Injury Imaging Flashcards
What are the standard projection for shoulder imaging?
Anterior-posterior (AP) External Rotation
AP Internal Rotation
What are the additional projections for shoulder imaging?
Axillary view
Scapular Y lateral view
What are the projections for AC joint imaging?
AP
Bilateral (with and without weights)
What are the projections for scapular imaging?
AP
Lateral
What does the shoulder AP external rotation imaging demonstrate?
Proximal 1/3 of humerus
Lateral 2/3 of clavicle
AC joint
Upper and lateral portion of the scapula
What are the key observations for AP external rotation shoulder imaging?
Greater tuberosity and lesser tuberosity (superimposed at mid-area of humeral head)
Medial portion of humeral head (partially superimposed in glenoid fossa)
Crest of spine of scapula
Superimposition of scapula behind rib cage
What should the width of the GH joint be?
5mm; note for increase or decrease
Which joint is superior to GH?
AC
What structural abnormalities should be observed for in AP External rotation view?
Increase in superimposition of humeral head; subluxation, dislocation
Decrease in superimposition of hmeral head; DJD
AC joint DJD, subluxation, dislocation
Calcium deposits in muscles, tendons or bursae
What does AP internal rotation demonstrate?
Proximal 1/3 of humerus
Lateral 2/3 of clavicle
AC joint
Upper and lateral portion of scapula
What are the key observations of AP internal rotation?
Greater tuberosity now superimposed over mid-area of humeral head
Lesser tuberosity seen in profile on the medial aspect of the HoH
Medial portion of humeral head partially superimposed in glenoid fossa
Crest of spine of scapula
Superimposition of scapula behind rib cage
Observe for calcium deposits in muscles, tendons, bursae
What structures are ossified at birth?
Only the clavicle, scapular body, humeral shaft and proximal humeral head are ossified
What ossification centres appear between the ages of 3-5 in the shoulder?
Greater and lesser tuberosities
What shape are the growth plates in paediatrics?
Cone shaped with apex pointed superiorly
What occurs at 16 years old in the shoulder?
Greater tuberosity fuses with humeral shaft
When does complete fusion occur?
20-22 years
What is the ossification process of the scapula from birth?
Coracoid process ossification centre appears at 1 year
Other scap structures at puberty
Fusion with rest of scap at 18-25
What does an axillary shoulder view demonstrate?
Inferosuperior axial projection of the GH joint
Exact relationship of humeral head to glenoid fossa
Esp. useful in evluation of GH dislocations
Rims of the glenoid fossa and coracoid process
What does the bilateral with and without weights demonstrate?
Bilateral AC joints for compression
Weights are added for a stress view to visualise instability
Entire length of clavicles
Both SC joints
Both shoulders in AP view
What are key observations in bilateral with and without weight views?
Assess AC joint space and coracoclavicular distance
What is visible with a grade 1 AC sprain?
Mild = minimal widening of AC joint space; coracoclaivular distance still within normal range
What is visible with a grade 2 AC sprain?
Moderate = widening of AC joint space to 1-1.5 cm with a 25-50% increase in coracoclavicular distance still within normal range
What is visible with a grade 3 AC sprain?
Severe = widening of AC joint space > 1.5cm with >50% increase in coracoclavicular distance
What are the main AC joint mechanisms?
Direct blow
Traction on arm
FOOSH
Fall on flexed elbow
