[en] A compact mouse MRI has been developed using a 1.0T yokeless permanent magnet and portable MRI console. The entire system was installed in a space measuring 2 m x 1 m. The imaging region was the cylindrical volume (35 mm diameter, 50 mm length) at the center of the magnet and was used for whole-brain or body imaging of mice. Whole-brain imaging took less than 90 min for T₁- and T₂-weighted 3D images with 2-mm slice thickness and 200-μm in-plane resolution. Body imaging took less than 30 min for T₁-weighted spin-echo and fast low angle shot (FLASH) 3D images with 0.5- to 1.0-mm slice thickness and 250- to 300-μm in-plane resolution. In addition to the compactness of the system, the mouse MRI has several advantages over high-field superconducting animal MRI systems in its accessibility to the specimen, similarity to clinical MRI in image contrast, capacity for biological isolation, and maintenance. The results obtained demonstrate the potential of this new system for routine imaging in biomedical laboratories. (author)

[en] Using 4 and 8-channel super-parallel magnetic resonance (MR) microscopes with a horizontal bore 2.34T superconducting magnet developed for 3-dimensional MR microscopy of the large Kyoto Collection of Human Embryos, we acquired T₁-weighted 3D images of 1204 embryos at a spatial resolution of (40 μm)³ to (150 μm)³ in about 2 years. Similarity of image contrast between the T₁-weighted images and stained anatomical sections indicated that T₁-weighted 3D images could be used for an anatomical 3D image database for human embryology. (author)

[en] Abstract Objective. To evaluate MR microscopic images of normal-appearing porcine hyaline cartilage (n=15) in vitro obtained with an MR microscope using an independent console system (MRMICS) at 1.5 T.Design and results. The MRMICS is a portable imaging system consisting of a radiofrequency system, gradient power supplies and a personal computer. The images from the MRMICS showed a laminar structure of porcine cartilage similar to the structure demonstrated with other MR imaging techniques. The laminar structures of the articular cartilage, were, however heterogeneous in respect of signal intensity and thickness, which varied according to the site resected. The MR laminar appearance was most comparable to the staining with Masson's trichrome for collagen.Conclusion. MRMICS is a useful add-on system for obtaining microscopic MR images of articular cartilage in vitro. (orig.)