Trans-cranial Doppler (TCD) is superior to trans-oesophageal Echo (TOE/TEE) for shunt detection in PFO.

Here's an interesting interview with Dr David Spence (Canada) at the recent International Stoke Conference, 2014. He confirms that trans-cranial Doppler (TCD) with contrast is superior to that of trans-thoracic (TTE) and trans-oesophageal (TOE/TEE ) echocardiography with contrast for the detection of intra-cardiac right to left shunt. This supports our own experience and justifies our decision to use TCD with contrast as the primary screening tool for PFO/ASD since 2009.

The investigators found that in 15% of patients that had a cryptogenic stroke and positive trans-cranial study, the PFO was missed on the trans-oesophageal echo. Furthermore, 20% of those PFO's that were missed were found to be significant shunts. Dr Spence goes on to conclude that the TCD is more sensitive than the traditional 'Gold Standard' tests and the grading system is more predictive of events than any other anatomic marker such as atrial septal aneurysm.