CT shoulder (protocol)

Last revised by Andrew Murphy on 23 Mar 2023

The CT shoulder protocol serves as an examination for the assessment of the shoulder joint. It is often performed as a non-contrast study. It can be combined with a CT arthrogram for the evaluation of labral injuries or the rotator cuff if MRI is contraindicated or in a postoperative setting where metallic implants are present.

Note: This article aims to frame a general concept of a CT protocol for the assessment of the shoulder. Protocol specifics will vary depending on CT scanner type, specific hardware and software, radiologist and perhaps referrer preference, patient factors e.g. implants, specific indications.

A typical CT of the shoulder might look like as follows:

Typical indications include the following 1-5:

The main purpose of a shoulder CT is the depiction of the three-dimensional bony morphology of the proximal humeral head and the glenoid bone 1-5

  • classification of proximal humeral and scapular fractures
  • preoperative planning
    • glenoid morphology, bone stock and glenoid version
    • depiction of cystic changes and bone erosions
  • characterization of osteolytic lesions, osteoid and/or chondroid matrix in bone tumors 2

A CT arthrogram of the shoulder can depict glenoid labral tears, cartilage injury and rotator cuff tears 4,5.

  • patient position
    • supine position 
    • ipsilateral arm next to the body - shoulder externally rotated (thumb points outward)
    • contralateral arm raised above the head
  • tube voltage
    • ≤140 kVp
  • tube current
    • as suggested by the automated current adjustment mode
  • scout
    • proximal half of the humerus to the skin above the acromioclavicular joint
  • scan extent
  • scan direction
    • craniocaudal
  • scan geometry
    • field of view (FOV): 120-250 mm (should be adjusted to increase in-plane resolution)
    • slice thickness: ≤1.25 mm, interval: ≤0.625 mm
    • reconstruction algorithm: bone, soft tissue
  • multiplanar reconstructions
    • axial images: perpendicular to the humeral shaft axis
    • coronal images: parallel to the scapular body axis
    • sagittal images: perpendicular to the scapular body axis 
    • slice thickness: ≤2 mm, overlap 50%
    • additional coronal and sagittal centered on the humeral stem might be obtained
  • 3D reconstruction
  • mindful patient positioning with external rotation of the upper limb prior to scanning might reduce reconstructions
  • the extent of the examination should be tailored to the specific indication and clinical question
  • reconstructions should be centered on the shoulder joint 
  • imaging of implants
  • 3D reconstruction techniques are beneficial for the assessment of glenoid bone stock and version measurements

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