Anatomy Radiology Flashcards
what shows up as black on an x-ray?
air
what shows up as grey on an x-ray?
fat
soft tissue
muscle
what shows up as white on an x-ray?
bone
what shows up as bright white on an x-ray?
metal
what four things need to be assessed when seeing if a chest x-ray is technically adequate?
projection
inspiration
rotation
penetration
what is the cardiothoracic ratio?
a ratio of max cardiac diameter to max thoracic diameter
what is a normal value for the cardio thoracic ratio?
less than 0.5
what type of x-ray can the cardio thoracic ratio be measured on?
PA only
what should be visible if a CXR is adequately inspired?
the anterior ends of at least six ribs
what should be seen if a CXR is correctly centred?
medial ends of the clavicles should be equidistant from the spinous processes of the upper thoracic vertebrae
which hila normally lies higher, left or right?
left
on a normal CXR, which diaphragm is normally higher?
right
what causes lobar collapse?
obstruction of a lobar bronchus
what happens to the density of a lung lobe when it collapses?
increases
drags the adjacent fissure out of position
what is seen on CXR in a left lower lobe collapse?
hemithorax looks small
increased density
loss of clarity of the medial aspect of the hemi diaphragm
what is seen on CXR in a left upper lobe collapse?
elevation of left hemi diaphragm
loss of clarity of the heart shadow
diffuse opacification
what is seen on CXR in a right upper lobe collapse?
volume loss
loss of clarity of the upper right mediastinum
density in right upper zone
elevation of the horizontal fissure
what is seen on CXR in a right middle lobe collapse?
loss of clarity of the right heart border
density in the right lower zone
right hemidiaphragm is preserved
what is seen on CXR in a right lower lobe collapse?
volume loss
loss of clarity of the hemidiaphragm
density in the right lower zone
depression of the horizontal fissure
what is seen on CXR in infection of the lingual?
left heart border becomes obscured
what is often seen on CXR when there is pleural fluid present?
blunting of the costophrenic angles
where are small pneumothoraces often found?
at the lung apex
how does a small pneumothorax appear on CXR?
dark crescent without lung markings
subtle
what interstitial opacities can be seen on CXR due to heart failure?
peribronchovascular cuffing
septal lines
what is another name for septal lines?
Kerley B lines
what five things are seen on CXR in heart failure? (ABCDE)
alveolar oedema (bat wing opacities) Kerley B lines cardiomegaly dilated upper lobe vessels pleural effusion
what is the normal position for the tip of an endotracheal tube?
5cm above the carina
what is the normal width for an endotracheal tube?
2/3 of the tracheal diameter
what is the most commonly seen malposition of an endotracheal tube?
tip in the right main bronchus or the oesophagus
what is the ideal position for an NG tube?
in the subdiaphragmatic position in the stomach
at least 10cm beyond the gastro-oesophageal junction
where should an NG tube be on CXR?
overlying the gastric bubble
what vessels can central lines be inserted via?
internal jugular
subclavian veins
what is another name for a central line?
central venous catheter (CVC)
where are PICC lines inserted?
via cephalic, basilic or brachial veins
what does PICC stand for?
peripherally inserted central catheter
where should the tip of a CVC be?
the cavoatrial junction
what is contrast enhanced CT used for in lung cancer?
assessing size
showing metastases
guiding biopsy of peripheral lesions
what is FDG-PET CT used for in lung cancer?
nodal metastases
distant metastases
delineating a tumour in an area of collapse
what is pneumoperitoneum?
when perforation of an organ results in gas in the peritoneal cavity
what imaging is done for an ischaemic stroke?
non contrast CT scan
what is the earliest sign of an ischaemic stroke on CT?
hyper dense segment of a vessel
shows the thrombus and is visible immediately
what is seen on CT a while after an ischaemic stroke and why?
a region of low density with volume loss
due to gliosis
what colour is acute blood on an unenhanced CT?
white
describe the appearance of an extradural haemorrhage on CT
biconvex shape
limited by suture lines
describe the appearance of a subdural haemorrhage on CT
semilunar shape
crosses the suture lines
what two types of x-ray are used to view the abdomen?
supine AXR
erect CXR
what can a supine AXR be used to assess?
bowel obstruction
what can an erect CXR be used for in abdominal disease?
hollow viscus perforation
what are three possible risks of contrast CT scans?
radiation exposure
contrast induced nephropathy
contrast allergy
for what organs is MRI the second line imaging option?
hepato-biliary
small bowel
pelvis
what imaging tools are used to investigate acute appendicitis?
- USS
2. CT if inconclusive
what are the US findings in acute appendicitis?
dilated appendix
round when compression applied
fluid
wall thickening
what are the CT findings in acute appendicitis?
>6mm diameter appendix wall thickening and enhancement thickening of the caecal apex inflammation perforate
what is the gold standard for imaging ureteric stones?
non contrast CT KUB
what is the investigation of choice for acute diverticulitis?
CT with IV contrast
what is the first line imaging in acute cholecystitis?
USS
what is CT good for in acute cholecystitis?
looking for complications
what imaging should be done if there is biliary tree dilatation in acute cholecystitis?
MRI
what are the USS findings in acute choleyctitis?
wall thickening
pericholecystic fluid
what are the CT findings in acute cholecystitis?
distension
wall thickening
hyperenhancement
fluid
what investigations are done for pancreatitis?
USS
CT
what investigations can be done for a perforation?
erect CXR
CT
what is the initial investigation in a small bowel obstruction?
AXR
what is the initial investigation for a large bowel obstruction?
AXR
what imaging can be done to look for bowel ischaemia?
CT
what is the investigation of choice for a leaking AAA?
CT
