PREOPERATIVE ASSESSMENT OF GASTRIC-CARCINOMA - VALUE OF 2-PHASE DYNAMIC CT WITH MECHANICAL IV INJECTION OF CONTRAST MATERIAL

OBJECTIVE. The purpose of this study was to evaluate the utility of tw o-phase dynamic CT performed with mechanical IV injection of a bolus o f contrast medium after oral intake of water in the preoperative stagi ng of gastric cancers. SUBJECTS AND METHODS. We performed incremental dynamic CT in 52 patients with pathologically proved gastric cancers, Dynamic CT findings were prospectively analyzed and correlated with su rgical and histopathologic findings. A total of 150 mi of nonionic con trast medium was administered IV with a power injector at a flow rate of 5 ml/sec for 30 sec, and two-phase images were obtained at 30 sec ( early phase) and 2 min (equilibrium phase) after the start of bolus in jection. RESULTS. Forty-one advanced gastric carcinomas showed a moder ate to marked degree of heterogeneous enhancement in the early phase a nd homogeneous enhancement of the entire lesion in the equilibrium pha se of dynamic CT. The primary tumors were correctly detected with dyna mic CT in five (56%) of the nine early gastric cancers and in 41 (95%) of the 43 advanced gastric cancers, The overall detection rate of gas tric cancers was 88% (46 of 52 cases). The accuracies of dynamic CT ac cording to TNM staging in determining the depth of tumor invasion, the degree of serosal invasion, and regional lymph node metastasis were 6 5% (34 of 52 cases), 83% (38 of 46 cases), and 70% (32 of 46 cases), r espectively. CONCLUSION. Our findings show that two-phase incremental dynamic CT with mechanical IV injection of a bolus of contrast medium after oral intake of water improves the diagnostic accuracy of CT over that provided by conventional CT in the preoperative staging of gastr ic cancers.