A biopsy remains imperative in diagnosing many pulmonary and pleural lesions, particularly in non-infectious diseases. Traditionally, percutaneous biopsy of the pulmonary or pleural lesions is performed under computed tomography (CT) guidance. However, CT-guided biopsy is associated with radiation exposure, dependence on the radiologist, transport of the patient to the radiology suite and additional cost. Further, iodinated contrast administration may be required in some patients, thus increasing the risk of contrast-induced nephropathy and limiting its use in seriously ill patients with restricted mobility. Also, CT-guided biopsy is not performed in real-time and is affected by respiration or discomfort causing patient movement. In the recent past, ultrasonography (USG) has evolved as an alternative to CT scan for biopsy of peripheral pulmonary and pleural lesions. USG-guided biopsy can be performed at the bedside, is cheaper and has no radiation exposure. USG has become an indispensable tool in the diagnosis and management of various pleural diseases. Recent studies have shown the diagnostic performance of USG-guided closed pleural biopsy is as good as that of medical thoracoscopy – a procedure which is more invasive and considered gold-standard for the evaluation of undiagnosed pleural effusion. Furthermore, USG-guided biopsy is associated with fewer complications, reduced length of hospital stay and can even be performed on out-patient basis. The drawback of USG is that it has a lower-resolution image compared to a CT scan and requires a learning curve. 

Contrast-enhanced ultrasound (CEUS) is a novel technique that involves the injection of an intravenous contrast agent consisting of sulfur hexafluoride (SonoVue; Bracco S.p.A., Milan, Italy) followed by a guided biopsy. CEUS allows for the more accurate detection of vasculature structures and necrotic areas, thus increasing the biopsy yield. Studies have evaluated the utility of CEUS predominantly in the field of gastroenterology and nephrology, but limited research ihas been done in pulmonary medicine. A 3-year prospective study by Wenwen Sun et al. found that CEUS better delineated the internal necrosis and obvious peripheral vessels compared to conventional ultrasound, and the diagnostic accuracy of CEUS-guided biopsy sampling was 98.91% without any serious adverse events. This is supported by a few other reports on CEUS-guided biopsy in pulmonology. To our knowledge, no such report is available from India. Hence, we are conducting this study to find out the overall clinical utility of CEUS compared to conventional ultrasound-guided biopsy in various pleural and pulmonary diseases, especially in the Indian setting.