A New Breast Density Assessment Method Using Portable Document Format

Area of Science:

• Radiology and Medical Imaging
• Breast Cancer Screening
• Quantitative Imaging

Background:

• Breast density assessment is crucial for risk-stratified and supplemental breast cancer screening.
• International studies on mammographic breast density are challenged by the cost and energy requirements of traditional mammography.
• A novel method using portable document format (PDF) for breast density assessment is being explored.

Purpose of the Study:

• To investigate the inter-method agreement between mammograms viewed on PDF and those on a workstation for subjective breast density assessment.
• To evaluate the feasibility of using PDF for breast density assessment in a research context.

Main Methods:

• Three radiologists assessed 200 normal bilateral mediolateral oblique view images twice, a month apart, using both PDF and workstation platforms.
• Intra-reader agreement was assessed by one reader performing two readings of the PDF set at a 1-month interval.
• Weighted kappa coefficient (κw) was used to quantify inter-method and intra-observer agreement.

Main Results:

• Substantial average inter-method agreement (κw = 0.74) was observed on a four-grade scale (fatty, scattered, heterogeneously dense, extremely dense).
• Almost perfect average inter-method agreement (κw = 0.81) was found on a two-grade scale (non-dense, dense).
• Intra-observer agreement was almost perfect on both four-grade (κw = 0.85) and two-grade (κw = 0.90) scales for PDF readings.

Conclusions:

• Mammography readings for breast density assessment demonstrate almost perfect inter-method agreement between PDF and workstation viewing platforms.
• The intra-observer agreement for breast density assessment using PDF is also almost perfect, indicating high reliability.
• PDF viewing is a reliable method for breast density assessment, potentially overcoming challenges associated with traditional mammography in international studies.