title: Isolated cerebral susceptibility artefacts in patients with malignant melanoma: metastasis or not?
abstract: OBJECTIVE
  While staging patients with malignant melanoma, cerebral susceptibility artefacts on T2*-weighted/susceptibility-weighted imaging (SWI) sequences without a correlate on contrast-enhanced T1-weighted images can be confusing. Without intravenous contrast enhancement, cavernomas, microhaemorrhages and melanin-containing metastases represent possible differential diagnoses for these findings. The purpose of this study was to find out, how often such lesions correspond to metastases.
  
  
  METHODS
  Brain MR images (1.5 T) of 408 patients with malignant melanoma but without cerebral metastases in the initial staging by MRI were reviewed retrospectively. Eighteen patients (5 female, 13 male) with malignant melanoma and signal intensity loss on T2*/SWI were included in our study. The average observation period was 19.6 months (6-46 months, 2006-2009).
  
  
  RESULTS
  In each of these 18 patients between one and seven hypointense lesions on T2*/SWI were found. None of these lesions developed into metastasis.
  
  
  CONCLUSIONS
  Focal areas of susceptibility artefacts in the brain parenchyma without corresponding abnormalities in contrast-enhanced T1 weighted images are unlikely to represent brain metastases.
  
  
  CONCLUSIONS
  • In melanoma patients early diagnosis of metastatic brain lesions is mandatory. • Melanin content and haemorrhage are potential reasons for MRI characteristics of melanoma metastases. • Susceptibility-weighted MRI visualises melanin and blood products. • Isolated cerebral susceptibility artefacts do not convert into melanoma metastases. • SWI/T2* sequences cannot replace Gd-enhanced sequences.
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University of Duisburg Essen Medical School, Hufelandstr. 55, 45122, Essen, Germany. Carolin.Gramsch@uk-essen.de
authors.forename: Carolin
authors.initials: C
authors.lastname: Gramsch
authors.forename: Sophia L
authors.initials: SL
authors.lastname: Göricke
authors.forename: Felix
authors.initials: F
authors.lastname: Behrens
authors.forename: Lisa
authors.initials: L
authors.lastname: Zimmer
authors.forename: Dirk
authors.initials: D
authors.lastname: Schadendorf
authors.forename: Andrej
authors.initials: A
authors.lastname: Krasny
authors.forename: Michael
authors.initials: M
authors.lastname: Forsting
authors.forename: Marc U
authors.initials: MU
authors.lastname: Schlamann
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D001921:Brain / Q000473:pathology*; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology* / Q000556:secondary; D003287:Contrast Media / Q000737:chemistry; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008543:Melanins / Q000737:chemistry; D008545:Melanoma / Q000175:diagnosis* / Q000473:pathology*; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging / Q000379:methods; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D003287:Contrast Media; D008543:Melanins