ObjectiveTo study the Young's modulus obtained by the real-time shear wave elastography (SWE) in healthy adults' parotid gland and submaxillary gland and to explore the probable factors affecting the Young's modulus, such as bilateral parotid and submaxillary gland, sex, age, height and weight. MethodsThere were 35 healthy volunteers who underwent SWE in parotid gland and submaxillary gland between December 3 and 18, 2013. The difference of Young's modulus in bilateral parotid and submaxillary gland, and the modulus values of different sex, age, height and weight groups were also compared. ResultsThe Young's modulus of parotid gland was (8.14±1.78) kPa, and the Young's modulus of submaxillary gland was (11.52±2.34) kPa. The differences of Young's modulus between the two sides of parotid gland and submaxillary gland were not statistically significant (P>0.05); the differences of Young's modulus of parotid and submaxillary gland between different sex, age, height and weight groups had no statistical significance, either (P>0.05). ConclusionThe real-time shear wave elastography can be applied to evaluate the elasticity of parotid and submaxillary gland and to lay the foundation for further diagnosis of salivary lesions.
Objective To explore the application value of shear wave elastography (SWE) combined with diaphragmatic thickening fraction (DTF) and rapid shallow breathing index (RSBI) in predicting the results of weaning of patients with mechanical ventilation. Methods Fifty-two patients with severe illness who were hospitalized in this hospital from January 2022 to September 2022 were treated with mechanical ventilation. After meeting the conditions for weaning, they underwent spontaneous breathing test, and the diaphragm function of patients was evaluated by measuring DTF using ultrasound technology and shear modulus (SM) using SWE technology. According to the weaning results, they were divided into weaning success group and weaning failure group, The differences of mechanical ventilation time, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score, respiratory rate, RSBI, oxygenation index, DTF, SM and other parameters between the two groups were compared. Multivariate logistic regression was used to analyze the factors affecting the withdrawal results. The receiver operator characteristic (ROC) curve was used to evaluate the predictive value of potential influencing factors on the withdrawal results. Results There were 39 cases of successful withdrawal and 13 cases of failure. There were significant differences in mechanical ventilation time, respiratory rate, RSBI, DTF and SM between the successful weaning group and the failure group (P<0.05). Through multivariate logistic regression analysis, RSBI [area under the ROC curve (AUC)=0.771, 95% confidence interval (CI) 0.589 - 0.953], DTF (AUC=0.806, 95%CI 0.661 - 0.951), SM (AUC=0.838, 95%CI 0.695 - 0.981) were independent factors that affected the results of withdrawal. The single parameter AUC was smaller than the combined index with RSBI≤70.48 times·min–1L–1, DTF≥30.0%, SM≥10.0 kPa as the cutoff value (AUC=0.937, 95%CI 0.714 - 1.0, diagnostic sensitivity, specificity and accuracy were 94.9%, 84.6% and 92.3% respectively). Conclusions SWE technology provides a new quantitative index for evaluating diaphragm function by evaluating diaphragm stiffness. Diaphragm stiffness combined with DTF and RSBI can better predict the successful withdrawal in patients with mechanical ventilation.