title: Effect of threshold growth as a major feature on LI-RADS categorization.
abstract: Liver Imaging Reporting and Data System (LI-RADS) uses major features (arterial phase hyperenhancement [APHE], "washout" [WO], "capsule," diameter, threshold growth [TG]) to codify probability of hepatocellular carcinoma for each observation. This study assessed the effect of removing TG as a major feature on LI-RADS categorization.
  
  
  
  In this HIPAA-compliant, IRB-approved study, all MR and CT clinical reports containing a standardized LI-RADS v2014 template between 4/15-1/17 were retrospectively reviewed for each LR-3, LR-4, and LR-5 reported observation. Two LI-RADS categories were then assigned: one using all LI-RADS major features and one after removing TG as a major feature. The two categories were compared descriptively.
  
  
  
  The study included 265 patients (172 [65%] male, mean age 63 [±10] years) with 489 observations (median diameter 14 mm, IQR 10-20 mm), of which 345 (71%) had APHE, 307 (63%) had WO, 86 (18%) had "capsule," and 72 (15%) had TG. Of 86 observations with TG, 47 (65%) were new observations ≥10 mm, 14 (19%) had diameter increase ≥50% in ≤6 months, and 11 (15%) had diameter increase ≥100% in >6 months. Using all major features, 214/489 (44%) observations were LR-3, 129/489 (26%) were LR-4, and 146/489 (30%) were LR-5. After removing TG, 237/489 (48%) were LR-3, 119/489 (24%) were LR-4, and 133 (27%) were LR-5. Removing TG caused a category downgrade for 35/489 (7%, 95% CI 5-10) observations, including 13/146 (9%, 95% CI 3-14) LR-5 observations.
  
  
  
  9% of LR-5 observations would be downgraded without TG.
authors.affiliation: Department of Radiology, Montefiore Medical Center, Bronx, USA. vichka17@hotmail.com.
authors.forename: Victoria
authors.identifier: http://orcid.org/0000-0002-5715-1403
authors.initials: V
authors.lastname: Chernyak
authors.affiliation: Department of Radiology, Montefiore Medical Center, Bronx, USA.
authors.forename: Mariya
authors.initials: M
authors.lastname: Kobi
authors.affiliation: Department of Radiology, Montefiore Medical Center, Bronx, USA.
authors.forename: Milana
authors.initials: M
authors.lastname: Flusberg
authors.affiliation: Department of Radiology, Montefiore Medical Center, Bronx, USA.
authors.forename: Kate C
authors.initials: KC
authors.lastname: Fruitman
authors.affiliation: The Liver Imaging Group, Department of Radiology, University of California, San Diego, La Jolla, USA.
authors.forename: Claude B
authors.initials: CB
authors.lastname: Sirlin
mesh_terms: D000465:Algorithms; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011873:Radiology Information Systems; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
keywords: Ancillary feature; Hepatocellular carcinoma; LI-RADS; Major feature; Threshold growth