Dual-energy Computed Tomography (DECT) Scan for Determination of Renal Stone Composition: A Phantom Study

Abstract

Background: Dual-energy computed tomography (DECT) scan has been proposed as an effective modality for determining the chemical composition of renal stone subtypes. Objectives: This study aimed to evaluate and compare the efficacy of DECT in the identification of renal stone type and composition versus biochemical analysis as the gold standard. Materials and Methods: The type of 146 renal stones, removed from patients by surgery, was determined in a medical laboratory. The stones were then inserted into the kidney of an anthropomorphic Rando phantom, and DECT scans were acquired. The stone type, specified by the scanner software, was compared with the results of biochemical analysis as the gold standard. Results: The DECT scans showed acceptable accuracy in identifying the chemical composition of renal stone subtypes. Based on the comparison of biochemical analysis and DECT results, the accuracy values for cystine, uric acid, and calcium-oxalate stones were 97%, 100%, and 97%, respectively. Conclusion: Based on the present results, DECT could detect pure uric acid, cystine, and calcium-oxalate stone types with high sensitivity. However, for mixed stones, the stone type, directly identified by DECT scan, was not reliable.