Hepatocellular carcinoma grading and recurrence prediction using T(1) mapping on gadolinium-ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging

The aim of the present study was to explore the value of T(1) mapping on gadolinium-ethoxybenzyl diethylenetriamine pentaacetic (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) for grading hepatocellular carcinoma (HCC) and predicting its recurrence rate. A retrospective study was performed that included 75 patients (66 men and 9 women; mean age, 52.89 years; age range, 23–79 years) with HCC who had undergone Gd-EOB-DTPA-enhanced MRI with T(1) mapping before surgery. The T(1) relaxation time of the 81 lesions and non-tumorous liver parenchyma in 75 patients with HCC were measured before Gd-EOB-DTPA was injected and then at 5, 10 and 20 min after administration, respectively. T(1[lesion (L)-hepatic parenchyma (H)]/H) (%) was calculated as the increment rate of the T(1) value in the lesions relative to the non-tumorous liver parenchyma. One-way analysis of variance and Spearman's correlation analysis was used to compare the differences and relationship of T(1) mapping values among the three grades of HCC. A total of 81 lesions were divided into well-differentiated HCC (grades I; n=21), moderately differentiated HCC (grades II; n=40) and poorly differentiated HCC (grades III; n=20) according to the histopathology. The T(1(L-H)/H) (%) value among grades I, II and III HCC on pre-contrast results and on post-contrast results at the 5-, 10- and 20-min hepatobiliary phase (HBP) were significantly different (P<0.05), and T(1(L-H)/H) (%) was correlated with the histological grade of HCC at each time point (r=0.637, r=0.554, r=0.499 and r=0.560, respectively, P<0.001). A total of 41 recurrence cases [grade I (n=5), grade II (n=23) and grade III (n=13)] were verified by imaging (CT, MRI or ultrasound) or reoperation. Patients with grade III and grade II HCC had higher recurrence rates compared with that in patients with grade I HCC (P<0.05; median recurrence times were 258 days, 605 days and undefined, respectively). According to the optimal cut-off point for the T(1(L-H)/H) (%) of the three grades of HCC, patients with HCC in the low T(1(L-H)/H) (%) value group (≤155.15%) had lower cumulative recurrence rates compared with that in the medium (T(1(L-H)/H) (%) >155.15% and T1((L-H)/H) (%) ≤241.20%) and high (T(1(L-H)/H) (%) >241.20%) value groups at the 20-min HBP (P<0.05; median recurrence times were undefined, 530 days and 447 days, respectively). These results indicate that the parameters of T(1) mapping would be beneficial for predicting the grading and recurrence of HCC.