Individual mass features most frequently assoc w/ benignity: 

• Oval shape

• Circumscribed margin

• Homogeneous or dark internal septations

• T2 hyperintensity

• Persistent delayed-phase kinetics

Individual non-mass features most frequently assoc w/ benignity:

• Focal or regional distribution

• Homogeneous enhancement

None of these features alone are sufficient to assign category 3 as CA can present w/ these individual features.

Features w/ the highest likelihoods of CA that justify category 5:

• Mass w/ spiculated margin

• Non-mass linear or segmental enhancement

A combination of findings on mammo and US is required to justify category 5.