Re-circulation artefact at the carotid bulb can be differentiated from true stenosis

Re-circulation artefact developing secondary to vortex flow at the bulb of the internal carotid artery is very difficult to distinguish from true stenotic defect on two-dimensional Fourier transformed time-of-flight magnetic resonance angiography (2D-FT TOF MRA). The purpose of our study is to identify appropriate distinguishing features of re-circulation artefact. We included 45 extracranial carotid arteries collected from 25 patients who underwent both 2D-FT TOF MRA and contrast medium based angiography. Review of the 45 vessels demonstrated re-circulation artefact in 21 vessels, true stenotic defect in 8 vessels, and no filling defect in 16 vessels on 2D-FT TOF MRA. We compared the findings of re-circulation artefact and true stenotic defect in 29 vessels excluding the 16 vessels without filling defect. The following were evaluated: (1) preservation of posterior wall contour; (2) marginal character of filling defect; (3) darkness of filling defect; (4) involvement of common carotid artery by filling de...