title: Central vascular structures as a characteristic finding of regenerative nodules using hepatobiliary phase gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid-enhanced MRI and arterial dominant phase contrast-enhanced US.
abstract: OBJECTIVE
  We investigated the characteristic findings of regenerative nodules (RNs) for differentiating early hepatocellular carcinoma (HCC) from high-grade dysplastic nodules (HGDNs) using magnetic resonance imaging (MRI) with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA; EOB-MRI) and contrast-enhanced ultrasonography (CEUS) in patients with chronic liver disease.
  
  
  METHODS
  Pathologically confirmed lesions (100 early HCCs, 7 HGDNs, and 20 RNs with a maximum diameter of more than 1 cm and mean maximal diameters of 15.5, 15.1, and 14.8 mm, respectively) were enrolled in this retrospective study. The signal intensities of these lesions during the hepatobiliary phase of EOB-MRI were investigated, and findings characteristic of RNs using this modality were also evaluated using CEUS.
  
  
  RESULTS
  Ninety-eight of the 100 early HCCs that were hypo-intense (n = 95), iso-intense (n = 2), or hyper-intense (n = 1) and the seven HGDNs that were hypo-intense (n = 6) or hyper-intense (n = 1) during the hepatobiliary phase of EOB-MRI exhibited centripetal vessels during the arterial dominant phase of CEUS, although one early HCC that was hypo-intense exhibited both centrifugal and centripetal vessels. Eighteen of the 20 RNs and one early HCC that were hyper-intense with a small central hypo-intensity and the remaining two RNs that were hyper-intense on EOB-MRI exhibited centrifugal vessels during the arterial dominant phase of CEUS. The small central hypo-intense area corresponded to central vascular structures in the lesion, such as the hepatic artery and portal vein running from the center to the periphery, when viewed using CEUS.
  
  
  CONCLUSIONS
  Central vascular structures may be a characteristic finding of RNs when observed during the hepatobiliary phase of EOB-MRI and the arterial dominant phase of CEUS.
authors: Gastroenterological Center, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama, Kanagawa, 232-0024, Japan.
authors: Kazuya
authors: K
authors: Sugimori
authors: Gastroenterological Center, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama, Kanagawa, 232-0024, Japan. kz-numa@urahp.yokohama-cu.ac.jp.
authors: Kazushi
authors: K
authors: Numata
authors: Department of Radiology, University Hospital of the Ryukyus, 207 Azakamihara, Nishihara-cho, Nakagami-gun, Okinawa, 903-0215, Japan.
authors: Masahiro
authors: M
authors: Okada
authors: Gastroenterological Center, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama, Kanagawa, 232-0024, Japan.
authors: Hiromi
authors: H
authors: Nihonmatsu
authors: Department of Radiology, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama, Kanagawa, 232-0024, Japan.
authors: Shigeo
authors: S
authors: Takebayashi
authors: Division of Gastroenterology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan.
authors: Shin
authors: S
authors: Maeda
authors: Pathological Department, Shonan Fujisawa Tokusyukai Hospital, 1-5-1 Kamidai, Tsujido, Fujisawa, Kanagawa, 251-0041, Japan.
authors: Masayuki
authors: M
authors: Nakano
authors: Gastroenterological Center, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama, Kanagawa, 232-0024, Japan.
authors: Katsuaki
authors: K
authors: Tanaka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: Contrast-enhanced ultrasonography; Early hepatocellular carcinoma; High-grade dysplastic nodule; Magnetic resonance imaging with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid; Regenerative nodule