title: Assessment of clinical and magnetic resonance imaging features of de novo hypervascular hepatocellular carcinoma using gadoxetic acid-enhanced magnetic resonance imaging.
abstract: OBJECTIVE
  To clarify the clinical and magnetic resonance imaging (MRI) features of de novo hypervascular hepatocellular carcinoma (HCC) using serial gadoxetic acid-enhanced MRI.
  
  
  METHODS
  The institutional review board approved this retrospective study. After review of 1007 MRI examinations in 240 patients with chronic liver disease, 17 newly developed hypervascular HCCs in 16 patients detected by follow-up from initial MRI examination without hepatocellular nodules were evaluated. The clinical and MRI findings such as previous treatment history for HCC, period to hypervascular HCC onset, presence or absence of hypovascular hypointense nodules on hepatobiliary phase before hypervascularization, and intralesional fat component were recorded or evaluated. Statistical evaluations included Fisher's exact test, χ2-test, and Mann-Whitney U-test.
  
  
  RESULTS
  In 17 HCCs, 12 (71%) were de novo hypervascular HCC without showing hypovascular hypointense nodule on hepatobiliary phase before hypervascularization (de novo group) and 5 (29%) were hypervascularized HCC developed during multistep hepatocarcinogenesis (multistep group). The incidence of previous treatment history for HCC in the de novo group (91%) was significantly higher than that in the multistep group (20%) (P = 0.013). The duration to hypervascular HCC onset from initial examination was shorter in the de novo group (mean, 291 days) than in the multistep group (mean, 509 days) (P = 0.035). The incidence of fat-containing lesion in the de novo group (0%) was lower than that in the multistep group (40%) (P = 0.074).
  
  
  CONCLUSIONS
  De novo hypervascular HCC is characterized by rapid growth, patients with previous treatment history for HCC, and lack of intralesional fat, compared to hypervascular HCC with multistep progression.
authors.affiliation: Department of Radiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tamada
authors.affiliation: Department of Hepatology and Pancreatology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Korenaga
authors.affiliation: Department of Radiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Yamamoto
authors.affiliation: Department of Radiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Higaki
authors.affiliation: Department of Radiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kanki
authors.affiliation: Department of Hepatology and Pancreatology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Sohji
authors.initials: S
authors.lastname: Nishina
authors.affiliation: Department of Hepatology and Pancreatology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Hino
authors.affiliation: Department of Radiology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Ito
keywords: de novo hepatocarcinogenesis; gadoxetic acid; hepatocellular carcinoma; hypervascularization; magnetic resonance imaging