title: MR imaging of hepatic metastases caused by neuroendocrine tumors: comparing four techniques.
abstract: OBJECTIVE
  The aim of our prospective study was to assess the MR imaging characteristics of hepatic metastases of neuroendocrine tumors and to determine the optimal MR sequence for their detection.
  
  
  METHODS
  Thirty-seven consecutive patients with liver metastases from neuroendocrine tumors underwent 1.5-T MR imaging of the liver comprising T2-weighted fast spin-echo with respiratory monitoring, breath-hold T2-weighted single-shot fast spin-echo, and T1-weighted gradient-recalled echo sequences before and after the injection of gadoterate dimeglumine. Images were reviewed independently by three observers for the number, location, and pattern of signal and enhancement of metastases.
  
  
  RESULTS
  A total of 359 metastases were detected, 279 on T2-weighed fast spin-echo, 231 on T2-weighed single-shot fast spin-echo, 272 on unenhanced T1-weighted, 322 on hepatic arterial phase, and 228 on portal venous phase images. Hepatic arterial phase images revealed the greatest number of metastases in 70% of patients, including 35 metastases seen only on this sequence, and was significantly superior to the unenhanced T1-weighted and portal venous phase sequences (p < 0.01). The lesion-to-liver contrast was significantly greatest with T2-weighed fast spin-echo sequences. The enhancement patterns of metastases were predominantly hypervascular, hypovascular, peripheral with progressive fill-in, and delayed in, respectively, 27, four, four, and two patients. Most metastases with peripheral enhancement and progressive fill-in were heterogeneous on T2-weighted images and were without globular peripheral enhancement.
  
  
  CONCLUSIONS
  Hepatic metastases of neuroendocrine tumors had a typical hypervascular pattern in 73% of patients. Hepatic arterial phase and fast spin-echo T2-weighed sequences are the most sensitive.
authors.affiliation: Department of Imaging, Institut Gustave-Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex, France.
authors.forename: Clarisse
authors.initials: C
authors.lastname: Dromain
authors.forename: Thierry
authors.initials: T
authors.lastname: de Baere
authors.forename: Eric
authors.initials: E
authors.lastname: Baudin
authors.forename: Joel
authors.initials: J
authors.lastname: Galline
authors.forename: Michel
authors.initials: M
authors.lastname: Ducreux
authors.forename: Valérie
authors.initials: V
authors.lastname: Boige
authors.forename: Pierre
authors.initials: P
authors.lastname: Duvillard
authors.forename: Agnès
authors.initials: A
authors.lastname: Laplanche
authors.forename: Hubert
authors.initials: H
authors.lastname: Caillet
authors.forename: Philippe
authors.initials: P
authors.lastname: Lasser
authors.forename: Martin
authors.initials: M
authors.lastname: Schlumberger
authors.forename: Robert
authors.initials: R
authors.lastname: Sigal
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008113:Liver Neoplasms / Q000098:blood supply / Q000175:diagnosis / Q000556:secondary*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017599:Neuroectodermal Tumors / Q000098:blood supply / Q000175:diagnosis / Q000556:secondary*; D011446:Prospective Studies