[The diagnostic accuracy and reproducibility of computed tomography with water distention and induced hypotonia in the preoperative staging of gastric tumors].

Thirty-five patients with gastric cancer were preoperatively examined with CT performed in the prone position. Patient preparation consisted in filling the stomach with tap water and i.v. glucagon administration. The CT images were independently reviewed by two radiologists, who staged each tumor according to the TNM classification. The results were compared with surgical and histological findings. The overall accuracy for T staging ranged 74-77%, overstaging 17-23%; understaging was 3%. Diagnostic sensitivity, specificity and accuracy for serosal invasion were 100%, 80%, 85% and 100%, 84% e 88%, respectively, for the two radiologists. The overall accuracy for N staging was 48% and 51% for the two observers, respectively. Considering N1 and N2 as a single group, accuracy ranged 68-77%. The interobserver agreement analyzed by the "K tests" was 80%, with a K index of 60%. CT performed with the patient in the prone position, after preparation with gastric wall hypotony and distension with water, is a valid technique permitting excellent depiction of the gastric wall and providing useful preoperative information to the surgeon.