IEEE J Transl Eng Health Med
April 2020
Objective: This study investigates the estimation of three dimensional (3D) left ventricular (LV) motion using the fusion of different two dimensional (2D) cine magnetic resonance (CMR) sequences acquired during routine imaging sessions. Although standard clinical cine CMR data is inherently 2D, the actual underlying LV dynamics lies in 3D space and cannot be captured entirely using single 2D CMR image sequences. By utilizing the image information from various short-axis and long-axis image sequences, the proposed method intends to estimate the dynamic state vectors consisting of the position and velocity information of the myocardial borders in 3D space.
View Article and Find Full Text PDFPurpose: To introduce a new realistic human skull phantom for the validation of synthetic CT images of cortical bone from ultra-short echo-time (UTE) sequences.
Methods: A human skull of an adult female was utilized as a realistic representation of skull cortical bone. The skull was stabilized in a special acrylic container and was filled with contrast agents that have T and T relaxation times similar to human brain.
The importance of assessing the metal-induced artefacts in magnetic resonance imaging (MRI)-guided brachytherapy is growing along with the increasing interest of integrating MRI into the treatment procedure of cervical cancer. Examples of metal objects in use include intracavitary cervical applicators and interstitial needles. The induced artefacts increase the uncertainties in the clinical workflow and can be a potential obstacle for the accurate delivery of the treatment.
View Article and Find Full Text PDFBackground And Purpose: The purpose of this work is to quantitatively investigate the artifacts and image distortions induced in the MR images by a recently proposed direction modulated brachytherapy (DMBT) tandem applicator prototype. This new MRI-compatible applicator allows better sparing of organs-at-risk (OAR) for cervical cancer patients, while providing conformal dose distributions to target volumes.
Materials And Methods: Specific phantom and tools were designed and manufactured for this study.
Purpose: To demonstrate a new multigradient echo bipolar acquisition sequence for fat quantification.
Theory And Methods: A multiecho bipolar acquisition is used such that the even echoes have opposite polarity to the odd echoes. In addition, the readout gradients alternate their polarities every other phase-encode line.
Purpose: To validate a fully automated adipose segmentation method with magnetic resonance imaging (MRI) fat fraction abdominal imaging. We hypothesized that this method is suitable for segmentation of subcutaneous adipose tissue (SAT) and intra-abdominal adipose tissue (IAAT) in a wide population range, easy to use, works with a variety of hardware setups, and is highly repeatable.
Materials And Methods: Analysis was performed comparing precision and analysis time of manual and automated segmentation of single-slice imaging, and volumetric imaging (78-88 slices).
Purpose: To propose a novel approach to water/fat separation using a unique smoothness constraint.
Theory And Methods: Chemical-shift based water/fat separation is an established noninvasive imaging tool for the visualization of body fat in various anatomies. Nevertheless, B0 magnetic field inhomogeneities can hamper the water/fat separation process.
Med Image Comput Comput Assist Interv
January 2013
While Magnetic Resonance Imaging is capable of separating water and fat components in the body, mapping of magnetic field inhomogeneities is essential for the successful application of this process. In this study, we address the problem of field map estimation using a convex-relaxed max-flow method. We propose a novel two-stage approach that leads to the global optimum of the proposed problem.
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