PFO size estimation using TCD: Are the measurements gender related?

There is an ongoing interest in using the findings of Transcranial Doppler (TCD) as a diagnostic technique for patent foramen ovale (PFO) determination. The aim of this study was to investigate the sensitivity of TCD for detection of PFO presence and the correlation of PFO size with the detected microbubble signals. The study group comprised of 103 individuals, healthy volunteers and patients with ischemic stroke or other cerebrovascular diseases. TCD was performed on all subjects, while the presence and size of PFO was estimated with Transesophageal Echocardiography (TEE). PFO diagnosis with TCD had a 92.68% sensibility, 89.47% specificity, 86.65% positive predictive value and 94.44% negative predictive value. PFO size was moderately correlated with the number of microembolic signals detected (rs = 0.404, p = 0.026). Further analysis for gender shown a strong correlation for men (rs = 0.781, p = 0.003), but no correlation for women (p = 0.92). Our results show that TCD is a good predictor of PFO in terms of sensibility and specificity. The correlation between the size of PFO on TEE and the number of microembolic signals detected on TCD is gender biased. Further anatomic and physiological studies are required to identify the reasons for this phenomenon