Quantification of calcium in solitary pulmonary nodules using single- and dual-energy CT.

Abstract

Separation of benign from malignant solitary pulmonary nodules by computed tomography (CT) is based on 2 assumptions: those that are calcified are benign, and high CT numbers reflect Ca deposition. Dual-energy CT was used to quantify the minimum detectable Ca content in simulated nodules [in an anthropomorphic chest phantom] independent of absolute CT number and to separate high CT numbers due to Ca from those due to high-density organic material. A mineral concentration of 20 mg/cm3 was detectable with this method. Dual-energy CT may be a more accurate method of detecting Ca in solitary pulmonary nodules than single-energy CT.