RESUMEN
Objective:To analyze the significance and factors influencing of CT scan under the modified Valsalva maneuver. Methods:Clinical data of 52 patients with hypopharyngeal carcinoma diagnosed from August 2021 to December 2022 were collected, all patients had calm breathing CT scan and modified Valsalva maneuver CT scan. Compare the exposure effect of the aryepiglottic fold, interarytenoid fold, postcricoid area, piriform fossa apex, posterior hypopharyngeal wall, and glottis with each CT scanning method. The effects of age, neck circumference, neck length, BMI, tumor site, and T stage on the exposure effect were analyzed. Results:In 52 patients, 50 patients（96.15%） completed CT scan at once time. The exposure effect of the CT scan under modified Valsalva maneuver in the aryepiglottic fold, interarytenoid fold, postcricoid area, piriform fossa apex, posterior hypopharyngeal wall was significantly better than CT scan under calm breathing（Z=-4.002, -8.026, -8.349, -7.781, -8.608, all P<0.01）, while CT scan under modified Valsalva maneuver was significantly worse in glottis than CT scan under calm breathing（Z=-3.625, P<0.01）. In the modified Valsalva CT scan, age had no obvious effect on the exposure effect. The exposure effect was better with long neck length, smaller neck circumference, smaller BMI and smaller T stage. The exposure of postcricoid carcinoma was better than pyriform sinus carcinoma and posterior hypopharyngeal wall carcinoma. But differences were not all statistically significant. Conclusion:The anatomical structure of the hypopharynx was clearly under CT scan with modified Valsalva maneuver, which clinical application is simple, but the effect of glottis was worse. The influence of age, neck circumference, neck length, BMI, and tumor T stage on the exposure effect still needs further investigation.