The effects of gating systems, number of runner, and their locations, in the Lost Foam Casting (LFC) of Aluminum alloy (A.413.0) were investigated. Six different gating systems, with one or two running systems were designed. X-ray radiography and the three axis-bending tests have been employed to evaluate the casting soundness and quality. The results revealed that gating systems have a major e...

An analysis of the effect of respiratory function on MR flow measures of the internal jugular vein (IJV) is presented. A novel 2D radial acquisition and reconstruction method allows for retrospective gating to both the cardiac and respiratory cycle. In-vivo scans of human volunteers verify the efficacy of the algorithm, showing increased IJV flow during inspiration and decreased flow during exp...

In this study, we evaluated the performance of an Elekta linac in the delivery of gated radiotherapy. Delivery accuracy was examined with an emphasis on the impact of using short gating windows (low monitor unit beam-on segments) or long beam hold times. The performance was assessed using a 20cm by 20cm open field with the radiation delivered using a range of beam-on and beam-off time periods. ...

The prediction as well as the gating of respiratory motion have received much attention over the last two decades for reducing the targeting error of the radiation treatment beam due to respiratory motion. In this article, we present a real-time algorithm for predicting respiratory motion in 3D space and realizing a gating function without pre-specifying a particular phase of the patient's brea...

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...

PURPOSE Respiratory motion correction remains a challenge in coronary magnetic resonance imaging (MRI) and current techniques, such as navigator gating, suffer from sub-optimal scan efficiency and ease-of-use. To overcome these limitations, an image-based self-navigation technique is proposed that uses "sub-images" and compressed sensing (CS) to obtain translational motion correction in 2D. The...

Despite technical advances, respiratory motion remains a major impediment in a substantial amount of patients undergoing coronary magnetic resonance angiography (CMRA). Traditionally, respiratory motion compensation has been performed with a one-dimensional respiratory navigator positioned on the right hemi-diaphragm, using a motion model to estimate and correct for the bulk respiratory motion ...

An improved version of motion-adapted gating useful in MR imaging is presented. Compared to other gating approaches, this advances method shows an improved ability to suppress motion artefacts at a reduced scan time. It is based on a k-space dependent weighting function and a realtime system feedback. During MR data acquisition patient motion ismonitored and only those profiles are accepted who...

Abstract Unmonitored cardiac images of a rat were acquired using standard gradient echo sequences to study the artefact ghosting mainly caused by heart and respiration motion. All imaging experiments performed transceiver circular-shaped coil preclinical magnetic resonance imager at 7 T. Heart showed along frequency encoding direction. However image quality was not drastically affected this typ...