Image Processing, Tomosynthesis, On Board Imaging, Radiation Therapy, Radiation Oncology, Registration.

摘要

The purpose of this paper is to investigate the use of electron-beam Computed Tomography (EBCT) dual energyscanning for improved differentiation of calcified coronary arteries from iodinated-contrasted blood, in fast movingcardiac vessels. The dual energy scanning technique can lead to an improved cardiac examination in a single breath holdwith more robust calcium scoring and better vessel characterization. Dual energy can be used for materialdiscrimination in CT imaging to differentiate materials with similar CT number, but different material attenuationproperties. Mis-registration is the primary source of error in a dual energy application, since acquisitions have to bemade at each energy, and motion between the acquisitions causes inconsistencies in the decomposition algorithm, whichmay lead to artifacts in the resultant images. Using EBCT to quickly switch x-ray source peak voltage potential (kVp),the mis-registration of patient anatomy is minimized since acquisitions at both energy spectra are completed in onestudy at the same cardiac phase. Two protocols for scanning the moving heart using EBCT were designed to minimizeregistration issues. Material basis function decomposition was used to differentiate regions containing calcium andiodine in the image. We find that this protocol is superior to CT imaging at one energy spectrum in discriminatingcalcium from contrast-enhanced lumen. Using dual energy EBCT scanning can enable accurate calcium scoring, andangiography applications to be performed in one exam.