<title>Design and evaluation of a slot-scanning full-field digital mammography system</title>

Abstract

The FDA has approved the SenoScan slot-scanning Full-Field Digital Mammography (FFDM) system. A high power Tungsten-target x-ray tube enables breast imaging with 0.22 s effective exposure time. A 21-cm x 29-cm area is scanned in less than 6 seconds, at a typical clinical technique of 30 kVp, 170 mA. The detector comprises a Thalium-doped Cesium Iodide scintillator coupled to a combination of four CCDs abutted along their narrow dimension to form a 10-mm by 210-mm slot. With the CCDs operated in time-delay-and-integration mode along the narrow dimension, the system functions in a continuous scanning (and x-ray illumination) mode. The MTF in the standard and high-resolution modes extend to 10-cycles/mm and beyond 14 cycles/mm respectively. The Detective Quantum Efficiency (DQE) curve starts at 50% at DC and extends to 10 cycles/mm in Standard mode. Accordingly the SenoScan system enables screening and diagnostic breast imaging with a limiting resolution approaching that of film-based systems. The overall system design and intrinsic scatter rejection efficiency directly translate in high DQE characteristics that enable screening at a significantly reduced (more than 60% reduction) patient dose.

Digital detectors for mammography: the technical challenges

“…Data are acquired by simultaneous scanning of the breast by a highly collimated X-ray beam and by the detector [1,[26][27][28]. With this geometry, only a fraction of the emitted X-ray output is used at each step of the exposure process so that the load for the X-ray tube is higher.…”

“…With this geometry, only a fraction of the emitted X-ray output is used at each step of the exposure process so that the load for the X-ray tube is higher. Tungsten-target X-ray tubes with high heat storage capacity have been specifically designed for clinical application [26][27][28]. Because of the reduction of scattered radiation through beam collimation, these systems operate without a grid, which permits a reduction of the dose to the patient.…”

“…Signal measurement is performed by the time delay integration (TDI) method [1,27]; continuous measurement of the signal at each point of the object examined is performed throughout slot-scanning, which increases the resulting signal. The effective exposure at a given point depends on the value of the current in the tube and on the slot-scanning time.…”

Effects of exposure equalization on image signal‐to‐noise ratios in digital mammography: A simulation study with an anthropomorphic breast phantom

“…A tungsten targetbased x-ray tube capable of high current output with a specially designed high-power generator has been successfully developed and used in a commercial slot-scan digital mammography (SSDM) system (SenoScan, Fischer Imaging Corporation, Denver, CO). [46][47][48] However, the requirement for x-ray tube current and generator output is even higher for SEDM imaging than for slot-scan imaging because higher mAs is required when the fan beam exposes an area containing dense tissue structures. 38 Several factors must be considered in selecting x-ray tube and generator for construction of the proposed SEDM system.…”

Scatter free imaging for the improvement of breast cancer detection in mammography

“…The beam is then collimated again after interaction with the breast in order to stop scattered X-rays. The narrow shape of the beam reduces the amount of scattered photons, therefore improving image quality [Besson et al, 2002]. However, this method does allow for a proportion of scatter to reach the image which leads to less of a reduction in dose than with a completely scatter free imaging system [Oppelt, 2011].…”