Advanced Physics for Brachytherapy 2018

Dual-energy x-ray CT material extr action

• CT images are represented by HU = 1000x( μ / μ w -1) – μ and μ w are the linear attenuation coefficients of a material and of water • dual-energy material extraction (DECT) is based on – Taking CT images at two tube voltages (e.g. 100 kVp and 140 kVp) – The farther apart the energy the better! – Parameterization of the linear attenuation coefficient results in ρ e and Z maps