[Diaphragm kinetics coupled with spirometry. M-mode ultrasonographic and fluoroscopic study; preliminary results]

Most techniques used so far for the evaluation of diaphragm kinetics are either invasive (electromyography, fluoroscopy), or indirect (respiratory pressures, impedance plethysmography). The aim of this study was to determine whether assessment with ultrasound or fluoroscopy differed, and which technique appeared more suitable in the investigation of quantitative hemidiaphragmatic displacement. Six patients (3 female, 3 male, aged 29 to 40) without respiratory disease were studied during systematic X-Ray chest examination, spirometry, and abdominal sonography. The amplitude of the right diaphragm motion could be measured in all patients with M-mode sonography as well as with fluoroscopy. The vertical ascending motion of the diaphragm measured by M-mode sonography, reached 60% of its maximum amplitude at 50% of inspiratory capacity. There was a significant correlation between the maximum amplitude of diaphragm motion as measured by M-mode sonography (5.8 +/- 0.4 cm; r = 0.89; p = 0.019) or fluoroscopy (5.6 +/- 0.7 cm; r = 0.84; p = 0.036) and the inspiratory capacity (2.73 +/- 0.39 l). M-mode sonography has technical, quantitative and qualitative advantages over fluoroscopy and should be the method of choice in the investigation of suspected diaphragmatic movement disorder. When coupled with other techniques like spirometry, this technique could represent a useful adjunct to functional respiratory studies.