Methodological accuracy of image-based electron-density assessment using dual-energy computed tomography

TL;DR

This paper evaluates the accuracy of image-based electron-density assessment using dual-energy CT, focusing on the intrinsic uncertainties of the simplest reconstruction-based algorithms for radiotherapy applications.

Contribution

It quantifies the methodological and calibration uncertainties of image-based electron-density estimation using dual-energy CT, highlighting the limits of current simple algorithms.

Findings

Identified the intrinsic uncertainties in image-based electron-density assessment.

Quantified the calibration errors affecting accuracy.

Provided insights into the limitations of simple DECT algorithms.

Abstract

Purpose: Electron density is the most important tissue property influencing photon and ion dose distributions in radiotherapy patients. Dual-energy computed tomography (DECT) enables the determination of electron density by combining the information on photon attenuation obtained at two different tube voltages. Most algorithms suggested so far use the CT numbers provided after image reconstruction as input parameters, i.e. are imaged-based. To explore the accuracy that can be achieved with these approaches, we quantify the intrinsic methodological and calibration uncertainty of the seemingly simplest approach.