Dustin K. Ragan

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The purpose of this work is to demonstrate a proof of feasibility of the application of a commercial prototype deformable model algorithm to the problem of delineation of anatomic structures on four-dimensional (4D) computed tomography (CT) image data sets. We acquired a 4D CT image data set of a patient's thorax that consisted of three-dimensional (3D)(More)
A fast spin echo two-point Dixon (fast 2PD) technique was developed for efficient T2-weighted imaging with uniform water and fat separation. The technique acquires two interleaved fast spin echo images with water and fat in-phase and 180 degrees out-of-phase, respectively, and generates automatically separate water and fat images for each slice. The image(More)
Dynamic contrast-enhanced (DCE-) MRI is often used to evaluate the response to experimental antiangiogenic therapies in small animal models of cancer. Unfortunately, DCE-MRI studies often require a substantial investment of both time and money to achieve the desired level of statistical significance. Multiple-mouse MRI has previously been used to improve(More)
Dynamic contrast-enhanced MRI is often used to assess the response to therapy in small animal models of cancer. Rigorous quantification of dynamic contrast-enhanced MRI data using common pharmacokinetic models requires dynamic determination of the concentration of contrast in tumor tissue and in blood. Measurement of the blood concentration, or vascular(More)
PURPOSE To test the ability of a multi-band RF pulse to reduce flow enhancement artifacts for steady state imaging without compromising temporal resolution or spatial coverage. MATERIALS AND METHODS Selectively spoiled composite RF pulses that provide simultaneous excitation and flow preparation were designed and tested by means of simulation, phantom,(More)
PURPOSE To determine whether Dixon-based fat separation techniques can provide more robust removal of lipid signals from multiple-mouse magnetic resonance imaging (MRI)-acquired images than conventional frequency selective chemical saturation techniques. MATERIALS AND METHODS A two-point Dixon technique was implemented using a RARE-based pulse sequence(More)
PURPOSE Prostate imaging requires optimization in young and old mouse models. We tested which MR sequences and field strengths best depict the prostate gland in young and old mice; and, whether prostate MR signal, size, and architecture change with age. TECHNIQUE Magnetic resonance imaging (MRI) of the prostate of young (2 months) and old (18 months) male(More)
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