An ultrasound measurement method for assessing diaphragm mobility during maximal respiration

This study proposes a new method B-mode ultrasound to assess right hemidiaphragm mobility during maximal respiration in healthy adults. In 29 healthy volunteers, the mean and coefficient of variation of diaphragmatic excursion measured by M-mode and a new B-mode measurements were compared, and their agreement was assessed using the Bland-Altman analysis. Intra-observer and inter-observer agreement were analyzed using intraclass correlation coefficients (ICC) in 15 healthy volunteers. The mean values for diaphragmatic mobility using M-mode and B-mode ultrasound methods were 6.03 ± 1.21 cm and 3.97 ± 0.93 cm, respectively, with coefficients of variation of 0.1103 ± 0.0627 and 0.0772 ± 0.0347. The Bland-Altman plot showed the consistency of the two methods. The ICCs for the first and second M-mode measurements by the senior physician, compared with those by the junior physician, were 0.851 (95% CI: 0.615-0.947), 0.671 (95% CI: 0.177-0.883), and 0.659 (95% CI: 0.168-0.877). For the B-mode ultrasound measurements, the corresponding ICC values were 0.812 (95% CI: 0.533-0.933), 0.832 (95% CI: 0.464-0.945), and 0.701 (95% CI: 0.208-0.896)." Measurements of diaphragmatic excursion using B-mode ultrasound show strong agreement with M-mode ultrasound in healthy volunteers, in addition to demonstrating lower variability and higher reproducibility.