NM

Question 1

What do you need to perform bone scintigraphy?

Answer 1

A source/supply for the radiopharmaceuticals you will use

A gamma camera with SPECT+/- CT capabilities

Question 2

What are the factors that determine radioactive tracer uptake by the bone?

Answer 2

Vascular supply to the bone

Osteoblastic activity

Question 3

How do bone scans show osteoblastic activity?

Answer 3

Diphosphonates localise avidly in bone by means of absorption and/or chemical interaction in the surface of the hydroxyapatite crystal where the phosphorous component interacts with the endogenous calcium to produce insoluble Tc-calcium phosphate complexes.

Question 4

What are the most common indications for bone scintigraphy?

Answer 4

Imaging malignancy (detection and follow-up of osteoblastic skeletal metastases)
Characterisation of bone lesions
Detection of fractures (for example, stress or insufficiency fractures)
Imaging painful prostheses (in cases of infection or loosening)
Osteomyelitis
Complex regional pain syndrome (CRPS)

Question 5

There is increased tracer uptake in the frontal region of the skull

Answer 5

hyperostosis frontalis interna - a common condition, especially in post-menopausal females.

Question 6

three-phase technique

Answer 6

obtained in blood flow and blood pool (Fig 1) in addition to the delayed phase:

Question 7

First phase: dynamic blood flow

Answer 7

obtained in blood flow and blood pool (Fig 1) in addition to the delayed phase:

Question 8

Second phase: blood pool

Answer 8

A ‘blood pool’ phase is obtained at 5 minutes. It reflects uptake in the extracellular fluid within bone, due to changes in capillary permeability and identifies regions of hyperaemia.

Question 9

Third phase: delayed phase

Answer 9

The delayed phase shows increased osteoblastic activity. This technique is commonly used in the investigation of:

Bone infection
Prosthesis loosening
Trauma
Reflex sympathetic dystrophy

Question 10

Bone scintigraphy is most commonly used in the imaging of metastatic disease, most frequently in patients with

Answer 10

breast and prostate cancer

Question 11

A bone scan with multiple focal lesions, distributed randomly throughout the axial skeleton, is highly suggestive of

Answer 11

mets

Question 12

Aetiology of a superscan may be:

Answer 12

Diffuse malignant disease (breast, prostate, lymphoma)
Metabolic bone disease (hyperparathyroidism, renal osteodystrophy)
Mastocytosis
Myelofibrosis

Question 13

Flare phenomenon is defined as

Answer 13

increase in the number or intensity of lesions after chemotherapy.

Breast cancer post-chemotherapy
Prostate cancer after treatment with a hormonal agent

Question 14

common sites of stress fractures are the:

Answer 14

Distal third of tibia
Distal fibula
The metatarsal shafts: Fig 1 shows an example from the fourth metatarsal, although it is usually the second and third metatarsals that are affected

Question 15

insufficiency fracture occurs when

Answer 15

normal stress is applied to bones that lack the elastic resilience of normal bone

Question 16

Avascular necrosis (AVN) sites

Answer 16

Distal femur
Humeral head
Body of the talus
Scaphoid
Navicular bone