title: MR imaging of hepatocellular carcinoma: relationship between lesion size and imaging findings, including signal intensity and dynamic enhancement patterns.
abstract: OBJECTIVE
  To assess the relationship between lesion size and MR imaging findings of pathologically-proven hepatocellular carcinoma (HCC).
  
  
  METHODS
  In a retrospective, single-center study, 37 consecutive patients were identified between 1999 and 2005 that underwent preoperative MRI and surgical resection of HCC. A total of 47 lesions (mean size = 6.85 cm, range = 1-25 cm) were assessed for signal intensity (SI), enhancement patterns, and secondary morphologic features. Interobserver rating, percentage enhancement, and contrast-to-noise-ratio (CNR) were determined. Lesions were assessed for combinations of typical MRI features. Regression analysis was used to assess relations between MRI findings and tumor size.
  
  
  RESULTS
  On fat-suppressed T2-weighted (T2w) fast-spin-echo, smaller lesions had lower SI compared to larger lesions (P < 0.05). In the arterial phase, smaller lesions showed significantly higher percentage enhancement compared to larger lesions (P < 0.05). In the delayed phase, smaller lesions showed less pronounced washout (P < 0.05). Heterogeneity of the lesions, including fatty infiltration, internal nodules, or mosaic pattern, was observed significantly more frequently in larger lesions (P < 0.001). The classic combination of high T2w signal, strong arterial enhancement, and delayed phase washout was present in 23 of 44 lesions (52%).
  
  
  CONCLUSIONS
  Smaller HCC often showed lower SI on T2w, more intense arterial enhancement, and less pronounced delayed washout compared to larger HCC.
authors.affiliation: Department of Radiology, University Medical Center Rotterdam, Rotterdam, The Netherlands. vandenbos.ic@gmail.com
authors.forename: Indra C
authors.initials: IC
authors.lastname: van den Bos
authors.forename: Shahid M
authors.initials: SM
authors.lastname: Hussain
authors.forename: Roy S
authors.initials: RS
authors.lastname: Dwarkasing
authors.forename: Wim C J
authors.initials: WC
authors.lastname: Hop
authors.forename: Pieter E
authors.initials: PE
authors.lastname: Zondervan
authors.forename: Robert A
authors.initials: RA
authors.lastname: de Man
authors.forename: Jan N M
authors.initials: JN
authors.lastname: IJzermans
authors.forename: Craig W
authors.initials: CW
authors.lastname: Walker
authors.forename: Gabriel P
authors.initials: GP
authors.lastname: Krestin
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D006528:Carcinoma, Hepatocellular / Q000473:pathology* / Q000601:surgery; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008113:Liver Neoplasms / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D012044:Regression Analysis; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA