Abstract:

Objective To investigate the diagnostic value of MRI in benign and malignant breast lesions with cluster ring enhancement. Methods The imaging signs of 68 patients with clustered ring enhancement who underwent MRI examination due to clinical palpation, ultrasound or X-ray examination for suspected malignant lesions in Tangdu Hospital of Air Force Military Medical University from October 2017 to July 2019 were retrospectively analyzed. The differences between benign and malignant lesions in the distribution pattern, T2 lipid suppression signal intensity, time-signal intensity curve (TIC), ductal dilatation, peripheral gland edema, pectoralis major edema were compared using χ ² test or Mann-Whitney U test, and the risk factors of MRI imaging signs of malignant breast lesions were analyzed using binomial logistic regression model. Results There were 68 cluster ring enhancement lesions in 68 patients, all of which were single lesions, among which 18 cases (26.5%) were benign, and the common lesions were plasma cell mastitis (9 cases). Fifty cases (73.5%) were malignant, and the most common type was invasive breast cancer (40 cases). Imaging features of plasma cell mastitis showed cluster ring enhancement, regional distribution, slightly high signal on fat suppression T2 image, type Ⅲ TIC, with ductal dilatation, edema of peripheral glands and pectoralis major. Imaging features of invasive breast cancer showed cluster ring enhancement, regional distribution, iso-signal on fat suppression T2 image, type Ⅲ TIC, no ductal dilatation, and edema of peripheral gland and pectoralis major. There were statistically significant differences in the intensity of fat-suppression T2 signal (Z=3.003, P=0.003) and duct dilatation (χ ²=7.174, P=0.007) between benign and malignant lesions. There were no significant differences in distribution (χ ²=5.510, P=0.313), TIC type (χ ²=3.538, P=0.133), peripheral gland edema (χ ²=0.164, P=0.686) and pectoralis major edema (χ ²<0.001, P>0.999). The analysis of binomial logistic regression model showed that fat-suppression T2 iso-signal (OR=0.182, 95%CI: 0.036-0.914, P=0.039) and no ductal dilatation (OR=0.198, 95%CI: 0.047-0.846, P=0.029) were the risk factors for breast malignant lesions. Conclusion Breast cancer MRI findings of cluster ring enhancement, fat-suppression T2 iso-signal and no ductal dilatation are related risk factors for malignant breast lesions. MRI is helpful for early detection and diagnosis of breast lesions.

Key words: Breast neoplasms, Magnetic resonance imaging, Cluster ring enhancement, Dynamic enhancement, T2 lipid suppression