A noninvasive method for early detection of MNNG-induced gastric cancer of male Wistar rat: ultrasonic study.

Gastric cancer is often diagnosed at advanced stages and there is no accurate method for its screening and diagnosis, especially in small animals. Here, we explain the application of B-mode ultrasound imaging (BMUI) for screening of gastric changes in the rat. Thus, male Albino Wistar rats, weighing 100-120 grams were randomly divided into two groups. The control group rats (n=10) were given water as routine; the remaining (n=90), were given N-methyl-N-nitro-N-nitrosoguanidine (MNNG, 100 μg/mL) in drinking water ad libitum for 40 weeks. Fifteen rats were killed at different time intervals and the others were sacrificed after 55 weeks. The BMUI of the stomach of animals after MNNG administration show some changes compared with the normal groups. Pathologic investigations of the stomach indicate cancer induction at different levels. The sensitivity and specificity of BMUI is 96.6% and 78.78%, respectively. Thus, it is a useful method of diagnosis of gastric cancer in rats.