Diagnosing carotid near-occlusion with 1 mm side-to-side asymmetry: a tough task made too easy

Excerpt

In this issue of Neuroradiology, Koskinen and colleagues present their idea: that carotid near-occlusion (a tight stenosis that causes a collapse of the distal artery) can be separated from conventional ≥50% stenosis by measuring the distal diameter and all cases with ≥1.0 mm side-to-side difference is a near-occlusion [1]. Their goal was “to facilitate the recognition and diagnosis of near-occlusion, and raise the notion that even when a subtle distal ICA LD [Luminal Diameter] reduction is present, a possible near-occlusion should be considered.” It is important to raise awareness of near-occlusions without full collapse, when the distal artery otherwise seems normal, albeit smaller than usual. Indeed, this issue is so important that we recently ranked it as one of the two major near-occlusion issues in most need of improvement [2]. Any neuroradiologist who is not well aware of the near-occlusion without full collapse would do well to apply this as a first step towards improved understanding. However, apart from raising initial awareness, we advocate against the use of this proposed 1.0 mm criterion for diagnosing near-occlusion. …