Abstract
Purpose
Evaluating sacral fractures is crucial in fragility fractures of the pelvis. Dual-energy CT (DECT) is considered useful for diagnosing unclear fractures on single-energy CT (SECT). This study aims to investigate the effectiveness of DECT in diagnosing sacral fractures.
Methods
Thirty cases suspected of sacral fractures who underwent SECT, DECT, and MRI, and were diagnosed for the presence of fractures by three inexperienced surgeons (group I) and three experienced surgeons (group E). Diagnoses were made initially using SECT (pre-DECT) and then reassessed including DECT (post-DECT). This process was repeated twice. Presence of fractures was determined based on MRI. Sensitivity, specificity, inter-rater and intra-rater reliability, and diagnostic accuracy were calculated. Diagnostic accuracy was statistically compared between two groups.
Results
Sensitivity was 0.73 in pre-DECT and 0.9 in post-DECT, while specificity was 0.83 in pre-DECT and 0.91 in post-DECT. Sensitivity significantly improved with the addition of DECT (McNemar test: p < 0.001). Intra-rater reliability (Fleiss' kappa coefficient) was 0.44 in pre-DECT and 0.76 in post-DECT. Inter-rater reliability (Cohen's kappa coefficient) was 0.6 in pre-DECT and 0.81 in post-DECT. Diagnostic accuracy was significantly lower in group I than group E in pre-DECT (P = 0.019, 0.048), but there was no significant difference between two groups in post-DECT.
Conclusion
Combined use of DECT with SECT improved the detection rate of sacral fractures and enhanced intra-rater and inter-rater reliability. High diagnostic accuracy was achieved regardless of the observer's experience. These results indicate that DECT is a useful imaging modality for diagnosing sacral fractures.