has a variable affinity for drugs, depending upon whether the channel is closed, open, or inactivated. Lack of direct evidence for altered gating of cardiac Na channels allowed for the suggesti...

The role of cardiac ryanodine receptor (RyR) gating in the initiation and propagation of calcium waves was investigated using a mathematical model comprising a stochastic description of RyR gating and a deterministic description of calcium diffusion and sequestration. We used a one-dimensional array of equidistantly spaced RyR clusters, representing the confocal scanning line, to simulate the f...

Meet Our Editorial Board Member Dr. Gerhard Meissner University of Northern Carolina, Chapel Hill, USA The laboratory’s research focuses on defining the molecular basis of Ca release channel (RyR) function in cardiac and skeletal muscle. RyRs are 2,200 kDa ion channels that release Ca ions in response to an action potential from the sarcoplasmic reticulum (SR), an intracellular Ca-storing compa...

This paper is the first description of a calcium-activated nonspecific cation channel in adult ventricular muscle. We report gating kinetics and ionic selectivity data from experiments performed at the single channel level. Calcium activation is described by a gating model wherein two ions are involved in the reaction. Channel gating exhibited marked voltage dependence. Ionic selectivity experi...