Comparison of Gd-EOB-DTPA-enhanced MRI and Contrast-enhanced Ultrasound for measuring tumor size of solitary hepatocellular carcinoma ≤ 5cm: A real-world study

Abstract Objective To retrospectively compare the performance of Gd-EOB-DTPA-enhanced MRI (CE-MRI) and Contrast-enhanced Ultrasound (CEUS) in measuring tumor size of solitary hepatocellular carcinoma (HCC) ≤5cm. Methods A total of 194 patients who met the inclusion criteria from January 2019 through May 2024 were included. Taken pathological results as the reference standard, The paired T-test and Bland–Altman analysis were conducted to assess the correlation and mean absolute error between the measured maximum diameter of HCC obtained from CE-MRI/CEUS and pathological results. Results The comparison of baseline characteristics showed that there was no significant difference between the two groups of patients undergoing MRI and CEUS (P > 0.05). Both CE-MRI and CEUS demonstrated good correlation (r > 0.7) with histological results. The paired T-test analysis revealed that CE-MRI exhibited a smaller mean absolute error (0.1 ± 6.3 mm, P = 0.224, 95%CI -0.099~0.123) compared to CEUS (4.8 ± 7.1 mm, P < 0.001, 95%CI 0.354~0.615). Furthermore, results from the subgroup of patients who underwent both CE-MRI (r = 0.896, mean absolute error 1.2 ± 4.8 mm, P = 0.094, 95%CI -0.021~0.258) and CEUS (r = 0.882, mean absolute error 3.9 ± 4.7 mm, P < 0.001, 95%CI 0.252~0.527) echoed the aforementioned conclusions. The Bland-Altman analysis indicated that both CE-MRI and CEUS consistently overestimated the size of HCC when compared to pathological results. CE-MRI (bias 0.12; 1.19 mm) demonstrated a smaller bias in both the overall patient population and the subgroup patients, as opposed to CEUS (bias 5.02; 3.90 mm). Conclusion In the preoperative assessment of tumor sizes for solitary HCC measuring ≤5cm, Gd-EOB-DTPA-enhanced MRI exhibited superior measuring accuracy and can be more clinically useful compared to CEUS.