Fig. 6

Derivation algorithm for the original CT-score and modified CT-scores. a represents original CT-score, mass-to-cortex corticomedullary attenuation ratio (MCAR): 1 = low (< 0.40); 2 = moderate (0.40 - 0.75) greater than 0.75; 3 = intense (> 0.75). Heterogeneity score (HS): 1 = completely homogeneous; 2 = mostly homogeneous; 3 = mixed heterogeneity; 4 = mostly heterogeneous; and 5 = completely heterogeneous. b represents modified CT-score 1 and 2 which combined with tumor-renal interface and standardized nephrographic reduction rate (SNRR) respectively; Heterogeneity score (HG): 0 − 1.2 as grade 1; 1.2 - 2.2 as grade 2; 2.2 - —3.2 as grade 3; 3.2 - —4.2 as grade 4; and > 4.2 as grade 5; MCAR: as above mentioned. c represents modified CT-score 3: combined with Major axis / Minor axis; HG and MCAR as above mentioned