Speaker
Silvia Pani
(U)
Description
Dual energy X-ray techniques allow an object to be decoupled into two components – typically, soft tissue and bone, or soft tissue and a contrast agent [1]. Such techniques normally rely on the acquisition of two images, requiring increased dose to the patient, and potentially carrying the risk of incorrect image registration due to patient motion.
This limitation is removed by using a spectroscopic, position-sensitive detector, which allows the two images to be obtained by integrating, pixel by pixel, appropriate bands of the spectrum transmitted from a conventional, polychromatic beam.
The HEXITEC collaboration [2] has developed a pixellated spectroscopic system based on CdTe detectors and dedicated read out electronics.
This paper will present results from dual-energy imaging for contrast agent mammography using custom-designed phantoms, commercial iodinated contrast agent agent (Niopam © 150, Bracco) and a HEXITEC system comprising a 1-mm thick, 20x20 mm2 CdTe sensor with 250 µm pixel pitch.
The dual-energy algorithm proved to perform consistently better, in terms of detail visibility, than a simpler K-edge subtraction algorithm, having less stringent requirements in terms of position and width of the spectral bands to be integrated. Results from the comparison between the two algorithms will be presented, as well as comparison with conventional dual-energy imaging.
Moreover, the dual energy algorithm was used for calculating the concentration of contrast agent in tubes of different diameter; the calculated concentration proved compatible with the actual one for a range of concentrations and of tube sizes.
**References**
[1] LA Lehmann et al. Generalized image combination in dual KVP digital radiography. Med Phys 1981, 8: 659.
[2] P Seller et al. Pixellated Cd(Zn)Te instrument. JInst, 2011: C12009
Author
Silvia Pani
(U)
Co-authors
Faith Green
(University of Surrey)
James Scuffham
(R)
Matthew Veale
(STFC Rutherford Appleton Laboratory)
Matthew Wilson
(STFC)
Paul Seller
(RAL)
Paul Sellin
(University of Surrey)
Prof.
Robert Cernik
(University of Manchester)
Mrs
Sarene Saifuddin
(University of Surrey)
