Abstract Objective： To evaluate the diagnostic value of two-phase multidetector-row spiral CT threedimensional reconstruction technique in TNM staging of gastric cancer. Methods： In 29 patients with gastric carcinoma pathologically conformed, plan scans were done firstly. Two-phase spiral CT was performed within one breathhold each. Distension of the stomach was achieved by intravenous application of anisodamine and effervescent granules. After bolus injection of contrast medium, scanning was performed in the arterial and venous phase, and the source images were thin reconstructed. The stomach to three-dimension analysis was constructed by volume rendering （VR） multiplanaz volume reconstruction （MPVR）, shaded surface display （SSD） and CT virtual gastroscopy （CTVG） technique. In combination with the sources images, gastric tumour invasion and lymph node metastasis was assessed, and TNM staging was performed. Results： In 29 cases of gastric carcinoma, the sensitivity and specificity of two-phase multidetector-row spiral CT three-dimensional reconstruction technique in T1, T2, T3 and Ta staging, the sensitivity and specificity was 50% and 50%, 87.5% and 77.8%, 83.3% and 76.9% and 100% and 80% respectively. For the N staging, the sensitivity and specificity in No, N1, and N2 N3 was 83.3% and 71.4%, 87.5% and 77.8% and 81.8% and 75% respectively. The sensitivity and the specificity for M1 staging was 100%. Conclusion： The reconstruction technique in combination with 16-slices spiral-CT can perform TNM staging well and effectively guide the choice of the surgical procedures for gastric cancer.
