Background/Aims
TCD bubble studies are used to screen for PFO in patients with stroke. Equipment cost impedes more widespread use. We evaluated the utility of an inexpensive hand-held POCUS device.
Methods
TCD PFO testing was performed in 25 patients with a standalone TCD device (Viasonics Dolphin) and POCUS device (Mindray TE Air), recording embolic signals (ES) from the middle cerebral artery (MCA). ES occurring during 1’ following agitated saline contrast injection were automatically counted by the Dolphin. A 3rdblinded sonographer manually counted TE Air ES offline. ES counts were graded from grade 0 (no ES) to grade 5 (curtain, too many to count).
Results
Sonographers encountered technical problems using the TE Air. Maintaining a good MCA signal during injection of contrast and Valsalva was difficult. A satisfactory insonation window was not obtained in one patient. 2 patients had grade 2-4 ES detected by the Dolphin after injection of contrast without Valsalva but these were not detected with the TE Air. 8 patients had grade 2-4 ES detected by the Dolphin after injection of contrast and Valsalva of whom only 5 also had grade 2-4 response with the TE Air. 6 patients had grade 5 ES detected by the Dolphin after injection of Valsalva but only 3 had a grade 5 response with the TE Air, probably explained by departure from the research protocol.
Conclusions
Although PFO testing can be performed using the TE Air there are technical challenges. Based on our experience, a standalone TCD device is preferred.