The rotate-plus-shift C-arm trajectory. Part I. Complete data with less than 180° rotation

Area of Science:

• Medical Imaging
• Radiology
• Cone-Beam CT

Background:

• C-arm cone-beam CT is crucial for intraoperative imaging.
• Traditional C-arm CT requires >180° rotation, which is often limited in mobile C-arms.
• Limited rotation range hinders full 3D imaging capabilities in many C-arm systems.

Purpose of the Study:

• To develop a novel trajectory for C-arm CT acquisition with limited rotational range (<180°).
• To enable fully sampled 3D data acquisition using C-arm systems with restricted mechanical rotation.
• To enhance the utility of C-arm devices for intraoperative 3D imaging.

Main Methods:

• A new rotate-plus-shift trajectory was designed, extending the effective angular range using linear shifts.
• Two linear shifts were incorporated at the beginning and end of a partial rotation scan.
• The method was validated on phantom and cadaveric examinations using prototype C-arm systems.

Main Results:

• The proposed trajectory successfully acquired fully sampled datasets without limited-angle artifacts.
• Image quality in reconstructions using the new trajectory was dramatically improved compared to standard limited-angle scans.
• Fine details were clearly visualized in rotate-plus-shift reconstructions, unlike artifact-dominated limited-angle scans.

Conclusions:

• The developed method enables 3D imaging on C-arms with <180° rotation, adding full 3D functionality.
• This approach preserves the handling comfort and usability of C-arm systems designed for 2D imaging.
• The method holds significant clinical potential for intraoperative 3D imaging, meeting growing demands.