Definition:

Prominent or conspicuous part or characteristic. In LI-RADS, refers to imaging characteristics used in categorization of observations.

Comments:

• Major features: Imaging features used to categorize as LR-3, LR-4, or LR-5 observations that are neither definite benign entities nor probable benign entities and that lack features of non-HCC malignancy or tumor in vein. See Table to review the use of major features to categorize such observations.
• Ancillary features: Imaging features that modify likelihood of malignancy. In isolation, these features do not permit reliable categorization of observations and hence are considered ancillary. Ancillary features are subdivided into those that may favor malignancy and those that may favor benignity.
  • Some ancillary features that favor malignancy specifically favor HCC as opposed to malignancy in general
  • Radiologists at their discretion may apply ancillary features that may favor malignancy to upgrade category (up to LR-4) and ancillary features that favor benignity to downgrade category
  • To maintain congruency with OPTN, ancillary features cannot be applied to upgrade category to LR-5. 
  • Click here to review the application of ancillary features for upgrading and downgrading categories.
• Major and ancillary features are summarized in table on left.