RESUMEN
To assess contrast transcranial Doppler [TCD] for detection of right-to-left shunt [RLSh]. We studied 30 patients aged between 25-45 years admitted to Al-Zahra Hospital, affiliated to Isfahan University of Medical Sciences, between May 2003 and May 2005. All patients underwent transesophageal echocardiography [TEE] with contrast and contrast TCD. Eleven [36.6%] patients had RLSh detected by TEE with contrast, and 19 [63.3%] patients had no shunt by TEE. Eighteen patients [60%] patients had no RLSh by contrast TCD, and 12 [40%] patients had RLSh by contrast TCD. Ten [33.3%] patients had RLSh by contrast TCD and TEE with contrast procedures. One patient had RLSh by TEE, and it was negative on TCD test, and 2 patients were positive on TCD test and negative in TEE. With contrast TEE as the gold standard, the sensitivity of contrast TCD was 90.9% and specificity was 89.4%, with an accuracy of 90%. Meanwhile, the positive predictive value of contrast TCD was 83.3% and the negative predictive value was 94.4%. In our study, the negative predictive value of contrast TCD was excellent. Therefore, this examination is able to exclude RLSh with a high level of confidence