title: Superparamagnetic iron oxide-enhanced magnetic resonance imaging is useful in predicting malignant potential of vascular transformation of hypointense hypovascular nodules on gadoxetic acid-enhanced magnetic resonance imaging.
abstract: OBJECTIVE
  To examine whether superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) can be used to assess the malignant potential of hepatic hypovascular nodules showing hypointensity during the hepatobiliary phase (HBP) on gadoxetic acid (Gd-EOB-DTPA)-enhanced MRI.
  
  
  METHODS
  The study included 42 patients with chronic liver disease who had small hypovascular nodules (5-15 mm) showing hypointensity during the HBP on Gd-EOB-DTPA-enhanced MRI. The SPIO-enhanced T2-weighted MRI analyzed whether the signal intensity of each nodule was high. Nodules were prospectively followed up until hypervascularization by periodic Gd-EOB-DTPA-enhanced MRI. Initial MRI findings and clinical variables were used to analyze predictive factors for hypervascularization.
  
  
  RESULTS
  We analyzed 77 nodules, of which 19 (25%) showed hypervascularization during the observation period. The cumulative rates for hypervascularization were 11% and 22% at 1 and 2 years, respectively. Hyperintensity was observed in 12 nodules (16%) on SPIO-enhanced T2-weighted MRI; among these, 7 (58%) showed hypervascularization, whereas 12 (18%) of the remaining 65 nodules without hyperintensity showed hypervascularization (P = 0.007). A Cox model revealed that independent predictors of hypervascularization included hyperintense nodules on SPIO-enhanced MRI (P < 0.001). The cumulative rates for hypervascularization in hyperintense nodules on SPIO-enhanced MRI were 52% at 1 year, whereas these rates were 3% for non-hyperintense nodules.
  
  
  CONCLUSIONS
  Superparamagnetic iron oxide-enhanced MRI is useful for predicting the malignant potential of vascular transformation of hypovascular nodules with hypointensity observed in the HBP on Gd-EOB-DTPA-enhanced MRI.
authors.affiliation: Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Takahide
authors.initials: T
authors.lastname: Nakazawa
authors.affiliation: Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Yamane
authors.affiliation: Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Kousuke
authors.initials: K
authors.lastname: Kubota
authors.affiliation: Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Haruki
authors.initials: H
authors.lastname: Uojima
authors.affiliation: Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Juichi
authors.initials: J
authors.lastname: Takada
authors.affiliation: Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Okuwaki
authors.affiliation: Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Hidaka
authors.affiliation: Department of Healthcare Administration, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Akitaka
authors.initials: A
authors.lastname: Shibuya
authors.affiliation: Department of Endoscopic Center, Shin-yurigaoka General Hospital, Kawasaki, Japan.
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Kokubu
authors.affiliation: Department of Diagnostic Radiology, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Matsunaga
authors.affiliation: Department of Gastroenterology, Internal Medicine, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Wasaburo
authors.initials: W
authors.lastname: Koizumi
keywords: gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid; hepatobiliary phase; hepatocellular carcinoma; hypervascularization; predictive factors; superparamagnetic iron oxide