Incidental pleural effusions detected on screening breast MRI

Area of Science:

• Radiology
• Oncology
• Thoracic Medicine

Background:

• Pleural effusions are a frequent complication of malignancy.
• Differentiating malignant from physiologic effusions on breast MRI is crucial.
• Physiologic effusions can be mistaken for pathological findings.

Purpose of the Study:

• To determine the incidence of physiologic pleural effusions in healthy women.
• To establish reference ranges for these effusions on screening breast MRI.
• To aid in the accurate interpretation of breast MRI findings.

Main Methods:

• Retrospective analysis of 200 women undergoing screening breast MRI.
• Exclusion of patients with malignancy, prior cancer, or cardiac/pulmonary disease.
• Measurement of pleural effusion size and laterality.

Main Results:

• 87% of healthy women had pleural effusions; 62% were bilateral.
• Right-sided effusions were more frequent (81.5%) and slightly larger (mean 3.3 mm) than left-sided (67.5%, mean 2.8 mm).
• Reference ranges established: up to 7 mm on the right, 5 mm on the left.

Conclusions:

• Small pleural effusions are common physiologic findings in screening breast MRI.
• These findings in healthy women should not warrant further diagnostic testing.
• Understanding these normal variations improves diagnostic accuracy and reduces unnecessary procedures.