OBJECTIVETo investigate the diagnostic value of contrast-enhanced ultrasonography (CEUS) in preoperative T-staging of gastric cancer.

METHODSA sulfur hexafluoride-filled microbubble ultrasound contrast agent and a continuous real-time imaging technique of contrast pulse sequencing were used. Normal gastric wall was examined by CEUS in 8 healthy volunteers and the results were compared with the findings on multislice computed tomography. Sixty-two patients with gastric cancer proved by biopsies who received preoperative CEUS examination were involved in this study, and the CEUS result was compared with postoperative pathological findings.

RESULTSThe normal gastric wall presented a one-layer structure in the portal venous phase and a three-layer structure in the arterial and equilibrium phase including a slightly hyper-enhanced inner layer, a hypo-enhanced intermediate layer, and a markedly hyper-enhanced outer layer, which corresponded histologically to the mucosal, submucosal, and muscular-serosal layer, respectively. The accuracy of transabdominal ultrasonography and CEUS in determining the T stage of gastric cancer was 72.9% and 88.1% respectively, and the difference was statistically significant (chi(2)=4.37, P=0.036).

CONCLUSIONSCEUS shows the normal gastric wall as a one- or a three-layer structure, which provides a theory base for CEUS in preoperative T-staging of gastric cancer. CEUS is a useful diagnostic method for preoperative T-staging of gastric cancer.