Technical Note: Comparison of first- and second-generation photon-counting slit-scanning tomosynthesis systems

Area of Science:

• Medical Imaging
• Radiology
• Biomedical Engineering

Background:

• Digital breast tomosynthesis (DBT) is an advanced imaging technique for breast-cancer detection.
• Photon-counting detectors offer potential advantages in spectral information and noise reduction for DBT.
• Developing improved DBT systems is crucial for enhancing screening and diagnostic accuracy.

Purpose of the Study:

• To introduce a second-generation photon-counting slit-scanning DBT system.
• To compare the geometry and image quality of the second-generation system with its first-generation predecessor.
• To present initial image quality assessments of the novel second-generation system.

Main Methods:

• The second-generation system utilizes a novel geometry with combined rotational and linear motion.
• Updated calibration routines were implemented for enhanced performance.
• Image quality was evaluated using in-slice modulation transfer function (MTF), artifact spread function (ASF), and detective quantum efficiency (DQE) at the image center.

Main Results:

• The in-slice 50% MTF improved in the chest-mammilla direction from 3.2 to 3.5 lp/mm.
• The zero-frequency DQE increased from 0.71 to 0.77, indicating improved detection efficiency.
• The new system demonstrated reduced in-slice variation of the tomographic angle and increased maximum compression height.

Conclusions:

• The second-generation DBT system's new geometry reduces tomographic-angle variation and enhances patient accessibility.
• Improvements in MTF and DQE are attributed to updated calibration procedures.
• The second-generation system retains the benefits of photon-counting technology while improving image quality and patient accommodation.