Contribution of diffusion weighted MRI to diagnosis and staging in gastric tumors and comparison with multi-detector computed tomography

Abstract

BackgroundDiagnostic 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.Patients and methodsWe 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.ResultsSensitivity 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%.ConclusionsThe 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.

Magnetic Resonance Imaging With Diffuse Weighted Imaging and Computed Tomography With Intravenous Contrast in Staging of Disseminated Ovarian, Stomach, Colorectal Cancer

“…Compared with other studies of the efficacy and relative efficacy of DWI/MRI in colorectal cancer [10,11], ovarian cancer [12,13] and stomach cancer [14,15], similar results are obtained, illustrating the reproducibility of the experiment regardless of the treatment center used, study protocols, and subjective evaluation of PCI ranking results. The obtained results allow us to recommend DWI/MRI for pre-operative staging at all three investigated localizations of the tumour process.…”

Imaging strategies in the management of gastric cancer: current role and future potential of MRI

“…An overview of the current literature on MRI with reported or calculated predictive values, sensitivity, specificity and accuracy for the assessment of nodal involvement is shown in T able 3. [30][31][32][33]35,38,40,41,43,44,[69][70][71][72][73] All 15 studies were prospective in nature and used histopathology as reference standard. As with other imaging modalities, size was the most frequently applied criterion on MRI to diagnose metastatic lymph nodes.…”

“…In total, 18 prospective studies describing the diagnostic performance of MRI in determining tumor detection and stage are described in Table 1. [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] Data on accuracy, sensitivity, specificity, predictive values, and over-and understaging are included. All studies used histopathology as reference standard.…”

“…In three studies, the readers were informed about the tumor location, which most likely increases the detectability of small and superficial gastric cancers. 30,31,37 In two other studies, it was stated that the readers were blinded for clinical findings, however, it was unclear whether this includes gastroscopy results. 41,45 All other included studies in Table 1 do no not report any information regarding blinding or non-blinding of the readers for gastroscopy results.…”

Comparison of DWI and 18F-FDG PET/CT for assessing preoperative N-staging in gastric cancer: evidence from a meta-analysis

“…Thus, DWI and 18 F-FDG PET/CT were unlikely to take the place of MDCT in the short term for lymph node staging of GC patients. Nevertheless, the higher sensitivity and lower specificity of DWI indicates that DWI and MDCT could be complementary imaging modalities and the combined utilization of the two techniques might improve the accuracy of lymph node staging [ 62 ].…”