Transforaminal Doppler: an alternative to transtemporal approach for right-to-left cardiac shunt assessment

Area of Science:

• Neurology
• Cardiology
• Medical Imaging

Background:

• Paradoxical thrombotic embolism via right-to-left shunt is a significant risk factor for ischemic stroke, particularly in younger individuals.
• Transtemporal Doppler is effective for detecting patent foramen ovale (PFO), but its utility is limited in patients with inadequate acoustic temporal bone windows.
• Acoustic bone window limitations affect up to 10% of younger patients, necessitating alternative diagnostic approaches.

Purpose of the Study:

• To evaluate transforaminal (foramen magnum) Doppler as an alternative to transtemporal Doppler for detecting and quantifying right-to-left cardiac shunts.
• To assess the efficacy of transforaminal Doppler in patients with recent stroke of undetermined origin.

Main Methods:

• Prospective study involving 74 patients who experienced a recent stroke of undetermined origin.
• Comparison of transforaminal Doppler measurements with transtemporal Doppler in the detection of right-to-left cardiac shunt.
• Quantification of right-to-left cardiac shunt using both Doppler techniques.

Main Results:

• A highly significant correlation was found between transforaminal Doppler and transtemporal Doppler methods.
• Transforaminal Doppler demonstrated effectiveness in detecting and quantifying right-to-left cardiac shunt.
• The study confirmed the feasibility of using transforaminal Doppler in the studied patient cohort.

Conclusions:

• Transforaminal Doppler serves as a valuable complement and alternative to transtemporal Doppler.
• This method can enhance the screening capabilities for right-to-left cardiac shunt caused by patent foramen ovale.
• Transforaminal Doppler may improve diagnostic yield in patients unsuitable for transtemporal assessment.