26. Everyone knows the causes but also the effects of effusions. It is an aggressive effusion in this case. Which effect is further demonstrated here? Tension effusion
(analogous to tension pneumothorax) shifts the mediastinum to the left; most recognizable by the contrast-enhanced ascending aorta, which is usually right of the midline. Total atelektasis of the lungs.

Agressive effusion
Bild 26
What are the black ties within the compressed lung?
(Click here for the answer)

Air containing airways = positive aerobronchography.

27. Can we see signs of "positive aerobronchography" in other entities? We may detect this sign most commonly in cases of pneumonia; in an estimated half of all pneumoniae. -

It is pneumonia in this case.
But the phenomenon is also found in the compression-atelektasis as shown in case study number 26. It is not found in obturation-atelektasis as it is produced by a bronchial carcinoma). In this patient we find a shadow (X-ray diagnosis) produced by a pneumonia (pathological diagnosis).

Bild 27
Why does "positive aerobronchography" sometimes consist partly of “black” points and partly in “grey” ties?
(Click here for the answer)

Black dots are bronchi running in the direction of radiation; dark grey stripes are bronchi taken from a vertical (perpendicular) perspective.

Pneumothorax tension
Bild 28
Back to the main topic: pneumothorax and/or effusion? Both are sometimes of little clinical significance. Should it be neglected here?
(Click here for the answer)

No. In this case it is an emergency. "Pneu" and effusion become dangerous if they shift the heart and/or mediastinum! Here is a tension pneumothorax: significant enlargement of the left chest cavity, total collapse of the lung and (until now) only moderate dislocation of the heart and mediastinum to the right. Can increase soon! Emergency!

compression atelektasis
Bild 29
Repetition: CT shows you an effusion. Can you pick out all of the three x-ray signs, that have already been discussed: "Atelektasis", "Aerobronchography" and "Mediastinal-shift"?
(Click here for the answer)

Yes we can! Despite a small adhesion of the pleurae the lung has collapsed. This compression atelektasis shows typical aerobronchography. The position of bifurcation helps to decide whether the effusion is space-occupying.

30. Insert of one "non pleural case”. The pathological picture is below. Here we are unable to make a pathological diagnosis, as we know too little. Therefore we can only make a diagnosis based on the X-ray.
Total shading of the left lung. Mediastinum and heart are warped towards the sick side; most obvious is the distortion of the trachea. That is only an X-ray diagnosis.

Bronchial obstruction atelektasis
Bild 30
What could be hidden behind this?
(Click here for the answer)

It is total  atelektasis. This is strongly supported by a high stand of diaphragm in sonography and the exclusion of effusion.