Abstract
BACKGROUND: Pneumothorax is a common complication after CT-guided transthoracic lung biopsy. Pneumothorax is most often diagnosed with a conventional chest X-ray after a two-hour observation period. Ultrasound has been shown to be superior to conventional X-rays in diagnosing pneumothorax in some settings and it can be repeated without radiation exposure. PURPOSE: The aim of the study was firstly to explore the sensitivity and specificity of thoracic ultrasound compared to conventional chest x-ray following CT-guided transthoracic lung biopsy, and secondly to investigate the dynamic changes of pneumothorax size using ultrasound. METHODS: This prospective study was conducted at Odense University Hospital in the Department of Radiology. Adult patients undergoing CT-guided lung biopsy were eligible for inclusion. A total of 26 patients were included in the study and were scanned five times in sitting upright and supine positions during the two-hour observation time using the FLUS Protocol. RESULTS: Pneumothorax was diagnosed via chest x-ray in 11 (42%) patients. With the patient in an upright position, the ultrasound had a sensitivity of 63.6% and a specificity of 93.3%. These numbers rose to 72.3% and 100% in the supine position. Monitoring the pneumothoraces showed a slight increase in size during the two hours. CONCLUSIONS: Ultrasound can be used to diagnose pneumothorax after CT-guided lung biopsy. All pneumothoraxes that were identified by ultrasound were detected within the first 30 min. The dynamic changes of pneumothoraxes showed that the size of the pneumothorax did not increase to a level where the patient needed intervention or admittance.