Lecture 14: MSK Imaging 2 - Upper Limb

Question 1

What are the characteristics of plain radiography?

Answer 1

utilises ionising radiation
different results based on patient positioning
several limitations

Question 2

What is a “series”?

Answer 2

a collection of views of a body area

Question 3

What is a “series” necessary for?

Answer 3

to adequately visualize the area of interest

Question 4

What is a “series” based on?

Answer 4

based on scenario and clinical question

Question 5

What is an AP view? What is a PA view?

Answer 5

AP = anterior -> posterior
PA = posterior -> anterior

Question 6

What does a lateral view of the wrist allow understanding of?

Answer 6

alignment of the lunate, capitate, scaphoid and radius

Question 7

What are the characteristics of computed tomography?

Answer 7

utilises ionising radiation
excellent spatial detail
excellent bone detail

Question 8

What are the characteristics of magnetic resonance imaging?

Answer 8

no ionising radiation

excellent spatial and soft tissue detail

Question 9

What are the signal intensities of a T1 weighted image?

Answer 9

bright: fat
intermediate: muscles
dark: water, tendon, fibrocartilage

Question 10

What are the signal intensities of a T2 weighted image?

Answer 10

bright: water
intermediate: fat
dark: muscle and fibrocartilage

Question 11

What is the clinical use of a T1 weighted image?

Answer 11

good anatomical detail
good for meniscal pathology
poor sensitivity for soft tissue injury

Question 12

What is the clinical use of a T2 weighted image?

Answer 12

good for soft tissue injury (esp. tendons)

Question 13

What are the signal intensities of proton density?

Answer 13

bright: fat
intermediate: water
dark: calcium, tendon, fibrocartilage

Question 14

What is the clinical use of proton density?

Answer 14

good anatomical detail (esp. menisci and ligaments)

Question 15

What can a fall with an arm at the side lead to?

Answer 15

fracture of the medial aspect of the clavicle

this is because the medial aspect of the clavicle is the weakest part of the bone

Question 16

What is the most common type of dislocation?

Answer 16

anterior dislocation of the glenohumeral joint -> shoulder appears flattened

Question 17

What is a Hill-Sachs lesion?

Answer 17

involves dislocation of the glenohumeral joint and impaction of the humeral head into the glenoid which leaves a structural deformation in the round humeral head

Question 18

What is a Bankart lesion?

Answer 18

reciprocal fracture to a Hill-Sachs lesion of the inferior aspect of the glenoid labrum

Question 19

What is the most common cause of a posterior glenohumeral joint dislocation and how can they be diagnosed?

Answer 19

electrocution / seizures

lightbulb sign

Question 20

What view is used for an inferior glenohumeral joint dislocation?

Answer 20

Garth’s view and patients present in a fixed abducted position

Question 21

What is the nature of the blood supply to the scaphoid? What does this mean for the scaphoid if it is fractured?

Answer 21

retrograde blood supply

high risk of non-union and avascular necrosis

Question 22

In which populations is proximal rupture of the biceps tendon common?
In which population is distal rupture of the biceps tendon common?

Answer 22

older populations

younger population

Question 23

What makes paediatric elbow imaging difficult?

Answer 23

ossification centres can mimic fractures

arise in a predictable order -> clinicians need to be aware of this

Question 24

What makes the radiocapitellar line useful?

Answer 24

consistent on all views/elbow positions

Question 25

Where must the anterior humeral line run?

Answer 25

it should run straight through the middle third of the capitulum

Question 26

What happens when there is a supracondylar fracture?

Answer 26

posterior displacement