Evaluation of endoscopic ultrasound image quality is necessary in endosonographic assessment of early gastric cancer invasion depth

We evaluated whether endoscopic ultrasonography (EUS) image quality affects the accuracy of diagnosing the vertical invasion depth of early gastric cancer (EGC). A total of 75 lesions in 75 patients suspected of having EGC were enrolled. All patients underwent EUS examination. Findings of EUS were compared with histopathologic results. We evaluated the effect of the following clinicopathologic factors: location, diameter, surface pattern, concomitant ulceration, histology type, and EUS image quality score. EUS image quality was scored based on detection repeatability, appropriate probe placement, and clarity of the five gastric wall layers including the lesion. Sixty-three lesions (84) were pathologically mucosal and 12 lesions (16) were submucosal cancer. Overall accuracy was 82.7. Significantly more lesions in the upper and middle portions of the stomach were incorrectly diagnosed than in the lower portion (P = 0.0019). Lesion diameter was significantly larger among incorrectly diagnosed lesions (P = 0.0257). Low-quality images were significantly more often associated with incorrectly diagnosed lesions than with correctly diagnosed lesions (P = 0.0001). Multivariate analysis revealed that EUS image quality was associated with EUS staging accuracy (odds ratio, 21.8; 95 confidence interval, 4.5137.6). Low-quality EUS images led to an incorrect diagnosis of invasion depth of EGC, independent of tumor location or size.