Imaging of the patient with chronic bronchitis: an overview of old and new signs.

Up to now, neither chest radiograph nor high-resolution computed tomography (HRCT) has much to offer to the diagnosis of patients with chronic bronchitis (CB). A lot of HRCT findings can be observed, but they cannot be regarded as specific for pure CB. Their evaluation is often subjective, and measurements are poorly reproducible. In order to better characterise the HRCT features of CB, further efforts are warranted. The finding of bronchial wall thickening may even be considered nonsensitive as well as nonspecific. CB should not only be equated with narrowing of the airway since thickness of the bronchial wall may vary among different stages of development. Small pits can often be detected along the inner surfaces of the large bronchi in patients with CB using volumetric thin-section CT. Sometimes, multiple pits give rise to the accordion-like appearance that was described using bronchography. In our experience, they often occur in patients with long-lasting CB. A better comprehension of the large airways abnormalities is important because it is likely that the same pathophysiologic process that causes small-airway obstruction also takes place in larger airways, where it has less functional effect.