Chest (lateral view)

Last revised by Rohit Sharma on 17 Apr 2024

The lateral chest view examines the lungs, bony thoracic cavity, mediastinum, and great vessels.

This orthogonal view to a frontal chest radiograph may be performed as an adjunct in cases where there is diagnostic uncertainty. The lateral chest view can be particularly useful in assessing the retrosternal and retrocardiac airspaces.

If locating a specific pulmonary opacity within the chest cavity, it would be useful for requesting doctors to ensure that the side of the opacity is mentioned in their clinical notes. This will allow radiographers/imaging technologists to image with the side of interest against the image receptor, hence reducing any magnification from an increased SID. Otherwise, a left lateral view is the default and preferred side as it demonstrates better anatomical detail of the heart. 

  • standing upright

  • left side of the thorax adjacent to the image receptor

    • left shoulder placed firmly against the image receptor

  • both arms raised above the head, preventing superimposition over the chest

    • arms can be placed on the head or holding onto handles, if available

  • chin raised out of the image field

  • midsagittal plane must be perpendicular to the divergent beam, therefore:

  • lateral projection

  • suspended inspiration  

  • centering point

  • collimation

    • superiorly 5 cm above the shoulder joint to allow proper visualization of the upper airways 

    • inferior to the inferior border of the 12th rib 

    • anteroposterior to the level of the acromioclavicular joints

  • orientation  

    • portrait 

  • detector size

    • 35 cm x 43 cm 

  • exposure

    • 100-110 kVp

    • 8-12 mAs

  • SID

    • 180 cm

  • grid

    • yes 

The entire lung fields should be visible superior from the apices inferior to the posterior costophrenic angle 

  • the chin should not be superimposing any structures 

  • there is superimposition of the anterior ribs 

  • the sternum is seen in profile 

  • superimposition of the posterior costophrenic recess

  • a minimum of ten posterior ribs are visualized above the diaphragm

  • the ribs and thoracic cage are seen only faintly over the heart

  • clear vascular markings of the lungs should be visible

The same principle of positioning can be applied to patients in a chair.

Before exposing ensure your patient is not leaning forward or backwards too much, this will result in anatomy being cut off.

Patients with a longstanding history of emphysema or COPD will have abnormally long lungs compared to the general population, remember this when collimating superior to inferior.

Side marker placement is imperative; patients can have congenital conditions that mimic a mirrored image 2

Patients with scoliosis may not demonstrate the traditional indicators of a correctly positioned lateral radiograph; it is important to note that patients with this condition particularly in the thoracic region will appear rotated by conventional evaluation, yet this is not the case. 

Remember to explain to your patient what you are about to do; that is, ask them to take a breath in and hold it. Many times this gives the patient time to prepare and results in better breath-hold and therefore a higher quality radiograph.

Always remember to tell your patient to breathe again!

Right lateral radiograph would project the posterior portion of right hemidiaphragm higher than the left hemidiaphragm, meanwhile the in left lateral radiograph, the posterior portion of the left hemidiaphragm is projected above the right hemidiaphragm. This is due to beam divergence of the x-ray with centering point above the diaphragm 3.

Posterior ribs farther from the image receptor will be projected more posteriorly, less sharp, and more magnified when compared to the ribs located near the radiograph 3.

The right oblique fissure will intersect the right hemidiaphragm more anteriorly when compared to the left oblique fissure either in left or right lateral radiographs 3.

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