Table 1.

The IOTA Simple Rules for Identifying a Benign or Malignant Tumor

Rules for predicting a malignant tumor (M-rules)
M1	Irregular solid tumor
M2	Presence of ascites
M3	At least four papillary structures
M4	Irregular multilocular solid tumor with largest diameter ≥100 mm
M5	Very strong blood flow (color score 4)
Rules for predicting a benign tumor (B-rules)
B1	Unilocular
B2	Presence of solid components with the largest diameter <7 mm
B3	Presence of acoustic shadows
B4	Smooth multilocular tumor with largest diameter <100 mm
B5	No blood flow (color score 1)