Cryo-Imaging and Software Platform for Analysis of Molecular MR Imaging of Micrometastases

Figure 4

Evaluation of tissue expansion from spatial maps of the determinant of Jacobian. MR images are registered using rigid body (c, d) and affine plus nonrigid (e, f) to the reference color cryo-image volume ((a) coronal, (b) sagittal). The determinant of the Jacobian (g, h) can be interpreted as fractional volume change, with values <1 and >1 representing volume expansion and shrinkage, respectively. The color bar ranges from 0.85 to 1.25. In (g), within regions of interest (ROIs, yellow boxes) from left to right, values are muscle 0.93 ± 0.03, kidney 0.94 ± 0.02, and spleen 0.95 ± 0.02, where standard deviations come from voxelwise analysis in the ROIs. In the (h) view, ROIs from left to right are spinal cord 0.91 ± 0.03, liver 0.92 ± 0.01, lungs 1.18 ± 0.05, and brain 0.97 ± 0.01. A value of 0.92 in the liver corresponds to ~8% expansion with freezing. The lung deflated and shrunk. Other animals showed similar expansion/shrinkage trends.

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