What is the CR angulation for the lateral projection of the cervicothoracic region swimmers technique when the shoulder can be depressed?

Citation, DOI & article data

Citation:

Murphy, A. Cervical spine (swimmer's lateral view). Reference article, Radiopaedia.org. (accessed on 08 Sep 2022) //doi.org/10.53347/rID-48437

Cervical spine swimmer's lateral view is a modified lateral projection of the cervical spine to visualize the C7/T1 junction. 

As technology advances, computed tomography has replaced this projection, yet there remain many institutions (especially in rural areas) where computed tomography is not readily available.

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This view is most often performed when a standard lateral view cannot image the cervicothoracic junction due to patients having a dense, muscular shoulder. It can help to visualize subluxation and fractures involving the inferior cervical spine, superior thoracic spine and adjacent soft tissue.

  • the patient is supine or erect, depending on trauma or follow up  
  • the detector is placed running parallel to the long axis of the cervical spine
  • the arm closest to the detector is placed above the patient's head, resting on the head for support
  • the opposite arm is placed by the patient's side, as posterior to the patient as possible (maintaining spinal precautions if they are in place)
  • image is taken on suspended expiration
  • lateral projection
  • centering point
    • 2.5 cm above the jugular notch at the level of T1
  • collimation
    • superior to C1
    • inferior to T3
    • anterior to the extent of the vertebral bodies
    • posterior to the spinous process
  • orientation  
    • landscape
  • detector size
    • 24 cm x 30 cm
  • exposure
    • 80-90 kVp
    • 120-150 mAs
  • SID
    • 100 cm
  • grid
    • yes
  • there should be a clear visualization of C7 to T1
  • the vertebral bodies are superimposed laterally
  • the articular pillars and zygapophyseal joints are superimposed

The concept of this projection is to clear the superimposing humeral heads of the cervical spine, the offset of the arms attempts to achieve this. This projection is technically demanding and very hard to replicate consistently.

The technique will vary from radiographer to radiographer; however, they will all have their pitfalls.

This projection is regularly high stakes in resuscitation rooms and is utilized to assess critical anatomy, for those who do not have the privilege to use a superior modality such as CT 1.

Here are some handy hints:

  • collimate incredibly tight, because this is such a high dose projection the scatter will be at an all-time high; collimation will alleviate this
  • take your time setting the patient up, rushing this projection will only cause you headaches down the road
  • use two filters, one filter anterior and one superior; this will even out the density
  • if the patient is not on spinal precautions i.e. follow-up examination for metal work, rotate the patient 10 degrees RAO to offset the humeral heads

References

Related articles: Imaging in practice

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