A Novel Approach for Implementation of Dual Energy Mapping Technique in CT-Based Attenuation Correction Using Single kV_P Imaging: A Feasibility Study

Abstract

In the CT-based attenuation correction methods, dual-energy technique (DECT) is the most accurate approach, which has been limited due to the increasing patient dose. In this feasibility study, we have introduced a new method that can implement dual-energy technique with only a single energy CT scan. In this method, with having the CT image in one energy, we generate the CT image at the second energy (from now we call it virtual dual-energy technique). The attenuation map at 511 keV was generated using bilinear (the most commonly used method in commercially available PET/CT scanners), dual-energy and virtual dual-energy technique in phantom and patients data. In the phantom study, the created attenuation map using mentioned methods are compared to the theoretical values calculated using XCOM cross section library. In the patient study, the generated attenuation map using dual-energy method is considered as gold standard. The results in the phantom data show 10.1%, 4.2% and 4.3% errors for bilinear, dual-energy and virtual dual-energy techniques respectively. Also, the results in the patient data show the virtual dual-energy has better agreement with the dual-energy method rather than the bilinear method especially in the bone tissue (1.5% and 8.9% respectively).