Characterization of common breast MRI abnormalities: comparison between abbreviated and full MRI protocols

Abstract

Rationale and objectives: To evaluate the diagnostic performance of abbreviated MRI (AB-MRI) in comparison to a full protocol MRI (FP-MRI) when evaluating common MRI abnormalities of a mass, non-mass enhancement and focus.

Materials and methods: This retrospective reader study was Institutional Review Board approved and Health Insurance Portability and Accountability Act (HIPAA) compliant. AB-MRIs were reviewed from May 2018-December 2019 to identify women with an abnormal AB-MRI, FP-MRI within six months of the AB-MRI and an elevated risk for breast cancer. Six breast radiologists initially interpreted and recorded findings from the AB-MRI. Immediately after reviewing the AB-MRI, the same radiologists interpreted and recorded findings from the FP-MRI. Findings were recorded in an electronic data collection form. Cohen's Kappa test was used to calculate agreement. P < 0.05 was considered statistically significant.

Results: Of 119 patients who had an AB-MRI, our final study comprised of 32 patients who had 64 breast MRIs (32 AB-MRI and 32 FP-MRI). The amount of fibroglandular tissue for AB-MRI and FP-MRI showed excellent intra-reader agreement [Kappa: 0.89-1.00 (P < 0.0001)]. Substantial to excellent intra-reader agreement [Kappa: 0.74-0.93 (P < 0.0001)] was demonstrated for all 6 readers when identifying abnormalities seen on AB-MRI and FP-MRI. Moderate to excellent intra-reader agreement [Kappa: 0.41-0.87(P < 0.0001)] was demonstrated between the AB-MRI and FP-MRI for the final BI-RADS assessment.

Conclusion: AB-MRI has acceptable intra-reader agreement with FP-MRI when characterizing common MRI abnormalities such as a mass, non-mass enhancement and focus suggesting that subsequent FP-MRI may not be needed.

Keywords: Abbreviated breast MRI; Breast MRI; Breast imaging.