Chest radiography cannot predict diaphragm function

• Published in: Respiratory medicine Vol. 99; no. 1; pp. 39 - 44
• Main Authors: Chetta, Alfredo, Rehman, Amer K., Moxham, John, Carr, Denis H., Polkey, Michael I.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2005; Elsevier; Elsevier Limited
• Subjects: Adult; Aged; Biological and medical sciences; Diaphragm; Diaphragm - diagnostic imaging; Diaphragm - physiopathology; Epidemiologic Methods; Female; Humans; Magnetic stimulation; Magnetics; Male; Medical sciences; Middle Aged; Phrenic Nerve - physiopathology; Pneumology; Radiography; Radiology; Respiratory Function Tests - methods; Respiratory Paralysis - diagnosis; Respiratory Paralysis - diagnostic imaging; Respiratory Paralysis - physiopathology; Radiology; Magnetic stimulation; Diaphragm; Radiography; Instrumental stimulation; Radiodiagnosis; Prediction; Magnetic stimulus; Instrumentation therapy; Exploration; Thorax
• ISSN: 0954-6111; 1532-3064
• DOI: 10.1016/j.rmed.2004.04.016

The finding of hemidiaphragm elevation on a chest radiograph, in absence of an ipsilateral lung disease, is assumed to indicate severe hemidiaphragm dysfunction. To test this hypothesis we retrospectively reviewed chest radiograph findings and corresponding twitch transdiaphragmatic pressure ( T W P DI) results from 42 (17 female, age range 22–79 years) consecutive patients who underwent phrenic nerve stimulation studies. Chest radiographs were independently reviewed in a blind manner by two radiologists. The interobserver agreement was moderate, the kappa value ranging from 0.48 (left hemidiaphragm) to 0.59 (lung parenchyma). Hemidiaphragm dysfunction was diagnosed if T W P DI of corresponding hemidiaphragm was less than 3.5 cm H 2O. The prevalence of patients with an elevated unilateral hemidiaphragm on chest radiograph was 64% and of patients with unilateral paralysis judged by T W P DI was 24%. Sensitivity, specificity, positive and negative predictive values for chest radiograph, as a diagnostic test for unilateral diaphragm dysfunction were 0.90, 0.44, 0.33 and 0.93, respectively. We conclude that the isolated elevation of hemidiaphragm on chest radiograph is of little value in the diagnosis of unilateral hemidiaphragm paralysis, though the condition is unlikely if diaphragm elevation is absent.