Michael A. Bernstein

Learn More
Whenever a linear gradient is activated, concomitant magnetic fields with non-linear spatial dependence result. This is a consequence of Maxwell's equations, i.e., within the imaging volume the magnetic field must have zero divergence, and has negligible curl. The concomitant, or Maxwell field has been described in the MRI literature for over 10 years. In(More)
We present a reconstruction method for phased array multicoil data that is compatible with phase contrast MR angiography. The proposed algorithm can produce either complex difference or phase difference angiograms. Directional flow and quantitative information are preserved with the phase difference reconstruction. The proposed method is computationally(More)
Three encoding strategies for the measurement of flow velocities in arbitrary directions with phase-contrast magnetic resonance imaging are presented; their noise and dynamic range performance are compared by means of theoretical analysis and computer simulation. A six-point measurement strategy is shown to be quite inefficient in terms of velocity variance(More)
Maxwell's equations imply that imaging gradients are accompanied by higher order spatially varying fields (concomitant fields) that can cause artifacts in MR imaging. The lowest order concomitant fields depend quadratically on the imaging gradient amplitude and inversely on the static field strength. Time-varying concomitant fields that accompany the(More)
It has been observed that fast spin-echo (FSE) images with a large field of view (>40 cm) in certain directions exhibit unusual ghosting artifacts that cannot be eliminated with existing ghost removal methods. These artifacts have been related to a higher-order magnetic field perturbation (known as the concomitant field, or Maxwell field) concomitant to the(More)
When a linear magnetic field gradient is used, spatially higher-order magnetic fields are produced to satisfy the Maxwell equations. It has been observed that the higher-order magnetic field produced by the readout gradient causes axial echo planar images acquired with a horizontal solenoid magnet to shift along the phase-encoding direction and lose image(More)
A method for minimizing field-echo delay in moment-nulled gradient-echo imaging is presented. Even though ramps are accounted for, the analysis yields simple closed-form solutions. The method is then generalized to the section-select waveform for three-dimensional volume imaging and to flow encoding for phase-contrast imaging. Three strategies for(More)
The article describes symptoms of anxiety, depression and PTSD among Bosnian (n=17) and Colombian (n=17) torture survivors served by the Florida Center for Survivors of Torture, a programme of Gulf Coast Jewish Family Services, Inc. Information from clients enrolled in the programme for six months or more was collated over a 14 month period in order to(More)
During the Cold War, economists utilizing mathematical methods in both the Soviet Union and the United States found they shared a common research project. After the Stalinist years in which they could communicate very little, they found that they had much to learn from each other. Mathematical economics came to bridge the divide between East and West even(More)
The glucuronidation of (1S,2R,3R,5R)-3-(hydroxymethyl)-5-[7-{[(1R,2S)-2-phenylcyclopropyl]amino}-5-(propylthio)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-3-yl]cyclopentane-1,2-diol (AZ11939714) was studied in UDP-glucuronic acid (UDPGA)-supplemented hepatic microsomes from rat, dog, and human liver. The major biliary metabolite of this compound after intraduodenal(More)