title: Contribution of diffusion weighted MRI to diagnosis and staging in gastric tumors and comparison with multi-detector computed tomography.
abstract: BACKGROUND
  Diagnostic performance of Diffusion-Weighted magnetic resonance Imaging (DWI) and Multi-Detector Computed Tomography (MDCT) for TNM (Tumor, Lymph node, Metastasis) staging of gastric cancer was compared.
  
  
  METHODS
  We used axial T2-weighted images and DWI (b-0,400 and b-800 s/mm2) protocol on 51 pre-operative patients who had been diagnosed with gastric cancer. We also conducted MDCT examinations on them. We looked for a signal increase in the series of DWI images. The depth of tumor invasion in the stomach wall (tumor (T) staging), the involvement of lymph nodes (nodal (N) staging), and the presence or absence of metastases (metastatic staging) in DWI and CT images according to the TNM staging system were evaluated. In each diagnosis of the tumors, sensitivity, specificity, positive and negative accuracy rates of DWI and MDCT examinations were found through a comparison with the results of the surgical pathology, which is the gold standard method. In addition to the compatibilities of each examination with surgical pathology, kappa statistics were used.
  
  
  RESULTS
  Sensitivity and specificity of DWI and MDCT in lymph node staging were as follows: N1: DWI: 75.0%, 84.6%; MDCT: 66.7%, 82%;N2: DWI: 79.3%, 77.3%; MDCT: 69.0%, 68.2%; N3: DWI: 60.0%, 97.6%; MDCT: 50.0%, 90.2%. The diagnostic tool DWI seemed more compatible with the gold standard method (surgical pathology), especially in the staging of lymph node, when compared to MDCT. On the other hand, in T staging, the results of DWI and MDCT were better than the gold standard when the T stage increased. However, DWI did not demonstrate superiority to MDCT. The sensitivity and specificity of both imaging techniques for detecting distant metastasis were 100%.
  
  
  CONCLUSIONS
  The diagnostic accuracy of DWI for TNM staging in gastric cancer before surgery is at a comparable level with MDCT and adding DWI to routine protocol of evaluating lymph nodes metastasis might increase diagnostic accuracy.
authors.affiliation: YuzuncuYil University DursunOdabas Medical Center, Department of Radiology, Van, Turkey.
authors.forename: Harun
authors.initials: H
authors.lastname: Arslan
authors.affiliation: Van Training and Research Hospital, Department of İnternal Medicine, Van, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Fatih Özbay
authors.affiliation: Van Training and Research Hospital, Department of General Surgery, Van, Turkey.
authors.forename: İskan
authors.initials: İ
authors.lastname: Çallı
authors.affiliation: YuzuncuYil University DursunOdabas Medical Center, Department of Medical Oncology, Van, Turkey.
authors.forename: Erkan
authors.initials: E
authors.lastname: Doğan
authors.affiliation: YuzuncuYil University DursunOdabas Medical Center, Department of General Surgery, Van, Turkey.
authors.forename: Sebahattin
authors.initials: S
authors.lastname: Çelik
authors.affiliation: YuzuncuYil University DursunOdabas Medical Center, Department of Radiology, Van, Turkey.
authors.forename: Abdussamet
authors.initials: A
authors.lastname: Batur
authors.affiliation: YuzuncuYil University DursunOdabas Medical Center, Department of Radiology, Van, Turkey.
authors.forename: Aydın
authors.initials: A
authors.lastname: Bora
authors.affiliation: YuzuncuYil University DursunOdabas Medical Center, Department of Radiology, Van, Turkey.
authors.forename: Alpaslan
authors.initials: A
authors.lastname: Yavuz
authors.affiliation: YuzuncuYil University DursunOdabas Medical Center, Department of Radiology, Van, Turkey.
authors.forename: Mehmet Deniz
authors.initials: MD
authors.lastname: Bulut
authors.affiliation: YuzuncuYil University DursunOdabas Medical Center, Department of Radiology, Van, Turkey.
authors.forename: Mesut
authors.initials: M
authors.lastname: Özgökçe
authors.affiliation: YuzuncuYil University DursunOdabas Medical Center, Department of Radiology, Van, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Çetin Kotan
keywords: MDCT; diffusion weighted imaging; gastric cancer; staging