Comparison of Ultrasonographic Renal Excursion to Fluoroscopic Diaphragmatic Excursion for the Assessment of Diaphragmatic Function in Patients with High Cervical Cord Injury

Objective: To compare the renal excursion detected by ultrasonography with the diaphragmatic excursion recorded by fluoroscopy in estimating the diaphragmatic function in patients with high cervical cord injury. Design: Prospective, blinded comparative study. Setting: A rehabilitation hospital affiliated with a medical university. Participants: Fifteen consecutively admitted patients with high cervical cord injury. Interventions: Not applicable. Main Outcome Measures: Chest radiographs, fluoroscopy of diaphragmatic motion, and ultrasonography of renal motion. Result: Of the 15 patients, 2 were diagnosed with hemidiaphragm paralysis using fluoroscopy and renal ultrasonography. The average diaphragmatic excursion was 59mm (range, 30-83mm) in 28 nonparalyzed hemidiaphragms. The average renal excursion was 49mm (range, 28-61mm). The correlation coefficient for fluoroscopic hemidiaphragm excursion and ultrasonographic renal excursion was .853. Conclusion: Ultrasonographic renal excursion and fluoroscopic diaphragmatic excursion correlated highly. With the fluoroscopy results as the criterion standard, the diagnostic sensitivity and specificity were both 100% for renal sonography. With the advantages of convenience of use, no radiation exposure, and high reproducibility, renal ultrasonography is recommended as a first-line screening and long-term follow-up tool for assessment of diaphragmatic function.