Diagnostic imaging Flashcards
what increased radiopacity?
whiter
what is increased radiolucency?
blacker
what are the five radiographic opacities?
air (black) fat soft tissue/fluid mineral (bone) metal (white)
what are the radiographic (röntgen) signs?
number size shape (include margins) location opacity
when appraising the radiographs quality, what must be assessed?
correct patient/region
two orthogonal views
views and labelling
technical quality
what needs to be assessed when looking at the technical quality of a radiograph?
exposure collimation position (well centred) contrast artefacts
what is the mass effect?
increases in mass will cause other tissue/organs to displace
what are the limitations of radiographs?
no information about function
still snapshot in time
what view of a thoracic radiograph should always be taken first?
dorsoventral (lateral will cause atelectasis)
what needs to be assessed on the overall radiograph of the thorax?
radiographic quality
phase of respiration
body condition
how do lungs appear different on radiographs during inspiration?
larger lungs so less opaque
how does obesity effect how the lungs look on a radiograph?
increased opacity
what are the thoracic/anatomical compartments that can be involved with radiographic changes?
pleural space/thoracic wall
mediastinum
lungs
what can cause decreased opacity of the thorax?
penumothorax
what three signs of pneumothorax can be seen on a radiograph?
air in pleural space
retraction of lung from thoracic margin
elevation of cardiac silhouette
how will pleural effusion appear on a radiograph?
border effacement of heart/diaphragm
pleural fissures
retraction of lung margins from thoracic wall
what anatomy is found in the mediastinum?
trachea
oesophagus
heart and vessels
lymph nodes
where is the most common place to find masses in the mediastinum?
cranioventral (lymph nodes and thymus)
what can cause diffuse distributed diffuse opacity of the lungs?
artefact
hypovolaemia
hyperinflation
what is a mediastinal shift?
when the mediastinum moves due to changes in lung volume
what are the lung patterns for localising lesions?
bronchial pattern
vascular pattern
interstitial pattern
alveolar pattern
what is seen with bronchial patterns?
increased visibility of bronchial walls (thick/increased opacity)
what lung pattern can air bronchograms be seen with?
alveolar patterns
what is the most common cause of interstitial lung patterns?
artifactual
how big do soft tissue nodules need to be in the lung to be seen on a radiograph?
4-5mm (aerated lungs)
what is the cardiac silhouette?
heart, pericardial contents, pericardium
what will be seen on a radiograph if the left side of the heart is enlarged?
tracheal elevation (heart taller)
caudal cardiac border straightening
left atrial enlargement (tenting)
what will be seen on a radiograph if the right side of the heart is enlarged?
increased width
increased sternal contact
rounded right side
what shape is the heart described as if there is right sided enlarged on a DV view?
reverse D
