Second-Look Ultrasound: When Things Are Not Always as They Seem

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Breast magnetic resonance imaging (MRI) is highly sensitive for detecting malignant lesions.
• Second-look ultrasound (SL-US) is used to evaluate MRI-detected lesions.
• Histological confirmation is the gold standard for breast lesion diagnosis.

Purpose of the Study:

• To compare size, morphology, and suspicion levels between SL-US and MRI-detected breast lesions.
• To assess the concordance of findings between SL-US and MRI.
• To determine the optimal imaging modality for guiding biopsy decisions.

Main Methods:

• Observational retrospective study of 224 patients undergoing SL-US for 235 MRI-detected lesions.
• Analysis of lesion size, morphology (BI-RADS lexicon), and BI-RADS categories for both MRI and US.
• Comparison of US-identified lesions with histological confirmation.

Main Results:

• SL-US identified 73.6% of MRI-detected lesions.
• Mean lesion size was 15.2 mm on MRI vs. 9.4 mm on US.
• Good correlation in size and morphology for foci and masses; nonmass enhancements appeared larger on MRI (P=0.0001).
• BI-RADS categories agreed in 44.6% of cases; MRI was more suspicious in 41.2% of cases.

Conclusions:

• SL-US findings show good agreement with MRI for size and morphology of foci and masses.
• Nonmass enhancements exhibit discrepancies in size and morphology between modalities.
• MRI findings generally demonstrate a higher degree of suspicion, supporting its primary role in biopsy decision-making.