M.J. Stoutjesdijk, J.J. Fütterer, C. Boetes, L.E. van Die, G. Jager & J.O. Barentsz
RATIONALE AND OBJECTIVE: The objective of this study was to evaluate the interobserver variability in reporting descriptive kinetic and morphologic enhancement features at breast magnetic resonance imaging.
MATERIALS AND METHODS: Four observers evaluated 103 lesions, 49 malignant and 54 benign, proven by histopathology. They used standardized terminology with the following characteristics: "early enhancement kinetics" and "late enhancement kinetics" in curves from both reader-determined and preset regions of interest (ROIs), "enhancement pattern," "shape," "margin," "internal enhancement," and a final assessment score. Agreement was calculated using the kappa statistic. Differences in agreement were calculated using Fisher exact test.
RESULTS: kappa was 0.27 for both early and late enhancement; preset ROIs improved kappa to 0.47 and 0.67, respectively (odds ratios, 1.7 and 4.5). kappa was 0.45 for pattern, 0.42 for shape, 0.26 for margin, 0.25 for internal enhancement, and 0.28 for final assessment.
CONCLUSIONS: There was considerable variability in the use of most generally accepted terms. The preparation of ROIs was a major source of variability in the interpretation of enhancement curves.