Haematological Disorders - finished

Question 1

Define thrombosis

Answer 1

Local coagulation or clotting of the blood in a part of the circulatory system

Question 2

Define atherosclerosis

Answer 2

A disease of the arteries characterized by the deposition of plaques of fatty material on their inner walls

Question 3

What is sickle cell anaemia

Answer 3

Congenital condition.
Erythrocyte sickling caused by abnormal haemoglobin. Local hypoxia causes erythrocytes to curve and elongate. Effort to maintain viability of RBC’s causes splenomegaly and marrow hyperplasia. Hyperplastic marrow leads to local ischaemia and necrosis.

Question 4

Who does sickle cell anaemia mostly present in?

Answer 4

African populations

Question 5

Which bones in sickle cell anaemia usually have radiological signs?

Answer 5

Multiple vertebral bodies
Femur
Humerus
Tibia 
Small tubular bones of hands, feet and skull.

Question 6

What is the clinical presentation of sickle cell anaemia?

Answer 6

After 6 months of age patient can develop fatigue, pallor, weakness.

Episodic crises of:

• Abdominal pain
• Jaundice
• Acute bone pain
• Splenomegaly
• Cardiomegaly
• Gallstones and
• Renal failure.

Question 7

What are the radiological manifestations of sickle cell anaemia?

Answer 7

Marrow Hyperplasia:

• Generalised osteopaenia
• Sparse and coarsened trabecular pattern
• Large vascular channels
• Widened medullary cavity
• Cortical thinning
• Loss of diaphyseal constriction in tubular bones

Skull changes:

• widened diploic space
• granual texture
• ‘hair on end’ trabecular pattern

Spine:

• Prominent osteoporosis with accentuated vertical trabeculae.
• H vertebrae

Small tubular bones:
- soft tissue swelling (as a result of infarction)

General:
- possible solid periosteal response as a result of increased blood viscosity and stasis causing increased pressure on bones (wolf’s law)

Question 8

How is an ‘H’ vertebrae formed?

Answer 8

After thrombosis of the centra nutrient vessel, central growth is inhibited, producing this characteristic ‘H’ shape.

Question 9

What is a DD for the middle part of the endplate in the ‘H’ shaped vertebra?

Answer 9

Line of Han - sclerosed vein or channel in vertebra

Question 10

Define thalassaemia:

Answer 10

Hereditary disorder of haemoglobin synthesis.

Question 11

Which population group does thalassaemia usually present in?

Answer 11

Mediterranean and asian/indian

Question 12

What is the clinical presentation of thalassaemia?

Answer 12

Pallor, lethargy, retarded growth, hepatosplenomegaly, inhibited sexual development, maxillary overgrowth.

Question 13

What are the radiographical appearances of thalassaemia?

Answer 13

Spine:

• involvement of the vertebral body and neural arch
• coarse trabeculae/honeycomb appearance
• thinned cortices
• normal endplates
• osteopaenia

Skull:

• radiating spicules (hair on end)
• widened diploe
• sinuses obliterated

Long bones:

• Erlenmeyer flask deformity (lack of normal metaphyseal-diaphyseal concave constriction)
• Widened medullary cavity
• Cortical thinning
• Honeycomb appearance to medulla

General:

• Osteopaenia
• ‘Honeycomb appearance’ (coarse trabecular patterns)
• Generalised cortical thinning
• Enlarged vascular channels
• ‘Hair on end’ radiating new bone spicules
• Enlarged, ‘bulbous’ posterior ribs

Question 14

What are some of the non-skeletal anomalies found in thalassaemia?

Answer 14

Cardiomegaly, posterior mediastinal masses, hepatosplenomegaly (as a result of extramedullary haematopoiesis).

Question 15

Why is bone in thalassaemia hypointense on MRI?

Answer 15

Because of the bone marrow hyperplasia in thalassaemia, yellow marrow gets replaced with red marrow, and as yellow marrow carries fat, the loss of yellow marrow makes images hypointense

Question 16

What is haemophilia?

Answer 16

A group of blood coagulation disorders characterised by a deficiency of specific clotting factors.

Question 17

What are the classic clinical features of haemophilia?

Answer 17

Varies with severity.

Severe haemophilia: patients can have spontaneous bleeding or bleeding from minor injuries
Can possibly have haematomas or haemarthrosis, which can cause joint degeneration (due to synovitis and pannus formation)
Haemarthrosis and its subsequent synovitis precipitates fibrosis, bone erosion, osteoporosis, growth disturbance and late cartilage degeneration.

Question 18

What are the radiological features of haemophilia

Answer 18

Soft tissue swelling
Juxtaarticular osteopaenia (due to hyperaemia)
- can become generalised with inactivity
Subchondral cysts 
Subchondral sclerosis
Poorly defined articular cortex
Pseudotumours
Enlarged femoral condyles (due to hyperaemia causing accelerated growth and maturation of epiphyseal cartilage)
In severe cases, ankylosis of joints. 

In severe cases, can see joint disorganisation with complete loss of joint space, articular fragmentation, sclerosis, osteophytes and bony misalignment.

Distal femur:

• grossly enlarged, osteoporotic, and irregular flattened contour to their WB surfaces (megacondyle)
• widening of intercondylar notch possibly because of repeated haemorrhage of the ACL and PCL

Proximal tibia:

• Tibial plateau may flatten
• Epiphysis is large and osteoporotic, with a thin cortex and accentuated vertical trabeculae