A prototype of a quasi-monochromatic system for mammography applications

Abstract

Improvement in image contrast and dose reduction, in mammographic x-ray imaging, can be achieved using narrow energy band x-ray beams in the 16-24 keV range. As part of an Italian Government funded project, a quasi-monochromatic system for mammography applications has been developed. The system is based on a tunable narrow energy band x-ray source operating in the 16-24 keV energy range. The bremsstrahlung beam is monochromatized via Bragg diffraction by a highly oriented pyrolytic graphite mosaic crystal (HOPG). The scanning system provides a large field (18 x 24 cm2) of quasi-monochromatic x-rays with energy resolution ranging from 10% at 18 keV to 17.2% at 24 keV. The system has been characterized in terms of fluence rate and energy resolution. An x-ray tube developed ad hoc allows us to acquire images in a reasonable time to minimize the motion blur. A qualitative analysis has been performed in order to know if the prototype system performances are far from a clinical application, by evaluating the spatial resolution, the field uniformity and the image quality as a function of the quasi-monochromatic beam energy. Dose evaluation has been performed as a function of the energy and compared to a conventional system for mammography. The quasi-monochromatic prototype system can produce comparable image quality at half the dose.

Contrast Enhancement in Mammography Imaging Including K Edge Filtering

“…A prototype of a quasi monochromatic diffraction system has also been developed for mammography (Baldelli and et al 2005). Advantages of the system are that it is tunable in the range of 18-24keV, and according to the authors, the dose can be decreased by half.…”

“…A similar system to that of Baldelli's (Baldelli and et al 2005) was developed for a combined breast SPECT -CT system (Gambaccini, Fantini et al 2001). It had the same advantages and disadvantages as the mammography system.…”

Carbon Nanotube X‐Ray for Dynamic Micro‐CT Imaging of Small Animal Models

“…One example is quasi-monochromatic CT. An X-ray source with a narrow energy bandwidth will improve contrast resolution and permit K-edge imaging and dual-energy imaging. Studies have also shown that a significant reduction of dose can be achieved using a quasi-monochromatic beam [64]. Although the advantages of monochromatic and quasi-monochromatic imaging have been convincingly demonstrated in synchrotron-based studies, it has so far not been adapted for preclinical and clinical imaging.…”

“…Although the advantages of monochromatic and quasi-monochromatic imaging have been convincingly demonstrated in synchrotron-based studies, it has so far not been adapted for preclinical and clinical imaging. The principal limitation is the prohibitive long imaging time if an X-ray tube is used [64][65][66]. We expect that by combining the MBFEX source with a multiplexing method, quasi-monochromatic micro-CT imaging can be performed in comparable scanning time as polychromatic micro-CT in the near future.…”

Design and characterization of a spatially distributed multibeam field emission x‐ray source for stationary digital breast tomosynthesis

“…15 The already long scanning time prevents further optimization of the x-ray energy spectrum which has the potential to increase the image contrast but requires a significantly higher x-ray output power in order to maintain a comparable imaging time. [16][17][18][19] In the current design, the scanning speed and the focal spot blurring are interconnected. To minimize the patient motion, the scanning speed should be as high as the detector frame rate allows.…”