Anatomy and Radiology Flashcards
1
Q
How is US created?
A
vibrating crystals and when this hits structures they are either transmitted on or reflected
2
Q
What do the different colours mean on US?
A
- White = reflected a lot of waves
- Dark = poorly reflected the sound wave energy
3
Q
What is the orientation of the US image?
A
- top = superficial
- bottom = deep
4
Q
What are the four factors on taking a US?
A
- Tilt: brightness can be altered by the probe
- Pressure: too little is loss of contact and too much veins will be obliterated
- Rotation: seeing nerves in different axes
- Alignment: sliding and subtle movement aligns the probe to structures of interest
5
Q
How do you tell direction of flow in colour doppler?
A
BART (blue away and red towards)
6
Q
What does bone look like on US?
A
hyperechoic periosteum with acoustic shadow below
7
Q
What do arteries look like on US?
A
anechoic, pulsatile, usually round
8
Q
What do veins look like on US?
A
anechoic, non-pulsatile and compressible
9
Q
What do nerves look like on US?
A
can be circular or oval with hyperechoic outline and speckled interior but more proximally they are hyperechoic interior due to less connective tissue
10
Q
What do tendons look like on US?
A
look like nerves but blend into muscle or into thicker tendon
11
Q
What do muscles look like on US?
A
hyperechoic mass with visible striae or hyperechoic fascia
12
Q
What are the common artefacts on US?
A
- acoustic shadowing: shadow behind acoustically opaque structure
- post-cystic enhancement: bright area behind a fluid filled structure
- reverberation: strong reflecting interface close to transducer eg vessel wall, needle or muscle fascia
13
Q
What are the important things to check before examining an XR?
A
- projection: PA is the best so the heart isn’t abnormally magnified as it is on AP
- inspiration: at least 6 anterior ribs visible
- rotation: medial ends of the clavicles should be equally distanced from the spinous processes
- penetration: enough radiation
14
Q
What is the normal size of the heart on an XR?
A
less than 50% of the thorax diameter
15
Q
What is the normal comparison of hila and diaphragms?
A
- left hilum usually sits slightly higher than the right
- right diaphragm should be slightly higher than the left
16
Q
Where are the places in an XR that pathology is commonly missed?
A
- lung apices eg pneumothoraces/tumours
- behind the heart eg hiatus hernia
- below diaphragm eg free gas/lines/tubes/bowel obstruction
- bones/soft tissues eg subcutaneous emphysema
17
Q
When does lobar collapse occur and what does this look like?
A
- obstruction of a lobar bronchus
- will look white as there is no air in it
18
Q
Where do the left lung lobes collapse to?
A
- lower lobe collapses down to behind the heart so left hemidiaphragm will be higher than right
- upper lobe collapses anteriorly onto the heart so the heart almost disappears ie veil like opacity
19
Q
Where do the right lung lobes collapse to?
A
- upper lobe collapses upwards and there is increased density in right upper zone, horizontal fissure can be seen also
- middle lobe collapse doesn’t tend to happen without a lower lobe collapse due to bronchus intermedius obstruction, loss of clarity of the right heart border
- lower lobe collapse will show volume loss on the right and loss of clarity of the right hemidiaphragm
20
Q
What is seen on XR with consolidation?
A
- air bronchograms (bronchus will contain air but surrounding lung won’t)
- no change in volume so diaphragms okay
- no mediastinal shift
21
Q
What is the progression of pulmonary oedema on XR?
A
- Dilation of the upper lobe vessels and cardiomegaly
- Interstitial opacities ie peribronchovascular cuffing and septal lines aka Kerley B lines
- Filling of alveoli with fluid, perihilar or batwing distribution and air bronchograms
22
Q
What are the ABCs of pulmonary oedema on XR?
A
Alveolar oedema Kerley B lines Cardiomegaly Dilated upper lobe vessels Pleural Effusion
23
Q
Where should endotracheal tubes sit?
A
- 5cm above carina
- not in a bronchus
- not in the oesophagus
24
Q
Where should nasogastric tubes sit?
A
- over gastric bubble
- in subdiaphragmatic position
- 10cm beyond gastro-oesophageal junction
25
Where do central venous catheters sit?
- right/left internal jugular or subclavian veins
| - tip should be at the cavoatrial junction
26
When is V/Q scan very good for PE?
pregnant patients as it is safer than gold standard which is CTPA
27
How can you tell the difference between PA and AP XR scans?
```
PA = can't see scapulae as they are out of the way from standing position
AP = heart abnormally large
```
28
What is easiest way to differentiate between CT and MRI?
bone is white on a CT but it is black on an MRI
29
What is the first and second line for brain imaging?
- CT is fast
| - MRI is second but first for spinal cord issues
30
What are the cisterns of the brain?
- suprasellar cistern (aka stellate)
- cisterna magna
- quadrigeminal cistern
31
What cistern does the circle of Willis sit in?
supracellar
32
What is the difference between T1 and T2 weighted MRI images?
- T1: fluid is black (anatomy seen better)
| - T2: fluid is bright (pathology seen better)
33
What is the main investigation for a stroke?
non-contrast CT
34
What is the earliest sign of stroke on CT?
hyper dense vessel due to clotted blood
35
What are the later signs of stroke on CT?
- loss of grey-white matter differentiation
- hypoattenuation
- early mass effect due to parenchymal swelling
36
What are the latest and permanent signs of stroke?
- gliosis (large cavity appears)
| - enlarging of the ventricles
37
What is the appearance of acute blood on a CT?
white
38
What are the main types of intracranial haemorrhage?
- intra axial
| - extra axial: extradural, subdural and subarachnoid
39
What are the most common hypertensive bleeds?
thalamic bleeds which are intra-axial
40
What is the presentation of an extradural haemorrhage?
lucid interval and then sudden deterioration with herniation
41
What are the most common causes of subdural haemorrhage?
- NAI in children
| - falls in elderly
42
What is XR used for in acute abdomen?
- supine for bowel obstruction
| - erect for hollow viscus perforation
43
What is US used for in acute abdomen?
- liver
- ascites
- female pelvic organs
- appendicitis in children
- aorta
44
What are the negatives of CT?
- large amounts of radiation
- allergy
- nephropathy
45
What is MRI second line for in acute abdomen?
- hepato-biliary
- pelvis
- small bowel
46
What are the differentials for RIF pain?
- appendicitis
- renal colic
- tuba-ovarian pathology
47
What is the radiology for appendicitis?
- in kids: US
| - in adults: US and CT to confirm
48
What is seen on US in appendicitis?
- aperistaltic and non-compressible dilated appendix
- ?black fluid around
- ?lymph nodes
49
What is seen on CT in appendicitis?
- appendiceal dilation
- potential fat stranding
- calcificated faceolith
50
What is the investigation for renal colic?
non-constrast CT
51
What are the differentials for LIF pain?
- diverticulitis
- colitis
- colorectal cancer
- renal colic
- tubo-ovarian pathology
52
What are the investigations for diverticulitis?
CT with contrast to confirm diverticula, inflammation and assess for complications eg perforation/fistulae/abscess
53
What are the differentials for epigastric and RUQ pain?
- biliary colic
- cholecystitis
- pancreatitis
- perforation
54
What is the best imaging for gallstones?
- US first line to assess gallbladder and stones
- MRI for biliary tree dilatation
- CT not good for stones
55
What is seen on US in gallstones?
- gallbladder wall thickening
| - pericholecystic fluid
56
What are the investigations for pancreatitis?
- US for causes ie gallstones
| - CT done many days after too look for complications
57
What is the imaging for perforation?
- XR for age under diaphragm
| - CT for fluid and inflammatory fat stranding
58
What are the differentials for abdominal pain and distention?
- small bowel obstruction
- large bowel obstruction
- masses
- ascites
59
What is the imaging for small bowel obstruction?
- XR to differentiate between small and large obstructions
| - CT is good too
60
What is the imaging for large bowel obstruction?
- XR to differentiate between small and large obstructions
| - CT confirms diagnosis, determines location, cause and complications
61
What are the differentials for sudden abdominal pain and shock?
- bowel ischaemia
- perforation
- pancreatitis
- leaking AAA
- ruptured AAA
- ruptured ectopic pregnancy
62
What is the investigation for bowel ischaemia?
CT
63
What is the investigation for leaking AAA?
CT
64
What is a flail chest?
more than three ribs fractured in more than one place
65
What do you look for on a chest XR in trauma?
- pneumothorax
- effusion
- pneumonia
- pneumoperitoneum
66
What do you look for on an abdominal XR in trauma?
- obstruction/ileus
| - pneumoperitoneum
67
What is Rigler's sign?
a sign of pneumoperiotneum as you can see both sides of the wall of the bowel
68
What is the anterior sail sign in the elbow?
enlarged fat pad due to joint effusion because of fracture
69
What is a Colles fracture?
distal forearm fracture that has moved dorsally
70
What is a Smith's fracture?
distal forearm fracture that has moved volarly
71
What is an important consideration with scaphoid fracture?
can be avascular necrosis of the proximal pole as the main blood supply is to the distal pole
72
What is the diagnosis of low BP and tachycardia in trauma until proven otherwise?
hypovolemia due to haemorrhage
73
What does fluid look liken US?
black
74
What is likely to be injured in a supracondylar humeral fracture?
ulnar nerve which runs posterior to medial epicondyle of elbow
75
What is different about the upper facial muscles?
CNVII is bilateral so there is forehead sparing in an UMN lesion
76
Where does the aotic arch begin and end?
T4/5 level
| also carina and sternal angle are here
77
What are the accessory muscles of respiration used when the scapulae are fixed on the legs?
- serratus anterior
- pectorlais minor
- pectoralis major
78
What nerve injury causes foot drop?
peroneal nerve/common fibular
79
What nerve injury causes claw hand?
ulnar
80
What nerve injury causes wrist drop?
radial
81
What nerve injuries do different parts of the humerus fracturing cause?
- surgical neck: axillary
- mid-shaft: radial
- supracondylar: ulnar
82
What nerve injury does a neck of fibula fracture cause?
common fibular/peroneal
