[The value of synthetic MRI in differential diagnosis of benign and malignant breast lesions].

Abstract

Objective: To explore the diagnostic value of synthetic magnetic resonance imaging (syMRI) quantitative parameters for benign and malignant breast lesions. Methods: From September 2018 to March 2019, a total of 43 cases of breast lesions which were confirmed by surgery and pathology in Cancer Hospital, Chinese Academy of Medical Sciences were enrolled in this study. All patients underwent syMRI sequence scans before and after enhancement except for conventional T2WI, DWI, and enhancement scans. GE AW4.7 workstation was used to generate syMRI parameter maps (T1, T2, proton density mappings), and ITK-SNAP software was used to delineate the volume of interest. The T1, T2, PD values before and after dynamic contrast enhanced (DCE) were obtained, and the change values of each parameter were calculated. Meanwhile, the apparent diffusion coefficient (ADC) and time intensity curve (TIC) of the lesions were measured. The differences of each parameter value were compared between benign and malignant breast lesions, and the receiver operating characteristic (ROC) curve was used to analyze the diagnostic performance of each parameter. Results: Among the 43 enrolled cases, 13 were benign and 30 were malignant. Among the syMRI parameters, the pre-enhancement parameters including T1pre (median 1 663.07 ms), T2pre (median 103.33 ms), post-enhancement parameters ΔT1 (median 1 022.68 ms) and ΔT2 (median 27.67 ms) of benign group, significantly higher than those of the malignant group (the medians were 1 141.74, 92.53, 664.95, and 16.19 ms, respectively, P<0.05). The ADC value of the benign group (median 1.66×10(-3)mm(2)/s) was significantly higher than that of the malignant group (median 1.00×10(-3)mm(2)/s, P<0.05). The benign group included 6 cases of TIC curve type Ⅰ, 5 cases of type Ⅱ, and 2 cases of type Ⅲ. The malignant group included 2 cases of TIC curve type Ⅰ, 17 cases of type Ⅱ, and 11 cases of type Ⅲ. The difference between the two groups was statistically significant (P<0.05). The area under the ROC curve (AUC) of T1pre before DCE was 0.869, higher than 0.806 of ADC and 0.697 of TIC. When the best cut-off value of 1 282.94 ms was chosen, the sensitivity and specificity of diagnosis were 76.9% and 93.3%, respectively. The combination of T1pre and T2pre can further improve the diagnostic performance (AUC=0.908). Conclusions: Among the syMRI quantitative parameters, T1pre, T2pre, ΔT1 and ΔT2 have good value for the differential diagnosis of benign and malignant breast lesions. T1pre has the best diagnostic performance, and the combination of T1pre and T2pre can further improve the diagnostic performance.