title: Experimental verification of ion stopping power prediction from dual energy CT data in tissue surrogates.
abstract: A two-steps procedure is presented to convert dual-energy CT data to stopping power ratio (SPR), relative to water. In the first step the relative electron density (RED) is calculated from dual-energy CT-numbers by means of a bi-linear relationship: RED=a HUscH+b HUscL+c, where HUscH and HUscL are scaled units (HUsc=HU+1000) acquired at high and low energy respectively, and the three parameters a, b and c has to be determined for each CT scanner. In the second step the RED values were converted into SPR by means of published poly-line functions, which are invariant as they do not depend on a specific CT scanner. The comparison with other methods provides encouraging results, with residual SPR error on human tissue within 1%. The distinctive features of the proposed method are its simplicity and the generality of the conversion functions.
authors.affiliation: Proton therapy Unit, APSS, Trento, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Farace
mesh_terms: D006801:Humans; D019047:Phantoms, Imaging; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*