MRI in staging advanced gastric cancer: Is it useful compared with spiral CT?

Purpose: During the last decade, rapid progress has been made in MR technol ogy. Our objective was to evaluate the role of MRI in staging advanced gast ric cancer (AGC; gastric cancer invading the muscularis propria) and to com pare it with that of spiral CT. Method: We prospectively performed both MR and CT examinations on 26 patien ts with AGC proven by endoscopic biopsy. Contrast-enhanced CT and nonenhanc ed MRI with a 1.0 T scanner using FLASH, HASTE, and true-FISP sequences wer e obtained in each patient after injection of antiperistaltic drug and inge stion of 1 L of tap water. Fifty-two sets of CT and MR images were analyzed by two radiologists in consensus without any information from other images . T and N staging of AGC was determined according to the TNM classification . All patients underwent surgery within 1 week after both examinations. Dia gnostic accuracy of each staging of AGC on CT or MRI was evaluated by compa rison with the pathologic results. Results: MRI was slightly superior to CT in T staging (81 vs. 73%, respecti vely; p < 0.05). Although MRI had a tendency to overstage the pathologic T2 cancer, positive predictability of T2 stage and sensitivity of T3 stage we re high (100%, respectively). Regarding the N staging, CT was slightly supe rior to MRI (73 vs. 65%; p > 0.05). However, both CT and MRI demonstrated t he tendency of understaging in N staging. Conclusion: Although MRI was superior to spiral CT in T staging, MRI cannot completely replace spiral CT in staging AGC because of its limitation in N staging.