Spotty Calcium on Cervicocerebral Computed Tomography Angiography Associates With Increased Risk of Ischemic Stroke

Abstract

Background and Purpose— Cervicocerebral vascular calcification on computed tomography angiography is a known sign of advanced atherosclerosis. However, the clinical significance of calcification pattern remains unclear. In this study, we aimed to investigate the potential association between spotty calcium and acute ischemic stroke. Methods— This study included patients with first-time nonlacunar ischemic stroke (N=50) confirmed by brain magnetic resonance imaging or nonenhanced head computed tomography, as well as control subjects with asymptomatic carotid atherosclerosis (N=50) confirmed by carotid ultrasonography. Subjects in both groups underwent contrast-enhanced cervicocerebral computed tomography angiography within a week after the initial imaging examination. Spotty calcification was evaluated at 11 arterial segments commonly affected by atherosclerosis along the carotid and vertebrobasilar circulation. Statistical analysis was performed comparing the frequency and spatial pattern of spotty calcification between the 2 groups. Results— Spotty calcification in the Stroke group was markedly more prevalent than that in the Control group (total SC count: 8.74±4.96 versus 1.84±1.82, P <0.001). The odds ratio (95% CI) for stroke was 2.49 (1.55–4.00) for spotty calcification at bilateral carotid bifurcation, 1.52 (1.13–2.04) at carotid siphon, and 1.98 (1.45–2.69) at all evaluated locations. A total number of 3 spotty calcifications were determined as the optimal cutoff threshold for increased risk of stroke. Spotty calcium showed significantly greater area under the receiver operating characteristics curve than total calcium volume irrespective of size (0.88 versus 0.77). Within the Stroke group, ipsilateral lateral side showed significantly more spotty calcium than the contralateral side (5.18±3.05 versus 3.56±2.67, P <0.001). Conclusions— Nonlacunar ischemia stroke was associated with markedly increased incidence of spotty calcification with a distinct spatial pattern on cervicocerebral computed tomography compared with subclinical atherosclerosis, suggesting the potential role of spotty calcification for improving the risk stratification for ischemic stroke.

Cervicocephalic Spotty Calcium for the Prediction of Coronary Atherosclerosis in Patients With Acute Ischemic Stroke

“…In this study, calcium was defined as a region with ≥1 contiguous pixel with CT attenuation ≥ 130 Hounsfield units in each image slice ( 16 ). SC was defined based on a length of calcium (extent of the calcification parallel to the longitudinal direction of the vessel on the curved MPR image) below 3 mm and a maximum arc below 90° ( 12 ). According to the NASCET, the cervicocephalic arteries stenosis is divided into none (0), mild stenosis (1–49%), moderate stenosis (50–69%), severe stenosis (70–99%), and occlusion.…”

“…Fan and colleagues reported that cervicocerebral spotty calcium (SC) may provide a potential means for improving non-invasive risk stratification for AIS. Compared with subclinical atherosclerosis, AIS is associated with a high incidence of SC on cervicocephalic CTA ( 12 ). The findings from this study suggest the additional clinical value of the differential analysis of vascular calcium beyond a more general wholesale measure of the total amount of calcium.…”

Regulation of Vascular Calcification by Reactive Oxygen Species

“…Vascular calcification is characterized by the accumulation of hydroxyapatite in the wall of large elastic arteries and coronary arteries. Vascular calcification has been related to increased risk of cardiovascular morbidities and complications [ 15 ], such as atherosclerotic plaque burden [ 16 , 17 , 18 ], myocardial infarction [ 19 , 20 , 21 ], coronary artery disease [ 22 , 23 ], ischemic stroke [ 21 , 24 ], postangioplasty dissection [ 25 ], and increased ischemic episodes in peripheral vascular disease [ 26 ]. Studies also indicate that coronary calcification may be predictive of or associated with sudden cardiac death [ 27 , 28 ].…”

X-ray Micro-Computed Tomography: An Emerging Technology to Analyze Vascular Calcification in Animal Models

“…As discussed in the Introduction, the structure and composition of an atheromatous plaque and, specifically, the size and distribution of intimal calcifications within the plaque are important risk factors for rupture and subsequent cardiovascular events [ 7 , 8 , 9 , 10 , 123 ]. Using 2-D histological approaches to analyze intimal calcification in pre-clinical animal studies has been associated with several drawbacks, including shearing artefacts and the inability to examine spatial heterogeneity in calcification throughout an intact blood vessel.…”

“…The distribution of calcifications within an atheromatous plaque can also impact plaque stability. For example, spotty calcifications which are classified as several mid-sized (~0.5 mm in diameter) calcium deposits spaced 1–3 mm apart, are associated with ‘high-risk’ plaques in coronary and carotid arteries [ 8 , 9 , 10 ].…”