title: Dynamic enhancement pattern of HCC smaller than 3 cm in diameter on gadoxetic acid-enhanced MRI: comparison with multiphasic MDCT.
abstract: OBJECTIVE
  The dynamic enhancement pattern of HCCs smaller than 3 cm in diameter on gadoxetic acid-enhanced magnetic resonance imaging (MRI) have not been extensively investigated. We aimed to evaluate the dynamic enhancement patterns of small HCCs (≤3 cm) on gadoxetic acid-enhanced magnetic resonance imaging (MRI) and compare enhancement patterns with multiphasic multidetector computed tomography (MDCT) based on tumour cellular differentiation and size.
  
  
  METHODS
  We retrospectively included 55 patients with 67 surgically confirmed small HCCs (≤3 cm) who underwent multiphasic MDCT and gadoxetic acid-enhanced MRI. Dynamic enhancement patterns were analysed according to tumour cellular differentiation and size. Hepatobiliary phase images were also analysed to assess their additional value.
  
  
  RESULTS
  The proportion of small HCCs demonstrating the typical enhancement pattern differed depending on tumour cellular differentiation on both MRI (P = 0.001) and MDCT (P = 0.001), but differed depending on tumour size only on CT (P = 0.008). Gadoxetic acid-enhanced MRI more sensitively depicted the typical enhancement pattern than CT for all tumours (P = 0.001), for moderately or poorly differentiated HCCs (P = 0.021) and for HCCs ≤2 cm (P = 0.001). 80% of tumours with atypical enhancement could be diagnosed as HCC based on tumour size and hepatobiliary phase images.
  
  
  CONCLUSIONS
  On both gadoxetic acid-enhanced MRI and multiphasic CT, the dynamic enhancement patterns of small HCCs (≤3 cm) differed according to tumour cellular differentiation. Gadoxetic acid-enhanced MRI more frequently demonstrated the typical HCC enhancement pattern than CT in small HCCs.
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Vivian Y
authors.initials: VY
authors.lastname: Park
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Yong Eun
authors.initials: YE
authors.lastname: Chung
authors.forename: Honsoul
authors.initials: H
authors.lastname: Kim
authors.forename: Mi-Suk
authors.initials: MS
authors.lastname: Park
authors.forename: Joon Seok
authors.initials: JS
authors.lastname: Lim
authors.forename: Ki Whang
authors.initials: KW
authors.lastname: Kim
authors.forename: Myeong-Jin
authors.initials: MJ
authors.lastname: Kim
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods; D009098:Multiphasic Screening / Q000379:methods; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: dynamic enhancement; gadoxetic acid; magnetic resonance imaging; multidetector computed tomography; small HCC