Background
Previous studies have shown that abbreviated magnetic resonance imaging (aMRI) compares well to full‐protocol MRI (fpMRI) in breast cancer (BC) screening, with the potential advantage of a less costly and complex examination. To our knowledge, the role for aMRI in staging BC has been poorly investigated, especially in assessing additional disease (ie, additional lesions compared to the index one prompting the examination).
Purpose
To compare aMRI and fpMRI in detecting additional disease in BC staging.
Study type
Retrospective monocentric cohort study.
Population
In all, 87 patients with 89 biopsy‐proven index lesions referred to staging fpMRI between January–June 2016.
Field Strength/Sequence
A 1.5T magnet using short tau inversion recovery (STIR) T2‐weighted imaging, echoplanar diffusion‐weighted imaging, and 3D fast long angle shot (FLASH) T1‐weighted imaging.
Assessment
During independent sessions, four readers with 1.5–20 years of experience in breast imaging, blinded to the pathological examination and previous imaging, assessed multifocal, multicentric, and contralateral additional lesions on fpMRI and aMRI (including precontrast T1‐weighted 3D FLASH sequence, first postcontrast subtracted T1‐weighted 3D FLASH sequence, and a transverse maximum intensity projection reconstruction).
Statistical Tests
We calculated the per‐lesion cancer detection rate (CDR), positive predictive value (PPV), and false discovery rate (FDR) for additional disease, assessing the significance of intrareader differences in CDR with the McNemar test.
Results
Pathological analysis found 36 additional lesions (multifocal, multicentric, and contralateral in 20, 15, and 1 cases, respectively). Readers' CDR was comparably high using aMRI (range 88.9–94.4%) or fpMRI (range 91.7–94.4%) (P > 0.05). PPV and FDR of aMRI (ranges 76.2–84.6% and 15.4–23.8%, respectively), and fpMRI (ranges 76.7–82.9% and 17.2–23.3%, respectively) were comparable on an intrareader basis. Using aMRI, two out of four readers induced two false‐negative cases (one case each) with presumably limited impact on surgical planning (multifocal cancers <1 cm in size).
Data Conclusion
aMRI was comparable to fpMRI in staging additional BC.
Level of Evidence: 3
Technical Efficacy: Stage 2
J. Magn. Reson. Imaging 2019;49:e222–e230.