General

Question 1

What are Hounsfield Units?

Answer 1

used universally in CT scanning

Radiodensity of air: -1000

Radiodensity of water: 0

Radiodensity of bone: +1000

Question 2

Two different types of thrombi

Answer 2

Arterial: made of platelet aggregates

Venous: made of fibrin and RBC

Question 3

Most common places to get venous thrombi and what are the consequences of this?

Answer 3

DVT

This can lead to a PE

(or can lead to a stroke if there is a congenital heart defect)

Question 4

Most common places to get dangerous arterial thrombi and what are the consequences of this?

Answer 4

Carotids, mural etc

can result in MI, unstable angina, ischamic stroke, manifestations of PAD (eg; acute limb ischaemia)

Question 5

What increases risk of mural thrombi (thrombi that attach to the wall of a blood vessel and cardiac chamber, seen in aorta or heart)

Answer 5

• Atrial Fibrillation
• Heart valve replacement
• DVT
• Acute MI
• Genetic coagulation disorder

Question 6

list the different stone types of nephrolithiasis (Kidney Stones)

Answer 6

Radiopaque:

• Calcium oxalate
• Struvite (triple phosphate) (can lead to staghorn calculi)

Radiolucent:

• Uric Acid
• Cystine

Question 7

Associations/causes of a perianal/abdominal fistula?

Answer 7

• Diverticulitis
• Crohns Disease
• Bowel/pelvic infections
• TB
• iatrogenic (post-surgical)
• Childbirth
• Pelvic malignancies

Question 8

What is Gliosis and when does it occur?

Answer 8

A non-specific reactive change of glial cells in response to the damage to the CNS (brain/spinal cord)

Question 9

Pleural Plaques (lesions of scar tissue, sometimes calcified) are caused because of?

Answer 9

• Asbestos exposure (20-30 post)

Question 10

Diffuse plerual thickening can be from?

Answer 10

• Diffuse pleural fibrosis
• Asbestos related pleural disease
• Malignant pleural mesothelioma
  *

Question 11

Pseudomyxoma peritonei

Answer 11

Progressive intraperitoneal mucinous ascites

Due to a mucin-producing neoplasm

Most commonly of the appendix “appendiceal mucocele”

Question 12

Stages of CHF on a plain chest radiograph

Answer 12

1. Upper Lobe Pulmonary Veins Enlarge
   
   • Upper usually smaller or equal to LL’s (change art:bronch)
   • Cardiomegaly
2. Interstitial Changes
   
   • Peribronchial cuffing/doughnut sign: describes haziness/increased density around bronchus or large bronchiole walls.
   • Kerley- B lines
   • Hazy contour of vessels
   • Thickened interlobar fissure
3. Pulmonary oedema
   
   • alveolar oedema; sometimes a central perihilar pattern, outward from the hilum “batwing”.
   • **air bronchograms can be seen with this**
   • Pleural effusion

Question 13

How do alveoli communicate?

Answer 13

Via the ‘Pores of Kohn”