Objective:
To explore the value of gadolinium-ethoxybenzyl-diethylenetriamine (Gd-EOB-DTPA) enhanced MRI T1 mapping in diagnosing and distinguishing dysplastic nodule (DN) and hepatocellular carcinoma (HCC) with different degrees of differentiation.
Methods:
A retrospective study in the first affiliated Hospital of Guangxi Medical University from September 2015 to December 2017 was conducted. Seventy-one patients with HCC or DN (a total of 79 lesions) that confirmed by biopsy or surgical pathology findings. Seventy-nine lesions were divided into DN (n=10), well differentiated HCC (n=15), moderately differentiated HCC (n=36) and poorly differentiated HCC (n=18) according to histopathology. All the patients underwent plain MRI scan and Gd-EOB-DTPA-MRI T1 mapping before surgery or needle biopsy. The T1 values of each lesion and non-tumorous liver parenchyma were measured on 20 min hepatobiliary phase (HBP) T1 mapping after Gd-EOB-DTPA administration, respectively. The increment rate of T1 value in lesions relative to non-tumorous liver parenchyma were calculated. One-way ANOVA was used to compare the differences of T1 value and the increment rate of T1 value of DN and 3 groups of HCC with different degrees of differentiation. Spearman correlation was used to evaluate the correlation between T1 mapping parameters and the malignancy degree of DN and HCC. Area under the receiver operating characteristic (ROC) curves were used to evaluate the efficacy of T1 mapping parameters in the differential diagnosis of DN and HCC with different degree of differentiation.
Results:
Significant differences were found in T1 value and increase rate of T1 value of DN and HCC with different degrees of differentiation (P< 0.05). The T1 value and increase rate of T1 value showed an increasing trend from DN to poorly differentiated HCC after enhancement. The T1 value and increase rate of T1 value were positively correlated with the malignancy of DN and HCC (r=0.418 and 0.634, P<0.01). There were significant differences in the increase rate of T1 value between well-differentiated HCC and moderately-differentiated, well-differentiated HCC and poorly-differentiated HCC, respectively (P<0.05). The area under ROC curve of T1 value and the increase rate of T1 value for differentiating DN from well-differentiated, moderately differentiated and poorly differentiated HCC was 0.933, 0.928, 0.939 and 0.867, 0.961, 0.961, respectively. The area under ROC curve of the increase rate of T1 value for differentiating well-differentiated HCC from moderately-differentiated, well-differentiated HCC from poorly-differentiated HCC was 0.770 and 0.844, respectively.
Conclusions
Gd-EOB-DTPA enhanced MRI combined with T1 mapping can provide valuable diagnostic information for identifying DN and HCC with different degrees of differentiation.