Λεξικό .. Bronchiectasis

Bronchiectasis is defined as irreversible dilatation of bronchi, resulting in dilated, usually thick-walled airways typically extending toward the lung periphery Immunodeficiency is prevalent and plays a causative role in some patients with bronchiectasis. Hypersensitivity reactions to Aspergillus, Candida, and other ubiquitous environmental fungi may also play an etiopathogenic role in this disease. Imaging has a key role in the identification of bronchiectasis. Over the years, imaging tests have become increasingly accurate in depicting the features of early bronchiectasis.

CT is the imaging method of choice after standard chest radiography for examining patients with suspected bronchiectasis. In most institutions throughout the world, CT has largely eliminated the need for bronchography in the diagnosis of bronchiectasis. Nonetheless, controversy persists concerning the overall accuracy of CT.[1].

The CT appearance of bronchiectasis varies, depending on the precise orientation of airways relative to the scan plane. Bronchi that course horizontally can be visualized along their length and are recognizable as “tramlines,” whereas vertically oriented airways typically appear as thick-walled, circular lucencies adjacent to branches of the pulmonary artery, resulting in a “signet-ring” appearance. In selected cases, the distribution of these may even suggest specific diagnoses, as for example, central bronchiectasis in patients with allergic bronchopulmonary aspergillosis[1]. Immunodeficiency is prevalent and plays a causative role in some patients with bronchiectasis. Hypersensitivity reactions to Aspergillus, Candida, and other ubiquitous environmental fungi may also play an etiopathogenic role in this disease.

1. McGuinness G, Naidich DP, Leitman BS, McCauley DI. Bronchiectasis: CT evaluation. AJR Am J Roentgenol. 1993 Feb;160(2):253-9.

2. Barker, A.F. et al: Humoral immunity in bronchiectasis. Ann. Allergy 59, No. 3, p. 179. 1987.