Ultrasound imaging measurements to determine reduced diaphragm thickness and relevance to breathing pattern disorders diagnosis in females

Background: Breathing pattern disorders (BPD) are commonly managed by physiotherapists. As no gold-standard assessment diagnostic tools are currently available, diagnosis is challenging. Ultrasound imaging has become popular in physiotherapy. This research examined diaphragm thickness using ultrasound imaging in females with BPD and healthy female controls to ascertain if diaphragm thickness at different measurement points related with reduced diaphragm thickness. Methods: Observational cross-sectional design was used. Two female groups were recruited from an outpatient setting: BPD group (n = 19) and control group (n = 18) with normal body mass index (BMI). BPD inclusion criteria assessment included: Nijmegen Questionnaire (NQ) score, respiratory rate, Hi-Lo test, and breath hold time. USI measured diaphragm thickness at the measurement points of: tidal exhalation (Tvex), tidal inhalation (Tvin), maximum inhalation (Tmax) and exhalation to residual volume (Tmin); diaphragm thickening fraction (TF) was calculated. Results: Results indicated significant differences of diaphragm thickness between the BPD and control groups at Tvex, Tvin, Tmax and TF on the left and Tvex and Tvin on the right side (P < 0.05). Conclusion: Diaphragm thickness is reduced in females with BPD when compared with healthy controls. Diaphragm measurement undertaken by USI may provide a useful assessment tool in BPD. Further research is required to validate this assessment and to broaden its use in BPD.