Association between vascular calcification in intracranial vertebrobasilar circulation and luminal stenosis

Introduction The study aims to assess the correlation and association between calcium burden and luminal stenosis in the vertebrobasilar circulation. Methods We evaluated 166 patients [mean age, 79.8 ± 8.8 (SD) with 93 males] with stroke symptoms. The calcification patterns were assessed on non-contrast CT (NCCT); quantitative calcium burden [Agatston-Janowitz (AJ) calcium score, volume, and mass] on the initial non-contrast phase of CT perfusion (CTP); and the qualitative and quantitative luminal stenosis on CT angiography (CTA) studies. We calculated the correlation coefficient and association between measures of calcium burden and luminal stenosis. Results Two hundred twenty-eight of 498 arteries (45.8%) had detectable calcification on NCCT and measurable stenosis in 169 of 498 arteries (33.9%) on CTA. We found a moderate correlation between qualitative calcium burden and qualitative (0.51 for R1 and 0.62 for R2, p < 0.01) as well as quantitative luminal stenosis (0.67 for R1 and 0.69 for R2, p < 0.01). There was a moderate correlation of AJ score (0.66), volume (0.68), and mass of calcification (0.60, p < 0.01) with luminal stenosis measurements. The quantitative calcium burden and luminal stenosis showed statistically significant differences between different qualitative categories of calcium burden ( p < 0.001 in both readers). However, severe stenosis was not seen even with the advanced circumferential wall calcification (mean stenosis of 35.3–40.7%). Conclusion Our study showed a moderate correlation between higher burden of vascular calcification and the degree of luminal stenosis. However, higher calcium burden and circumferential wall calcification were not associated with severe luminal stenosis.