A Highly Integrated High-Resolution Cone Beam CT System for Intraoperative Imaging in Minimally Invasive Cochlear Surgery

Utilizing cone beam computed tomography (CBCT) to monitor minimally invasive surgery (MIS) is essential for ensuring surgical safety, particularly in high-precision procedures such as cochlear implantation (CI). Existing CBCT systems—including whole-body units and those tailored for ear diagnostics, dentistry, or head imaging—are typically bulky and poorly integrated, limiting their utility in intraoperative environments. To address this gap, we propose a highly integrated, high-resolution CBCT system specifically designed for intraoperative cochlear MIS. The system incorporates a dual-joint robotic structure, enabling both compact integration and mechanical flexibility by allowing the imaging chain to be folded to accommodate other surgical instruments. From a measurement perspective, the system is engineered to optimize key imaging performance parameters through a balance between field of view (FOV), spatial resolution, and mechanical stability. Geometric parameters were quantitatively optimized to minimize rotational bending moments, ensuring consistent and precise scanning. Imaging performance was systematically assessed using four types of phantoms. Quantitative measurements demonstrated a spatial resolution of $150~\mu $ m (3.3 lp/mm), a contrast-to-noise ratio (CNR) of 8.63 at a 2.65% contrast level, and a 3-D uniformity deviation (UD) of 1.8%. In addition, qualitative validation was conducted using a live pig and a human cadaver head to simulate real clinical conditions. These findings highlight the system’s capability to deliver accurate, repeatable, and measurement-driven intraoperative imaging, offering enhanced safety and precision for cochlear MIS. The work contributes not only to imaging system integration but also to quantitative measurement methodology aligned with the focus of instrumentation and measurement research.