[1] Photon-counting mammography improves dose efficiency compared to conventional technologies,[2] and enables spectral imaging.
The MicroDose system is based on an array of silicon strip detectors in a multi-slit configuration that is scanned across the object to acquire an image.
Each channel comprises an amplifier and a shaper, which convert the charge to a pulse with an amplitude proportional to the energy of the impinging photon.
[2] Improved dose efficiency in photon-counting mammography compared to conventional technologies is mainly enabled by: Even though equal weighting of photons, intrinsic to photon-counting detectors, improves dose efficiency compared to energy-integrating detectors, a higher weighting of low-energy photons is generally optimal because x-ray contrast drops with increasing photon energy when the photo-electric effect dominates and away from any absorption edges, which holds true for mammography without contrast agents.
[12] Photon-counting detectors can measure the energy spectrum of the incident photons, a technique broadly referred to as spectral imaging.
[15][16] High-atomic-number contrast agents add additional energy dependencies to the object and can be separated from soft tissue, often referred to as K-edge imaging.
Further, the slit-scanning technique is expected to provide additional benefit because scatter rejection based on conventional anti-scatter grids is challenging to implement at a range of projection angles.
The spectral resolution of photon-counting detectors can potentially be used to reduce the coherence requirements of phase-contrast imaging setups.