Variability in the description of morphologic and contrast enhancement characteristics of breast lesions on magnetic resonance imaging

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: K was 0.27 for both early and late enhancement; preset ROIs improved K 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.