Accuracy of transthoracic sonography in detection of pneumothorax after sonographically guided lung biopsy: prospective comparison with chest radiography.

OBJECTIVE: The purpose of this study was to prospectively evaluate the accuracy of transthoracic sonography in the detection of pneumothorax after transthoracic sonographically guided lung biopsy.

SUBJECTS AND METHODS: Transthoracic sonography was performed on 285 patients after transthoracic sonographically guided lung biopsy. Disappearance of the sliding lung and comettail artifacts and appearance of reverberation artifacts were considered evidence of pneumothorax. Upright chest radiography was performed within 30 minutes of transthoracic sonography. If a discrepancy between transthoracic sonographic and chest radiographic findings occurred, CT was performed. When it was diagnosed, pneumothorax was sonographically monitored. After visualization of resolution of pneumothorax, chest radiography was performed to confirm the resolution.

RESULTS: Pneumothorax occurred in eight (2.8%) of the patients. Transthoracic sonography depicted all cases of pneumothorax and excluded pneumothorax in the other cases. Chest radiography did not depict one case of pneumothorax, which was confirmed on CT. Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were all 100% for transthoracic sonography and 87.5%, 100%, 100%, 99.6%, and 99.6%, respectively, for chest radiography. The 95% confidence intervals (CI) of the differences in sensitivity, negative predictive value, and overall accuracy were -10% to 35%, -0.1 to 0.9%, and -0.1 to 0.9%. Transthoracic sonographic visualization of resolution of pneumothorax was always confirmed with chest radiography.

CONCLUSION: These preliminary results suggest that transthoracic sonography is as effective as chest radiography in the detection of pneumothorax after transthoracic sonographically guided lung biopsy and may become the method of choice for excluding, diagnosing, and monitoring pneumothorax after transthoracic sonographically guided biopsy. Chest radiography may be needed only for assessment of the extent of pulmonary collapse after transthoracic sonographic diagnosis of pneumothorax or in the presence of discrepancy between transthoracic sonographic findings and clinical presentation.