Differentiation of collagens I, II, and III by second order susceptibility imaging

Second order susceptibility (SOS) microscopy is used as a contrast mechanism for distinguishing types I and III collagen in tissues. In addition, relative proportion of collagen type was determined by analyzing the histograms of SOS ratios. Our results show that second order susceptibility is an effective metric for differentiating types I and III collagen without extrinsic labeling.