title: Distinguishing clinical and imaging features of nodular regenerative hyperplasia and large regenerative nodules of the liver.
abstract: OBJECTIVE
  Nodular regenerative hyperplasia (NRH) and large regenerative nodules (LRN) are distinct types of hepatocellular nodules that have been confused in the radiology literature. However, distinction is critical because their clinical significance is quite different. Our purpose was to review the clinical and imaging findings in a series of patients with NRH and LRN in order to identify distinguishing clinical and imaging features.
  
  
  METHODS
  This was a retrospective case series. The clinical and imaging features were compared in 36 patients with pathological proof of NRH and 23 patients with pathological evidence of LRN.
  
  
  RESULTS
  NRH and LRN have different predisposing factors and imaging findings. NRH is often associated with organ transplantation, myeloproliferative disease, or autoimmune processes. Livers with NRH typically do not have enhancing nodules; none of the present patients with NRH had enhancing liver masses. In contrast, LRN are often associated with Budd-Chiari syndrome. Enhancing liver masses were noted in 19 (83%) of the 23 patients with LRN. The p values for the comparisons were less than 0.001 for both enhancing liver masses and hepatic vein thrombosis.
  
  
  CONCLUSIONS
  NRH and LRN can have distinct clinical presentations and imaging appearances. LRN often result in enhancing liver nodules, whereas NRH usually does not. Clinical and imaging information enables the distinction of LRN and NRH in many cases.
authors.affiliation: Departments of Radiology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
authors.forename: J T
authors.initials: JT
authors.lastname: Ames
authors.forename: M P
authors.initials: MP
authors.lastname: Federle
authors.forename: K
authors.initials: K
authors.lastname: Chopra
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000175:diagnosis / Q000000981:diagnostic imaging; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology*; D008107:Liver Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008115:Liver Regeneration; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult
chemical_list: D003287:Contrast Media