Large-scale cryosectioning technique allows in vitro correlation of magnetic resonance imaging and gross histologic findings in the wrist

To enhance the usefulness of magnetic resonance imaging (MRI) in the clinical assessment of wrist joint pathology, we correlated findings from consecutive MRIs of cadaver wrists with findings from gross histologic sections of these wrists, using the sections as the standard of reference. The study required a sectioning technique that allowed preparation of large-scale sections closely matching corresponding MRIs in size and sectioning plane. We adapted a large-scale cryosectioning technique for undecalcified bone, previously described in the literature, to our study of 16 formalin fixed cadaver wrists. After subjecting each wrist to MR imaging with a wrist coil, we cryosectioned the entire wrist joint, from the distal ulna and radius to the proximal metacarpals, in the frontal plane, which corresponded to the MR images. The cryostat's tissue stage was mounted on a ball and socket-like joint that allowed corrections of the sectioning plane, enabling us to obtain sections in a plane closely resembling the corresponding MRIs. We stained the cryosections by a safranin-O fast green method modified to minimize hydration. When cryosections whose portions detached from the slide during staining were eliminated, morphologic comparison of the remaining coverslipped sections with photos of the corresponding tissue block surface taken before sectioning revealed that the sections were accurate representations of the wrist. The sections were deemed suitable as a standard of reference for comparison of the corresponding MRIs. The large-scale sectioning technique and modified staining method can be used in further comparison studies aimed at refining MRI techniques to permit greater differentiation of joint structures on the MRT.