Region-of-interest cone beam computed tomography (ROI CBCT) with a high resolution CMOS detector

Area of Science:

• Medical Imaging
• Radiology
• Biomedical Engineering

Background:

• Standard flat panel detectors (FPD) in cone beam computed tomography (CBCT) offer limited resolution (<3 lp/mm) for 3D vascular rendering.
• Existing high-resolution systems typically have a small field of view (FOV), restricting their use to small animal imaging.

Purpose of the Study:

• To evaluate a region-of-interest (ROI) CBCT approach using a high-resolution CMOS detector on a C-arm angiography gantry.
• To compare the imaging performance of the CMOS detector against a standard FPD for visualizing fine details.

Main Methods:

• A high-resolution CMOS detector (75 μm pixels) was mounted on a commercial FPD-based C-arm angiography gantry using a motorized detector changer.
• Both CMOS and FPD detectors were used to image a cylindrical CT phantom and neuro stents under identical collimator settings and rotational protocols.
• Images were reconstructed for the FPD (10 cm x 10 cm FOV) and CMOS detector (3.84 cm x 3.84 cm FOV).

Main Results:

• Reconstructed images from the CMOS detector showed comparable contrast to FPD images.
• The CMOS detector significantly improved the delineation of small objects, such as neuro stent struts (~70 μm), compared to the FPD.
• 3D renderings clearly demonstrated superior detail visualization with the CMOS detector.

Conclusions:

• The high-resolution CMOS detector integrated into a CBCT system enhances the visualization of fine vascular structures beyond the capabilities of standard FPDs.
• This ROI CBCT technique holds significant potential for improving clinical diagnostic accuracy and interventional procedures.
• Further development is warranted to fully realize the clinical impact of this advanced imaging approach.