Medical Image Coordinate System to World Space Conversion: A Comprehensive Guide

To achieve the conversion from the medical image coordinate system to the world space coordinate system, the transformation matrix from the CT image coordinate system (CT) to the world space coordinate system (W) needs to be solved, which can be expressed as equation (1):

(1)

In the equation, the matrix ' is the transformation matrix from the personalized marker coordinate system (M) to the world space coordinate system defined by the monocular camera, which can be obtained by the monocular camera based on visual tracking to identify the marker. The matrix ' is the transformation matrix from the two-dimensional X-ray image coordinate system (X) to the three-dimensional CT image coordinate system, which can be obtained by 2D/3D image registration. The matrix ' is the transformation matrix from the personalized marker to the two-dimensional X-ray image coordinate system, which needs to be solved by determining the pose of the marker in the X-ray image.