A prototype of a quasi-monochromatic system for mammography applications
| Autor: | M C Gilardoni, Mauro Gambaccini, P Baldelli, A. Tuffanelli, Angelo Taibi |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Materials science
Image quality Astrophysics::High Energy Astrophysical Phenomena Physics::Medical Physics Pilot Projects Radiation Dosage Risk Assessment Sensitivity and Specificity Radiation Protection Optics Highly oriented pyrolytic graphite Risk Factors Radiology Nuclear Medicine and imaging Radiometry Image resolution Range (particle radiation) Radiological and Ultrasound Technology Phantoms Imaging business.industry Motion blur Bremsstrahlung Reproducibility of Results Bragg's law Equipment Design Equipment Failure Analysis Feasibility Studies business Energy (signal processing) Mammography |
| Zdroj: | Physics in Medicine and Biology. 50:2225-2240 |
| ISSN: | 1361-6560 0031-9155 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|