Source and detector configurations on the surface of the P-Scan near-infrared imager (not to scale). Sixteen sources and eight detectors are placed on the surface of the near-infrared imager, forming a 4 × 4 matrix. The overall size of the probe matrix is 50.8 mm × 50.8 mm. (i, j), pixels at the intersection of the ith row and the jth column. Tissue blood oxygen saturation ([StO2]) and total hemoglobin concentration ([Hbt]) values were calculated at each pixel (i, j).