Correlation between MRI and biopsies under second look ultrasound

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Magnetic Resonance Imaging (MRI) detects breast lesions missed by mammography and ultrasound, termed "second look" lesions.
• Establishing clear indications for second look ultrasound and biopsy is essential for accurate breast cancer diagnosis.

Purpose of the Study:

• Analyze target displacement between MRI and ultrasound.
• Define BIRADS (Breast Imaging Reporting and Data System) morphological criteria to predict benign or malignant lesions.
• Evaluate the agreement between MRI and ultrasound in interpreting morphological criteria.
• Establish optimal indications for second look ultrasound and biopsy.

Main Methods:

• Retrospective, monocentric review of patients with breast abnormalities initially detected by MRI.
• Inclusion of patients who underwent second look ultrasound and biopsy.
• Documentation of lesions using BIRADS lexicon for both MRI and ultrasound.
• Follow-up of patients for 2-5 years.

Main Results:

• Of 108 biopsied lesions, 76% were benign and 24% malignant.
• Circumscribed contours and Type I enhancement on MRI, and round/oval shape with circumscribed contours on ultrasound, indicated benignity (NPV > 0.85).
• Agreement between MRI and ultrasound was weak for shape (Kappa=0.09) and contours (Kappa=0.23).
• MRI overestimated lesion size compared to ultrasound (p=0.0001).

Conclusions:

• Second look ultrasound is recommended for MRI-detected abnormalities, including BIRADS 3 lesions.
• Biopsy indications should be broad, with clip placement and follow-up MRI to confirm benignity.
• Risk factors alone are unreliable for guiding second look ultrasound indications.