Figure 1: Barium swallow showing hold up of contrast at the cardio-esophageal junction.

(Click on image to enlarge)

Figure 2: Delay imaging of the barium swallow from Figure 1, showing greater hold up of contrast at the cardio-esophageal junction and dilatation of the distal esophagus.

(Click on image to enlarge)



Achalasia is a condition involving the oesophagus in which there is failure of organized peristalsis with impaired relaxation at the level of lower oesophageal sphincter.   The oesophagus becomes dilated with a typically tight narrowing at the gastro-oesophageal junction (GOJ; Figure 1-4).


Peristalsis in the distal smooth muscle segment of the oesophagus is impaired due to an abnormality of Auerbach plexus resulting in weak uncoordinated contractions.  Also known as the myenteric plexus it provides motor innervation to both layers of the muscular layer, having both parasympathetic and sympathetic input.


The motility of the oesophagus is resultantly impaired, which becomes dilated, with slow or reducing emptying into the stomach.


A barium swallow is the radiological investigation of choice – revealing both the dynamic and structural abnormalities of achalasia.


These include:

a.    A dilated oesophahgus (Figure 1 & 2)

b.    An air-fluid level in the distal oesophagus (reflecting impaired emptying; Figure 2)

c.    Distal narrowing at the GOJ, given a characteristic ‘bird’s beak’ appearance (Figure 3 & 4)

d.    No filling of the stomach

e.    Atonic or adyamic peristalsis


Achalasia predisposes to a number of problems including:

a.    Aspiration pneumonia  ( static column of fluid in the dilated oesophagus )

b.    Secondary candidiasis

c.    In a small percentage, an increased risk of malignancy ( irritation of the mucosa from chronic stasis)


A number of treatment options exist:

a.    Oesophageal dilatation ( endoscopically or radiologically )

b.    Botulinum toxin injection

c.    A myotomy


Figure 3: Delay image of barium swallow showing greater hold up of contrast at the cardio-esophageal junction with dilatation of the distal esophagus.

(Click on image to enlarge)

Figure 4: Annotated image of Figure 3 showing the bird's beak feature of Achalasia.

(Click on image to enlarge)


Similar appearances can occur in the spine.  A single vertebral body may be involved, which is expanded and sclerotic to which the term an ivory vertebra is given (Figures 4 & 5).  Metastases and lymphoma can give a similar appearance.




Images and text contributed by

Dr Ian Bickle, Department of Radiology,RIPAS Hospital.


All images are copyrighted and property of RIPAS Hospital.