W3- Radiological Evaluation of the Shoulder

Question 1

What is the lightbulb sign and what is it indicative of?

Answer 1

The humeral head is forced into internal rotation as it dislocates posteriorly, giving appearance of a lightbulb.

Question 2

What is a Hill-Sachs lesion?

Answer 2

Injury that occurs secondary to an anterior shoulder dislocation. The humeral head ‘collides’ with the anterior part of the glenoid, causing a lesion, bone loss, defect and deformity of the humeral head.

Question 3

• What is generally the first study for the shoulder?
• When do we utilize CTs on the shoulder?
• When do we utilize MRIs on the shoulder?

Answer 3

• Radiograph
• With complex fractures and to assist with surgical decisions.
• When results are anticipated to effect treatment decisions.

Question 4

Advanced Imaging Planes:

• Axial
• Oblique sagittal = Parallel to __________.
• Oblique coronal = Parallel to __________.

Answer 4

• Oblique sagittal = Parallel to glenoid fossa.

- Oblique coronal = Parallel to supraspinatus muscle.

Question 5

CT Shoulder Indications. (4)

Answer 5

• Severe trauma.
• Assessing fx alignment/displacement.
• Identifying loose bodies in GHJ.
• If MRI contraindicated, RTC pathology and other health conditions for which MRI is typically indicated.

Question 6

What can we see in an axial view of the shoulder? (5)

Answer 6

• GH articulation
• Articular cartilage injury
• Avulsions at greater tubercle
• Bankart lesion
• Hill-Sach’s lesion

Question 7

What can we see in an oblique sagittal view of the shoulder? (3)

Answer 7

• ACJ degeneration
• Subacromial space
• Acromion morphology

Question 8

What can we see in an oblique coronal view of the shoulder? (6)

Answer 8

• Labrum
• GH joint surfaces
• Glenoid rim
• Greater tubercle
• Subacromial space
• Acromion morphology

Question 9

MRI General Indications. (6)

Answer 9

• Soft tissue injuries (RTC lesion, long head of bicep lesion, subacromial soft tissue, labral lesions, joint surface abnormalities, muscle disorders, synovial disorders)
• Bone dysfunction (marrow, neoplasm, infection)
• Intra-articular
• Congenital/developmental conditions
• Vascular conditions
• Neurologic condition

Question 10

MRI of the shoulder can be helpful in staging and monitoring of certain health conditions such as what?

Answer 10

• frozen shoulder

- inflammatory arthropathy