Purpose: To develop a protocol which optimizes contrast, resolution and scan time for three-dimensional (3D) imaging of the human eye in vivo using a 7 Tesla (T) scanner and custom radio frequency (RF) coil. Materials and Methods:Initial testing was conducted to reduce motion and susceptibility artifacts. Three-dimensional FFE and IR-TFE images were obtained with variable flip angles and TI times. T 1 measurements were made and numerical simulations were performed to determine the ideal contrast of certain ocular structures. Studies were performed to optimize resolution and signalto-noise ratio (SNR) with scan times from 20 s to 5 min.Results: Motion and susceptibility artifacts were reduced through careful subject preparation. T 1 values of the ocular structures are in line with previous work at 1.5T. A voxel size of 0.15 Â 0.25 Â 1.0 mm 3 was obtained with a scan time of approximately 35 s for both 3D FFE and IR-TFE sequences. Multiple images were registered in 3D to produce final SNRs over 40. Conclusion:Optimization of pulse sequences and avoidance of susceptibility and motion artifacts led to high quality images with spatial resolution and SNR exceeding prior work. Ocular imaging at 7T with a dedicated coil improves the ability to make measurements of the fine structures of the eye.

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In the course of the publication the design, fabrication, and experimental evaluation of a planar microcoil for nuclear magnetic resonance ͑NMR͒ spectroscopy with a 360 m inner diameter integrated to a low-noise metal-semiconductor field-effect transistor is presented. The impedance matching of the coil and transistor was achieved by adjusted coil geometry, while an appropriate microfabrication process including air bridge contacts and a multilayer metal stack was developed for the necessary susceptibility matching of the coil metallization. The NMR spectra of experiments in an 11.75 T magnet ͑corresponding to 500 MHz͒ show the amplification of the signal by the integrated transistor. Due to previous experiments, we wanted to ensure that the whole signal emerged from the sensitive volume of the microcoil.

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The intravascular contrast medium P792 showed significantly less LE and CNR in comparison to Gd-DOTA and P846, suggesting that it does not show marked extravasation from tumor neocapillaries and does not significantly cross the disrupted blood brain-barrier in this rat glioma model. In distinction, P846 provides comparable enhancement properties at a field strength of 3 Tesla to the extracellular contrast agent Gd-DOTA, using the adjusted dose, suggesting that it crosses the disrupted blood-brain-barrier and tumor capillaries, most likely based on the decreased molecular weight as compared with P792. At the same time, the high relaxivity of this compound allows for decreasing the injected gadolinium dose by a factor of 4 whereas providing comparable enhancement properties when compared with a standard extracellular Gd-chelate (Gd-DOTA) at a dose of 0.1 mmol/kg body weight.

Until now, direct, non-invasive i n vivo studies on water and metabolite distribution in living sponges have not been possible. Here we apply for the first time the noninvasive technique of nuclear magnetic resonance (NMR) irnaging to determine the spatial distribution of water in the marine sponge Subentes domuncula. After transfer of the sponge into deuterated water (D20) for a short incubation period of 18 rnin, no significant water exchange was observed, nelther In S. domuncula nor in the hermit crab livlng in symbiosis with it, suggesting D 2 0 to be an ideal contrast enhancing agent for NMR imaging of sponges. Thus, NMR imaging provides a promising technique for the detection (and possibly quantdication) of the distribution and transport of water both by diffusion and active transport in a living sponge.

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