Experimental results with dual-energy penalized weighted least-squares image reconstruction for X-ray transmission tomography

The authors experimentally evaluate the performance of our previously reported penalized weighted-least squares (PWLS) dual-energy (DE) method. The method is expected to ultimately find its application in positron emission tomography (PET) attenuation correction and quantitative computed tomography (QCT). Both applications require highly accurate density estimates along with a low radiation dose, or in other words low X-ray flux. The authors´ earlier study on computer-generated sets of data showed that De PWLS method is superior to a standard FBP-based DE method. The authors are particularly interested to what extent the performance of their method is affected by photon scatter in the body and the polychromaticity of the X-ray source, as neither scatter nor polychromaticity were taken into account in the computer-generated sets of data. The accuracy of the method and its dependence on X-ray source flux is illustrated and compared to previously reported simulation results