Paradoxical thrombotic embolism via right-to-left cardiac shunt (RLS) is a risk factor of cryptogenic ischemic stroke. Transtemporal Doppler (TTD) is a valid method used in the detection of patent foramen ovale (PFO). Temporal acoustic bone windows are missing with increasing age and in some younger subjects. We studied prospectively whether Doppler ultrasound of the cervical arteries (submandibular internal carotid artery [ICA] and vertebral artery [VA]) is an alternative, when compared to TTD, in the detection and quantification of PFO.