Value of MRI in the diagnosis of benign and malignant of breast cystic lesion with thin-wall

Objective: To investigate the value of differential diagnosis of benign and malignant of breast cystic lesion with thin-wall in MRI. Methods: Retrospective analysis from January 2012 to December 2016 Liaoning Cancer Hospital diagnosis confirmed by surgery and pathology, and a total of 81 lesions (76 patients) of breast cystic lesions with thin-wall on MRI enhanced images (thickness no more than 5 mm, mural node less than 10 mm and solid position less than 50%) were enrolled. All patients underwent bilateral breast plain scan and dynamic contrast-enhanced scan. Using MRI breast imaging reporting and data system (BI-RADS) standard to analyze the MRI plain scan and dynamic contrast-enhanced scan images. Analysis of the margin of the lesion, internal enhancing features and time signal intensity curve (TIC) type and other characteristics. The feature of wall margin, thickness and enhancement form, mural nodules and internal septation morphological were analysed by Chi-square test. TIC type and wall nodule position were analysed by Fisher method. Wall nodule sizes were analysed by using independent sample t test. Results: Of the 81 lesions, 67 were benign lesions and 14 were malignant. Among benign lesions, 56 were with well-defined margin, 58 were with uniform wall thickness and 7 were with mural nodule. Among malignant lesions, 5 were with well-defined margin, 8 were with uniform wall thickness and 9 were with mural nodule, which showed statistically significant difference between benign and malignant lesions (P < 0.05). Of the 9 malignant lesions with wall nodules, 7 were located outside the wall, 1 between the wall, and 1 within the wall. Of the 7 benign lesions with wall nodules, 4 were located between the wall, 1 within the wall and 2 outside the wall, which were significant difference in the location of nodules between benign and malignant lesion (x² = 6.228, P = 0.043). There was no significant difference between benign and malignant lesions in the homogeneous enhancing, internal separations and wall nodule size (P > 0.05). Nine lesions can not obtain TIC to analyse enhancement degree due to thin linear enhancement of cyst wall. Through the analysis of TIC type of 58 benign lesions and 14 malignant lesions, Type I and type II TIC were more commonly presented in benign lesions. Type II and type III were more commonly found in malignant lesions, and TIC types were statistically different (P < 0.05). There was no significant difference in the degree of cystic wall enhancement (P > 0.05). Conclusion: Most of breast cystic lesion with thin-wall are benign lesion, cystic wall enhancement characteristics combined with time-signal intensity curve helps to find malignant lesion. (authors)