Inflammation and fibrosis of bronchial walls lead to the appearance of parallel tram track lines. Tram track sign may be used in chest radiography or ct to denote the thickened non tapering parallel walls of cylindrical bronchiectasis.
Bronchiectasis is characterized by irreversible widening of the medium sized airways ectasia.
Tram track bronchiectasis. Gambaran tram track densitas garis paralel densitasberbentuk ring. The term tram tracks is also used to describe the basement membrane duplication found on light microscopy. When found in the lungs tram tracks are radiologic signs that are usually accompanied by pulmonary edema in cases of congestive heart failure and bronchiectasis tram tracks are caused by bronchial wall thickening and can be detected on a lateral chest x ray.
Thin walled cysts i e dilated bronchi forming sacs possibly with air fluid levels late stage bronchiectasis. Overall there appears to be an increase in bronchovascular markings and bronchi seen end on may appear as ring shadows. Bronchus should start tapering as the diameter of the bronchus progressively decreases whereas in the patients with bronchiectasis this tapering is not seen as the bronchial wall is destroyed and dilated see the images below.
It should not be confused with other tram track signs elsewhere in the body. Signs on cxr are the identification of. Mild form shows tram track appearance.
Imaging plays a pivotal role in the diagnosis of bronchiectasis. Tram track opacities are seen in cylindrical bronchiectasis and air fluid levels may be seen in cystic bronchiectasis. Overall there appears to be an increase in bronchovascular markings and bronchi seen end on may appear as ring shadows 8.
However many cases of bronchiectasis are difficult to appreciate with chest radiography. Tram track opacities are seen in cylindrical bronchiectasis and air fluid levels may be seen in cystic bronchiectasis. Cxr is usually the initial study performed in both suspected bronchiectasis and the evaluation of nonspecific respiratory symptoms such as dyspnoea and haemoptysis when bronchiectasis may be identified incidentally.
The three most important mechanisms that contribute to the pathogenesis of bronchiectasis are infection airway obstruction and peribronchial fibrosis. Has parallel tram track lines or. In moderate to severe cases a tram track appearance of parallel and ringlike opacities related to the thickened walls of dilated bronchi and tubular densities related to mucus filled dilated airways can be seen at chest radiography.
Imaging of bronchiectasis bronchiectasis is defined as irreversible dilatation of a portion of the bronchial tree. High resolution computed tomography hrct is the cornerstone in.