Flashcards in Chest X-rays Deck (43)
Describe how x-rays work
An electromagnetic wave of high energy and a very short wavelength
Absorbed to different degrees by different tissues due to density
What colour is gas on an x-ray?
What colour is fat on an xray?
What colour is calcification on an xray?
What is the normal projection of a chest x-ray?
Posterior to anterior on the patient
When would an AP projection CXR be performed?
If the patient was very unwell
Sitting for this
What can't we comment on in AP CXRs?
Size of the heart
Will be enlarge due to being AP
What is the correct inclusion of a chest xray?
Just above the 1st to the costophrenic angles
Past the lateral margins of the ribs
How do we check for rotation in a CXR?
Look at the alignment of the spinous processes and the clavicles
Where do the lungs come down to an a CXR normally?
Between the 5th and 7th anterior ribs at the mid-clavicular line
We ask the patient to breathe in and hold it
What differs on the CXR if the patient gives incomplete inspiration?
Heart looks bigger
Increases lung markings (can see more clearly)
What is the penetration and what is adequate for a CXR?
The degree to which to x-rays have passed through the body
Adequate = vertebrae just visible through the heart and the complete left hemidiaphragm is visible
What is an artifact on a CXR?
External/iatrogenic material which obstructs view
Eg. Buttons, hair, vascular lines, pacemakers
How do we talk about the position of something in the lungs on a CXR?
Talk about zones
Upper, middle and lower
Don't mention lobes unless you are absolutely sure
Describe the things to note/look for when checking the anatomy of a CXR
Trachea - deviated
Hila - left should be slightly higher than right
Diaphragm - sharp angles
Aortic knuckle on the left
Should you be able to see the pleura?
Unless pleural effusion
Describe the systematic approach to CXR evaluation
Comment on projection and adequacy (rotation, inspiration and penetration)
A = airway
B = breathing
D = diaphragm
E = everything else - bones and soft tissues
Check review areas
What are review areas?
Areas that we commonly miss pathology on CXRs
Name the review areas for CXRs
Paratracheal stripe (lymph nodes)
AP window (between aortic arch and pulmonary artery)
Edges of films
What is silhouette sign on a CXR?
Adjacent structures of differing densities form a crisp silhouette
Loss of this contour can locate pathology
'Loss of the silhouette sign'
What things can push the mediastinum away?
What things can pull the mediastinum towards?
Fibrosis of lung
What is a pneumothorax?
Air trapped in the pleural space
What is the most common cause of pneumothorax?
(Laceration of pleura eg from fractured rib)
In people with which diseases is a spontaneous pneumothorax most likely to occur?
How do we define a large pneumothorax?
Lung edge > 2 cm from the inner chest wall at the level of the hilum
What signs do we see of pneumothorax on a CXR?
Area of blackness
Mediastinal shift away
Visible pleural edge
What is a pleural effusion?
Collection of fluid in the pleural space
Describe what you see for a pleural effusion on a CXR
Uniform white areas
Loss of costophrenic angles