A study of wall thickness of gastric antrum: comparison among normal, benign and malignant gastric conditions on MDCT scan.

OBJECTIVE To evaluate the normal antral wall thickness on MDCT and to determine the optimal cut-off value for differentiating normal and benign from malignant gastric wall thickening. MATERIAL AND METHOD MDCT scans of 154 patients, 22 malignancies, 66 benign conditions, and 66 normal findings, whose underwent both gastroscopy and MDCT within 30 days were retrospectively reviewed. The degree of gastric distention, antral wall thickness, pattern of wall thickness, and enhancement, the presence or absence of perigastric fat stranding and perigastric lymphadenopathy were evaluated. ROC curve analysis was used to determine the optimal cut-off value of antral wall thickness to differentiate normal and benign from malignant antral wall thickening. RESULTS The antral wall thickness in malignancy, benign and normal groups were 16.64 +/- 7.28 mm, 5.265 +/- 2.21 mm, and 5.68 +/- 2.13 mm, respectively. There was statistically significant difference between the normal and malignant group (p < 0.001) as well as benign and malignant group (p < 0.001). Whereas, there was no significant difference between normal and benign group (p = 0.78). By using a 10 mm-cutoff value, the sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) for prediction of gastric malignancy were 81.8%, 97.7%, 97.0%, 85.7%, and 95.5%, respectively. Most gastric malignancies had diffused irregular gastric antral wall thickening (87.7%), heterogeneous enhancement with obliterated normal gastric wall layering (88.1%), perigastric fat stranding (72.7%), and perigastric lymphadenopathy (72.7%). CONCLUSION Normal antral wall thickness ranges from 1 to 16 mm, depends on degree of antral luminal distention. The authors suggest 10 mm antral wall thickness as the optimal cut-off point for differentiating malignancy and non-malignancy conditions. Moreover the diffuse irregular wall thickening, heterogeneous wall enhancement, presence of perigastric fat stranding and perigastric lymphadenopathy often associate with malignancy. These findings are particularly helpful in interpreting MDCT of patients with inadequate antral luminal distention.