Chest X-Rays Flashcards
Which view is the standard one?
PA
In which view does the heart appear larger?
AP
How do you know if the exposure is normal?
Can just see the vertebrae through the heart
What is the alphabet approach for looking for things on a CXR?
A - airway B - bones C - circulation D - diaphragm E - extra-thoracic F - fields
What do you look for in A?
Airways Is the trachea central? Can it be seen all the way down? Look at bronchi and left and right hilar Left is normally higher than right.
What do you look for in B?
Bones
- fractures
- notches
- dislocations
What do you look for in C?
Circulation
- cardio thoracic ratio
- aortic arch - location, aortic-pulmonary window (aortic knob)
- pulmonary vessels and hila
- right heart border (right atrium), left heart border (left ventricle)
What do you look for in D?
Diaphragm
- air underneath it?
- raised?
What do you look for in E?
Extrathoracic
- shoulder joints
- air under skin
What do you look for in F?
Fields of lungs
- equal on both sides?
- any masses?
- consolidation?
- vascular markings?
- collapse?
From where should vascular markings not be visible?
Should not be visible in the lateral third
Which bronchus do inhaled objects usually go down?
The right
When are lung fissures seen more clearly?
If there is fluid eg pleural effusion
What are a few extra points you should look for?
Lung fissures
Rotation
Silhouette sign
How do you check for rotation?
Look at difference between central end of clavicle and centre of trachea. Should be equal on both sides
What is the silhouette sign?
When adjacent structures of different density form a crisp silhouette. Loss of the contour can locate a pathology.
What are the borders that can be lost and what does this mean?
Right heart border - right middle lobe affected
Left heart border - lingula
Paratracheal stripe - mediastinal disease
Chest wall - lung/pleura/rib affected
Aortic knuckle - anterior mediastinum or upper lobe
Diaphragm - lower lobe
Horizontal fissure - anterior segment of upper lobe
What is the lingula?
Part of the left lower lobe which wraps itself over the left ventricle
What is a pleural effusion?
Collection of fluid in the pleural space
What is seen in a pleural effusion on a CXR?
White area and loss of costophrenic angle
Hemidiaphragm can be obscured
Get a meniscus of the upper border
Difficult to pick up in a supine CXR
What is a pneumothorax?
Presence of air/gas in the pleural space, causing lung collapse
Features of a pneumothorax on a CXR?
‘Large’ if lung is more than 2cm away from inner chest wall
Mediastinal shift away from the affected lung
Depressed hemidiaphragm
Visible pleural edge, lung markings not visible beyond this edge
Common causes of a pneumothorax?
Trauma with laceration of the visceral pleura by a fractured rib
What is consolidation?
Filling of the alveoli/small airways with anything that isn’t air eg
- pus (pneumonia)
- blood (haemorrhage)
- fluid (oedema)
- cells (cancer)
What is a space-occupying legion?
A mass in the lung
-nodule if 3cm
Causes of lesions in the lung?
Malignancies (primary or metastasis)
Benign mass lesion
Inflammatory
Congenital
What can lesions mimic?
A bone lesion
Cutaneous lesion
Nipple shadow
What is lobar collapse? Causes?
Loss of volume within a lung lobe.
Luminal - aspirated foreign material, mucous plugging, iatrogenic
Mural - bronchogenic carcinoma
Extrinsic - compression by adjacent mass
How does a collapsed lung appear on a CXR?
Squashed blob around the hilum - dense whiteness
Tissue has collapsed so now has the density of normal tissue
What other features are there on a CXR that indicate lung/lobar collapse?
Mediastinal shift towards the collapse
Elevation of hemidiaphragm
Crowding of pulmonary vessels
