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Prepolarized MRI (PMRI) with pulsed electromagnets has the potential to produce diagnostic quality 0.5- to 1.0-T images with significantly reduced cost, susceptibility artifacts, specific absorption rate, and gradient noise. In PMRI, the main magnetic field cycles between a high field (B(p)) to polarize the sample and a homogeneous, low field (B(0)) for(More)
PURPOSE To compare signal-to-noise ratios (SNRs) and T*(2) maps at 3 T and 7 T using 3D cones from in vivo sodium images of the human knee. MATERIALS AND METHODS Sodium concentration has been shown to correlate with glycosaminoglycan content of cartilage and is a possible biomarker of osteoarthritis. Using a 3D cones trajectory, 17 subjects were scanned(More)
PURPOSE To deploy clinically, a combined parallel imaging compressed sensing method with coil compression that achieves a rapid image reconstruction, and assess its clinical performance in contrast-enhanced abdominal pediatric MRI. MATERIALS AND METHODS With Institutional Review Board approval and informed patient consent/assent, 29 consecutive pediatric(More)
A 16-channel receive-only, closely fitted array coil is described and tested in vivo for bilateral breast imaging at 3 T. The primary purpose of this coil is to provide high signal-to-noise ratio and parallel imaging acceleration in two directions for breast MRI. Circular coil elements (7.5-cm diameter) were placed on a closed "cup-shaped" platform, and(More)
Hyperpolarized [1-(13) C]pyruvate ([1-(13) C]Pyr) has been used to assess metabolism in healthy and diseased states, focusing on the downstream labeling of lactate (Lac), bicarbonate and alanine. Although hyperpolarized [2-(13) C]Pyr, which retains the labeled carbon when Pyr is converted to acetyl-coenzyme A, has been used successfully to assess(More)
We report metabolic images of (13)C, following injection of a bolus of hyperpolarized [1-(13)C] pyruvate in a live rat. The data were acquired on a clinical scanner, using custom coils for volume transmission and array reception. Proton blocking of all carbon resonators enabled proton anatomic imaging with the system body coil, to allow for registration of(More)
We describe the electronics for controlling the independently pulsed polarizing coil in a prepolarized magnetic resonance imaging (PMRI) system and demonstrate performance with free induction decay measurements and in vivo imaging experiments. A PMRI scanner retains all the benefits of acquiring MRI data at low field, but with the higher signal of the(More)
Introduction Prepolarized MRI (PMRI) [1,2] is an inexpensive MRI architecture that uses a mid-field copper wire magnet (B p) for longitudinal magnetization growth and a low-field magnet (B 0) for spatial encoding and data acquisition, as shown in Fig. 1. This setup offers the SNR of mid-field imaging combined with the benefits of low-field imaging, which(More)
PURPOSE To design, construct, and validate a semiflexible 64-channel receive-only phased array for pediatric body MRI at 3T. METHODS A 64-channel receive-only phased array was developed and constructed. The designed flexible coil can easily conform to different patient sizes with nonoverlapping coil elements in the transverse plane. It can cover a field(More)
Q-spoiling is the process of decoupling an MRI receive coil to protect the equipment and patient. Conventionally, Q-spoiling is performed using a PIN diode switch that draws significant current. In this work, a Q-spoiling technique using a depletion-mode Gallium Nitride HEMT device was developed for coil detuning at both 1.5 T and 3 T MRI. The circuits with(More)
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