Intracranial Vasculopathies Research Articles

Role of Vessel Wall Magnetic Resonance Imaging in the Diagnosis of Intracranial Vasculopathies

Role of Vessel Wall Magnetic Resonance Imaging in the Diagnosis of Intracranial Vasculopathies

Abstract TP182: Vessel Wall MRI in Diagnosis and Prognosis of Intracranial Vasculopathy

Introduction: High resolution vessel wall MRI (VWMRI) has been increasingly used in stroke patients to evaluate the arterial pathologies and underlying cause of stroke. We aimed to explore VWMRI features of intracranial vasculopathies in ischemic stroke patients and assess their associations with stroke mechanism and with clinical outcome. Methods: Ischemic stroke or TIA patients with intracranial vasculopathy as the potential cause of stroke were included if they underwent VWMRI (3D T1-weighted, pre- & post- contrast, resolution isotropic 0.625 mm). The VWMRI features including the number of arterial lesions with thickened wall, presence of T1 hyperintensity, degree of enhancement [absent (0), mild (1), significant (2 =similar to infundibulum)], pattern of enhancement [eccentric, concentric, and mixed (both)] were evaluated by board certified neuroradiologists. Primary outcome was defined as recurrent stroke or other cardiovascular events. The association between clinical characteristic VWMRI features & clinical outcome were examined. Results: A total of 46 patients [29 (63%) males; mean age (SD) 55.7 (15) years] were included. Among 41 patients (89%) had at least one lesion with thickened wall, 21 patients (51.2%) had multiple lesions, 28 (68.3%) had T1 hyperintensity, 39 (95%) had contrast enhancement (eccentric n=24, concentric n=10, mixed n=5 ) and 27 (66%) had significant enhancement. Overall, VWMRI suggested a different pathological mechanism of stroke in 16 patients comparing with the original impression. Higher creatinine and lower HDL levels were significantly (p<0.05) associated with presence of multiple vs single lesion on VWMRI. LDL was significantly (p=0.04) higher in those with eccentric vs concentric enhancement. The median follow-up was 28.4 (IQR 13- 47) months, and primary outcome occurred in 6 (13.3%) patients. VWMRI features were not associated with the primary outcome. Conclusions: Presence of some degree of enhancement is common (95%) in patients with ischemic stroke attributed to intracranial vasculopathies. The VWMRI features were not associated with the primary clinical outcome. VWMRI may help to clarify the etiology of the stroke mechanisms. These findings warrant further evaluation in larger studies.

High-resolution vessel wall magnetic resonance imaging in intracranial vasculopathies: an experience from eastern India.

To evaluate the role of high-resolution intracranial vessel wall imaging (HR-IVWI) in differentiation of various intracranial vasculopathies in addition to luminal and clinical imaging in the largest cohort of Indian stroke patients. A single-center, cross-sectional study was undertaken recruiting consecutive stroke or TIA patients presenting within a month of onset, with luminal irregularity/narrowing upstream from the stroke territory. The patients were initially classified into TOAST and Chinese ischemic stroke sub-classification (CISS) on the basis of clinical and luminal characteristics and reclassified again following incorporation of HR-IVWI findings. In our cohort of 150 patients, additional use of HR-IVWI led to a 10.7 and 14% change in initial TOAST and CISS classification respectively (p < 0.001). In TOAST classification, 12 "undetermined aetiology" were reclassified into intracranial atherosclerotic disease (ICAD), 1 "undetermined aetiology" into CNS angiitis and 1 "undetermined aetiology" into arterial dissection. Similarly, in CISS 19 "undetermined aetiology" was reclassified into 16 large artery atherosclerosis (LAA) and 3 "other aetiology" consisting of one CNS angiitis, Moyamoya disease (MMD) and arterial dissection each. Two initial classification of MMD by CISS and TOAST were changed into ICAD. The observed change in diagnosis following incorporation of HR-IVWI was proportionately highest in ICAD (LAA) subgroup (TOAST-9.3%, CISS-12%). Adjunctive use of HR-IVWI, to clinical and luminal assessment, can significantly improve diagnostic accuracy during evaluation of intracranial vasculopathies, with its greatest utility in diagnosing in ICAD, CNS angiitis and dissection. HR-IVWI allows clearer etiological distinction of intracranial vasculopathies having therapeutic and prognostic implications.

Abstract WP96: Quantitative Imaging Markers On Vessel Wall Magnetic Resonance Imaging Correlate With Disease Activity And Treatment Response In Cerebral Vasculopathies

Introduction: Little is known about the utility of vessel wall magnetic resonance imaging (VWMRI) in assessing treatment response in various inflammatory and non-inflammatory intracranial vasculopathies, and if there is any correlation of vessel wall enhancement (VWE) with disease activity. We aimed to quantitatively investigate the differences in VWE patterns on follow-up VWMRI in patients with primary CNS vasculitis (PCNSV), secondary CNS vasculitis (SCNSV) and intracranial atherosclerotic disease (ICAD). Methods: VWMRI scans of patients with a confirmed diagnosis of either PCNSV, SCNSV or ICAD presenting to our tertiary care center between January 2015 and January 2021 were reviewed. Inclusion criteria were age greater than 18 years and at least 2 VWMRI scans available, including one from time of first clinical presentation with active disease. For each patient, 20 arterial segments were evaluated on VWMRI for the presence of VWE and the total number of enhancing arterial segments were reported. Percent concentricity, median number of enhancing arterial segments (MEAS) and percent change in MEAS was calculated and compared across all 3 diagnoses. Results: A total of 28 patients met study inclusion criteria (median age 47, 43% male) and had a diagnosis of either PCNSV (n=6), SCNSV (n=7) or ICAD (n=15). Median time to follow-up VWMRI was 22, 20 &amp; 11 weeks for PCNSV, SCNSV &amp; ICAD respectively. On initial VWMRI, the MEAS was 7 for each PCNSV &amp; SCNSV and 6 for ICAD. Higher percent concentricity of VWE was seen more with PCNSV (92.3%) and SCNSV (71.4%) compared to ICAD (22.2%). All (100%) patients with PCNSV and 2 (33%) patients with SCNSV were treated with immunosuppression whereas 3 (50%) patients with SCNSV were treated with antimicrobials. All patients with PCNSV and SCNSV improved clinically whereas those with ICAD progressed or remained stable. The MEAS on follow up VWMRI decreased with treatment in patients with PCNSV (43% decrease) and SCNSV (14% decrease) but increased in those with ICAD (16% increase) and correlated clinically with disease activity and treatment response. Conclusion: Percent concentricity and MEAS on VWMRI may be useful non-invasive markers to monitor disease activity &amp; treatment response in patients with intracranial vasculopathies.

Sensitivity and specificity of vessel wall MRI sequences to diagnose central nervous system angiitis

Magnetic resonance imaging (MRI) with intracranial vessel wall (IVW) sequences is able to directly characterize disease processes affecting the VW increasing the accuracy of intracranial vasculopathies differential diagnosis. Nevertheless, data concerning the specificity and sensitivity of this technic for diagnosis of angiitis of the central nervous system (ACNS) are scant. We aimed at quantifying the IVW abnormalities in a cohort of primary and secondary ACNS and assessing the specificity of ACNS-associated IVW MRI abnormalities. We retrospectively included 36 patients with a diagnosis of ACNS with IVW imaging and we compared IVW MRI abnormalities with those of fifty successive patients admitted at the stroke unit for acute neurological deficit (stroke-unit-group). Since an ACNS was retained as cause of the acute neurological deficit in two patients in the stroke-unit-group, they were finally included in the ACNS group. In our cohort, headache and cognitive disorders were present in 29 and 55% of cases respectively, seizure were rare (n = 5, 13%). CSF analysis were abnormal in 29 patients (76%). MRI showed lesion with restricted diffusion in 82% of patients (n = 31). In 71% of our ACNS population (n = 27) multifocal vessel abnormalities were described in angiographic MRI sequences. Digital subtraction angiography (DSA) was performed in 14 patients and it was suggestive of an ACNS in 11 (79%). Brain-meningeal biopsy was performed in two cases (5%). The typical ACNS-associated IVW abnormalities, i.e., the multifocal concentric VW enhancement with wall thickening, was found in the 95% of ACNS patients (n = 36) whereas it was reported in 4% (n = 2) of the stroke-unit-group (specificity and sensitivity of concentric VW enhancement for ACNS diagnosis of 95% and 94%, respectively). IVW enhancement co-localized with multifocal angiographic stenosis in ACNS patients. The clinical, laboratory and imaging findings were comparable to those of previously described ACNS cohorts in the literature, and particularly to those of DSA-diagnosed patients. Our results suggest that concentric VW enhancement could efficaciously identify patients affected by medium-sized vessels CNS vasculitis with a specificity of 95% and sensitivity of 94%. Further studies with larger samples are necessary to confirm our findings.

Pediatric Stroke: The Clinical and Etiological Spectrum: An Observational Study from a Tertiary Care Stroke Clinic, Kolkata, India

In different geographical regions, the clincoetiological spectrum of childhood stroke varies widely and studies from Eastern India is lacking. To determine the clinicoetiological spectrum of childhood stroke and their outcome. This study was conducted in a stroke clinic of a tertiary care hospital of Kolkata over a period of 18 months. All children below 12 years diagnosed as stroke were included. On the basis of clinical examination, relevant laboratory investigations and radioimaging etiologies were determined. Appropriate statistical methods were used to analyze the data gathered from these patients using a preformed proforma. Among the 70 pediatric stroke patients, the most common clinical presentation was found to be hemiparesis (61.42%) followed by seizure (30.00%) and aphasia (25.71%), respectively. Vasculopathies (30.00%) were found to be the most common etiology of childhood stroke followed by infective meningoencephalitis and craniocervical trauma (14.28% each). Ischemic stroke comprised 71.4% of cases. During discharge, 20 cases (28.57%) showed complete recovery, whereas 40 cases (57.14%) had persistent neurodeficit [Pediatric Stroke Outcome Measure (PSOM) score >1], 12 cases (17.14%) had recurrent stroke, 8 cases (11.42%) died, and only 2 (2.85%) patients were lost to follow-up. Out of those 40 cases having persistent neurodeficits during discharge had recovered too at follow-up at 18th month. At presentation PSOM score in 40 cases (57.14%) was >5 and at follow-up at 18th month, only 8 cases (11.42%) had PSOM score of >5. The commonest etiologies of stroke in pediatric patients presenting at our hospital were found to be intracranial vasculopathies, infection, and trauma. Ischemic stroke was the predominant type. Eighteen-month follow-up showed complete recovery from acute neurological deficits in most of the patients. Dubey S, Ghosh R, Chatterjee S, et al. Pediatric Stroke: The Clinical and Etiological Spectrum: An Observational Study from a Tertiary Care Stroke Clinic, Kolkata, India. Indian J Phys Med Rehab 2019;30(3):74–80.

High-resolution MR vessel wall imaging in determining the stroke aetiology and risk stratification in isolated middle cerebral artery disease

High-resolution MR vessel wall imaging (HRVWI) can characterise vessel wall pathology affecting intracranial circulation and helps in differentiating intracranial vasculopathies. The aim was to differentiate intracranial pathologies involving middle cerebral artery (MCA) in patients with ischemic stroke and characterise the high-risk plaques in intracranial atherosclerotic disease (ICAD) using HRVWI. Patients with ischemic stroke with isolated MCA disease with ≥ 50% luminal narrowing by vascular imaging were enrolled within 2weeks of onset and underwent high-resolution (3T) intracranial vessel wall imaging (VWI). The pattern of vessel wall thickening, high signal on T1-weighted images, juxtaluminal hyperintensity, pattern and grade of enhancement were studied. The TOAST classification before and after HRVWI and the correlation of the recurrence of ischemic events at 3months with imaging characteristics were analysed. Of the 36 patients, the mean age was 49.53 ± 15.61years. After luminal imaging, by TOAST classification, 12 of 36 patients had stroke of undetermined aetiology. After vessel wall imaging, lesions in MCA were analysed. Of them, 23 patients had ICAD, 8 had vasculitis, and 2 had partially occlusive thrombus in MCA. The ability of HRVWI to bring a change in diagnosis was significant (p = 0.031). Of the 23 patients with ICAD, 12 patients had recurrent strokes within 3months. The presence of grade 2 contrast enhancement (p = 0.02) and type 2 wall thickening (p = 0.03) showed a statistically significant association with recurrent ischemic events. High-resolution MRVWI can help in identifying the aetiology of stroke. The HRVWI characteristics in ICAD can help in risk stratification.

Vessel Wall Magnetic Resonance Imaging in Cerebrovascular Diseases.

Cerebrovascular diseases are a leading cause of disability and death worldwide. The definition of stroke etiology is mandatory to predict outcome and guide therapeutic decisions. The diagnosis of pathological processes involving intracranial arteries is especially challenging, and the visualization of intracranial arteries’ vessel walls is not possible with routine imaging techniques. Vessel wall magnetic resonance imaging (VW-MRI) uses high-resolution, multiparametric MRI sequences to directly visualize intracranial arteries walls and their pathological alterations, allowing a better characterization of their pathology. VW-MRI demonstrated a wide range of clinical applications in acute cerebrovascular disease. Above all, it can be of great utility in the differential diagnosis of atherosclerotic and non-atherosclerotic intracranial vasculopathies. Additionally, it can be useful in the risk stratification of intracranial atherosclerotic lesions and to assess the risk of rupture of intracranial aneurysms. Recent advances in MRI technology made it more available, but larger studies are still needed to maximize its use in daily clinical practice.

Primary Angiitis of the Central Nervous System - Diagnosis and Management.

Primary angiitis of central nervous system (PACNS) is a rare idiopathic disorder affecting blood vessels of brain, spinal cord, and meninges, consequently leading to infarct and less frequently hemorrhage. CNS vasculitis can also occur as part of systemic vasculitis or secondary to autoimmune diseases or infections. The clinical manifestations of PACNS are non-specific and no single laboratory investigation or neuroimaging finding can reliably diagnose this condition. Histopathological evidence of transmural inflammation of blood vessels of CNS is the gold standard, but is generally pursued subsequent to conventional angiogram (CA) because of its invasive nature. The differentials of PACNS are exhaustive and include systemic vasculitis, secondary vasculitis, non-inflammatory intracranial vasculopathies, demyelination, and neoplasm. These alternative conditions can often be distinguished by history, examination, immunological testing, cerebrospinal fluid analysis, and neuroimaging. CA can detect vasculitic changes in the large to medium cerebral arteries but the specificity is low. Recent advancements in vessel wall imaging techniques have further enabled the distinction of various intracranial vasculopathies from CNS vasculitis. The disease has considerable morbidity and fatality unless timely treatment with immunosuppressive agents is initiated. Induction therapy with glucocorticoids and cyclophosphamide followed by azathioprine, mycophenolate mofetil, or methotrexate as maintenance therapy is the cornerstone of management. Biological agents such as rituximab and anti-tumour necrosis factor alpha inhibitors (infliximab and etanercept) may be used in refractory cases. This review discusses the approach to the diagnosis, determinants of outcome, and management.

Value of vessel wall magnetic resonance imaging in the diagnosis and management of cerebrovascular diseases

Abstract Background Intracranial atherosclerosis, one of the leading causes of ischemic stroke, is associated with an increased risk for recurrent stroke and dementia. Objective This work was carried out to assess suspicious lesions detected by Magnetic Resonance Angiography (MRA) and Computed Tomgraphy Angiography (CTA) for further evaluation by vessel wall MRI . Patients and methods This study was conducted on 16 patients who were admitted to Ain Shams University Specialized Hospital with establilished diagnosis of stroke (11 patients with intracranial atherosclerosis, 3 patients with CNS vasculitis and 2 patients with Moya-moya disease ) performing MRI brain including magnetic resonance angiography (MRA) that showed intracranial stenosis, who then referred to Misr Radiology Center for the evaluation of intracranial vasculopathies by vessel wall MR Imaging using 3.0-tesla (T) field strengths. Results The results showed statistically significant difference between groups as regard to significant intracranial stenosis (&amp;gt;50%). It was prominent among moya moya disease group (100.0%) followed by intracranial atherosclerotic groups (81.8%), whereas CNS vasculitis group shows mild intracranial stenosis (0.0%). Conclusion Intracranial vessel wall MR imaging is an adjunct to conventional angiographic imaging

Current Clinical Applications of Intracranial Vessel Wall MR Imaging

Intracranial vessel wall MR imaging (VWI) is increasingly being used as a valuable adjunct to conventional angiographic imaging techniques. This article will provide an updated review on intracranial VWI protocols and image interpretation. We review VWI technical considerations, describe common VWI imaging features of different intracranial vasculopathies and show illustrative cases. We review the role of VWI for differentiating among steno-occlusive vasculopathies, such as intracranial atherosclerotic plaque, dissections and Moyamoya disease. We also highlight how VWI may be used for the diagnostic work-up and surveillance of patients with vasculitis of the central nervous system and cerebral aneurysms.

T2-Weighted Whole-Brain Intracranial Vessel Wall Imaging at 3 Tesla With Cerebrospinal Fluid Suppression.

BackgroundT2-weighted (T2w) intracranial vessel wall imaging (IVWI) provides good contrast to differentiate intracranial vasculopathies and discriminate various important plaque components. However, the strong cerebrospinal fluid (CSF) signal in T2w images interferes with depicting the intracranial vessel wall. In this study, we propose a T2-prepared sequence for whole-brain IVWI at 3T with CSF suppression.MethodsA preparation module that combines T2 preparation and inversion recovery (T2IR) was used to suppress the CSF signal and was incorporated into the commercial three-dimensional (3D) turbo spin echo sequence-Sampling Perfection with Application optimized Contrast using different flip angle Evolution (SPACE). This new technique (hereafter called T2IR-SPACE) was evaluated on nine healthy volunteers and compared with two other commonly used 3D T2-weighted sequences: T2w-SPACE and FLAIR-SPACE (FLAIR: fluid-attenuated inversion recovery). The signal-to-noise ratios (SNRs) of the vessel wall (VW) and CSF and contrast-to-noise ratios (CNRs) between them were measured and compared among these three T2-weighted sequences. Subjective wall visualization of the three T2-weighted sequences was scored blindly and independently by two radiologists using a four-point scale followed by inter-rater reproducibility analysis. A pilot study of four stroke patients was performed to preliminarily evaluate the diagnostic value of this new sequence, which was compared with two conventional T2-weighted sequences.ResultsT2IR-SPACE had the highest CNR (11.01 ± 6.75) compared with FLAIR-SPACE (4.49 ± 3.15; p < 0.001) and T2w-SPACE (−56.16 ± 18.58; p < 0.001). The subjective wall visualization score of T2IR-SPACE was higher than those of FLAIR-SPACE and T2w-SPACE (T2IR-SPACE: 2.35 ± 0.59; FLAIR-SPACE: 0.52 ± 0.54; T2w-SPACE: 1.67 ± 0.58); the two radiologists’ scores showed excellent agreement (ICC = 0.883).ConclusionThe T2IR preparation module markedly suppressed the CSF signal without much SNR loss of the other tissues (i.e., vessel wall, white matter, and gray matter) compared with the IR pulse. Our results suggest that T2IR-SPACE is a potential alternative T2-weighted sequence for assessing intracranial vascular diseases.

High-Resolution Magnetic Resonance Vessel Wall Imaging for the Evaluation of Intracranial Vascular Pathology.

Intracranial vessel wall imaging (IVWI) is an advanced MR imaging technique that allows for direct visualization of the walls of intracranial blood vessels and detection of subtle pathologic vessel wall changes before they become apparent on conventional luminal imaging. When performed correctly, IVWI can increase diagnostic confidence, aid in the differentiation of intracranial vasculopathies, and assist in patient risk stratification and prognostication. This review covers the essential technical underpinnings of IVWI and presents emerging clinical research highlighting its utility for the evaluation of multiple intracranial vascular pathologies.

The diagnostic contribution of intracranial vessel wall imaging in the differentiation of primary angiitis of the central nervous system from other intracranial vasculopathies.

The aim of this study is to demonstrate the diagnostic effect of VWI in differentiating PACNS from other vasculopathies and its role in post-treatment follow-up in PACNS patients in this study. In this prospective study, we included patients with clinical suspicion of PACNS who presented with new-onset ischemic events and had significant intracranial large vessel stenosis on DSA or MRA. VWI was performed on all patients. The imaging findings and final diagnoses were recorded. Control VWI was performed on patients with PACNS diagnosis after at least 3 months of treatment, and the change in findings was also evaluated. Twenty-three patients were included in the study had a median age of 40 (range 12-58). The most common clinical manifestations were focal neurologic deficits. According to the initial clinical evaluation, 10 patients (43.5%) were classified as PACNS and 13 patients (56.5%) as indeterminate for PACNS. After incorporating the VWI findings, the diagnosis of PACNS was confirmed in all clinically diagnosed PACNS patients. Concentric wall thickening and contrast enhancement were statistically significant in the PACNS group (p <0.001). According to concentric thickening and VWE features, sensitivity and specificity in distinguishing PACNS and other vasculopathies were 95.2%, 75% and 95.2%, 68.8%, respectively. Vessel wall enhancement regressed in 7 of 9 patients during a median follow-up period of 8 months (range 5.5-11.5) in PACNS patients who followed up. VWI seems a new and useful imaging method in the differential diagnosis of PACNS and might be a useful adjunct for post-treatment follow-up.

High-Resolution Vessel Wall Imaging in Primary Angiitis of Central Nervous System.

Background:High-resolution vessel wall imaging (HRVWI) can aid in differentiating the various intracranial vasculopathies, but has been sparingly used in the diagnosis of primary angiitis of central nervous system (PACNS). This study is aimed to describe the vessel wall imaging characteristics of PACNS.Materials and Methods:Patients with confirmed diagnosis of PACNS according to the Calabrese and Mallek criteria who had abnormal HRVWI were included in this retrospective descriptive study. Magnetic resonance image of brain, conventional four-vessel cerebral digital subtraction angiogram, and HRVWI were read by a neuroradiologist. The vessel wall parameters assessed were T1W and T2W appearances, pattern of wall thickening and contrast enhancement, and remodeling index.Results:HRVWI done in 21 patients with PACNS yielded abnormality in 20 (95.2%) who were included in the analysis. The mean age at presentation was 42.55 ± 9.48 years and 14 (70%) were males. The median number of vessels involved were four (range 2–12). The commonest vessels affected were proximal middle cerebral artery (70%) and internal carotid artery (55%). Vessel wall thickening was concentric, eccentric, and absent in 12 (60%), 1 (5%), and 7 (35%) patients, respectively. Vessel wall enhancement was diffuse in 17 (85%), eccentric in 1 (5%), and absent in 2 (10%) patients. One patient had T2W hyperintense stenotic lesion. Remodeling index was negative in 11 (55%) patients.Conclusion:Distinctive vessel wall appearances were observed by HRVWI in PACNS, concentric vessel wall thickening and enhancement being more frequent. Hence, HRVWI can be considered as an additional noninvasive imaging modality in the diagnosis of PACNS.

Detection and Quantification of Symptomatic Atherosclerotic Plaques With High-Resolution Imaging in Cryptogenic Stroke.

High-resolution vessel wall imaging (HR-VWI) is a powerful tool in diagnosing intracranial vasculopathies not detected on routine imaging. We hypothesized that 7T HR-VWI may detect the presence of atherosclerotic plaques in patients with intracranial atherosclerosis disease initially misdiagnosed as cryptogenic strokes. Patients diagnosed as cryptogenic stroke but suspected of having an intracranial arteriopathy by routine imaging were prospectively imaged with HR-VWI. If intracranial atherosclerotic plaques were identified, they were classified as culprit or nonculprit based on the likelihood of causing the index stroke. Plaque characteristics, such as contrast enhancement, degree of stenosis, and morphology, were analyzed. Contrast enhancement was determined objectively after normalization with the pituitary stalk. A cutoff value for plaque-to-pituitary stalk contrast enhancement ratio (CR) was determined for optimal prediction of the presence of a culprit plaque. A revised stroke cause was adjudicated based on clinical and HR-VWI findings. A total of 344 cryptogenic strokes were analyzed, and 38 eligible patients were imaged with 7T HR-VWI. Intracranial atherosclerosis disease was adjudicated as the final stroke cause in 25 patients. A total of 153 intracranial plaques in 374 arterial segments were identified. Culprit plaques (n=36) had higher CR and had concentric morphology when compared with nonculprit plaques (P≤0.001). CR ≥53 had 78% sensitivity for detecting culprit plaques and a 90% negative predictive value. CR ≥53 (P=0.008), stenosis ≥50% (P<0.001), and concentric morphology (P=0.030) were independent predictors of culprit plaques. 7T HR-VWI allows identification of underlying intracranial atherosclerosis disease in a subset of stroke patients with suspected underlying vasculopathy but otherwise classified as cryptogenic. Plaque analysis in this population demonstrated that culprit plaques had more contrast enhancement (CR ≥53), caused a higher degree of stenosis, and had a concentric morphology.

Vessel wall MR imaging for the detection of intracranial inflammatory vasculopathies.

Intracranial vasculopathies are routinely investigated by lumen-based modalities such as magnetic resonance angiography (MRA), computed tomography angiography (CTA), and digital subtraction angiography (DSA). These techniques are useful to analyze the vessel lumen, allowing to detect vessel stenosis or occlusion. However, the primum movins of the disease, i.e., an abnormal thickening of the vessel wall, remains within the arterial wall. The vasculopathy can moreover be present without always narrowing the lumen or modifying its regularity. Hence, there is a need to detect directly and analyze vessel wall abnormalities. Development of 3D high-resolution black blood sequences for intracranial vessel wall MR imaging (VW-MRI) enabled routine clinical applications not only vasculitis, but also of intracranial atherosclerotic disease (ICAD), intracranial dissections, reversible intracranial dissections, reversible cerebral vasoconstriction syndrome (RCVS), Moyamoya disease, and intracranial aneurysms. This high-resolution intracranial VW- MRI approach is increasingly used on a clinical basis at many centers to solve diagnostic problems, especially in patients with ischemic stroke or intracranial hemorrhage. An expert consensus Guideline from the American Society of Neuroradiology provides recommendations for clinical implementation of intracranial vessel wall MRI. There are several technical aspects needed to be considered when implementing VW-MRI in intracranial vessels, including flow suppression, both in blood and cerebrospinal fluid (CSF), spatial resolution and signal-to-noise ratio (SNR). In this article, we review the technical aspects of VW-MRI, and recommend applications for vascular diseases including non-occlusive intracranial vasculopathies, Moyamoya disease, and identifying culprit plaques. We also give a focus on the utility of VW-MRI for determining stroke etiology in adults and in children and young adults.

Intracranial Vessel Wall MRI in Cryptogenic Stroke and Intracranial Vasculitis

Introduction: Intracranial vasculopathies easily elude classic stroke work-up. We aim in this work to show that vessel wall-MRI could prove an efficient alternative to digital subtraction angiography for the diagnosis of intracranial vasculopathies by identifying intracranial arterial vessel walls anomalies and contrast enhancement, suggestive of angiitis of the central nervous system. Materials and methods: Clinical and imaging characteristics of stroke patients diagnosed with primary angiitis of the central nervous system based on vessel wall-MRI were retrospectively reviewed and the clinical and imaging features of angiitis associated with intracranial vessel walls anomalies and contrast enhancement detailed. Results: Twenty patients were included (mean age was 59 years old). All patients were admitted for focal neurological deficits of sudden onset that were recurrent in 13 subjects. Cognitive impairment, headache and seizures occurred in, respectively, 13, 5, and 2 patients. Cerebrospinal fluid analysis was abnormal in 15 patients. In MRI, FLAIR sequences showed ischemic infarcts in 20 patients and DWI showed acute infarct in 15 patients. Digital subtraction angiography was performed in 11 patients and disclosed proximal and distal multifocal stenosis in 10 patients along distal irregularities in different vascular territories in 7. For all of our patients, VW-MRI revealed a concentric contrast enhancement of arterial walls, localized in multiple vascular territories, suggesting angiitis. Abnormalities on digital subtraction angiography and/or MR-Angiography, and vessel wall-MRI were consistent in all patients. Conclusions: This report underlies the added value of vessel wall-MRI to the diagnosis of underlying intracranial vasculopathy, particularly primary angiitis of the central nervous system, without the use of invasive endovascular techniques and the yield of vessel wall-MRI in the work-up of cryptogenic stroke.

Reversible Cerebral Vasoconstriction Syndrome: an Update of Recent Research

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by recurrent thunderclap headaches (TCH) and reversible segmental and multifocal vasoconstriction of cerebral arteries. Noninvasive neuroimaging such as computed tomography (CT), and magnetic resonance imaging (MRI) are widely used to assess cerebral vasculature, ischemic or hemorrhagic stroke, and posterior reversible encephalopathy (PRES). The significant differential diagnoses of RCVS center on the clinical presentation of headache and similar radiographic features including aneurysmal subarachnoid hemorrhage (SAH), cervical artery dissection, and central nervous system vasculitis (CNS-V). In this review we present a comprehensive overview of RCVS with the newest findings in the reported literature. Pathophysiology: Several surrogate markers including plasma endothelin-1 (E-1) have been investigated to elucidate the pathogenesis of RCVS. Clinical evaluation and diagnosis: The RCVS2 score is a simple scoring system has been proposed to distinguish RCVS from other intracranial vasculopathies. Neuroimaging: High-resolution contract-enhanced MRI (HR-MRI) vessel wall imaging is a feasible tool in differentiating vessel wall patterns of RCVS and CNS-V. Treatment: Early initiation of calcium channel blockers effectively prevents recurrent TCH and shorten the clinical courses. Clinical scoring system and newer imaging tools are helpful for the early distinction of RCVS. These approaches may serve increased sensitivity and specificity for the diagnosis and lead to appropriate management in RCVS patients.

High-resolution Compressed-sensing T1 Black-blood MRI : ANew Multipurpose Sequence in Vascular Neuroimaging?

In vasculopathies of the central nervous system, reliable and timely diagnosis is important against the background of significant morbidity and sequelae in cases of incorrect diagnosis or delayed treatment. Magnetic resonance imaging (MRI) plays amajor role in the detection and monitoring of intracranial and extracranial vascular pathologies of different etiologies, in particular for evaluation of the vessel wall in addition to luminal information, thus allowing differentiation between various vasculopathies. Compressed-sensing black-blood MRI combines high image quality with relatively short acquisition time and offers promising potential in the context of neurovascular vessel wall imaging in clinical routine. This case review gives an overview of its application in the diagnosis of various intracranial and extracranial entities. An optimized high-resolution compressed-sensing black-blood 3D T1-weighted fast (turbo) spin echo technique (T1 CS-SPACE prototype) precontrast and postcontrast application at 3T was used for the evaluation of various vascular conditions in neuroradiology. In this article seven cases of intracranial and extracranial arterial and venous vasculopathies with representative imaging findings in high-resolution compressed-sensing black-blood MRI are presented. High-resolution 3D T1 CS-SPACE black-blood MRI is capable of imaging various vascular entities in high detail with whole head coverage and low susceptibility for motion artifacts and within acceptable scan times. It represents ahighly versatile, non-invasive technique for the visualization and differentiation of awide variety of neurovascular arterial and venous disorders.