A novel direct-indirect dual-layer flat-panel detector for contrast-enhanced breast imaging: Experimental assessment

Area of Science:

• Medical Imaging
• Radiology
• Biomedical Engineering

Background:

• Contrast-enhanced digital mammography (CEDM) and tomosynthesis (CEDBT) use low-energy (LE) and high-energy (HE) images to visualize iodinated lesions.
• Conventional dual-shot (DS) methods acquire LE and HE images separately, risking patient motion artifacts that obscure lesions.
• A direct-indirect dual-layer flat-panel detector (DI-DLFPD) is proposed to acquire LE and HE images simultaneously, eliminating motion artifacts.

Purpose of the Study:

• To experimentally validate CEDM and CEDBT imaging using a prototype DI-DLFPD.
• To compare lesion conspicuity between DI-DLFPD and conventional DS methods.
• To optimize k-edge filters for the DI-DLFPD based on breast thickness.

Main Methods:

• CEDM and CEDBT images were acquired using both DI-DLFPD and a conventional DS detector at similar radiation doses.
• Image quality and iodine conspicuity were evaluated using the figure of merit (FOM = SDNR^2 / MGd).
• K-edge filter selection for DI-DLFPD was assessed across various breast thicknesses.

Main Results:

• DI-DLFPD achieved a ~233% improvement in iodine object FOM compared to DS images due to motion artifact elimination.
• Iodine quantification accuracy was enhanced with the DI-DLFPD.
• Optimal iodine signal-difference-to-noise ratio (SDNR) was achieved using a sliver filter for 4 cm breasts and a Tin filter for 8 cm breasts.

Conclusions:

• The first-generation DI-DLFPD prototype demonstrates significant improvements for CEDM and CEDBT.
• The DI-DLFPD effectively eliminates patient motion artifacts, enhancing lesion detection.
• A practical strategy for optimizing x-ray filters based on compressed breast thickness was recommended for DI-DLFPD.