Influence of Heel effect and of nonuniformity of emitted spectra on dual-energy subtraction in computed radiography

Because of beam hardening in the target, the energy distribution of the x-radiation emitted by a conventional x-ray tube differs from different directions of emission. This fact is generally neglected in dual-energy subtraction imaging. In this paper we study the influence of the non- uniformity of the energy spectrum of emitted radiation on dual-energy subtraction. Experiments with synthetic (aluminum) phantoms and with dual-energy images of humanoid chests (made with a computed radiography system) give more insight in the degree to which dual-energy subtraction is affected by the described effects.

[1]  H K Huang,et al.  A fast dual-energy computational method using isotransmission lines and table lookup. , 1987, Medical physics.

[2]  J W Oestmann,et al.  "Single-exposure" dual energy digital radiography in the detection of pulmonary nodules and calcifications. , 1989, Investigative radiology.

[3]  Brent K. Stewart,et al.  Dual Energy Radiography Using A Single Exposure Technique , 1987, Medical Imaging.

[4]  A. Macovski,et al.  Generalized image combinations in dual KVP digital radiography. , 1981, Medical physics.

[5]  E. Nickoloff,et al.  Radiographic detail and variation of the nominal focal spot size: the "focal effect". , 1992, Radiographics : a review publication of the Radiological Society of North America, Inc.

[6]  R. C. Murry,et al.  Christensen's physics of diagnostic radiology , 1990 .

[7]  G. Barnes,et al.  Semiempirical model for generating tungsten target x-ray spectra. , 1991, Medical physics.

[8]  C A Mistretta,et al.  Conventional chest radiography vs dual-energy computed radiography in the detection and characterization of pulmonary nodules. , 1994, AJR. American journal of roentgenology.

[9]  M. Sonoda,et al.  Computed radiography utilizing scanning laser stimulated luminescence. , 1983, Radiology.

[10]  Patrick Wambacq,et al.  Calibration phantom for dual-energy basis material absorption measurements , 1996, Medical Imaging.

[11]  T Kozuka,et al.  Single-exposure dual-energy chest images with computed radiography. Evaluation with simulated pulmonary nodules. , 1993, Investigative radiology.

[12]  L T Niklason,et al.  Simulated pulmonary nodules: detection with dual-energy digital versus conventional radiography. , 1986, Radiology.

[13]  A. Macovski,et al.  Dual-energy x-ray projection imaging: two sampling schemes for the correction of scattered radiation. , 1988, Medical physics.