Ji C, et al. - For predicting difficult airway, the overall accuracy of radiological measurements was assessed. Also, a meta-analysis of published studies was carried out to compare the diagnostic value between the radiological measurements and the modified Mallampati score. Compared with modified Mallampati score, CT, X-ray and US had much better diagnostic value. In predicting difficult airway, ultrasound had diagnostic indices and the area under curve similar to those of CT and X-ray. It can be considered as prior diagnostic strategy in this condition as it is easy, readily available, incur low cost, and free from radiological hazards.