Radiological signs of collapse Direct Displacement of interlobar fissures Loss of aeration Vascular or bronchial crowding
Radiological signs of collapse Indirect Elevation of hemidiaphragm Mediastinal displacement Hilar diaplacement Compensatory hyperinflation
Frontal and lateral chest radiographs. The cause of the collapse is a bronchogenic carcinoma; the endobronchial component is visible as an abrupt cut-off of the left main bronchus. There is marked displacement of the right lung anteriorly and posteriorly across the midline (arrows). Note the marked anterior hyperlucency of the thorax on the lateral view.
Herniation of both retrosternal lung and azygo- esophageal reflection.
Complete collapse of the left lung. The tip of the endotracheal tube is beyond the carina and down the right bronchus, causing collapse of the left lung and compensatory hyperinflation of the right lung which has herniated across the midline.
Total right lung collapse in a neonate. The patient was ventilated for respiratory distress syndrome and the cause of the total lung collapse was a mucus plug
Signs in collapse Shifting granuloma sign: change in position of the granuloma d/t hyperinflation
Luftsichel sign: overinflated segment of the ipsilateral lower lobe occupies the space between the mediastinum and the medial aspect of the collapsed upper lobe resulting in a paramedian translucency. This sign is commoner on the left side.
Juxtaphrenic peak sign: upper lobe collapse (both upper and middle lobe on the right side) causes a small triangular density at the highest point of the dome of diaphragm d/t traction and reorientation of inferior accessory fissure.
Golden S sign: the combination of collapse and mass centrally results in a focal convexity with a concave outine peripherally (sign is useful only for right upper lobe and bilateral lower lobe)
CT equivalent of Golden S sign: concavity of fissure with adjacent convexity (useful in all lobes), highly suggestive of bronchogenic carcinoma.
CT mucus bronchogram sign: on contrast enhanced CT there are low attenuation areas within the high attenuation collaped lung representing inspissated secretions in airways.
Superior triangle sign: triangular density to the right of mediastinum seen in right lower lobe collapse d/t displacement of anterior junctional structures.
Combined right middle and right lower lobe collapse. On the frontal view the increased density extends to the right costophrenic angle. On the lateral view the increased density also extends from the anterior to the posterior chest wall. The cause in this case was a bronchogenic carcinoma obstructing the bronchus intermedius
Bilateral lower lobe collapse. Bilateral triangular densities are seen with obscuration of the medial portions of the hemidiaphragm s. The cause was mucous plugging
Consolidation Defined as the decreased volume of air in the lung, with normal lung volume.
Common causes Pnemonia Cardiogenic/non cardiogenic pulmonary edema Hemorrhage Aspiration Neoplasms like alveolar cell carcinoma Alveolar proteinosis
Air bronchogram sign: It is produced by the radiographic contrast between the column of air in airway and the surrounding opaque acini.