Quantum gx2 microct imaging system

For the imaging studies, we used a Quantum GX2 microCT Imaging System (Perkin Elmer, Waltham, MA, USA). The embedded nerve was placed in a 36 mm bed. The microCT scanner was warmed up as recommended by the manufacturer. We imaged a cross-sectional field of view that was 36 mm x 36 mm. Each scan spanned 1.8 cm of nerve length, with 0.3 cm overlap (i.e., 16.67%) between adjacent scans to serve image reconstruction. The barium-marked grooves were used for x-ray navigation to the appropriate markings. The resultant images had 72 μm isotropic voxel resolution.
Post-hoc sub-block reconstruction was performed with Rigaku software provided by Perkin Elmer. Each sub-block reconstruction was a 5.12 × 5.12 × 5.12 mm³ cube and adjacent sub-blocks overlapped by 0.1 mm (20% overlap); the resolution of final reconstruction was 10 μm voxel size (isotropic). Images were exported as DICOM files for further processing. After down-sampling frames along the longitudinal axis by 10-fold, blocks were co-registered and stitched using ImageJ (FIJI, Version 2.1.0/1.53c).^{40 (link)} The final image dataset consisted of a stack of TIFF images of the nerve cross section every 100 μm along the nerve. 3D visualizations were generated by Simpleware^™ ScanIP software (Synopsys, Mountain View, CA).

Fore limbs and hind limbs were dissected from sacrificed mice and micro-CT imaging was performed. Micro-CT images were acquired on the Quantum GX2 microCT Imaging System (PerkinElmer, Waltham, MA). CT image sets acquisitions lasted 4 min and utilized beam parameters of 88 μA and 90 kV with X-ray filter of Cu 0.06 + Al 0.5.