Gastric tumors: radiologic-pathologic correlation and accuracy of T staging with dynamic CT.

Abstract

Incremental dynamic computed tomography (CT) was prospectively performed in 89 patients with gastric tumors (78 gastric cancers, five malignant lymphomas, and six submucosal tumors) after the intake of 400 mL of water, and findings were compared with those obtained at pathologic examination. Dynamic CT of healthy control subjects (15 patients without gastric lesions) showed the gastric wall as a two- or three-layered structure (multilayered pattern): a markedly enhanced inner layer; an intermediate layer of low attenuation; and (sometimes) an outer layer of slightly high attenuation, which corresponded histologically to the mucosal layer, submucosal layer, and muscular-serosal layer, respectively. In 68 lesions that were removed at surgery, the detectability of early and advanced gastric cancers and the accuracy of classification of gross appearance and serosal invasion as determined with CT were 53%, 92%, 80%, and 80%, respectively. All detected advanced gastric cancers were seen as enhanced areas with the destruction of the multilayered pattern. Differentiation between infiltrating gastric cancer (n = 5) and malignant lymphoma (n = 5) was successful. Five of six submucosal tumors were demonstrated as having an overlying intact mucosal layer.

Evaluation of preoperative staging in advanced gastric cancer with MRI

“…Furthermore, the limited spatial resolution often misses tiny metastases [1] . Cho JS suggested that dynamic CT be used to improve the diagnostic accuracy in the preoperative staging of gastric cancer [9] .…”

“…Cho JS suggested that dynamic CT be used to improve the diagnostic accuracy in the preoperative staging of gastric cancer [9] . As endoscopic US is invasive and its performance requires special skills [1] , it is difficult to perform on patients with advanced gastric cancer. For MRI, however, no special preparation is required.…”

“…It is also helpful for patients who have to undergo radiotherapy [8] . There have been many reports about preoperative staging in advanced gastric cancer with CT [1,7,9] and endoscopic US [2,3] . The staging accuracy by CT and US is 42%-69% and 81%-92%, respectively.…”

“…Location was classified according to four areas: Cardia fundus, corpus, antrum and entire stomach. A gastric wall > 1 cm thick was considered abnormal [1,5,6] . According to the criteria [5] proposed by Matsushita M, the degree of serosal invasion observed by MR imaging was classified as MRT-1 (no abnormal findings), MRT-2 (presence of a clear hypointense band or clear fat plane surrounding the lesion) (Figures 1 and 2), MRT-3 (presence of irregular margin or fat signal blurring around the lesion) ( Figures 3 and 4), or MRT-4 (presence of contiguous extention of lesion signal to adjacent organs or definite involvement of adjacent structures), ( Figure 5).…”

“…Nevertheless, computed tomography and ultrasonography are used for diagnosis in patients with known gastric cancer as well as in complementary studies for the evaluation of extraserosal invasion, metastasis to lymph nodes and other organs [1][2][3] . However, there have only been a few studies that have utilized magnetic resonance imaging (MRI) for gastric cancer.…”