A prototype of a quasi-monochromatic system for mammography applications

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.

[1]  Angelo Taibi,et al.  Patient dose in full-field digital mammography: an Italian survey , 2004, European Radiology.

[2]  C. J. Kotre,et al.  Mammographic image restoration using maximum entropy deconvolution. , 2004, Physics in medicine and biology.

[3]  Robert J. Jennings,et al.  Evaluation of x-ray sources for mammography , 1993, Medical Imaging.

[4]  J. Coebergh,et al.  Breast carcinoma diagnosis, treatment, and prognosis before and after the introduction of mass mammographic screening , 2004, Cancer.

[5]  M. Säbel,et al.  Recent developments in breast imaging. , 1996, Physics in medicine and biology.

[6]  R. Price,et al.  Near-monochromatic X-ray beams produced by the free electron laser and Compton backscatter. , 1990, Investigative radiology.

[7]  Sartaj Sahni,et al.  Leaf sequencing algorithms for segmented multileaf collimation. , 2003, Physics in medicine and biology.

[8]  C. J. Kotre,et al.  Additional factors for the estimation of mean glandular breast dose using the UK mammography dosimetry protocol. , 2000, Physics in medicine and biology.

[9]  A. Taibi,et al.  Evaluation of a dichromatic X-ray source for dual-energy imaging in mammography , 2002 .

[10]  M Gambaccini,et al.  Niobium/molybdenum K-edge filtration in mammography: contrast and dose evaluation. , 1996, Physics in medicine and biology.

[11]  R. J. Eastgate,et al.  Optimal x-ray spectra for screen-film mammography. , 1981, Medical physics.

[12]  M Gambaccini,et al.  Mammography with synchrotron radiation. , 1995, Radiology.

[13]  M. Gambaccini,et al.  Dose and image-quality evaluation in synchrotron radiation mammography , 2004, European Radiology.

[14]  S Suryanarayanan,et al.  Full breast digital mammography with an amorphous silicon-based flat panel detector: physical characteristics of a clinical prototype. , 2000, Medical physics.

[15]  Zhenxue Jing,et al.  Characterization of a full-field digital mammography detector based on direct x-ray conversion in selenium , 2002, SPIE Medical Imaging.

[16]  Filippo Frontera,et al.  Narrow energy band X-rays via mosaic crystal for mammography application , 1995 .

[17]  J A Seibert,et al.  A comparison of mono- and poly-energetic x-ray beam performance for radiographic and fluoroscopic imaging. , 1994, Medical physics.

[18]  S. C. Prasad,et al.  Laser-based microfocused x-ray source for mammography: feasibility study. , 1997, Medical physics.

[19]  Bonvicini,et al.  The Mammography Project at ELETTRA , 1997 .

[20]  F. Frontera,et al.  Bragg diffraction technique for the concentration of hard x-rays for space astronomy. , 1992, Applied optics.

[21]  H. Genz.  Intense and monochromatic X-rays by channeling radiation , 1994 .

[22]  R. Hendrick,et al.  Performance comparison of full-field digital mammography to screen-film mammography in clinical practice. , 2002, Medical physics.

[23]  M Gambaccini,et al.  Spatial resolution measurements in quasimonochromatic x rays with mosaic crystals for mammography application. , 2001, Medical physics.

[24]  Joseph A. O'Sullivan,et al.  Deblurring subject to nonnegativity constraints , 1992, IEEE Trans. Signal Process..

[25]  W. Knüpfer,et al.  Feasibility study of a channeling radiation source for applications in the X-ray region , 1994 .

[26]  J A Rowlands,et al.  X-ray detectors for digital radiography. , 1997, Physics in medicine and biology.

[27]  K. Marten,et al.  Average glandular dose with amorphous silicon full-field digital mammography - Clinical results , 2002, RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin.

[28]  A. Del Guerra,et al.  Small-field imaging properties of narrow energy band X-ray beams for mammography , 1995, 1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record.

[29]  D. Dance.  Monte Carlo calculation of conversion factors for the estimation of mean glandular breast dose. , 1990, Physics in medicine and biology.

[30]  Martin J Yaffe,et al.  Contrast-enhanced digital mammography: initial clinical experience. , 2003, Radiology.

[31]  E A Sickles.  Breast imaging: a view from the present to the future. , 1985, Diagnostic imaging in clinical medicine.

[32]  M Gambaccini,et al.  Dual-energy imaging in full-field digital mammography: a phantom study. , 2003, Physics in medicine and biology.