Artefacts at a glance: differentiating features of artefactual stenosis from true stenosis at the genu of the petrous internal carotid artery on TOF MRA

Aim To investigate the distinguishing features of artefactual stenosis from true stenosis at the genu of the petrous internal carotid artery (ICA) on time of flight (TOF) magnetic resonance angiography (MRA). Materials and methods Both TOF MRA and digital subtraction angiography (DSA) were performed in 65 patients with 74 vessels who demonstrated artefactual stenosis in 43 patients with 50 vessels and true stenosis in 22 patients with 24 vessels. The following findings of the signal loss were compared between the two groups: (1) margin, (2) darkness, (3) the presence of bilaterality, (4) the presence of tandem arterial stenosis, (5) the location of the epicentre, and (6) length. Results In five out of the six evaluated items, statistically significant differences were present between the two groups ( p p =0.706). Conclusion Several MRA features can be useful for suggesting artefactual stenosis rather than true stenosis at the genu of the petrous ICA on TOF MRA.