Ultrasonographic evaluation of diaphragmatic motion

To evaluate the technical feasibility and utility of ultrasonography in the study of diaphragmatic motion at our institution.

The study consisted of 2 parts. For part I, in 23 volunteers we performed 23 studies on 46 hemidiaphragms with excursions documented on M-mode ultrasonography For part II, in 22 patients we performed 52 studies in 102 hemidiaphragms. In 50 studies both hemidiaphragms were studied, and in another 2 studies only 1 hemidiaphragm was studied. Patients' ages ranged from birth to 66 years (mean, 23 years). There were 16 male and 6 female patients. Indications for the study were (1) suggestion of paralysis of the diaphragm (n = 22); (2) if the diaphragm was already known to be paralyzed, for evaluation of response to phrenic nerve or pacer stimulation (n = 9); and (3) follow-up of previous findings (n = 21). Patients were examined in the supine position in the longitudinal semicoronal plane from a subcostal or low intercostal approach. Motion was documented with real-time ultrasonography and measured with M-mode ultrasonography.

Of the 102 clinical hemidiaphragms studied, findings included normal motion (n = 42), decreased motion (n = 22), no motion (n = 6), paradoxical motion (n = 10), positive pacer response (n = 13), negative pacer response (n = 2), positive phrenic stimulation (n = 6), and negative phrenic stimulation (n = 1). There were no failures of visualization.

Ultrasonography proved feasible and useful in evaluating diaphragmatic motion. In our practice it has replaced fluoroscopy. Ultrasonography has advantages over traditional fluoroscopy, including portability, lack of ionizing radiation, visualization of structures of the thoracic bases and upper abdomen, and the ability to quantify diaphragmatic motion.