Tomosynthesis implementation with adaptive online calibration on clinical C-arm systems

Area of Science:

• Medical Imaging
• Radiological Physics
• Interventional Radiology

Background:

• Cone-beam computed tomography (CBCT) provides essential 3D and 2D imaging for medical interventions.
• Diagnostic tomosynthesis techniques reduce radiation dose by acquiring specific information.
• Integrating tomosynthesis into CBCT systems may offer dose reduction benefits for interventions.

Purpose of the Study:

• To investigate the performance of an implemented circular tomosynthesis technique on a CBCT device.
• To evaluate the feasibility of using circular tomosynthesis for applications requiring specific data, such as locating high-contrast objects.

Main Methods:

• Circular tomosynthesis scan trajectory implemented using step-and-shoot on a clinical C-arm device.
• Online calibration algorithm utilizing prior 3D CBCT data to correct imaging geometries, compared against offline calibration.
• Evaluation using a ball bearing phantom across three scenarios to assess robustness against object deviations and positioning.

Main Results:

• Circular tomosynthesis tested on ball bearing and anthropomorphic phantoms.
• Calibration demonstrated robustness against isocenter shifts and object deviations.
• Precise determination of high-contrast object positions and shapes achieved (max deviation 0.31 mm), despite limited angle artifacts with 100 projections.

Conclusions:

• Circular tomosynthesis is a viable approach for medical procedures requiring precise localization of high-contrast objects.
• This technique has the potential to significantly reduce radiation dose exposure in specific interventional scenarios.
• Further development could enhance its applicability in dose-sensitive interventional procedures.