A Prototype System Of Upright Dedicated Cone-Beam Breast Ct

Purpose: Current dedicated cone-beam breast CT (CBBCT) systems typically adopt a pendant geometry for patient comfort and mechanical compatibility with a breast biopsy device. In this work, we design and construct a prototype system of upright CBBCT with a compact size, such that mammography devices can be readily replaced in current clinical rooms. The system performance on spatial resolution, CT accuracy and field-of-view (FOV) size are evaluated via preliminary phantom studies.Materials and Methods: The prototype system consists of a mono-block x-ray source, a flat panel detector, a slip ring for signal transmission, a servo motor and a rotating gantry. The relative positions and angles of x-ray source and detector are carefully designed to ensure a large FOV with almost zero dead space on the chest side. The slip ring is used to accommodate a breast stretching device designed to stretch the breast length to match the same imaging volume size as in a prone gesture.Results: The designed prototype system has a size of 1950mm, 1200mm, and 660mm in height, length and width, respectively. On the Catphan (R) 600 phantom, the acquired CBBCT images have an average CT number error of less than 0.5% and an image non-uniformity of 0.19%. An in-house water phantom with inserted thin tungsten wires is designed to evaluate the system capability on imaging small calcifications. The results show that our system successfully images small high-contrast objects with a diameter of 30.m.Conclusion: We have developed a prototype upright CBBCT system with a compact size, a high imaging accuracy and spatial resolution.