1) Radiology of the Musculoskeletal System

Question 1

What is a radiograph?

Answer 1

A projectional image generated by passage of x rays through an object

Question 2

In what direction do X-rays travel?

Answer 2

A straight line

Question 3

What will stop an X-ray?

Answer 3

Materials with lots of electrons
Dense materials
E.g. bones and metals

Question 4

What are the advantages of radiographs?

Answer 4

Quick
Readily available
Cheap

Question 5

When is an X-ray used?

Answer 5

Skeletal trauma
Joint injury
E.g. fractures or joint dislocation
Evaluation of chronic bone or joint pathologies
E.g. chronic osteomyelitis, chronic joint arthritis or chronic septic arthritis

Question 6

What is a fracture?

Answer 6

A complete or incomplete break in the continuity of the bone

Question 7

What is a CT scan?

Answer 7

Computed tomography

Diagnostic imaging procedure that uses radiation to build cross sectional images or slices of the body

Question 8

What is easier to see in CT than X-ray?

Answer 8

Soft tissues
Subtle undisplaced bone fractures
Spinal fractures

Question 9

What are the advantages of a CT?

Answer 9

Cross sectional 
Thin slices of the body 
Good at assessing complex bone trauma 
Fast 
Multiplaner and 3D reconstruction

Question 10

What are the disadvantage of CT scans?

Answer 10

Involves significant radiation and poor soft tissue detail

Question 11

What is an MRI?

Answer 11

Non invasive method of mapping the 8nternal structures
Utilises Magnetic resonance of the hydrogen nuclei to produce high quality cross sectional images of the body in any plane
No ionising radiation as uses radio frequency

Question 12

What is MRI assessment used for?

Answer 12

Assessment of bones, joints and associated soft tissues like ligaments

Question 13

What is MRI poor at showing?

Answer 13

Microstructure of the bone

Question 14

What are the advantagesof MRI scans?

Answer 14

Excellent for imagine of soft tissue structures like ligaments, tendons and muscles
Detailed anatomy of the joints
Excellent for bone marrow imaging

Question 15

What are the disadvantages of MRI scans?

Answer 15

Scan takes a long time, around 45-60 minutes and the patient has to stay still in the tunnel
Noisy environment
Claustrophobic patients can’t tolerate the scan
Non compatible with metallic or electronic devices like pacemakers

Question 16

How strong is the MRI magnetic field?

Answer 16

Strong enough to move cars

Iron, nickel and cobalt are affected

Question 17

What is ultrasound used for?

Answer 17

Imaging of soft tissues
Good at finding fluid collections or joint effusions
Good for assessing tendons and muscles if ruptures
No radiation

Question 18

What are the advantages of ultrasound?

Answer 18

No radiation
No adverse events
Excellent soft tissue resolution for superficial soft tissues
Excellent imaging modality for assessment or tendons and peripheral nerves
Fluid collections
Superficial foreign bodies
Dynamic imaging
Excellent for image guided MSK intervention

Question 19

What are the disadvantages of ultrasound?

Answer 19

Operator dependant
Poor deep tissue resolution
Limited bone and intra Articulation imaging

Question 20

What are the three phases of bone healing?

Answer 20

Inflammatory phase
Reparative phase- soft callus and hard callus
Remodelling phase

Question 21

What is nuclear imaging?

Answer 21

Radioisotope-labelled
Biologically active drugs
Administered to the patient to serve as a marker of biological activity
Used to assess metabolically active bone such as when it tries to localise
Bone forming metastatic lesions
Healing fractures
Areas of osteomyelitis