title: Comparison of FDG-PET/CT and MR with diffusion-weighted imaging for assessing peritoneal carcinomatosis from gastrointestinal malignancy.
abstract: OBJECTIVE
  To assess the accuracy of FDG-PET/CT and MR with diffusion-weighted imaging (MR-DWI) for diagnosing peritoneal carcinomatosis (PC) from gastrointestinal malignancies.
  
  
  METHODS
  Thirty consecutive patients referred for staging of gastrointestinal malignancy underwent FDG-PET/CT and MR-DWI in this retrospective study. Extent of PC was characterised by dividing the peritoneal cavity into three sites in each patient: right and left supramesocolic areas and inframesocolic level (total 90 sites). Presence of PC was confirmed either by surgery (18/30) or by follow-up (12/30).
  
  
  RESULTS
  PC was confirmed in 19 patients (19/30). At a total of 90 sites, 27 showed proven PC. On a patient-based analysis, sensitivity, specificity, PPV, NPV and accuracy were respectively 84%, 73%, 84%, 73% and 80% for PET/CT and 84%, 82%, 89%, 75% and 83% for MR-DWI. On a site-based analysis, overall sensitivity and specificity of PET/CT (63%, 90%) and MR-DWI (74%, 97%) were not statistically different (P = 0.27). In the supramesocolic area, MR-DWI detected more sites involved than PET/CT (7/9 vs. 4/9). The sensitivities of PET and MR were lower for subcentimetre tumour implants (42%, 50%). Interobserver agreement was very good for PET/CT and good for MR-DWI.
  
  
  CONCLUSIONS
  FDG-PET/CT and MR-DWI showed similar high accuracy in diagnosing PC. Both techniques underestimated the real extent of PC because of decreased sensitivity for subcentimetre lesions.
  
  
  CONCLUSIONS
  FDG-PET/CT and MR-DWI showed similar high accuracy for diagnosing peritoneal carcinomatosis. • In the supramesocolic area, MR-DWI could be more sensitive than PET/CT. • Both techniques showed lower sensitivity for subcentimetre lesions. • Interobserver agreement was very good for PET/CT and good for MR-DWI.
authors.affiliation: Department of Nuclear Medicine, Université Paris 13, CHU Avicenne, 125 rue de Stalingrad, 93000, Bobigny, France. michael.soussan@avc.aphp.fr
authors.forename: Michael
authors.initials: M
authors.lastname: Soussan
authors.forename: Gaëtan
authors.initials: G
authors.lastname: Des Guetz
authors.forename: Vincent
authors.initials: V
authors.lastname: Barrau
authors.forename: Vanessa
authors.initials: V
authors.lastname: Aflalo-Hazan
authors.forename: Gabriel
authors.initials: G
authors.lastname: Pop
authors.forename: Ziad
authors.initials: Z
authors.lastname: Mehanna
authors.forename: Edmond
authors.initials: E
authors.lastname: Rust
authors.forename: Thomas
authors.initials: T
authors.lastname: Aparicio
authors.forename: Richard
authors.initials: R
authors.lastname: Douard
authors.forename: Robert
authors.initials: R
authors.lastname: Benamouzig
authors.forename: Philippe
authors.initials: P
authors.lastname: Wind
authors.forename: Véronique
authors.initials: V
authors.lastname: Eder
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D042241:Early Diagnosis; D005260:Female; D019788:Fluorodeoxyglucose F18; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D010534:Peritoneal Neoplasms / Q000175:diagnosis*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18