Bronchiectasis can be diagnosed through several methods. The first step is to obtain a detailed medical history, which may include a potential cause of bronchiectasis. Simply listening to the breathing may provide initial information.
HRCT or a high-resolution computed tomography scan is the most common and reliable way to check for bronchiectasis. This noninvasive test takes pictures of the airways and other structures in the chest to assess the extent of lung damage. It will show if one or both lungs are affected and in what areas.
Chest X-rays may also provide information, but the pictures are not as detailed as those of CT scans and may not reveal up to 50% of bronchiectasis cases. Therefore, chest X-rays are not considered the standard of care for diagnosis.
Blood tests may reveal an underlying medical condition, described above, that can lead to bronchiectasis. Blood tests can also help to determine whether an infection exists.
A physician might order a sputum culture. Laboratory analysis of the culture can determine the presence of bacteria or fungi that cause infections associated with bronchiectasis. The diagnostic test for NTM is very specific and differs from a routine culture and sensitivity. The sputum test for NTM is an acid fast bacilli (AFB) test.
Lung function tests, such as spirometry, measure lung size and airflow, that is, how much air can be breathed in and out and how well the lungs deliver oxygen to the blood. These tests help show the extent of lung damage. These tests might be ordered to diagnose lung and airway diseases, compare lung function to expected levels of function, monitor whether the disease is stable or worsening, and determine the effectiveness of treatment. These tests do not diagnose bronchiectasis but are an important measure in an overall assessment of lung health.
A bronchoscopy might be performed if a patient does not respond to treatment or a diagnosis is uncertain. This procedure looks inside the lung airways. It involves inserting a bronchoscope tube with a light and small camera through the nose or mouth, down the throat into the trachea (windpipe), and to the bronchi and bronchioles of the lungs. Bronchoscopy can show whether a blockage exists in the airways and whether sputum specimens should be collected for laboratory testing.