The Effects of Formalin Fixation and Crosslinking on MRI Contrast in Bovine Nasal Cartilage Explants
Fishbein K, Gluzband Y, Kaku M, Togore H, Shapses S, Yamauchi M, Spencer R
National Institutes of Health
MR microscopy studies are often performed on formalin-fixed tissue samples, since fixation improves stability and compatibility with histology. However, little is known about MR contrast changes upon fixation, particularly in non-neural tissue. Accordingly, we investigated the effect of formalin fixation on T2 and magnetization transfer (MT) in bovine nasal cartilage, a spatially-homogeneous model for articular cartilage. We found significant decreases in T2 and increases in MT effects. These changes persist upon washout of residual formalin. Based on biochemical analyses, we attribute these latter effects to formaldehyde-induced crosslinking, which may immobilize GAG sidechains, thereby enhancing their contribution to MT in cartilage.