Comparison of Four Dual-Energy CT Scanner Technologies for Determining Renal Stone Composition: A Phantom Approach

Area of Science:

• Radiology
• Medical Imaging
• Urology

Background:

• Dual-energy CT (DECT) is valuable for assessing renal stone composition.
• Limited comparative data exist for multivendor DECT technologies.
• This study addresses the need for performance comparison across different DECT systems.

Purpose of the Study:

• To compare the diagnostic performance of four DECT technologies.
• To evaluate DECT for renal stone composition analysis at standard and low radiation doses.
• To assess the impact of different acquisition protocols on DECT performance.

Main Methods:

• In vitro phantom study with 71 urinary stones of known composition.
• Scans performed on four DECT technologies: rapid kilovolt peak switching DECT (rsDECT), dual-source DECT, twin-beam DECT (tbDECT), and dual-layer detector-based CT (dlDECT).
• Analysis using effective atomic number and dual-energy ratio indexes; performance assessed via area under the receiver operating characteristic curve (AUC).

Main Results:

• All DECT technologies, except tbDECT, achieved AUC > 0.95 for differentiating urate stones.
• Moderate accuracy (AUC: 0.70-0.83) was observed for differentiating calcium oxalate monohydrate stones.
• Brushite stones were differentiated from urate stones with AUC > 0.99.
• No significant performance difference was found between standard- and low-dose acquisitions or between vendor-recommended and dose-optimized protocols.

Conclusions:

• All four DECT technologies effectively determine renal stone composition at both standard and low doses.
• Performance is influenced by scanner parameters, DECT technique, and specific stone composition.
• DECT is a reliable tool for non-invasive renal stone characterization.