Radial endobronchial ultrasound (radial EBUS) is a diagnostic procedure used to examine the airway walls and nearby structures using a specialized ultrasound probe on the tip of a bronchoscope. It allows for real-time imaging of the bronchial walls and can aid in the diagnosis and staging of lung cancer, as well as the evaluation of other pulmonary conditions.

Here's an overview of the radial endobronchial ultrasound procedure:

1. Preparation: Prior to the procedure, the patient may receive local anesthesia to numb the throat and reduce discomfort. Conscious sedation or general anesthesia may also be administered to help the patient relax or perform more extensive interventions.

2. Insertion of the radial EBUS bronchoscope: The radial EBUS bronchoscope is inserted through the nose or mouth and guided into the airways. It is equipped with a rotating ultrasound transducer located at the tip of the scope.

3. Imaging and evaluation: Once the radial EBUS bronchoscope is in position, the ultrasound probe is activated, emitting ultrasound waves that create real-time images of the airway walls and surrounding structures. The bronchoscopist can manipulate the bronchoscope to visualize different areas of the airways and obtain detailed images.

4. Biopsy or sampling: In some cases, radial EBUS can be used to guide needle aspirations or biopsies. Specialized tools can be passed through the working channel of the bronchoscope to obtain tissue samples from abnormal areas, lymph nodes, or masses near the airway walls. These samples can be sent for further analysis in a pathology laboratory.

5. Post-procedure care: Following the procedure, the patient is monitored for any immediate complications, such as bleeding or respiratory distress. Patients may experience a sore throat, cough, or mild bleeding, which typically resolve within a short time. Recovery time is usually minimal, and patients can often resume normal activities shortly after the procedure.

Radial endobronchial ultrasound is a valuable tool in pulmonary medicine for evaluating airway walls, identifying lesions or tumors, and assisting in the diagnosis and staging of lung cancer. It is typically performed by a pulmonologist or interventional bronchoscopist who has specialized training and expertise in radial EBUS techniques.