Fig. 2
From: Desktop 3D printed anatomic models for minimally invasive direct coronary artery bypass
Cartesian coordinate system for distance measurements made from anatomic volumes. A The bed of the CT scanner and the OR are considered identical for the measurements with the positive “Z-axis” defined as pointing towards the patient’s head. The X and Y axis were then determined by the right-hand rule for spatial relationships by respect to the CT scanner or the operating room table and (B) along the orientation of the anatomic parts segmented for 3DP. Volume rendering after image segmentation shows the same orientation of the cartesian coordinates. Since all the measurements are differences, a specific definition of the origin (x, y, z = 0, 0, 0) was not necessary