HRCT Chest Findings in Bronchitis

Direct Airway Abnormalities

The American College of Radiology recommends that bronchial wall thickening, present in 57-62% of cases, is the most common and significant finding in bronchitis patients on HRCT, and can be quantitatively measured, showing significant association with cough symptoms in patients with chronic airway disease 1, 3
Bronchial wall thickening may appear as diffuse thickening along visible airways, and is neither highly sensitive nor specific for bronchitis alone, as it can be seen in multiple airway diseases 4

Air trapping is a critical indirect finding that appears as a mosaic attenuation pattern on expiratory CT scans, present in 31-35% of bronchitis cases, and indicates functional small airway obstruction even when airways appear structurally normal 1, 5, 6
Additional indirect features include subsegmental atelectasis, ground-glass opacities, and bronchiolectasis, which are more prevalent in patients with concurrent chronic rhinosinusitis 1, 5, 6

Expiratory imaging is essential because many bronchiolar abnormalities are only visible on expiratory cuts, and air trapping and mosaic attenuation require expiratory phase imaging for detection 5, 6
HRCT limitations include inability to visualize normal bronchioles, and clinically significant disease may exist despite normal HRCT findings 5, 6

HRCT findings correlate with clinical severity, with bronchial wall thickening showing quantitative association with cough symptoms, and centrilobular nodules, atelectasis, and ground-glass opacities more prevalent in patients with concurrent chronic rhinosinusitis 1, 3
HRCT may be normal or noncontributory in many symptomatic patients, and should be reserved for specific indications rather than routine screening 3

The American College of Radiology recommends reserving HRCT for patients failing empiric treatment, symptoms persisting beyond 8 weeks, indeterminate chest radiograph findings, and clinical suspicion of structural abnormalities like bronchiectasis 2, 6, 7
HRCT can detect bronchiectasis, bronchial wall thickening, and other findings missed by standard chest radiography in up to 34% of cases 1, 2, 7