title: MR imaging of hepatic metastasis in patients with malignant melanoma: evaluation of suspected lesions screened at contrast-enhanced CT.
abstract: OBJECTIVE
  To evaluate the magnetic resonance (MR) imaging feature of suspected hepatic metastasis in patients with malignant melanoma which showed intermediate findings on screened contrast-enhanced computed tomography (CECT).
  
  
  METHODS
  MR imaging was performed in 38 patients (22 men, 16 women; mean age, 58 years) whose CECT findings were intermediate. Hepatic metastases had been diagnosed on MR imaging in 23 of the 38 patients. Verification of hepatic metastasis was made by histological examination: ultrasonographic-guided needle biopsy (n=3), autopsy (n=3), and surgical resection (n=1), or by an obvious progression in number and/or size of the lesions on follow-up MR imaging (n=24). Two diagnostic radiologists reviewed MR images by consensus. The median follow-up duration was 14.2 months.
  
  
  RESULTS
  Abnormal findings were detected in 31 patients on MR images, and undetected in the remaining seven patients resulting in false-positive on CECT. The mean size of the lesion was 11.0mm. False-positive results were obtained in two lesions which disappeared on follow-up MR imaging. In six patients, lesions were considered as hepatic cysts on MR images. As a result, a total of 35 hepatic metastases were detected on MR images. Of these, 18 patients demonstrated typical melanotic appearance on MR images which showed shortened T1 and T2 relaxation times, and five patients demonstrated atypical melanotic appearance. In 16 patients, extra-hepatic metastases were also developed.
  
  
  CONCLUSIONS
  MR imaging could rule out hepatic metastasis in patients with malignant melanoma which showed intermediate findings on screened CECT, and could detect additional extra-hepatic metastases.
authors.affiliation: Division of Diagnostic Radiology, National Cancer Center Hospital, 5-1-1, Tsukiji, Chuo-ku, 104-0045, Tokyo, Japan. ksofue@ncc.go.jp
authors.forename: Keitaro
authors.initials: K
authors.lastname: Sofue
authors.forename: Ukihide
authors.initials: U
authors.lastname: Tateishi
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Tsurusaki
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Arai
authors.forename: Naoya
authors.initials: N
authors.lastname: Yamazaki
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D007479:Iopamidol; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008403:Mass Screening / Q000379:methods; D008545:Melanoma / Q000175:diagnosis* / Q000556:secondary*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D007479:Iopamidol