title: The role of diffusion-weighted imaging in the detection of hepatic metastases from colorectal cancer: A comparison with unenhanced and Gd-EOB-DTPA enhanced MRI.
abstract: OBJECTIVE
  To compare the role of DWI vs. gadoxetic-acid-disodium enhanced MRI in the detection of colorectal hepatic metastases.
  
  
  METHODS
  Fifty-four patients with 115 hepatic metastases were included in this retrospective study, approved by the Ethical Board. All patients underwent intraoperative-ultrasound and surgical resection within two weeks after MRI. Images were grouped in 4 sets, which were analyzed by two radiologists in different sessions: unenhanced T1-T2w (set A), set A plus DWI (set B), set A plus gadoxetic-acid-disodium (set C), set A plus DWI plus gadoxetic-acid-disodium (set D). For each set, metastases presence/size/site was reported. Interobserver agreement and statistical significance were assessed by Cohen's kappa and Mc-Nemar's test, respectively.
  
  
  RESULTS
  Readers' agreement was always very good (k>0.80). Mean sensitivity values were 84.3/92.1/95.6/97.3% for set A/B/C/D, respectively. Mean specificity, positive predicted, negative predicted, and accuracy values strongly and progressively increased in the various set too: from 62.5% (set A) to 85.0% as for specificity, from 92.8% to 97.3% as for positive predicted value, from 41.0% to 85.1% as for negative predicted value, and from 81.1% to 95.5% as for accuracy. For each reader from set A to D, the number of false negatives progressively decreases.
  
  
  CONCLUSIONS
  For both readers, DWI improved all statistical parameters in the unenhanced examinations, as for nodules either smaller or greater than 1cm, while in the EOB-enhanced examinations DWI prevalently increased specificity/negative predictive value.
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, Radiodiagnostic Unit n. 2, University of Florence-Azienda Ospedaliero-Universitaria Careggi, Largo Brambilla 3, Florence 50134, Italy. Electronic address: stefano.colagrande@unifi.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Colagrande
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, Radiodiagnostic Unit n. 2, University of Florence-Azienda Ospedaliero-Universitaria Careggi, Largo Brambilla 3, Florence 50134, Italy. Electronic address: ale.andro@hotmail.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Castellani
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, Radiodiagnostic Unit n. 2, University of Florence-Azienda Ospedaliero-Universitaria Careggi, Largo Brambilla 3, Florence 50134, Italy. Electronic address: cosimo.nardi@unifi.it.
authors.forename: Cosimo
authors.initials: C
authors.lastname: Nardi
authors.affiliation: Department of Health Science, University of Florence, viale GB Morgagni 48, Florence 50134, Italy. Electronic address: chiara.lorini@unifi.it.
authors.forename: Chiara
authors.initials: C
authors.lastname: Lorini
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, Radiodiagnostic Unit n. 2, University of Florence-Azienda Ospedaliero-Universitaria Careggi, Largo Brambilla 3, Florence 50134, Italy. Electronic address: linda.calistri@unifi.it.
authors.forename: Linda
authors.initials: L
authors.lastname: Calistri
authors.affiliation: Departement of Neurosciences and Imaging, Section of Radiological Imaging, "G. d'Annunzio" University-Ospedale SS. Annunziata, Via dei Vestini, Chieti 66013, Italy. Electronic address: a.filippone@rad.unich.it.
authors.forename: Antonella
authors.initials: A
authors.lastname: Filippone
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology / Q000556:secondary*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: Colorectal cancer; Diffusion weighted imaging; Focal liver lesion(s); Magnetic resonance imaging; Metastases