Results and conclusions Insonation of the Rosenthal and other intracranial veins through the classical transtemporal window, based on anatomical assumption, but never before validated by means of FIT study, was confirmed. Moreover, in all five subjects, FIT demonstrated the possibility of insonating the petrosal sinuses and the cavernous sinus area through the novel transcondylar approach. In conclusion, the feasibility of FIT of the intracranial veins potentially permits to study subjects in different postures and/or at the bed of non-transportable patients, after the initial MRI acquisition. Finally, the novel transcondylar approach allows obtaining haemodynamic information from the cavernous and the petrosal sinuses usually not investigated by TECD alone.