Rotational micro-CT using a clinical C-arm angiography gantry

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Radiology

Background:

• Standard rotational angiography (RA) systems offer limited resolution (<4 lp/mm) for 3D vascular rendering.
• Micro-computed tomography (micro-CT) provides higher resolution (>10 lp/mm) but is not suitable for clinical imaging.
• Existing clinical systems lack the resolution for detailed visualization of small vascular structures.

Purpose of the Study:

• To develop and evaluate a 3D rotational micro-angiography (RMA) system for high-resolution clinical imaging.
• To combine the high resolution of micro-angiographic fluoroscopy (MAF) with the wide field of view of clinical RA systems.
• To reduce radiation dose while improving image quality for vascular imaging.

Main Methods:

• Mounted a micro-angiographic fluoroscope (MAF) with high resolution (>10 µm/pixel) onto a clinical FPD-based RA gantry.
• Acquired MAF image sequences and supplemented with lower-dose, full-field-of-view (FFOV) FPD RA sequences to eliminate truncation artifacts.
• Calibrated the gantry and spatially aligned MAF and FPD images, scaling pixel values for accurate reconstruction.

Main Results:

• The 3D RMA (MAF-FPD) system achieved significantly improved resolution (FWHM of stent struts: ~192 µm) compared to FPD alone (~313 µm).
• MAF and FPD images were successfully aligned (correlation coefficient improved from 0.65 to 0.97).
• The dual-acquisition approach allows for lower-dose FPD acquisition without compromising overall image quality.

Conclusions:

• The developed 3D RMA system enables high-resolution imaging of vascular structures in patients.
• This technique offers superior detail compared to standard FPD-based RA.
• The system has the potential to reduce patient integral dose while enhancing diagnostic accuracy.