Imaging of the heart and lungs Flashcards
What are the different modalities for imaging the heart and lungs?
CXR CT US/ECHO MRI Angiography
When is an AP CXR carried out?
only used in pts too unwell to stand - as it magnifies the heart
What are the problems with supine CXR?
Supine film enlarges the heart, pleural effusions and pneumothoraces difficult to detect and poorer inspiration
What is a good inspiration for CXR and what are the problems if it is insufficient?
5 anterior ribs
underinspired film causes apparent congestion and may miss lesions at lung bases
What does it mean by rotation in terms of CXR?
Spinous process relation to the medial ends of the clavicles
altered transradiancy of the lungs and abnormal mediastinum
What is the right level of penetration in a CXR?
Dark enough to see T6
not too dark to assess lungs
What is the correct terminology to use in terms of density with CXR?
soft tissue (fat)
air
calcific
metallic/contract
What is the silhoutte sign?
localizing abnormality on the CXR
- principle of using normal borders to identify where an abnormality is in relation to this structure
What mediastinal contours are you looking for in a CXR?
Right atrium ascending aorta SVC aortic knuckle left pulmonary artery left ventricle
How do you assess the heart size on an CXR?
cardiothoracic ratio = heart width/thorax width
eyeball assessment is reasonable
look for supporting signs of LV failure:
- pulmonary/interstitial oedema
- pleural effusions
-cardiac surgery/ventricular pacing, upper vessels larger than lower
What does the hila consist of?
bronchi
pulmonary arteries
pulmonary veins
lymph nodes
What are the different types of CT of the thorax?
main form of imaging the thorax
- fast multislice CT shows heart well too
HRCT vs helical contrast enhanced CT
- HRCT samples lung and is or diffuse parenchymal disease
- CECT includes the whole of the chest and is for cancer small nodules etc
What is echocardiography?
no ionising radiation easily available and quick non invasive functional assessment of the heart limited by acoustic window
What is the function of MRI in imaging the thorax?
limited use for lung pathology due to lack of spatial resolution compared to CT
slow, relatively inaccessible, difficult to use with seriously ill
excellent for anatomical and functional assessment of the heart
excellent for mediastinum and aorta
What is angiography?
invasive
used for clarification of diagnosis prior to treatment
facilitates stents, angioplasty
