Abdominal (lateral view)

The lateral view abdominal radiograph is a less common projection of the abdomen, it is different from the lateral decubitus view of the abdomen and looks more like a lateral lumbar spine view.

Indications

This projection is often requested as a useful problem-solving view that can complement frontal views of the abdomen, often utilised in the context of foreign bodies, to visualise soft tissue masses, umbilical hernia, or prevertebral pathology such as aortic aneurysm or calcifications ².

This view also better visualise lines such as a shunt (or a part of a dedicated shunt series).

Patient position

• the patient may be either erect or recumbent, with her or his side against the detector

• legs may be flexed for balance ²

• arms raised ²

• lower bound of the field of view should contain the inferior pubic ramus

• the x-ray is taken in full expiration ²

Technical factors

• supine lateral projection

•  centring point

  • the midcoronal plane at the level of the iliac crest

• collimation

  • anterior-posterior to the skin margins 

  • superior to the diaphragm

  • inferior to the level inferior pubic rami

• orientation

  • portrait

• detector size

  • 35 cm x 43 cm ²

• exposure

  • 70-80 kVp

  • 30-120 mAs; AEC should be used if available

• SID

  • 100 cm ²

• grid

  • yes

Image technical evaluation 

• the projection can be confirmed lateral via the lateral appearance of the vertebral bodies

• skin border is not burnt out (a filter may be required to address this) 

• no blurring of the bowel gas due to respiratory motion 

Practical points

• the lateral abdomen can be useful to visualise rectal gas and differentiate colonic ileus from a distal colonic obstruction however it does not offer much information about bowel gas from the frontal view 

• this projection can be done erect or supine, often used to localise foreign bodies or as part of a shunt series when there is a high degree of winding of the line