A malignant query mass and three retrieved masses (k=3) by our CBIR scheme using the ED measure: (a) A malignant query mass, (b) first retrieved mass, (c) second retrieved mass, and (d) third retrieved mass. The biopsy results of (a)–(d) are malignant. The similarity ratings from three radiologists (R1, R2, and R3) estimating the similarity between the query mass and the retrieved masses are (b) 2, 7, and 8; (c) 5, 6, and 8; (d) 7, 6, and 6.