Middle Cerebral Artery Plaque Research Articles

Geometry of Terminal Internal Carotid Artery Bifurcation May Be Associated With Middle Cerebral Artery Plaque Ulceration: A Three-Dimensional Rotational Angiography Study.

Geometry of Terminal Internal Carotid Artery Bifurcation May Be Associated With Middle Cerebral Artery Plaque Ulceration: A Three-Dimensional Rotational Angiography Study.

Plaque enhancement of middle cerebral artery and pre-stroke diet are associated with prognosis of subacute ischemic stroke: A prospective high-resolution MR vessel wall imaging study

ObjectivesTo explore the value of middle cerebral artery (MCA) plaque characteristics in predicting the outcomes of subacute ischemic stroke and the incremental value of the previous diet on predictive performance. MethodsOne hundred and thirty-seven subacute ischemic stroke patients attributed to MCA plaques were included and analyzed in this prospective study. The National Institute of Health Stroke Scale (NIHSS) score, Mediterranean Diet Adherence Screener (MEDAS) score, and other clinical data were assessed. The plaque area, degree of stenosis, plaque burden, enhancement ratio, remodeling type, and intraplaque hemorrhage were measured using high-resolution MR vessel wall imaging (HR-VWI). Multivariable logistic regression analysis and receiver operating characteristic curve analysis were performed to assess the predictive performance of clinical and plaque characteristics for subacute ischemic stroke outcomes at 3 months. ResultsPatients with poor outcomes exhibited high NIHSS scores, and low MEDAS scores (P<0.001). Plaque burden, enhancement ratio, and degree of stenosis were significantly higher in patients with poor outcomes (P<0.001). Multivariate analyses further indicated that NIHSS score (P=0.001), MEDAS score (P=0.013), and enhancement ratio (P=0.011) were independent predictors of subacute ischemic stroke outcomes. The three models’ area under the curve (AUC) values were 0.811, 0.844, and 0.794. Combining these three factors resulted in an AUC of 0.908 (P<0.001). ConclusionsThe combination of NIHSS score, MEDAS score, and enhancement ratio showed significant superiority in the prognostic evaluation of subacute ischemic stroke. Clinical data combined with plaque characteristics improves the accuracy of 3-month outcome prediction on subacute ischemic stroke.

Small vessel disease burden and prognosis of recent subcortical ischaemic stroke differ by parent artery atherosclerosis.

Parent artery atherosclerosis is an important aetiology of recent subcortical ischaemic stroke (RSIS). However, comparisons of RSIS with different degrees of parent artery atherosclerosis are lacking. Prospectively collected data from our multicentre cohort (all were tertiary centres) of the Stroke Imaging Package Study between 2015 and 2017 were retrospectively reviewed. The patients with RSIS defined as a single clinically relevant diffusion-weighted imaging positive lesion in the territory of lenticulostriate arteries were categorized into three subgroups: (1) normal middle cerebral artery (MCA) on magnetic resonance angiography and high-resolution magnetic resonance imaging (HR-MRI); (2) low-grade MCA atherosclerosis (normal or <50% stenosis on magnetic resonance angiography and with MCA plaques on HR-MRI); (3) steno-occlusive MCA atherosclerosis (stenosis ≥50% or occlusion). The primary outcome was 90-day functional dependence (modified Rankin Scale score >2). The clinical and imaging findings were compared between subgroups. A total of 239 patients (median age 60.0 [52.0-67.0] years, 72% male) were enrolled, including 140 with normal MCA, 64 with low-grade MCA atherosclerosis and 35 with steno-occlusive MCA atherosclerosis. Patients with steno-occlusive MCA atherosclerosis had the largest infarct volume. Low-grade MCA atherosclerosis was independently associated with cerebral microbleeding, more severe perivascular spaces in basal ganglia and higher total cerebral small vessel disease burden. Low-grade MCA atherosclerosis was an independent determinant of 90-day functional dependence (odds ratio 3.897; 95% confidence interval 1.309-11.604). Our study suggested RSIS with varying severity of parent artery atherosclerosis exhibits distinctive clinical and neuroimaging characteristics, with low-grade MCA atherosclerosis associating with higher cerebral small vessel disease burden and worse prognosis.

Association of Morphology of Lenticulostriate Arteries and Proximal Plaque Characteristics With Single Subcortical Infarction: A Whole-Brain High-Resolution Vessel Wall Imaging Study.

We aimed to investigate the association of characteristics of lenticulostriate artery (LSA) morphology and parental atheromatous disease (PAD) with single subcortical infarction (SSI) and to explore whether the LSA morphology is correlated with proximal plaque features in asymptomatic PAD. Patients with acute SSI were prospectively enrolled and classified as large- and small-SSI groups. The clinical data and imaging features of LSA morphology (branches, length, dilation, and tortuosity) and middle cerebral artery plaques (normalized wall index, remodeling index, enhancement degree, and hyperintense plaques) were evaluated. Logistic regression was performed to determine the association of large SSIs with morphologic features of LSAs and plaques. The Spearman correlation between the morphologic characteristics of LSAs and plaque features in asymptomatic PAD was analyzed. Of the 121 patients recruited with symptomatic PAD, 102 had coexisting asymptomatic contralateral PAD. The mean length of LSAs (odds ratio, 0.84 [95% CI, 0.73-0.95]; P=0.007), mean tortuosity of LSAs (odds ratio, 1.13 [95% CI, 1.05-1.22]; P=0.002), dilated LSAs (odds ratio, 22.59 [95% CI, 2.46-207.74]; P=0.006), and normalized wall index (odds ratio, 1.08 [95% CI, 1.01-1.15]; P=0.022) were significantly associated with large SSIs. Moreover, the normalized wall index was negatively correlated with the mean length of LSAs (r=-0.348, P<0.001), and the remodeling index was negatively correlated with the mean tortuosity of LSAs (r=-0.348, P<0.001) in asymptomatic PAD. Our findings suggest that mean length of LSAs, mean tortuosity of LSAs, dilated LSAs, and normalized wall index are associated with large SSIs. Moreover, plaque features in asymptomatic PAD are correlated with morphologic features of LSAs.

Relationship between the intravascular enhancement sign on three-dimensional T1-weighted turbo spin echo and intraluminal thrombus in middle cerebral artery atherosclerosis

PurposeTo investigate the association between the intravascular enhancement sign (IVES) and intraluminal thrombus (ILT) detected by high-resolution magnetic resonance vessel wall imaging (HR-VWI) in patients with middle cerebral artery (MCA) atherosclerosis. MethodThe data of patients who underwent HR-VWI between May 2021 and May 2023, including clinical information, the number of IVES vessels, stenosis degree, ILT, plaque features on 3D T1-weighted turbo spin echo sequences, and signal intensity ratio (SIR) on 3D time-of-flight magnetic resonance angiography, were retrospectively analyzed. Correlation and logistic regression analyses were performed. ResultsA total of 194 MCA plaques were identified in 132 patients (103 [53 %] on the left). Atherosclerosis with, relative to without, ILT was associated with a higher incidence of ischemic events, higher plaque enhancement and stenosis degrees, more vessels with IVES, and lower remodeling ratio, lumen area, wall area, total vessel area, and SIR. Multivariate logistic regression analysis showed significant and independent associations of the number of IVES vessels (OR = 1.089; 95 % CI [1.013–1.170]; P = 0.020) and SIR (OR = 0.007; 95 % CI [0.0004–0.124]; P < 0.001) with ILT. The number of vessels with the IVES (AUC = 0.81, 95 % CI [0.75–0.87]; P < 0.001) and SIR (AUC = 0.88, 95 % CI [0.82–0.94]; P < 0.001) sufficiently diagnosed ILT, and the AUC of the combination of the IVES and SIR was 0.89 (95 % CI [0.84–0.94]; P < 0.001). ConclusionThe number of IVES vessels and SIR are independent risk factors for ILT. They may provide new monitoring targets for stroke prevention in patients with atherosclerotic stenosis.

HDL subfractions determined by microfluidic chip electrophoresis predict the vulnerability of intracranial plaque: A HRMRI study

AimHigh-density lipoprotein (HDL) can be divided into several subfractions based on density, size and composition. Accumulative evidence strongly suggests that the subfractions of HDL have very different roles in the pathogenesis of atherosclerosis. The purpose of this study was to further delineate the relationship between HDL subfractions extracted by microfluidic chip electrophoresis and the vulnerability of plaques in patients with intracranial atherosclerosis with a high-resolution magnetic resonance imaging (HRMRI) study. MethodsWe prospectively enrolled patients with single atherosclerotic plaque in the middle cerebral artery (MCA) or basilar artery (BA) between July 2020 and Dec 2022 and performed 3-tesla HRMRI on the relevant artery. The HDL cholesterol concentration and HDL subfractions (HDL-2a, HDL-2b and HDL-3) percentage were analyzed in serum samples from the same patients by electrophoresis on a microfluidics system. ResultsA total of 81 MCA or BA plaques [38 (46.9%) symptomatic and 43 (53.1%) asymptomatic] in 81 patients were identified on HRMRI. Patients with symptomatic plaques had a significantly lower HDL-2b level than asymptomatic plaques [symptomatic vs. asymptomatic: 0.16 (0.10–0.18) vs. 0.27(0.21–0.34), p = 0.001]. After adjusting for demographics and vascular risk factors, logistic regression showed that HDL-2b was inversely associated with asymptomatic plaques (B = −0.04, P = 0.017). According to receiver operating characteristic (ROC) curve model analysis, the cutoff point of HDL-2b in predicting asymptomatic plaques was 0.21 mmol/L (Area under curve: 0.719, specificity: 73.7%, sensitivity: 72.1%). Furthermore, plaque enhancement on HRMRI (P < 0.001), positive remodeling (P < 0.001), plaque load (P < 0.001) and luminal stenosis (P < 0.001) were superior among patients with HDL-2b < 0.21 mmol/L. ConclusionsOur data showed that serum HDL-2b levels may serve as a biomarker for predicting vulnerability in intracranial atherosclerotic plaques.

Differences in distribution and features of carotid and middle cerebral artery plaque in patients with pial infarction and perforating artery infarction: A 3D vessel wall imaging study

PurposeAtherosclerotic plaques of carotid artery (CA) and middle cerebral artery (MCA) are important causes of acute ischemic stroke (AIS). This study was designed to jointly assess the plaque distribution and features of CA and MCA in AIS patients with pial infarction (PI) and perforating artery infarction (PAI), and to investigate the associations between plaque characteristics and ischemic infarction patterns. MethodsImaging data of sixty-five patients from a cross-sectional study were reviewed. All the patients had acute infarction in the MCA territory on diffusion weighted imaging (DWI) and underwent CA and MCA vessel wall imaging (VWI). The CA and MCA plaque presence and high-risk features on the ipsilateral side of infarction were analyzed. The brain infarction lesions were divided into PI group vs. non-PI group, and PAI group vs. non-PAI group. Different plaque distribution types and plaque features were compared in each two groups, and their associations were investigated using binary logistic regression. ResultsSixty-five patients (mean age, 54.6 ± 10.1 years; 61 men) were included. The CA high-risk plaque (OR: 5.683 [1.409–22.929], P = 0.015) and MCA plaque presence (OR: 3.949 [1.397–11.162], P = 0.010) were significantly associated with PI. MCA plaques that involved the orifice of the perforating arteries were significantly associated with PAI (OR: 15.167 [1.851–124.257], P = 0.011). ConclusionCA and MCA plaques show distinct distribution and high-risk features in patients with PI and PAI. Combined intracranial and extracranial arteries imaging should be considered for the evaluation of the symptomatic ischemic patients.

Correlation of the middle cerebral artery atherosclerotic plaque characteristics with ischemic stroke recurrence: a vessel wall magnetic resonance imaging study.

This study aims to analyze the imaging features of atherosclerotic plaques in the middle cerebral artery (MCA) of patients with recurrent ischemic stroke using vessel wall magnetic resonance imaging (VWMRI) and investigate the correlation between these imaging features and the recurrence of ischemic stroke. Consecutive patients with ischemic stroke caused by atherosclerotic stenosis of the MCA were collected. The patients were divided into recurrent and non-recurrent ischemic stroke groups. We obtained VWMRI images of MCA plaques using 3.0T MRI by black-blood sequences, and the differences in VWMRI characteristics and clinical information between the two groups were compared. A binary Logistic regression model was used to analyze the VWMRI characteristics and clinical information related to ischemic stroke recurrence. 179 patients were collected from August 2018 to May 2020, and 81 patients were included in the study. The recurrent ischemic stroke group patients had a higher stenosis rate (0.69 vs 0.64). Meanwhile, the rate of centripetal wall thickening was significantly higher in patients with recurrent ischemic stroke (33.3% vs 11.7%). Binary Logistic regression analysis showed that sex (P=0.036, OR:2.983, CI:1.075-8.279), stenosis rate (P=0.038, OR:148.565, CI:1.331-16583.631), and vessel wall thickening pattern (P=0.012, OR:0.171, CI:0.043-0.678) were related to ischemic stroke recurrence. The patients with ischemic stroke caused by atherosclerotic stenosis of MCA, female patients, and those with concentric wall thickening and a high degree of stenosis have a higher risk of recurrence. Our results suggest that VWMRI is a valuable tool for predicting the risk of ischemic stroke recurrence in patients with MCA plaques.

Evaluating Middle Cerebral Artery Plaque Characteristics and Lenticulostriate Artery Morphology Associated With Subcortical Infarctions at 7T MRI.

Lenticulostriate artery (LSA) obstruction is a potential cause of subcortical infarcts. However, MRI LSA evaluation at 3T is challenging. To investigate middle cerebral artery (MCA) plaque characteristics and LSA morphology associated with subcortical infarctions in LSA territories using 7-T vessel wall MRI (VW-MRI) and time-of-flight MR angiography (TOF-MRA). Prospective. Sixty patients with 80 MCA atherosclerotic plaques (37 culprit and 43 non-culprit). 7-T with 3D TOF-MRA and T1-weighted 3D sampling perfection with application-optimized contrast using different flip angle evolutions (SPACE) sequences. Plaque distribution (superior, inferior, ventral, or dorsal walls), LSA origin involvement, LSA morphology (numbers of stems, branches, and length), and plaque characteristics (normalized wall index, maximal wall thickness, plaque length, remodeling index, intraplaque hemorrhage, and plaque surface morphology (regular or irregular)) were assessed. Least absolute shrinkage and selection operator regression, generalized estimating equations regression, receiver operating characteristic curve, independent t-test, Mann-Whitney U test, Chi-square test, Fisher's exact test, and intra-class coefficient. A P value <0.05 was considered statistically significant. Plaque irregular surface, superior wall plaque, longer plaque length, LSA origin involvement, fewer LSA stems, and shorter total and average lengths of LSAs were significantly associated with culprit plaques. Multivariable logistic analysis confirmed that LSA origin involvement (OR, 28.51; 95% CI, 6.34-181.02) and plaque irregular surface (OR, 8.32; 95% CI, 1.41-64.73) were independent predictors in differentiating culprit from non-culprit plaques. A combination of LSA origin involvement and plaque irregular surface (area under curve = 0.92; [95% CI, 0.86-0.98]) showed good performance in identifying culprit plaques, with sensitivity and specificity of 86.5% and 86.0%, respectively. 7-T VW-MRI and TOF-MRA can demonstrate plaque involvement with LSA origins. MCA plaque characteristics derived from 7-T VW-MRI showed good diagnostic accuracy in determining the occurrence of subcortical infarctions. 2 TECHNICAL EFFICACY: Stage 3.

Wall Shear Stress Associated with Stroke Occurrence and Mechanisms in Middle Cerebral Artery Atherosclerosis.

Various mechanisms are involved in the etiology of stroke caused by atherosclerosis of the middle cerebral artery (MCA). Here, we compared differences in plaque nature and hemodynamic parameters according to stroke mechanism in patients with MCA atherosclerosis. Consecutive patients with asymptomatic and symptomatic MCA atherosclerosis (≥50% stenosis) were enrolled. MCA plaque characteristics (location and plaque enhancement) and wall shear stress (WSS) were measured using high-resolution vessel wall and four-dimensional flow magnetic resonance imaging, respectively, at five points (initial, upstream, minimal lumen, downstream, and terminal). These parameters were compared between patients with asymptomatic and symptomatic MCA atherosclerosis with infarctions of different mechanisms (artery-to-artery embolism vs. local branch occlusion). In total, 110 patients (46 asymptomatic, 32 artery-to-artery embolisms, and 32 local branch occlusions) were investigated. Plaques were evenly distributed in the MCA of patients with asymptomatic MCA atherosclerosis, more commonly observed in the distal MCA of patients with artery-to-artery embolism, and in the middle MCA of patients with local branch occlusion. Maximum WSS and plaque enhancement were more prominent in the minimum lumen area of patients with asymptomatic MCA atherosclerosis or those with local branch occlusion, and were more prominent in the upstream area in those with artery-to-artery embolism. The elevated variability in the maximum WSS was related to stroke caused by artery-to-artery embolism. Stroke caused by artery-to-artery embolism was related to plaque enhancement and the highest maximum WSS at the upstream point of the plaque, and was associated with elevated variability of maximum WSS.

A method to distinguish the different etiological mechanisms of single subcortical infarction.

Although lenticulostriate artery (LSA) territorial infarcts usually appear as single subcortical infarctions (SSIs) on imaging, they are caused by various etiological mechanisms. We aimed to investigate the correlation between LSA morphology and the location or size of infarcts. Besides, we explored whether the location or size of infarcts can predict the presence of middle cerebral artery (MCA) plaques and distinguish the different etiological mechanisms of SSI patients. We prospectively included patients with acute SSI in the LSA territory. The MCA plaques, infarct features, including the number of infarct slices, lowest infarct layer index (LILI), volume, maximum area and diameter, and LSA morphological characteristics, including the number of stems and branches, length, distance, and tortuosity were evaluated. A total of 105 patients were enrolled. Both the average length and average distance of LSAs were negatively correlated with the maximum infarct area (P=0.048, P=0.028, respectively) and maximum infarct diameter (P=0.016, P=0.010, respectively) on axial examination and were positively correlated with LILI (P=0.020, P=0.003, respectively). The number of LSA branches was associated with the number of infarct slices (P=0.040) and LILI (P=0.043). Moreover, we found that when the LILI=1 or 2 and the number of infarct slices ≥3, the SSI patients were more likely to have MCA plaques (P=0.045). SSI patients with a LILI=1 or 2 and infarct slices of ≥3 were more likely to have MCA plaques. Our findings might provide a simple and feasible method to distinguish the different underlying mechanisms of SSIs for clinicians.

Wall characteristics of atherosclerotic middle cerebral arteries in patients with single or multiple infarcts: A high-resolution MRI Study.

Understanding the stroke mechanism of middle cerebral artery (MCA) atherosclerosis may inform secondary prevention. The aim of this study was to explore the relationship between vascular wall characteristics and infarction patterns using high-resolution magnetic resonance imaging (HRMRI) and diffusion-weighted imaging (DWI). From November 2018 to March 2021, patients with acute ischemic stroke due to MCA atherosclerotic disease were retrospectively analyzed. The wall characteristics of atherosclerotic MCA, including conventional characteristics and histogram-defined characteristics, were evaluated using HRMRI. Patients were divided into single-infarction and multiple-infarction groups based on DWI, and wall characteristics were compared between the two groups. Of 92 patients with MCA plaques, 59 patients (64.1%) had multiple infarcts, and 33 (35.9%) had single infarcts. The histogram-defined characteristics showed no differences between the single-infarction and multiple-infarction groups (P>0.05). Plaque burden, degree of stenosis, and prevalence of intraplaque hemorrhage (IPH) were significantly greater in the multiple-infarction group than in the single-infarction group (plaque burden: P = 0.001; degree of stenosis: P = 0.010; IPH: P = 0.019). Multivariate analysis showed that plaque burden (odds ratio: 1.136; 95% confidence interval: 1.054-1.224, P = 0.001) and IPH (odds ratio: 5.248; 95% confidence interval: 1.573-17.512, P = 0.007) were independent predictors for multiple infarction. IPH and plaque burden are independently associated with multiple infarcts. HRMRI may provide new insight into the mechanisms underlying the different MCA infarction patterns.

HR-MRI findings of intracranial artery stenosis and distribution of atherosclerotic plaques caused by different etiologies.

To investigate the etiology of intracranial artery stenosis and the distribution characteristics of intracranial artery atherosclerotic stenosis using high-resolution magnetic resonance imaging (HR-MRI). A total of 262 patients with intracranial artery stenosis that underwent HR-MRI from November 2019 to December 2020 were retrospectively enrolled. The etiology of intracranial anterior and posterior circulation artery stenosis was analyzed, and the relationship between the location of plaques and the distribution characteristics of plaques and the occurrence of ischemic stroke was summarized. A total of 276 plaques were identified with HR-MRI. There were 101 cases (36.59%) in the middle cerebral artery (MCA), 14 cases (5.07%) in the posterior cerebral artery (PCA), 90 cases (32.62%) in vertebral artery (VA), and 71 cases (25.72%) in the basilar artery (BA). The infarct rate of ventral and superior wall MCA plaques was higher than that of dorsal and inferior wall (63.33% vs 31.25% P = 0.021) (100.00% vs 50% P = 0.022). MCA with plaques throughout the course had the greatest degree of stenosis (P < 0.001). Sphenoid segment (M1) of MCA was most susceptible (85 cases, 84.16%), MCA plaques were most common in the proximal M1 segment (35 cases, 34.65%), and most BA plaques were found in the distal segment (28 cases, 39.44%). PCA plaques were most frequently involved in traffic anterior segment (P1) (7 cases, 50.00%). HR-MRI could provide accurate imaging reference for clinical evaluation of intracranial arterial stenosis and formulation of treatment plans. The intracranial arterial plates mostly appeared in the middle cerebral artery and vertebral artery. Middle cerebral arteries with atherosclerotic plaques are more likely to narrow.

Association of carotid artery geometries with middle cerebral artery atherosclerosis

Background and aimsEvidence shows that artery geometries play a role in atherogenesis by influencing blood flow dynamics. However, whether upstream artery geometries influence downstream atherosclerosis remains unclear. We aimed to investigate whether carotid artery geometries were associated with middle cerebral artery (MCA) atherosclerosis. MethodsWe reviewed our institutional database of 3-dimensional head-neck combined high-resolution magnetic resonance imaging. The carotid artery geometries, carotid atherosclerosis, MCA configurations, and MCA atherosclerosis were examined. The associations between carotid artery geometry and MCA atherosclerosis were also analyzed. A final model integrating carotid artery geometries was established, and the incremental diagnostic value was evaluated and compared to a basic model that included only traditional risk factors. ResultsAmong the 575 artery units of the ipsilateral carotid artery and MCA, the artery units with MCA plaques (n = 273) were associated with a larger bifurcation angle (odds ratio [OR], 1.138 per 10-degree increase; 95% confidential interval [CI], 1.023–1.264) and kinking-type extracranial internal carotid artery (ICA; OR, 2.193; 95%CI, 1.283–3.748) compared with those without MCA plaques (n = 302). These associations were independent of traditional risk factors, carotid atherosclerosis, and MCA configuration. A larger carotid bifurcation angle was also associated with tandem ICA and MCA atherosclerosis (OR, 1.211 per 10-degree increase; 95%CI, 1.110–1.321). The incremental diagnostic value of carotid artery geometry to traditional risk factors was revealed by comparing the area under the curves of the two diagnostic models (basic model, 0.673 vs. final model, 0.701; p = 0.016). ConclusionsCarotid artery geometries are independently associated with ipsilateral MCA atherosclerosis, providing new insights into the pathophysiology of intracranial atherosclerosis.

Lenticulostriate artery length and middle cerebral artery plaque as predictors of early neurological deterioration in single subcortical infarction.

Early neurological deterioration (END) is not a rare phenomenon in single subcortical infarction (SSI; traditionally known as lacunar infarction) patients. Predictors of END in SSI patients are uncertain. We aimed to investigate the association between infarct lesion characteristics, penetrating artery morphology, carrier artery plaque features and END using whole-brain vessel-wall imaging. We prospectively collected data from SSI patients without stenosis of the corresponding carrier artery. The infarct lesion size and location, lenticulostriate artery (LSA) morphological characteristics, and features of the middle cerebral artery (MCA) plaques involving M1 segment adjacent to LSA origin on the symptomatic side were compared between patients with or without END. A total of 74 participants were enrolled, of whom 23 cases (31.1%) showed END. Multivariable logistic regression analysis adjusted for baseline National Institutes of Health Stroke Scale score and axial maximal diameter of infarct lesion revealed that the patients with MCA plaques adjacent to the LSA origin were more likely to develop END (odds ratio (OR) = 3.87, 95% confidence interval (CI) = 1.21-12.33), while with longer average length of LSAs were less likely to occur END (OR = 0.21, 95% CI = 0.05-0.92). MCA plaques located adjacent to the LSA origin and average length of LSAs on the symptomatic side were independent predictors of END in SSI patients. This finding might provide new insights into the mechanisms of the neurological progression in SSI and facilitate therapeutic interventions.

Assessing the characteristics and diagnostic value of plaques for patients with acute stroke using high-resolution magnetic resonance imaging.

A comprehensive understanding of atherosclerotic plaques aids physicians in evaluation and treatment of stroke. This study set out to evaluate the characteristics and diagnostic value of atherosclerotic plaques in patients with acute stroke and stenotic middle cerebral artery (MCA) using high-resolution magnetic resonance imaging. Sixty-five consecutive patients with transient ischemic attack or recent ischemic stroke were prospectively recruited. All enrolled patients underwent routine magnetic resonance scans and cross-sectional scans of the stenotic MCA vascular wall. Differences in vascular wall parameters and location, the enhancement degree, and remodelling patterns of plaques in the stenotic MCA were compared between symptomatic (n=30) and asymptomatic (n=35) groups of patients. The statistically significant indicators were then subjected to logistic regression analysis to identify which factors could better predict acute stroke. Compared with the asymptomatic group, the symptomatic group had a smaller lumen area (LA) (P=0.027), larger plaque area (P<0.001), larger remodelling index (P<0.001), more superior/posterior plaques (P=0.001), more obviously enhanced plaques (P<0.001), and a greater number of PR patterns (P<0.001) in the stenotic MCA. Logistic regression analysis showed that the plaque area, remodelling patterns, LA in the stenotic MCA, enhancement degree, and plaque location were predictors of acute stroke. The combination of the plaque area and LA in the stenotic MCA, and the plaque enhancement degree had optimal predictive value (area under the curve =0.927). A larger plaque area and smaller LA in the stenotic MCA, and obvious plaque enhancement might indicate that a patient is prone to acute stroke.

Standard-Dose Atorvastatin Treatment in Patients With Symptomatic Middle Cerebral Artery Atherosclerotic Stenosis: A Vessel Wall Magnetic Resonance Imaging Study.

Background and Purpose: Ischemic stroke can be caused by atherosclerotic lesions of the middle cerebral artery (MCA). Some studies have described the effects of statin treatment on carotid artery plaques, but little is known about the effects of statin treatment on MCA plaques. The purpose of this study was to validate the efficacy of standard-dose atorvastatin (20 mg/day) in patients with symptomatic MCA atherosclerotic stenosis (SMAS) in northern China.Materials and Methods: This study is a prospective, single-arm, single-center, 12-month follow-up observational study monitoring imaging, and clinical outcomes of standard-dose atorvastatin treatment among patients with SMAS. The primary outcomes were changes in vessel wall magnetic resonance imaging (VWMRI) and serum lipid profiles before and after (1, 3, 6, and 12 months) statin treatment.Results: A total of 46 patients were recruited for this study, and 24 patients completed the follow-up. During the follow-up period, serum non-high-density lipoprotein cholesterol concentrations gradually decreased in the patients. Fourteen patients (54.33%) had a reversal of MCA plaques and 10 patients (41.67%) had no significant progression of MCA plaques and remained stable at the follow-up endpoint. At the 12 months follow-up time-point, the treatment did not reverse vascular remodeling or change the shape and distribution of plaques. Altered serum low-density lipoprotein cholesterol (LDL-C) concentrations in patients were strongly associated with plaque reversal.Conclusion: Vessel wall magnetic resonance imaging could accurately characterize changes in MCA plaques after lipid-lowering therapy. Standard-dose atorvastatin treatment could stabilize and reverse plaques in northern Chinese patients with SMAS.

Non-invasive assessment of intracranial wall shear stress using high-resolution magnetic resonance imaging in combination with computational fluid dynamics technique

In vivo studies on association between wall shear stress (WSS) and intracranial plaque are deficient. Based on the three-dimensional T1-weighted high-resolution magnetic resonance imaging (3DT1 HR-MRI) data of patients with low-grade stenotic (<50%) atherosclerotic middle cerebral artery (MCA) and subjects with normal MCA, we built a three-dimensional reconstructed WSS model by computational fluid dynamics (CFD) technique. Three-dimensional registration of the CFD model to the HR-MRI was performed with projections based on the resolution and thickness of the images. The relationships between the WSS at each side of the vessel wall and plaque location were analyzed. A total of 94 MCA plaques from 43 patients and 50 normal MCAs were analyzed. In the normal MCAs, WSS was lower at the ventral-inferior wall than at the dorsal-superior wall (proximal segment, p < 0.001; middle segment, p < 0.001) and lower at the inner wall than at the outer wall of the MCA curve (p < 0.001). In atherosclerotic MCAs, similar low WSS regions were observed where plaques developed. The WSS ratio of the ventral-inferior wall to the dorsal-superior wall in atherosclerotic MCAs was lower than that in normal MCAs (p = 0.002). The WSSinner-outer ratio in atherosclerotic MCAs was lower than that in normal MCAs (p = 0.002). Low WSS was associated with MCA atherosclerosis formation and occurred mainly at the ventral-inferior wall, which was anatomically opposite the orifices of penetrating arteries, and at the inner wall of the MCA curve. Overall, the results were well consistent with the low WSS theory in atherosclerosis formation. The reconstructed WSS model is a promising novel method for assessing an individualized vascular profile once validated by further studies.

Association of Plaque Features with Infarct Patterns in Patients with Acutely Symptomatic Middle Cerebral Artery Atherosclerotic Disease

Background and PurposeUnderstanding the stroke mechanism of middle cerebral artery (MCA) atherosclerosis is important for stroke triage and future trial design. The aim of this study was to characterize intrinsic MCA plaque and acute cerebral infarct in vivo by using high-resolution black-blood (BB) and diffusion-weighted magnetic resonance (MR) imaging and to investigate the relationship between plaque features and infarct patterns. MethodsA single-center retrospective study was conducted at a tertiary referral center between March 2017 and August 2019. Patients consecutively admitted for acute ischemic stroke with MCA stenosis underwent diffusion-weighted and BB MR imaging. Plaque features and infarct patterns were assessed. The association between plaque features and infarct patterns (binary variable: single/multiple) was evaluated using a multivariate logistic regression model. ResultsOf 49 patients with MCA atherosclerotic stenosis, diffusion-weighted MR imaging showed that 28 patients (57%) had multiple acute cerebral infarcts and 21 patients had single acute cerebral infarcts. In contrast to single infarct, multiple infarcts were associated with greater plaque burden (81.9±7.24 versus 71.3±13.7; P=0.012). A multivariate logistic regression model adjusted for 7 potential confounders confirmed a statistically significant positive association between plaque burden and multiple acute infarcts (adjusted R2 =0.432, P< 0.001). The rate of plaque surface irregularity was significantly greater in patients with multiple infarcts than those with single infarct (71% versus 43%, P=0.044). For single acute penetrating artery infarct, patients with infarct size > 2cm had greater plaque burden compared with patients with infarct size < 2cm (75.3±13.4 versus 63.4±10.9; P = 0.016). ConclusionsIncreased plaque burden, plaque surface irregularity in patients with MCA stenosis is associated with its likelihood to have caused an artery-to-artery embolism that produces multiple cerebral infarcts, especially along the border zone region, and increased plaque burden may promote subcortical single infarct size by occluding penetrating arteries. Our results provide important insight into stroke mechanism of MCA atherosclerosis.

Hemodynamics is associated with vessel wall remodeling in patients with middle cerebral artery stenosis.

To evaluate the relationship between hemodynamics and vessel wall remodeling patterns in middle cerebral artery (MCA) stenosis based on high-resolution magnetic resonance imaging and computational fluid dynamics (CFD). Forty consecutive patients with recent ischemic stroke or transient ischemic attack attributed to unilateral atherosclerotic MCA stenosis (50-99%) were prospectively recruited. All patients underwent a cross-sectional scan of the stenotic MCA vessel wall. The parameters of the vessel wall, the number of patients with acute infarction, translesional wall shear stress ratio (WSSR), wall shear stress in stenosis (WSSs), and translesional pressure ratio were obtained. The patients were divided into positive remodeling (PR) and negative remodeling (NR) groups. The differences in vessel wall parameters and hemodynamics were compared. Correlations between the parameters of the vessel wall and hemodynamics were calculated. Of the 40 patients, 16 had PR, 19 had NR, and the other 5 displayed non-remodeling. The PR group had a smaller lumen area (p = 0.004), larger plaque area (p < 0.001), normal wall index (p = 0.004), and higher WSSR (p = 0.004) and WSSs (p = 0.023) at the most narrowed site. The PR group had more enhanced plaques (12 vs 6, p = 0.03). The number of patients with acute stroke in the PR group was more than that in the NR group (11 vs 4, p = 0.01). The remodeling index (r = 0.376, p = 0.026) and plaque area (r = 0.407, p = 0.015) showed a positive correlation with WSSR, respectively. Hemodynamics plays a role in atherosclerotic plaques and vessel wall remodeling. Individuals with greater hemodynamic values might be more prone to stroke. • Stenotic plaques in middle cerebral artery with positive remodeling have smaller lumen area and larger resp. higher plaque area, normal wall index, translesional wall shear stress ratio, and wall shear stress than negative remodeling. • The remodeling index and plaque area are positively correlated with translesional wall shear stress ratio. • Hemodynamic may help to understand the role of positive remodeling in the development of acute stroke.