the Doppler angle of insonation has a significant effect on spectral Doppler velocity measurements. It is crucial that duplex criteria are standardised with a fixed angle of insonation and that this angle is consistently used during velocity estimations.

duplex scanning is an important noninvasive diagnostic modality in patients with cervical artery dissection. Staccato flow along the extracranial ICA strongly indicates the presence of spontaneous ICA dissection.

in patients with conclusive duplex scan findings there is no need to perform angiography prior to lower limb reconstruction.