title: Evaluation of the peritoneal carcinomatosis index with CT and MRI.
abstract: BACKGROUND
  The aim was to determine the incremental value of MRI compared with CT in the preoperative estimation of the peritoneal carcinomatosis index (PCI).
  
  
  METHODS
  CT and MRI examinations of patients with peritoneal carcinomatosis were evaluated. CT images were first analysed by two observers who determined a first PCI (PCICT). Then, the two observers reviewed MRI examinations in combination with CT and determined a second PCI (PCICT+MRI). The sensitivity and negative predictive value of the two imaging sets were determined using surgery as a reference standard (PCIRef).
  
  
  RESULTS
  CT plus MRI was more accurate in predicting the surgical PCI than CT alone. The absolute difference between PCICT+MRIand PCIRefwas lower than that between PCICTand PCIRef(mean(s.d.) 3·96(4·10) versus 4·89(4·73); P = 0·010). The number of true-positive findings increased from 106 to 125 for reader 1 and from 117 to 132 for reader 2 with the adjunct of MRI. For both readers, an increased sensitivity was obtained when both MRI and CT were used (from 63 to 81 per cent for reader 1; from 44 to 81 per cent for reader 2). The increase in sensitivity was greater for patients with a moderate volume of disease.
  
  
  CONCLUSIONS
  The combination of CT and MRI improved the preoperative estimation of PCI compared with CT alone.
authors.affiliation: Department of Body and Interventional Imaging, Hôpital Lariboisière, Assistance Publique - Hôpitaux de Paris (AP-HP), Université Diderot-Paris 7 and Institut National de la Santé et de la Recherche Médicale (INSERM) U965, AP-HP, Paris, France.|Department of Radiology, McGill University Health Centre, Montreal, Quebec, Canada.
authors.forename: A
authors.identifier: http://orcid.org/0000-0002-8732-5603
authors.initials: A
authors.lastname: Dohan
authors.affiliation: Department of Radiology, Hôpital Robert-Debré, Reims, France.
authors.forename: C
authors.initials: C
authors.lastname: Hoeffel
authors.affiliation: Department of Body and Interventional Imaging, Hôpital Lariboisière, Assistance Publique - Hôpitaux de Paris (AP-HP), Université Diderot-Paris 7 and Institut National de la Santé et de la Recherche Médicale (INSERM) U965, AP-HP, Paris, France.
authors.forename: P
authors.initials: P
authors.lastname: Soyer
authors.affiliation: INSERM-Unité Mixte de Recherche en Santé 1138 Team 22, Cordeliers Research Centre, Paris Descartes University, Department of Medical Informatics and Public Health, European George Pompidou Hospital, AP-HP, Paris, France.
authors.forename: A S
authors.initials: AS
authors.lastname: Jannot
authors.affiliation: Department of Radiology, Centre Hospitalier Lyon Sud - Hospices Civils de Lyon, Lyon 1 University, Equipe Mixte de Recherche 3738, Lyon, France.
authors.forename: P-J
authors.initials: PJ
authors.lastname: Valette
authors.affiliation: Department of Radiology, Centre Hospitalier Lyon Sud - Hospices Civils de Lyon, Lyon 1 University, Equipe Mixte de Recherche 3738, Lyon, France.
authors.forename: A
authors.initials: A
authors.lastname: Thivolet
authors.affiliation: Department of Digestive and Oncological Surgery, Centre Hospitalier Lyon Sud - Hospices Civils de Lyon, Lyon 1 University, Equipe Mixte de Recherche 3738, Lyon, France.
authors.forename: G
authors.initials: G
authors.lastname: Passot
authors.affiliation: Department of Digestive and Oncological Surgery, Centre Hospitalier Lyon Sud - Hospices Civils de Lyon, Lyon 1 University, Equipe Mixte de Recherche 3738, Lyon, France.
authors.forename: O
authors.initials: O
authors.lastname: Glehen
authors.affiliation: Department of Radiology, Centre Hospitalier Lyon Sud - Hospices Civils de Lyon, Lyon 1 University, Equipe Mixte de Recherche 3738, Lyon, France.
authors.forename: P
authors.initials: P
authors.lastname: Rousset
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000592:standards; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010534:Peritoneal Neoplasms / Q000175:diagnosis*; D012015:Reference Standards; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000592:standards