title: Alveolar echinococcosis: correlation between hepatic MRI findings and FDG-PET/CT metabolic activity.
abstract: OBJECTIVE
  To correlate the appearance of alveolar echinococcosis (AE) hepatic lesions in magnetic resonance imaging (MRI) as defined by Kodama, to the metabolic activity visualized in 18-fluoro-deoxyglucose positron emission tomography combined with computed tomography (PET/CT).
  
  
  METHODS
  Forty-two patients diagnosed with AE and who underwent both MRI and PET/CT were included. The forty-two hepatic lesions were divided into five types according to Kodama's classification by three independent readers blinded with regard to the PET/CT information. Concerning PET/CT, two independent readers, unaware of the MRI information, considered the results as positive when an increased FDG-uptake was observed at 1 or 3 h after FDG-injection, and as negative when no increased uptake was noted. Inter-observer agreement was assessed by using κ statistics.
  
  
  RESULTS
  Forty-two lesions were counted and the mean diameter of overall evaluated lesions was 6.3 cm. One lesion (2.4%) was categorized as type 1, 11 (26.2%) as type 2, 24 (57.1%) as type 3, 3 (7.1%) as type 4, and 3 (7.1%) as type 5. The inter-observer analysis found a κ coefficient of 0.96. All type-1, 90.9% of type-2 and 87.5% of type-3 lesions showed an increased FDG-uptake on PET/CT images. All non-microcystic AE liver lesions (types 4 and 5) showed no abnormal increased FDG-uptake on PET/CT images. The inter-observer analysis at 1 and 3 h found a κ coefficient of 0.95 and 0.92, respectively.
  
  
  CONCLUSIONS
  In patients with AE liver lesions, the absence of microcysts on MRI is strongly correlated to a metabolically inactive disease.
authors: Department of Radiology, University Hospital, 3 Boulevard Fleming, 25030, Besançon, France.
authors: Amel
authors: A
authors: Azizi
authors: Oleg
authors: O
authors: Blagosklonov
authors: Ahmed
authors: A
authors: Lounis
authors: Louis
authors: L
authors: Berthet
authors: Dominique-Angèle
authors: DA
authors: Vuitton
authors: Solange
authors: S
authors: Bresson-Hadni
authors: Eric
authors: E
authors: Delabrousse
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004443:Echinococcosis; D004444:Echinococcosis, Hepatic / Q000175:diagnosis* / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D015588:Observer Variation; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18