Hans Bornefalk MS, Presenter: Nothing to Disclose

John Morton Lewin MD, Abstract Co-Author: Nothing to Disclose

Mats Lundqvist PHD, Abstract Co-Author: Nothing to Disclose

Mats Danielsson PHD, Abstract Co-Author: Nothing to Disclose

To estimate the potential gain in tumor detectability when using an energy sensitive photon counting detector in dual-energy contrast-enhanced digital subtraction mammography.

By means of an electronic threshold, an energy sensitive photon counting detector allows the simultaneous formation of a low- and high-energy image by splitting the spectrum just above the k-edge of iodine (located at 33.2 keV). This eliminates the otherwise deteriorating overlap between low-and high-energy spectra. Furthermore, the method allows the low energy image to be built up from a larger fraction of x-rays with energies close to the k-edge of iodine than when two separate high and low energy spectra are used. As the difference in attenuation of iodine is maximal at the k-edge, this will increase the iodine contrast in the image. The large tail of low-energy photons from the characteristic lines of molybdenum, which contribute poorly to image contrast but highly to patient dose, can be eliminated resulting in a further increase of the signal-difference-to-noise ratio at any given dose. The method is also illustrated on an experimental setup of the detector.

The level of anatomical clutter supression obtained with this method is equivalent to or better than that with separate low- and high-energy beams. Theoretical calculations, verified on phantom images acquired on the experimental setup of the detector, indicate that the increase in signal-difference-to-noise ratio at a given dose is about 140% when compared with the clinical examination by Lewin et~al (Radiology 2003; 229:261-268).

Using energy sensitive photon counting detector can greatly improve the detectability of lesions using contrast-enhanced dual-energy digital subtraction mammography.

M.L.,M.D.: Mats Danielsson and Mats Lundqvist own stock in Sectra Mamea AB.

Bornefalk, H, Lewin, J, Lundqvist, M, Danielsson, M, Improved Dual-Energy Contrast Imaging Using an Energy Sensitive Photon Counting Detector and Spectrum-Splitting.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4418366.html