Why the study?
Transcranial Doppler ultrasound (TCD) is non-invasive, but its diagnostic performance for patent foramen ovale relative to other modalities is unclear.
Does transcranial Doppler ultrasound (TCD) improve sensitivity for right-to-left shunt detection compared to transthoracic echocardiogram (TTE) in patients with ischemic stroke or TIA?
Observational (n=92)
No
Does transcranial Doppler ultrasound (TCD) improve sensitivity for right-to-left shunt detection compared to transthoracic echocardiogram (TTE) in patients with ischemic stroke or TIA?
Absolute Event Rate: 94% vs 50%
p-value: p=0.039
Transcranial Doppler ultrasound offers high sensitivity for detecting right-to-left shunts in stroke/TIA patients, making it a valuable non-invasive screening tool compared to TTE.
Background and aims Patient foramen ovale (PFO) is a stroke risk factor evaluated using transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE), transcranial Doppler ultrasound (TCD), and cardiac computed tomography (CCT). TCD is non-invasive, but its diagnostic performance relative to other modalities is unclear. We hypothesized that TCD has high sensitivity but low specificity for PFO detection. Methods We conducted an IRB-approved, single-center retrospective study of patients undergoing TCD for right-to-left shunt (RLS) detection between January 2024 and April 2025. Patients were identified from the Neurosonology Laboratory Quality Database. Records were reviewed for demographics, comorbidities, and TTE, TEE, and CCT findings. Sensitivity, specificity, and positive and negative predictive values were calculated for TCD, TTE, and CCT relative to TEE, the gold standard. The sensitivity and specificity of TCD versus TTE were compared using McNemar test. Results Ninety-two patients were included. Mean age was 52.66 ± 15.78 years, and 51% were female; qualifying events included ischemic stroke or transient ischemic attack. RLS was detected in 53 patients (57.6%) by TCD, 17 (30%) by TTE, 18 (28.5%) by TEE, and 3 (21%) by CCT. TCD demonstrated 94% sensitivity and 53% specificity, (PPV 66%, NPV 89%). TTE showed 50% sensitivity and 82% specificity (PPV: 75%, NPV 61%), while CCT showed 33% sensitivity and 100% specificity (PPV 100%, NPV 33.3%). TCD had significantly higher sensitivity than TTE for RLS detection (p=0.039) with a non-significant difference in specificity (p=0.062), using TEE as the reference. Conclusions TCD has high sensitivity for RLS detection in patients with ischemic stroke or transient ischemic attack. Conflict of interest Rachel Knopp: nothing to disclose; Kelly Flemming: nothing to disclose; Eugene Scharf: nothing to disclose; Zafer Keser: nothing to disclose; Jessica Prink: nothing to disclose; Shari Johnson: nothing to disclose; Guy Reeder: nothing to disclose; Robert Brown: nothing to disclose; William Harmsen: nothing to disclose; Muhib Khan: nothing to disclose Table 1 - belongs to Results
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Knopp et al. (2026) conducted an observational in Patent foramen ovale / right-to-left shunt (n=92). Transcranial Doppler ultrasound (TCD) vs. Transthoracic echocardiogram (TTE) and Transesophageal echocardiogram (TEE) was evaluated on Sensitivity for right-to-left shunt detection relative to TEE (p=0.039).
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