Welcome to part 2 of the intussusception series – check out part 1 here.

Let’s suppose that you work in a place without 24 hour ultrasound, and you get a toddler that is having intermittent episodes of belly pain. You think she has intussusception. You recall that there are some X-ray findings that can help make you feel better about ruling it out. But, you’re really worried about this kid. Why not just do the ultrasound yourself? Can’t be that difficult can it?

How good is an ultrasound at diagnosing intussusception?

The sensitivity and specificity approaches 100% in the hands of a good sonographer.

What are the characteristic findings on ultrasound?

These talented sound wave technicians look for the following classic findings in ileo-colic intussusception:

Target sign shows layers of invaginated bowel

Target sign in intussuscpetion

Target sign in intussusception

Another target sign in intussusception

Sagittal view of intussusception
sagittal view of intussusception

sagittal view of intussusception

Lack of perfusion in the intussusceptum on color doppler: may indicate intestinal ischemia
Doppler ultrasound shows no flow in the center of the target

Doppler ultrasound shows no flow in the center of the target

Can Emergency Medicine physicians be trained to do it?

One recent study from Taiwan asked this particular question, and found that yes, they can. Chang et al. noted that, as expected, physicians that had received ultrasound training were better able to make the diagnosis –  with “the diagnostic sensitivity of the ultrasound training group

[being] significantly higher (90% vs. 79%, p = 0.034).” How and when to get the training – now that’s the question.

Tune in tomorrow for part 3.