Analysis of Obesity And Axillary Lymph Nodes on Mammography

Abstract

Fat-infiltrated lymph nodes mostly seen on mammograms (MG) of the elderly and obese women. We analyzed the fat infiltration of lymph nodes for its potential use in estimating body mass index (BMI). 2D digital MG of 157 women assessed by one breast radiologist and one radiology resident. For each patient, the largest lymph node chosen as the index by analyzing the medial, lateral oblique (MLO) views. The width and length of the node and the hilum, the cortex, and the Hilo-cortical ratio (HCR) were measured. Breast density was categorized according to the ACR BI-RADS 4th edition and divided into two groups as dense and non-dense. Obesity was defined as BMI ≥ 30 kg/m2, overweight as BMI <30 and ≥ 25 kg/m2, normal weight as BMI <25 kg/m2. The association of lymph node dimensions and hilum dimensions, breast density, and age with BMI were analyzed. P <0.05 were considered as statistically significant. Good inter-observer agreements were found for most measurements, although the agreement of cortex width was low. The lymph node dimensions, hilum dimensions, HCR increased significantly with increasing BMI for the measurements of reader 1 (p<0.001 for all). In reader 2, only widths of lymph node and hilum related (p<0.05). Cortex width was not associated with BMI. There was a statistically significant relationship between BMI and mammographic density. Obese women had more non-dense breasts (p <0.001). Conclusion axillary lymph node fatty content was found related to BMI and could use as an indicator of obesity.