Strategically acquired gradient echo (STAGE)-derived MR angiography might be a superior alternative method to time-of-flight MR angiography in visualization of leptomeningeal collaterals.

OBJECTIVES: This study aimed to compare the performance of strategically acquired gradient echo (STAGE)-derived MR angiography and time-of-flight MR angiography (TOF-MRA) in visualization of leptomeningeal collaterals (LMCs). METHODS: Between May 2018 and January 2020, 75 participants (47 healthy volunteers and 28 intracranial atherosclerotic disease [ICAD] patients) undergoing TOF-MRA and STAGE-MRA were prospectively included. Image quality was scored at the internal carotid artery (ICA) terminus, proximal middle cerebral artery (MCA), and LMCs. Quantitative analysis included calculation of contrast-to-noise ratios (CNRs) in the M1-4 segments and number of LMCs counted in the line signal intensity profiles. Comparisons of image qualitative scores, CNRs, and number of LMCs were calculated using the Wilcoxon rank-sum test. RESULTS: Image qualitative scores were significantly higher in STAGE-MRA than in TOF-MRA for the ICA terminus, proximal MCA, and LMCs (ps < 0.05) in 75 participants. When referred to digital subtraction angiography (DSA) in 25 ICAD patients, STAGE-MRA showed higher qualitative scores only at LMCs. CNRs in the M1-4 segments were significantly higher in STAGE-MRA than in TOF-MRA (218.7 ± 90.7 vs 176.2 ± 72.6, 195.7 ± 86.0 vs 146.6 ± 71.7, 176.4 ± 71.6 vs 125.8 ± 61.1, 126.2 ± 62.9 vs 78.8 ± 43.6; all ps < 0.001). STAGE-MRA showed more LMCs (11.4 ± 3.4) than TOF-MRA (8.4 ± 3.3) with p < 0.05. CONCLUSIONS: STAGE-MRA might be superior to TOF-MRA in qualitative and quantitative assessment of LMCs in both healthy volunteers and ICAD patients; thus, it may serve as an alternative method in evaluating LMC. KEY POINTS: • Strategically acquired gradient echo (STAGE)-derived magnetic resonance angiography is a newly developed sequence with a pair of rephasing/dephasing gradient echoes. • STAGE-MRA enables higher image qualitative score, improves contrast-to-noise ratio, and shows greater number of leptomeningeal collaterals (LMCs) in healthy volunteers and patients with intracranial atherosclerotic disease. • LMC visualization by STAGE-MRA shows good to excellent inter-observer agreement.

Tagging SNPs in the MTHFR gene and risk of ischemic stroke in a Chinese population.

Stroke is currently the leading cause of functional impairments worldwide. Folate supplementation is inversely associated with risk of ischemic stroke. Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism. The aim of this study is to examine whether genetic variants in MTHFR gene are associated with the risk of ischemic stroke and fasting total serum homocysteine (tHcy) level. We genotyped nine tag SNPs in the MTHFR gene in a case-control study, including 543 ischemic stroke cases and 655 healthy controls in China. We found that subjects with the rs1801133 TT genotype and rs1801131 CC genotype had significant increased risks of ischemic stroke (adjusted odds ratio (OR)=1.82, 95% confidence interval (CI): 1.27-2.61, p=0.004; adjusted OR=1.99, 95% CI: 1.12-3.56, p=0.01) compared with subjects with the major alleles. Haplotype analysis also found that carriers of the MTHFR CTTCGA haplotype (rs12121543-rs13306553-rs9651118-rs1801133-rs2274976-rs1801131) had a significant reduced risk of ischemic stroke (adjusted OR=0.53, 95% CI: 0.35-0.82) compared with those with the CTTTGA haplotype. Besides, the MTHFR rs1801133 and rs9651118 were significantly associated with serum levels of tHcy in healthy controls (p<0.0001 and p=0.02). These findings suggest that variants in the MTHFR gene may influence the risk of ischemic stroke and serum tHcy.

Middle cerebral artery thrombus susceptibility-weighted imaging mapping predicts prognosis.

BACKGROUND: Susceptibility weighted imaging and mapping (SWIM) of magnetic resonance imaging (MRI) is used to evaluate cerebral arterial thrombosis. The aim of this research was to assess susceptibility, length, and clot burden score (CBS) of thrombus in the middle cerebral artery (MCA) and their relationship with cerebral infarction and early clinical prognosis in patients with acute or subacute cerebral infarction. METHODS: In total, 56 patients with acute or subacute cerebral infarction (with the time from onset to admission less than 72 h) and only unilateral MCA occlusion were included in the current study. All the patients had the corresponding susceptibility vessel sign (SVS) on susceptibility-weighted imaging (SWI). Parameters including susceptibility, length, and CBS of thrombus were obtained from SWI and SWIM. The differences in susceptibility of different portions of the thrombus were compared with each other by one-way ANOVA test. The relationship between susceptibility and stroke onset time was further analyzed by Spearman correlation analysis, in addition to the relationships between susceptibility, length, CBS, diffusion-weighted imaging-Alberta stroke program early CT score (DWI-ASPECTS), and admission and discharge National Institutes of Health Stroke Scale (NIHSS). RESULTS: The susceptibility among different portions and different segments of thrombus showed no statistical difference. The susceptibility and length were weakly yet negatively correlated with DWI-ASPECTS (rs=-0.382, -0.457; P=0.004, 0.000). The susceptibility was weakly yet positively correlated with admission NIHSS and discharged NIHSS (rs=0.403, 0.430; P=0.002, 0.001). CBS was weakly yet positively correlated with DWI-ASPECTS (rs=0.349; P=0.008) and weakly yet negatively correlated with admission and discharged NIHSS (rs=-0.375, -0.335; P=0.004, 0.012). CONCLUSIONS: The susceptibility remained consistent regardless of location, length, and onset time, which indicates that the thrombus composition was similar when detected on SWI less than 72 h from the onset. Susceptibility and CBS may help to predict clinical severity and short-term clinical prognosis to some extent.