Figure 1: MR tomographic images on 4.7 T using T2*- (a, d, and g), T2- (b, e, and h), and T1-weighted images (c, f, and i) in a mouse 2 (a–c), 8 (d–f), and 24 hours (g–i) after stereotactic collagenase injection. The hematoma appears hypointense on T1 as early as 2 hours after collagenase injection and does not change in signal intensity and homogeneity over the first 24 hours. The blooming effect of T2*-weighted sequences makes the hematoma appear larger and needs referencing with T1- and T2-weighted images. T2-weighted images reveal a rim of hyperintensity surrounding the hypointense core as early as 8 hours. There is no evidence of hematoma enlargement over the first 24 hours.