Flashcards in Chest Imaging Deck (40)
what colour is air on CXR?
what colour is fat on CXR?
what colour is soft tissue/ muscle on CXR?
what colour is bone on CXR?
what colour is metal on CXR?
what to check when looking at a CXR?
how do you tell if there is adequate projection on CXR?
ratio of cardiac diameter to horizontal thoracic diameter is <50%
how do you tell if a CXR is adequate inspired?
anterior ends of at least 6 ribs are visible (remember the ribs you can see are posterior)
how do you tell if a CXR if adequately rotated?
medial ends of clavicles equidistant from spinous processes of upper thoracic vertebra
which hila is higher?
left due to the heart
which side of the diaphragm is higher?
right due to the liver
what should the hila look like on CXR?
if not= bilateral hilar lymphadenopathy
review areas on CXR
1. lung apices
2. behind the heart
3. below the diaphragm
4. bone and soft tissues
why do you need to look at the lung apices on CXR?
masses (Pancoast tumour)
what to look for behind the heart on CXR?
what to look for below the diaphragm on CXR?
tube e.g. NG
what to look for in bones and tissues on a CXR?
evidence of previous surgery e.g. axillary clips
how many lobes does each lung have?
left= 2 lobes
right= 3 lobes
fissure in the right lung
what causes a lobar collapse?
obstruction of a lobar bronchus
causes of lobar collapse
why does the lobe collaspe?
air is resorbed, loses volume and collapses
pleural space abnormalities
1. pleural effusion
how does a pleural effusion appear on an erect CXR?
pleural fluid collects at lung bases and forms the curved appearance of a meniscus at lung edges blunting the costophrenic angles
what causes a pneumothorax?
rupture of the visceral pleura allows air to rush in from the lungs every time the patient inspires
air accumulates impairing respiratory function
why is tension pneumothorax an emergency?
displaces heart and diaphragm
signs of pulmonary oedema
A (alveolar oedema- batwing opacities)
B (kerley B lines)
D (dilated upper lobe vessels)
E (pleural effusion)
what is CXR used to confirm the placement of?
endotracheal tubes (ET)
nasogastric tubes (NG)
central venous lines
where should an endotracheal tube sit?
5cm above carina