Comparison of non-contrast vessel wall imaging and 3-D time-of-flight MRA for atherosclerotic stenosis and plaque characterization within intracranial arteries

PurposeWe compared the ability of intracranial high-resolution vessel wall imaging (VWI) without gadolinium and 3-D time-of-flight (3D-TOF) MRA techniques to characterize intracranial arterial stenosis and arterial wall plaque consistent with atherosclerotic plaque.MethodsConsecutive intracranial VWI examinations performed within 2 months of a 3D-TOF exam with at least 1 noted plaque was included. Examinations assessed 17 vessel segments for plaque and diameters of stenotic and normal segments using double oblique reformatted images. Results were compared with the VWI and 3D-TOF exams considered the reference standard for plaque and luminal stenosis, respectively.ResultsAssessed segments totaled 286 from 17 patients. Proximal segment sensitivity and specificity for luminal stenosis detection with VWI was 92.5% and 82.1%, respectively, whereas for assessing plaque with 3D-TOF it was 59.4% and 98.3%, respectively. The mean intra-rater difference in luminal diameter measurements between VWI and 3D-TOF at normal segments and at the area of maximal stenosis was 0.02 mm (SD 0.51 mm) and 0.08 mm (SD 0.66 mm), respectively.ConclusionsIntracranial VWI demonstrated reasonably high sensitivity and specificity for luminal stenosis assessment using 3D-TOF as a reference standard, while 3D-TOF demonstrated low sensitivity for plaque detection. Our results suggest that VWI can be used for simultaneous assessment of luminal stenosis and plaque in the intracranial arteries.     

The ability of magnetic resonance black blood vessel wall imaging to evaluate blunt cerebrovascular injury following acute trauma

Background and purposeBlunt cerebrovascular injury (BCVI) is associated with a significant risk of ischemic stroke when left untreated. Cross-sectional imaging is vital to early BCVI diagnosis and treatment; however, conventional luminal vessel imaging is limited in its ability to evaluate for vessel wall pathology. The purpose of this study is to evaluate the ability of vessel wall magnetic resonance imaging (VWI) to detect and evaluate BCVI in acutely injured trauma patients relative to neck computed tomographic angiography (CTA).Materials and methodsTrauma patients with suspected BCVI on initial neck CTA were prospectively recruited for VWI evaluation. Two neuroradiologists blinded to patient clinical history and CTA findings evaluated each artery independently on VWI and noted the presence and grade of BCVI. These results were subsequently compared to neck CTA findings relative to expert clinical consensus review. Interrater reliability of VWI for detecting BCVI was evaluated using a weighted Cohen κ-statistic.ResultsTen trauma patients (40 cervical arteries) were prospectively evaluated using both CTA and VWI. Out of 18 vascular lesions identified as suspicious for BCVI on CTA, six lesions were determined to represent true BCVI by expert consensus review. There was almost perfect agreement between VWI and expert consensus regarding the presence and grade of BCVI (κ = 0.82). This agreement increased when considering only low grade BCVI. There was only fair agreement between CTA and expert clinical consensus (κ = 0.36). This agreement decreased when considering only low grade BCVI.ConclusionsVWI can potentially accurately identify and evaluate BCVI in acutely injured trauma patients with excellent inter-rater reliability.     

Evaluation of vessel-wall contrast-enhancement on high-resolution MRI in European patients with Moyamoya disease

ObjectivesData regarding MR vessel-wall imaging (VWI) in patients with Moyamoya disease (MMD) is sparse, particularly in non-asian cohorts. We contribute data regarding the frequency of vessel wall contrast-enhancement (VW-CE) and its potential clinical significance in a European patient group.Materials and methodsPatients with a diagnosis of MMD who were examined by VWI were included in the study. VW-CE of stenoocclusive lesions of the terminal internal carotid artery and/or its proximal branches was rated qualitatively. Changes of VW-CE on available follow-up were recorded. VW-CE was correlated with diffusion-restricted lesions and magnetic resonance angiography (MRA) findings.ResultsEleven patients (eight female, three male) were included. Twenty-eight stenoocclusive lesions were analyzed, of which 16 showed VW-CE (57.1%). VW-CE was mostly concentric (n=15), rather than eccentric (n=1). In all three patients in whom follow-up VWI was available, changes of VW-CE were documented. Diffusion-restricted lesions were more frequently related to stenoocclusive lesions with VW-CE (n=9) than without VW-CE (n=2), bordering statistical significance. The affected arteries were assessed as stenotic and as occluded in 14 cases each and VW-CE was seen significantly more often in stenotic (n=12) than in occluded arteries (n=4). No correlation was found between the presence of VW-CE and moyamoya stages determined by MRA.ConclusionsOur data suggest that concentric VW-CE is a relatively frequent finding in European MMD patients. VW-CE may change over time and occur in certain stages, possibly representing “active stenosing”. Larger studies are needed to validate these findings and determine the clinical relevance of VW-CE in MMD.     

Characterization of non-stenotic plaques in intracranial arteries with multi-contrast,multi-planar vessel wall image analysis

ObjectivesNon-stenotic plaques have been observed in intracranial arteries but are less understood compared to those in coronary and carotid arteries. We sought to compare plaque distribution and morphology between stenotic and non-stenotic intracranial plaques with MR vessel wall imaging (VWI) and quantitative image analysis.Materials and methodsTwenty-four patients with intracranial arterial stenosis or luminal irregularity on clinical imaging were scanned with a multi-contrast VWI protocol. Plaques were detected as focal wall thickening on co-registered multiplanar reformats of multi-contrast VWI, with assessment of the location and morphology. TOF-MRA was independently reviewed for any appreciable stenosis using the WAISD criteria.ResultsAcross 504 arterial segments, a total of 80 plaques were detected, including 23 (29%) with stenosis on TOF-MRA, 56 (70%) without, and 1 (1%) not covered by TOF-MRA. Plaques involving the ICA were more likely to be non-stenotic than those involving other segments (80% versus 55%, p = 0.030) whereas the basilar artery (40%) and PCA (33%) had the lowest proportions of non-stenotic plaques. Maximum wall thickness, indicative of plaque burden, correlated poorly with degree of stenosis (p = 0.10) and overlapped substantially between stenotic and non-stenotic plaques (1.9 [1.5, 2.4] versus 2.0 [1.5, 2.2] mm, p = 0.074).ConclusionsIntracranial plaques without appreciable stenosis on TOF-MRA represent a large proportion of lesions throughout arterial segments but disproportionately affect the ICA. Morphological characterization of plaques with and without stenosis shows that luminal stenosis is a poor indicator of the underlying burden of intracranial atherosclerosis.     

Lacunar stroke attributable to radiation-induced intracranial arteriopathy

We report the rare presentation of lacunar stroke syndrome secondary to single perforator mouth occlusion from radiation-induced middle cerebral artery (MCA) stem arteriopathy. A 30-year-old female had acute-onset right-sided ataxic hemiparesis and dysarthria. As a child, she had a medulloblastoma of the posterior fossa and had surgery followed by cranial radiotherapy. She had no significant vascular risk factors. Acute CT showed extensive bilateral basal ganglia and left thalamic calcification; DWI showed a left internal capsule lacunar infarct; and MRA and CTA showed a 50% stenosis of the proximal left MCA.     

Intracranial dissection mimicking transient cerebral arteriopathy in childhood arterial ischemic stroke

Transient cerebral arteriopathy is a frequent cause of childhood arterial ischemic stroke. Differentiating this condition from intracranial carotid artery dissection is challenging but important for initial treatment. We describe 4 cases from the International Pediatric Stroke Study of intracranial carotid artery dissection, initially misdiagnosed as transient cerebral arteriopathy. Presentations were abrupt, with focal neurological deficits in 4, preceding headache in 3, and minor trauma in 1. Infarcts involved the anterior circulation, and magnetic resonance angiography showed unilateral arterial stenosis/occlusion. None had evidence of dissection. All received anticoagulation or thrombolysis. Three died from refractory intracranial hypertension. Intracranial carotid artery dissection was confirmed postmortem (n = 3) and on dedicated MR wall imaging showing intramural hematoma (n = 1). In differentiating transient cerebral arteriopathy from intracranial carotid artery dissection, routine magnetic resonance angiography is unreliable and adjunctive conventional angiography, gadolinium magnetic resonance angiography, or dedicated MRI wall imaging should be considered.     

3.0T HRMRI头颈联合技术对症状性MCA狭窄患者颅内外动脉管壁病变的诊断价值

目的探讨症状性大脑中动脉(MCA)狭窄患者颅内外动脉管壁病变特点和3.0T高分辨磁共振成像(High-resolution magnetic resonance imaging,HRMRI)头颈联合技术的临床应用价值。方法 11例症状性MCA狭窄患者接受三维增强磁共振血管成像(3D ce-MRA)与3.0T HRMRI的T_1w-db SPACE平扫和T_1w-db SPACE增强扫描,并结合头颈部颅内外动脉管壁不间断联合扫描新技术。结果共扫描11例患者的88处颅内外动脉管壁,其结果发现:1例中枢神经系统血管炎,其左侧MCA及左侧颈内动脉(ICA)颅内段在T_1w-db SPACE像上表现为管壁环形增厚及环形强化;1例颅内动脉夹层,其左侧MCA在T_1w-db SPACE像呈长条状高信号,相应高信号在T_2wdb SPACE像上为等低信号;9例动脉粥样硬化患者均合并双侧MCA粥样硬化斑块,表现为管壁偏心性增厚,其中8例(88.9%)合并颅内外动脉粥样硬化,增强扫描见6例(67%)颅内外动脉粥样硬化斑块均有强化。比较3D ceMRA与HRMRI结果发现,88处血管中,23处血管的3D ce-MRA与HRMRI均未见明显异常;31处血管的3D ceMRA与HRMRI显示相对一致,即3D ce-MRA显示狭窄或者扩张、HRMRI显示管壁呈不同程度的增厚或附壁斑块;34处血管的3D ce-MRA与HRMRI显示欠一致,其中,26处血管的3D ce-MRA大致正常而HRMRI显示管壁增厚(5处)或斑块(21处),8处血管的3D ce-MRA显示轻度狭窄(6处)或扩张(2处)而HRMRI显示管腔外径及管壁均大致正常。判断颅内外动脉异常的组间一致性可(3D ce-MRA、HRMRI的Kappa值分别为0.67、0.69,P0.001)。结论 3.0T HRMRI头颈联合技术可清晰地显示颅内外动脉的管壁结构和病变特点,识别3D ce-MRA未能发现的狭窄,甄别动脉狭窄的病因,对颅内外动脉管壁病变的诊断具有较高的临床应用价值。     

Multifocal arterial wall contrast – enhancement in ischemic stroke: A mirror of systemic inflammatory response in acute stroke

PurposeIntracranial plaque gadolinium enhancement revealed by high-resolution MRI imaging (HR MRI) is considered as a marker of plaque inflammation, a contributing factor of plaque unstability. The aim of the present study was to assess the distribution of gadolinium enhancement in intracranial atherosclerosis.MethodsSingle center analysis of ischemic stroke patients with intracranial atherosclerotic stenosis of M1 or M2 segments of middle cerebral artery, or terminal internal carotid artery (ICA) based on CT-angio or MR-angio. High-resolution MRI imaging (HRMRI) was performed within 6 first weeks following the index event, with 3DT2 BB (black-blood) and 3D T1 BB MR sequences pre and post-contrast administration.ResultsWe identified 8 patients with 14 plaques, 4 were deemed non-culprit and 10 culprit. All culprit plaques (10/10 plaques) and 3 out of 4 non-culprit plaques showed a gadolinium enhancement.ConclusionAt the acute/subacute stage of stroke, a gadolinium enhancement may affect multiple asymptomatic intracranial plaques and may reflect a global inflammatory state.     

The clinical value of head-neck joint high-resolution vessel wall imaging in ischemic stroke

Background and PurposeTo study the feasibility and clinical utility of head-neck joint high-resolution vessel wall imaging (HNJ-VWI) in the assessment of ischemic stroke.MethodsWe reviewed our institutional HNJ-VWI database. Patients with transient ischemic attack (TIA) or ischemic stroke were included. Abnormal findings of intracranial and/or extracranial artery were assessed on three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA) and HNJ-VWI modified from high-resolution 3D T1 sequence and classified into three groups including intracranial, extracranial and coexisting based on the locations. Etiologies of stroke were recorded according to Trial of Org 10172 in Acute Stroke Treatment criteria.ResultsOne hundred and ten consecutive patients were studied. 3D TOF MRA displayed 71.8% (79/110, based on patients) abnormal arteries (stenosis or occlusion) , while HNJ-VWI displayed 96.3% (106/110) abnormal arteries (plaque,wall thickness and occlusion) including four isolated extracranial lesions and ten coexisting lesions. The etiologies of TIA/ischemic stroke included large artery atherosclerosis (80 cases), cerebral small vessel disease (6 cases), cardiogenic (2 cases), dissection (6 cases), vasculitis (4 cases), moyamoya disease (6 cases), others (2 cases) and undetermined (4 cases). For patients with atherosclerosis stroke, re-infarctions were more common in coexisting group than intracranial group (extracranial vs. intracranial vs coexisting: 0% vs. 9.1% vs. 43.7%, p = 0.001).ConclusionsHNJ-VWI is a feasible and valuable technique in assessment of ischemic stroke by detecting extracranial and intracranial artery abnormalities with one-step scan.     

MR Intracranial Vessel Wall Imaging: A Systematic Review

The purpose of this systematic review is to identify trends and extent of variability in intracranial vessel wall MR imaging (VWI) techniques and protocols. Although variability in selection of protocol design and pulse sequence type is known, data on what and how protocols vary are unknown. Three databases were searched to identify publications using intracranial VWI. Publications were screened by predetermined inclusion/exclusion criteria. Technical development publications were scored for completeness of reporting using a modified Nature Reporting Summary Guideline to assess reproducibility. From 2,431 articles, 122 met the inclusion criteria. Trends over the last 23 years (1995‐2018) show increased use of 3‐Tesla MR (P < .001) and 3D volumetric T1‐weighted acquisitions (P < .001). Most (65%) clinical VWI publications report achieving a noninterpolated in‐plane spatial resolution of ≤.55 mm. In the last decade, an increasing number of technical development (n = 20) and 7 Tesla (n = 12) publications have been published, focused on pulse sequence development, improving cerebrospinal fluid suppression, scan efficiency, and imaging ex vivo specimen for histologic validation. Mean Reporting Summary Score for the technical development publications was high (.87, range: .63‐1.0) indicating strong scientific technical reproducibility. Innovative work continues to emerge to address implementation challenges. Gradual adoption into the research and scientific community was suggested by a shift in the name in the literature from “high‐resolution MR” to “vessel wall imaging,” specifying diagnostic intent. Insight into current practices and identifying the extent of technical variability in the literature will help to direct future clinical and technical efforts to address needs for implementation.     

Arterial Wall Imaging in Angiographically Occult Spontaneous Subarachnoid Hemorrhage : New Insight into the Usual Suspect

ObjectiveThe etiology of angiographically occult spontaneous subarachnoid hemorrhage (AOsSAH) is unclear. Three-dimensional (3D) high-resolution vessel wall magnetic resonance imaging (HVM) might be useful in detecting the hidden arterial wall angiopathy in patients with AOsSAH. We aimed to demonstrate the feasibility of HVM for detecting the arterial cause of AOsSAH. MethodsPatients, who were diagnosed with AOsSAH in the first evaluations and underwent HVM, were enrolled. Their clinical and radiologic data were retrospectively reviewed. Especially, focal enhancement of arterial wall on HVM and repetitive catheterized angiograms were precisely compared. ResultsAmong 251 patients with spontaneous SAH, 22 patients were diagnosed with AOsSAH in the first evaluations (8.76%). After excluding three patients who did not undergo 3D-HVM, 19 patients were enrolled and classified as convexal (n=2) or perimesencephalic (n=4), and diffuse (n=13) groups. In convexal and perimesencephalic groups, no focal enhancement on HVM and no positive findings on repetitive angiography were noted. In diffuse group, 10 patients showed focal enhancement of arterial wall on HVM (10/13, 76.9%). Repeated angiography with 3D reconstruction revealed four patients of angiographically positive causative arteriopathy and possible lesion in one case in the concordant location of intramural enhancement on 3D-HVM (5/10, 50%). Three of them were treated with endovascular stent insertion. All patients, except one, recovered with good clinical outcome (3-month modified Rankin score, 0 and 1). Conclusion3D-HVM was useful in detecting hidden true arteriopathy in AOsSAH. It may provide new insights into the etiologic investigation of AOsSAH by proving information about the arterial wall status.     

Serial Radiological Findings in Meningovascular Neurosyphilis Presenting as Acute Ischemic Stroke: A Case Report

BackgroundMeningovascular neurosyphilis, a form of early neurosyphilis, can cause infectious arteritis, which can be complicated by cerebral infarction. High-resolution vessel wall imaging (HR-VWI) is one of the techniques used to directly visualize the vessel wall. Herein, we present a rare case of meningovascular neurosyphilis, in which intracranial arterial vasculitis was evaluated using HR-VWI.Case presentationA 22-year-old man with no medical history of any condition was brought to the emergency room with one day history of right upper and lower extremity weakness. Diffusion-weighted magnetic resonance (MR) imaging showed a high signal from the left putamen to the corona radiata, and MR angiography showed stenosis of the right internal carotid artery (ICA) and the bilateral middle cerebral arteries (MCAs). HR-VWI showed thickening, along with smooth, intense, and concentric enhancement of the right ICA and the bilateral MCAs. The patient was diagnosed with neurosyphilis based on the findings of the blood tests and cerebrospinal fluid examination. The patient's symptoms gradually improved after treatment with intravenous penicillin G and oral antiplatelet agents. HR-VWI, performed approximately 6 months after the treatment, revealed improvement in the contrast enhancement of the vessel wall and the vascular stenosis.ConclusionTo the best of our knowledge, this is the first report of meningovascular neurosyphilis that evaluated the course of treatment using HR-VWI. Our report highlights the effectiveness of HR-VWI to determine the effects of treatment on meningovascular neurosyphilis.     

Isolated intracranial fibromuscular dysplasia of the posterior cerebral artery

Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory arterial disease that most commonly affects the renal and internal carotid arteries, but intracranial FMD is very rare. We report a patient with FMD involving the posterior cerebral arteries (PCAs). A 24 year old female was presented with a 4 day history of right homonymous hemianopsia with throbbing headache in the left temporo-occipital area. The brain magnetic resonance imaging (MRI) revealed an acute ischemic stroke in the left PCA territory, while the Time of Flight (TOF) magnetic resonance angiogram (MRA) showed segmental luminal irregularities in the left proximal PCA. The conventional angiogram revealed the “string of beads” appearance, a characteristic that is pathognomonic for FMD. The patient’s inhospital clinical course was stable, while there was no recurrence of stroke. This is the second report of FMD of the PCA. Notwithstanding incredibly rare incidences of isolated intracranial FMD and nonspecific findings of MRA, such a pathophysiology should be considered as the cause for a stroke in young patients, especially those with no cardiovascular risk factor.     

糖尿病患者颈动脉斑块磁共振成像特征与急性脑缺血病灶形态关系研究

目的 探讨2型糖尿病患者颈动脉斑块磁共振成像（magnetic r esonance i maging，MRI）特征与相应供 血区急性脑缺血病灶形态的关系。 方法 横断面研究，入组临床急性颈内动脉供血区缺血性卒中患者，排除心源性卒中，在发病一周 内行颈动脉磁共振管壁成像（magnetic resonance vessel wall imaging，MR-VWI）检查和常规MRI [包括 磁共振血管成像（magnetic resonance angiography，MRA）和弥散加权成像（diffusion-weighted imaging， DWI）]检查，评估症状侧颈动脉斑块负荷和成分特征以及颅内外动脉管腔狭窄度，根据DWI上梗死灶 形态对急性脑缺血病灶形态和体积进行分析。 结果 共入选140例急性缺血性卒中患者，其中68例（48.6%）为2型糖尿病患者，多因素回归分析显 示2型糖尿病是症状侧颈动脉斑块富脂质核发生的独立危险因素[比值比（odds ratio，OR）3.35，95% 可信区间（confidence interval，CI）1.33～8.43]；在兼具富脂质核斑块的患者中，2型糖尿病组颈内动脉 区域急性脑缺血病灶体积（[ 15.45±8.97）ml vs（9.09±8.64）ml，P=0.011]和大穿支动脉梗死发生率 [34.0% vs 13.2%，P =0.024）]显著高于非糖尿病组。 结论 颈动脉供血区急性缺血性卒中患者中，2型糖尿病与症状侧颈动脉动脉粥样硬化斑块MRI特征， 尤其是富脂质核密切相关，且更易发生大穿支动脉的梗死，提示MR-VWI细致化分析结合糖尿病因素 有助于临床对缺血性卒中风险的分层和个体化诊治。     

高分辨MRI技术对动脉粥样硬化斑块的 评价

识别动脉粥样硬化斑块及其易损性能有效地预测高危人群,减低心脑血管临床事件的发
生。磁共振作为一项无创检查手段,可以观察斑块的形态和易损性,并进行综合评价。本文就磁共
振成像技术对动脉粥样硬化斑块的形态功能学检查做一简要综述。     

Single gene disorders causing ischaemic stroke

Abstract Stroke is the third most common cause of death and the leading cause of long-term neurological disability in the world. Conventional vascular risk factors for stroke contribute approximately to only forty to fifty percent of stroke risk. Genetic factors may therefore contribute to a significant proportion of stroke and may be polygenic, monogenic or multi-factorial. Monogenic (single gene) disorders may potentially account for approximately one percent of all ischaemic stroke. Monogenic stroke disorders include conditions such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) and hereditary endotheliopathy, retinopathy, nephropathy and stroke (HERNS). In addition, other monogenic conditions such as sickle cell and Fabry disease also lead to stroke. These monogenic disorders cause either small vessel or large vessel stroke (or a combination of both) and serve as useful models for understanding and studying conventional stroke and cerebrovascular disease and its accompaniments such as vascular dementia.