CT scan is not required for the diagnosis of bronchitis. It is recommended when a change in symptoms suggests a complication, such as pneumonia, pneumothorax, an alternate diagnosis (e.g. thromboembolic disease),  or when lung volume reduction surgery or lung transplantation is needed.
Hyperinflation is the usual finding on chest CT scan.
CT is useful in excluding other underlying pulmonary disease and in preoperative assessment.
Bronchitis CT
Bronchiectasis CT
Lung abscess CT
Bronchitis laboratory tests
Cough CT
Bronchiolitis CT scan
Chronic bronchitis CT
Hemoptysis CT scan