High-resolution MR imaging of the rat spinal cord in vivo in a wide-bore magnet at 17.6 Tesla

Abstract

The objective was to demonstrate the feasibility and to evaluate the performance of high-resolution in vivo magnetic resonance (MR) imaging of the rat spinal cord in a 17.6-T vertical wide-bore magnet. A probehead consisting of a surface coil that offers enlarged sample volume suitable for rats up to a weight of 220 g was designed. ECG triggered and respiratory-gated gradient echo experiments were performed on a Bruker Avance 750 wide-bore spectrometer for high-resolution imaging. With T * 2 values between 5 and 20 ms, good image contrast could be obtained using short echo times, which also minimizes motion artifacts. Anatomy of healthy spinal cords and pathomorphological changes in traumatically injured rat spinal cord in vivo could be visualized with microscopic detail. It was demonstrated that imaging of the rat spinal cord in vivo using a vertical wide-bore high-magnetic-field system is feasible. The potential to obtain high-resolution images in short scan times renders high-field imaging a powerful diagnostic tool.

Longitudinal measurements of syrinx size in a rat model of posttraumatic syringomyelia

“…An appropriate threshold (manually chosen) was applied to all images to delineate the syrinx (hyperintense signal) from the gray and white matter. Once the area of the syrinx and whole spinal cord cross-section was determined in each section, the pixel value for each MRI slice was used to calculate the syrinx volume in mm 3 . Lesion volume was calculated by multiplying total lesion pixel count with individual voxel volume.…”

Imaging Microglial/Macrophage Activation in Spinal Cords of Experimental Autoimmune Encephalomyelitis Rats by Positron Emission Tomography Using the Mitochondrial 18 kDa Translocator Protein Radioligand [18F]DPA-714

“…Imaging of rat spinal cord in vivo poses particular challenge because of its small diameter (1-3 mm) (Behr et al, 2004), and spinal cord MRI is rarely performed in experimental studies. Still, much of the physical disability related to MS is probably mediated by spinal cord lesions, which can progress independently of brain disease.…”

“…4) (Chauveau et al, 2009;Martín et al, 2010). To account for the small diameter of the rat spinal cord, ranging from 1 to 3 mm (Behr et al, 2004), PET images were reconstructed using both conventional 2D-OSEM (Fig. 5 A, B) and FMAP (Fig.…”

Post-mortem assessment of rat spinal cord injury and white matter sparing using inversion recovery-supported proton density magnetic resonance imaging

“…However, they can be used on human post-mortem material, including PD imaging. 12 In the long run, the transfer of this kind of sequence to in vivo high-resolution rat 13,14 or even mouse 15 spinal cord MRI may be feasible if faster image acquisition proves to be of sufficient quality. With in vivo MRI, the present assessment at a single time point after the recovery period (which is a significant limitation to any post-mortem investigation) could be overcome and replaced by a continuous assessment of the lesion and correlation with behavioural parameters.…”