Abstract: Objective The aim of this study was to investigate the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantitative parameters in the differential diagnosis of small benign and malignant liver space-occupying lesions (LSOL). Methods 83 patients with LSOL were admitted to our hospital between March 2020 and March 2022, the patients included had their liver lesions less than 3 cm, and all underwent DCR-MRI scan to obtain the volume transfer constant (Ktrans), rate constant (Kep), extravascular extracellular volume fraction (Ve) and initial area under the curve (IAUC) by Tissue4D software automatically at region of interest. The diagnosis was pathologically confirmed from post-operational or fine needle aspiration tissues. The diagnostic efficacy was assessed by the receiver operating characteristic (ROC) curves. Results Out of the 83 patients with LSOL, the pathological examination found benign lesions in 38 cases and malignant ones in 45 cases; the Krans, Kep, Ve and IAUC in malignant lesions were (0.4±0.2)min^-1, (0.9±0.3)min^-1,(0.5±0.2) and (37.2±7.1), all significantly greater than [(0.1±0.1)min^-1, (0.4±0.2)min^-1, (0.3±0.1) and (11.1±2.9), respectively, P<0.05] in their adjacent liver tissues, and also much greater than [(0.2±0.1)min^-1, (0.4±0.3)min^-1, (0.3±0.2) and (22.1±5.7), respectively, P<0.05] in benign lesions; the ROC analysis showed that the combination of Krans, Kep, Ve and IAUC in differentiating small intrahepatic LSOL was much superior to any parameter alone, with the AUC of 0.920, the sensitivity of 95.0%, and the specificity of 78.5%(P<0.05). Conclusion The DCE-MRI quantitative parameters are efficacious in the differential diagnosis of small benign and malignant intrahepatic LSOL.

Key words: Liver space-occupying lesion, Dynamic contrast-enhanced magnetic resonance imaging, Volume transfer constant, Differential diagnosis