Luftsichel Sign

[Reasonable Rascal]

http://www.emedicine.com/shared/pub/xrotw/0019.jpg

BACKGROUND

A chest radiograph was obtained in a 74-year-old man to evaluate for progressive dyspnea.

Hint Luft = air; sichel = crescent.

[TJ Carr]

Otay, I'm a idjit :o :o


Other than a x-ray what in the heck should I be looking at:confused: :confused:

How about a x-ray 101 class for us unedjumacted idjits :D :D

[tangent]

looks like a collapsed lung or massive hemothorax...

[Craig]

Basic x-ray 101

air = black

bone = white

fluid / tissue = grey to white


What is lung ? - its air sacks filled with air (ie black) and connectice tissue holding it together (ie white) so a mesh pattern of black and white

The heart and bits in the middle are solid structures filled with blood so looks white.

The trachea is filled with air and comes down from the neck in the midline - or should be in the middle

Lastly look at the bones (white) for any obvious breaks)

For this Chest x-ray

look for symmetry of the lung fields - they should be the same consistency and roughly the same size (allowing for the heart on the left)

the lungs should extend with their white markings all the way out to the edge of the lung fields ie - you should be able to see white/grey lines all the way to the edges

the mediastinum (the heart and bits in the middle) should be sitting nicely in the middle

The air shadow (black) of the trachea coming down from the neck should be in the middle - is it ?

Whats happening here ?

Do the lungs look the same ? same size ? same "colour" ?

Is the mediastinum in the middle ? If its not - its either been pulled over to the side its sitting on (by collapsed lung or something else) or pushed over from the other side (by a large pneumothorax or hyperinflation of a lung)

I tell our students - if you dont know what you are looking at just describe it - and usually things fall into place.

Tangent - Do a collapsed lung and a haemothorax look the same ? What would you expect to see for each ?

How about some more guesses

Craig

[TJ Carr]

Excellent info Craig, thanks much!!!!!

Now I'm not a unedjumacted idjit, but just a idjit
:D :grin:

[Flotsam]

Looks like collapse of the left upper lobe - you can see air around the aortic knob, the area where the LUL usually sits is opaque, but there is normal looking lung at the costophrenic angle at the left bottom, and no blunting of the CP angle - no significant effusion - so not likely massive hemothorax. Trachea is deviated somewhat to the left, most likely from the collapse. As to why it's collapsed...? Maybe a mucous plug in one or the major bronchi? Recent bad pneumonia?

Sam

[Reasonable Rascal]

Congrats to our members, good call!

Answer

Collapse of the left upper lobe: With complete collapse, the left upper lobe retracts medially and superiorly. The superior segment of the left upper lobe hyperextends and produces a crescent of lucency along the mediastinum and aortic knuckle. This crescent of air is termed the luftsichel sign. Other features of left upper lobe collapse are present, including tracheal deviation and elevation of the hilum and the diaphragm.