Differential Diagnosis of Benign and Malignant Level Tumors in Children by Quantitative MRI with Intracellular Contrast Agent

Abstract

Purpose: Тo determine the possibilities of quantitative assessment of mpMRI with EOB-DTPA in the differential diagnosis of benign and malignant tumors in children.Material and methods: 30 patients (male — 17, female — 13) with 83 tumors underwent MRI. Age ranged from 5 months to 20 years. All children underwent MRI on 3T or 1.5T MR-scanners using body coil. Fat saturated T1WI were performed before and after hepatotropic MR-contrast agent (gadoxetic acid) injection in arterial, portal, venous and delayed phases (1, 5, 20, 40 min). Tumors were divided into 2 groups: benign (52) and malignant (31). In this work we use only pre- and postcontrast T1WI. Diagnosis was confirmed histologically (all malignant and a part of benign FLL) and long-term MRI follow-up studies (for benign). To eliminate influence of external factors we used coefficients for each MR-program, the signal was normalized to intact liver parenchyma, spleen, abdominal aorta and v. cava inferior, also normalization to native series has been performed. Coefficients were compared for malignant and benign tumors using Student’s t-test, significantly different parameters were further used to build mathematical model by constructing a logistic regression with step-by-step selection of the most informative values.Results: Regression model is presented by formula. The model is informative and statistically significant (p < 0.001). If A>0.5 tumors has a malignant nature if А ≤ 0.5–benign. Model sensitivity and specificity are 0.862 and 0.925, respectively.Conclusion: Our model could be an excellent assistance in differentiation of benign and malignant focal liver lesions and reduces diagnostic path, effects the proper patients management.