A lung biopsy is a medical procedure used to collect a small sample of lung tissue for examination. Doctors perform this test to diagnose lung diseases, such as lung cancer, infections, or inflammatory conditions. The sample is usually obtained using a thin needle, which is guided by imaging techniques like CT scans to ensure accuracy. After the biopsy, the tissue sample is sent to a laboratory where a pathologist examines it under a microscope. This helps determine the presence of any abnormal cells or diseases. The results can guide treatment options and help doctors understand the patient's condition better.