PURPOSE: To evaluate whether the accuracy of invasion depth assessment in gastric carcinoma in vitro can be improved with high-resolution spatial compound sonographic imaging. MATERIALS AND METHODS: In sixteen fresh gastric specimens obtained from patients with preoperatively biopsyproven gastric carcinoma, normal and lesional areas were scanned using conventional and compound imaging technique with a 15-MHz linear transducer. Two radiologists independently compared the sharpness and the contrast of images obtained with two different modes and determined the layers invaded by cancer with consensus. The invasion depths by images were compared with histopathologic results. RESULTS: The sharpness and the contrast in normal and lesional areas were significantly higher in compound imaging (p<0.01) than those in conventional imaging and interobserver agreement was over moderate, with kvalue of 0.41 to 0.86. But the accuracy in invasion depth assessment was 68.8% (11/16) on conventional imaging and 75% (12/16) on compound imaging and not different significantly between two modes (p>0.05). CONCLUSION: High-resolution spatial compound sonographic imaging has improved image quality, compared with conventional imaging, but the accuracy of invasion depth assessment in gastric carcinoma was not significantly different.