QUANTITATIVE ANALYSIS OF LIVER IRON DEPOSITION BASED ON DUAL-ENERGY CT IN THALASSEMIA PATIENTS

Objective: To explore the feasibility and accuracy of liver iron deposition based on dual-energy CT in thalassemia patients.

Materials and methods: 105 thalassemia patients were examined with dual-energy CT and MR liver scanning. Dual-energy CT was performed to measure CT values on 80kVp, 140kVp and virtual iron content (VIC) imaging, ΔH was figured out by the difference CT values between 80kVp and 140kVp. Using the liver iron concent (LIC) obtained by FerriScan as standard setting, the correlation between CT measurements and LIC was compared. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance for dual-energy CT in liver iron quantification and stratification. 

Results: The correlation analysis between CT measurements and LIC showed that 80kVp, 140kVp, VIC and ΔH all had a high-positive correlation with LIC (P<0.001). The correlation analysis among different degree groups of VIC, ΔH and LIC showed that the normal, moderate, severe groups of VIC and ΔH had moderate or high positive correlations with that of LIC (P<0.01), but the mild group had no correlation (P>0.05). ROC analysis revealed that the corresponding optimal cutoff value of VIC were -2.8, 6.3,11.9 HU (corresponds to 3.2,7.0,15.0 mg/g dry weight) respectively, while the ΔH were 5.1, 8.4, 17.8HU, respectively. The area under the receiver operating characteristic curves (AUCs) for both VIC and ΔH increased with the increase of LIC thresholds.

Conclusion: Dual-energy CT can accurately evaluate liver iron deposition quantification and stratification, which contribute to predict the status of liver iron deposition of thalassemia patients.