Magnetic resonance microscopy at 17.6-tesla on chicken embryos in vitro

The non-destructive nature and the rapid acquisition of a three-dimensional image makes magnetic resonance microscopy (MRM) very attractive and suitab le for functional imaging investigations. We explored the use of an ultra h igh magnetic field for MRM to increase image quality per image acquisition time. Improved image quality was characterized by a better signal-to-noise ratio (SNR), better image contrast, and higher resolution compared to image s obtained at lower magnetic field strengths. Fixed chicken embryos at seve ral stages of development were imaged at 7.0-T (300 MHz) and at 17.6-T (750 MHz). Maximum Intensity projection resulted In three-dimensional vascular images with ample detail of the embryonic vasculature. We showed that at 75 0 MHz frequency, an Image with approximately three times better SNR can be obtained by T-1-weighting using a standard gadolinium contrast agent, compa red to the same measurement at 300 MHz.. The image contrast improved by aro und 20 percent and the contrast-to-noise ratio improved by almost a factor of 3.5. Smaller blood vessels of the vascular system were identified at the high field, which indicates a better image resolution. Thus, ultra high fi eld is beneficial for MRM and opens new areas for functional imaging resear ch, In particular when SNR, resolution, and contrast are limited by acquisi tion time. (C) 2001 Wiley-Liss, Inc.