Determination of the monoplane 3D system geometry in X-ray imaging guidance

Abstract

A simple method for determination of the geometric parameters of monoplane stereo x-ray system is proposed in this paper. According to the principle of perspective projection, a monoplane stereo imaging model was established. The geometric parameters required for 3D point recovering were described. Applying the perspective projection rule and similar triangles concept, the system geometry can be calculated with three calibration line segments in 3D space. Calibration accuracy analysis has been performed. A cube phantom with radio-opaque line segments of known length and orientation is employed during calibration procedure. Experiments were carried out using a CCD based monoplane stereo x-ray system prototype. The results are consistent with the expected value predicated by theoretic analysis. Our promising application of this technique for the system calibration lies in digital mammography imaging guidance, but applications in other type of radiographic imaging are possible also.