The spatial distribution of radiodense breast tissue: a longitudinal study

Area of Science:

• Radiology
• Medical Imaging
• Breast Cancer Research

Background:

• Mammographic breast density is a key breast cancer risk factor.
• Previous research used whole-breast average density, ignoring spatial distribution.
• Understanding density distribution is crucial for risk assessment.

Purpose of the Study:

• To investigate the spatial distribution of mammographic density within the breast.
• To analyze the spatial autocorrelation of regional breast density.
• To determine factors influencing density clustering.

Main Methods:

• Divided mammograms into 48 regions to calculate overall and regional percent density (PD).
• Calculated spatial autocorrelation (Moran's I) for regional PD to assess clustering.
• Compared clustering between breasts and with age, BMI, parity, and age at first birth.

Main Results:

• Breast density exhibits a spatially clustered pattern (median Moran's I = 0.31).
• High-density areas predominantly cluster centrally, irrespective of overall density.
• Clustering is similar between breasts and stable with age; it decreases with increasing BMI.

Conclusions:

• Breast tissue density distribution is spatially autocorrelated, typically centralizing high-density areas.
• Density clustering is consistent within individuals and across populations, with minimal age or reproductive influence.
• Increasing BMI is associated with reduced spatial clustering of breast density.