1. HETI SPONSORED RADIOLOGY ESSENTIALS TEACHING
Dr Noel Young
Department of Radiology
Westmead Hospital

2. BASIS OF THIS TALK
Recommendations to HETI by Intern / RMO advisory group.

3. OTHER CONSIDERATIONS Should follow your University Imaging teaching.
Key points of:
recognising key pathologies,
understanding clinical contexts for radiology requesting
understanding context of reports per individual patient requirements / status,
keeping your boss happy.

4. With PACS in all NSW public hospitals, seeing all patients’ images is easy.
But interpretation is still the big issue.

5. DIFFERENTIAL FORCES IN RADIOLOGY
Cost to Government
Cost to patient
Radiation cost to patient VS
Keeping patients happy
Keeping lawyers at bay
Differential clinical needs

6. TALK DIVIDED INTO THREE PARTS
Part I – CT Brain
Part II – CT Abdomen and Pelvis
Part III – Abdominal Ultrasound (A)
– + Doppler Ultrasound (B)

7. Key Learning Objectives
PART I: CT BRAIN
Key Learning Objectives
When / what to request -
contrast issues
sedation issues
How to look at a CT Brain.
Common pathologies.

8. Question: When to request?
Answer: When your boss wants it.
(Side issue – 4 hour Emergency objectives)
Real test – how to get Radiology to do it.
Answer: Communicate
(best done by going to the Department)

9. Question: When to sedate? Answer:
Whenever you want nice pictures and patient non-cooperative.
When patient is crashing.
(n.b. - be nice to your anaesthetist! – you have little that anaesthetists need!)

10. Question: How to interpret? Answers:
Remember normal anatomy
Look systematically – ask key questions -
is there raised ICP
is there blood
is there an infarct
is there normal white / grey differentiation
Go ask someone more experienced (n.b. - Your university should have taught this stuff – you have already paid for it!).

11. COMMON PATHOLOGIES TO RECOGNISE
Raised ICP
Recent territorial infarct
Blood - EDH (be careful!)
- SDH
- SAH
- focal haematomas

12. Right old middle cerebral artery infarct. 1. No mass effect. 2
Right old middle cerebral artery infarct. 1. No mass effect. 2. Margins of the infarct are well defined.

13. CT – recent left PICA infarct involving the cerebellum. 1
CT – recent left PICA infarct involving the cerebellum. 1. Ill defined low density change. 2. Mass effect with compression of the 5th ventricle.

14. CT – Acute right posterior cerebral artery infarct, involving the occipital lobe. 1. The area of low density is ill-defined. 2. Local mass effect is present.

15. CT – Acute infarct of right cortical hemisphere. 1
CT – Acute infarct of right cortical hemisphere. 1. Loss of grey-white differentiation. 2. Compression of right lateral ventricle.

16. Small extra-dural – right temporal region. Note the lentiform shape

17. Small left acute extra-dural haemorrhage
Small left acute extra-dural haemorrhage. Local mass effect with cortical sulcal effacement is present.

18. CT – Large right extra-dural haematoma. Significant mass effect.

19. CT – Acute left subdural haematoma. Massive mass effect
CT – Acute left subdural haematoma. Massive mass effect. Significant shift of midline structures to the right. Note crescent shape of haematoma.

20. Diffuse intraventricular blood and subarachnoid haemorrhage
Diffuse intraventricular blood and subarachnoid haemorrhage. There is effacement of sulcal spaces globally indicating raised intracranial pressure.

21. Diffuse intraventricular blood and subarachnoid haemorrhage
Diffuse intraventricular blood and subarachnoid haemorrhage. There is ventricular dilatation.

22. Subarachnoid haemorrhage involving the basal cisterns.

23. Left sylvian fissure and traumatic subarachnoid haemorrhage
Left sylvian fissure and traumatic subarachnoid haemorrhage. A subtle finding. Due to a small, ruptured, left MCA aneurysm.

24. 1. Right subdural chronic haematoma. It is low density. 2
1. Right subdural chronic haematoma. It is low density. 2. Small amount of more recent blood (higher density) anteriorly.

25. IV CONTRAST ISSUES Iodinated, isotonic contrast used.
Beware bad renal function (when pre-med with NAC, don’t forget the saline).
Beware history iodine allergy
YES – allergy exists (anaphylaxis!)
Every hospital has a pre-med protocol

26. CT BRAIN (SURVIVAL KIT)
Is there white stuff around (blood)?
Is there dark stuff around (infarct)?
Is there raised intracranial pressure (can’t see sulci or cisterns)?

27. PART II: CT ABDOMEN / PELVIS
Key Learning Objectives
When / what to request -
contrast (IV and oral) issues
How to look at a CT abdomen.
Common pathologies.

28. Question: When to request?
Answer: When your boss tells you.
Question: What to request?
Answer: Go ask your friendly neighbourhood radiologist
(n.b. - please supply relevant clinical information).

29. HOW TO INTERPRET
Actually, CTs of the abdomen are a lot more complex than CTs of the brain.
Need best images to have a fighting chance.

30. HOW TO INTERPRET Remember what they taught you at University.
Be systematic, follow the anatomy.

31. HOW TO INTERPRET General principles Does the liver look OK -
is there a tumour
are the bile ducts dilated
is there a collection
Does the pancreas look OK -
is there a mass
is it swollen
is there fluid around it

32. HOW TO INTERPRET General principles continued
Is there free peritoneal gas
Is there free peritoneal fluid
Is there a peritoneal collection
Are there renal collecting systems dilated
Is the aorta too big
Is there blood around the place

33. COMMON PATHOLOGIES Perforation
free intraperitoneal gas
can see on CT little as 5 ml
look in anterior abdomen
look in region falciform ligament of liver
(n.b. - post abdomen surgery, free gas can persist up to three weeks)

34. COMMON PATHOLOGIES when large bowel >5 cm diameter
b. Obstruction
when large bowel >5 cm diameter
when small bowel >3 cm diameter
actually better seen on plain AXR
CT better to define
masses
bowel wall thickening

35. COMMON PATHOLOGIES if caecum >9 cm diameter – risk of perforation
b. Obstruction continued
if caecum >9 cm diameter – risk of perforation
beware toxic megacolon (gas and wall thickening in transverse colon)
look for other lesions

36. COMMON PATHOLOGIES fluid densities round, walled main scenarios
c. Collection
fluid densities
round, walled
main scenarios
around pancreas in pancreatitis
in subphrenic spaces
in pelvis after bowel surgery

37. CT – very dilated intrahepatic bile ducts.

38. CT - Metastases – gross ascites with tumour in peritoneum.

39. CT – 1. Ascites – due to peritoneal metastases. 2
CT – 1. Ascites – due to peritoneal metastases. 2. Metastasis to right lobe liver.

40. CT - acute cholecystitis. 1. Thickened gallbladder wall. 2
CT - acute cholecystitis. 1. Thickened gallbladder wall. 2. Fluid around gallbladder.

41. Subphrenic collection and percutaneous drain.

42. Subphrenic collection and percutaneous drain.

43. Severe, acute pancreatitis. 1. Diffuse pancreatic necrosis. 2
Severe, acute pancreatitis. 1. Diffuse pancreatic necrosis. 2. Calcified gallstones.

44. Acute pancreatitis & gallstones. Severe pancreatic necrosis.

45. CT – small pancreas pseudocyst, following previous pancreatitis.

46. CT - Rectus haematoma – on Warfarin. The blood is layered.

47. CXR – 1. Right subphrenic abscess. 2. Right subpulmonic pleural fluid.

48. CT – Mild appendicitis. Thickened wall of appendix.

49. CT – 1. Recto-sigmoid carcinoma, mass-like lesion. 2
CT – 1. Recto-sigmoid carcinoma, mass-like lesion. 2. Metastases to liver.

50. CT – Severe appendicitis

51. CT ABDO / PELVIS (SURVIVAL KIT)
Is there free gas?
Are bowel loops dilated?
Is there a lump in the liver?
Is the pancreas swollen?
Are the renal collecting systems too big?
(these are >90% of conditions you need to identify)

52. PART III (A): ABDOMINAL ULTRASOUND
Key Learning Objectives
When to do Ultrasound VS
When to do a CT
Patient considerations -
fasting
size
How to interpret

53. Question: When to do an Ultrasound?
Answers:
if looking at gallbladder and biliary tree pathology
if pregnant
in Emergency - portability

54. Question: What can’t be seen on Ultrasound?
Answer: Actually quite a lot. Particularly -
AAA (rupturing)
free gas
pancreatitis

55. Question: ? Fasting
Answer: if looking for gallstones (otherwise gallbladder is contracted). Fasting for at least 6 hours.
Question: When too big to bother?
Answer: If over 100 kg
Question: When to not bother asking for Ultrasound?
Answer: Pretty much anytime after sun sets
(n.b. – you can always get a CT)

56. HOW TO INTERPRET (1) Really quite hard Go do a course BUT ……..
You are going to be expected to do it in the future …….in Emergency

57. HOW TO INTERPRET (2) Key things to look for
Is the CBD too big – normal ≤7 mm
Has the liver a “smooth” appearance
Are there GB calculi
Are the renal collecting systems diluted
Is there an aortic aneurysm – normal ≤3 cm

58. Ultrasound – mild appendicitis. 1
Ultrasound – mild appendicitis. 1. The wall of the appendix is thickened. 2. No fluid around appendix.

59. Ultrasound - dilated biliary tree.

60. Ultrasound - dilated biliary tree. 1
Ultrasound - dilated biliary tree. 1. The channel in front is the dilated CBD. 2. The channel in the back is the portal vein.

61. Ultrasound – 1. CBD. 2. CBD is dilated at 1 cm.

62. Ultrasound – Acute cholecystitis. 1. Gallbladder is thickened. 2
Ultrasound – Acute cholecystitis. 1. Gallbladder is thickened. 2. The gallbladder lumen is filled with material.

63. Ultrasound - dilated renal collecting system.

64. Ultrasound - ureteric calculus causing the collecting system obstruction.

65. ABDOMINAL ULTRASOUND (SURVIVAL KIT)
Is the bile duct dilated?
Is there stuff in the gall bladder?
Is the aorta too big?
Are the renal collecting systems dilated?
(these are >90% of conditions you need to identify).

66. PART III (B): ULTRASOUND DOPPLER
Key Learning Objectives
Indications
Interpretation

67. Question: What are indications to request?
I will change the question – What are the usual clinical scenarios?
Presence of DVT in leg veins (most common)
Presence of thrombus in arm veins (post-lines)
Looking for abdominal AAA (CT is better)
Looking for arterial ischaemia -
leg arteries
neck arteries

68. INTERPRETATION VASCULAR ULTRASOUND
Very difficult
Only for expert operators
Best advice to you -
Read the reports (not always done!)
Go ask the reporter if you have a query.

69. Ultrasound of abdominal aortic aneurysm – transverse view.

70. Ultrasound of abdominal aortic aneurysm – longitudinal view.

71. Doppler ultrasound – right femoral vein – thrombus.

72. Doppler ultrasound – right femoral vein – thrombus in long view.

73. Doppler ultrasound – right ICA – plaque with stenosis.

74. Doppler ultrasound – right ICA – stenosis – colour flow image.

75. CLOSING COMMENTS
This is a teaching file on subjects considered priority by previous RMOs OK
BUT ……
Plain AXR interpretation far more important for you guys early in your medical career.