Inflammatory Type Focal Cerebral Arteriopathy of the Posterior Circulation in Children: A Comparative Cohort Study.

BACKGROUND: Inflammatory type focal cerebral arteriopathy (FCA-i) in the anterior circulation (AC) is well characterized, and the focal cerebral arteriopathy severity score (FCASS) reflects the severity of the disease. We identified cases of FCA-i in the posterior circulation (PC) and adapted the FCASS to describe these cases. METHODS: In this comparative cohort study, patients from the Swiss NeuroPaediatric Stroke Registry with ischemic stroke due to FCA-i between January 2000 and December 2018 were analyzed. A comparison between PC and AC cases regarding pediatric National Institutes of Health Stroke Scale score and pediatric stroke outcome measure and FCASS was performed. We estimated infarct size by the modified pediatric Alberta Stroke Program Early Computed Tomography Score in children with AC stroke and the adapted Bernese posterior diffusion-weighted imaging score in the PC. RESULTS: Thirty-five children with a median age of 6.3 (interquartile range, 2.7-8.2 [95% CI, 0.9-15.6]; 20 male; 57.1%) years with FCA-i were identified. The total incidence rate was 0.15/100 000/year (95% CI, 0.11-0.21). Six had PC-FCA-i. Time to final FCASS was longer in the PC compared with AC; the evolution of FCASS did not differ. Initial pediatric National Institutes of Health Stroke Scale score was higher in children with FCA-i in the PC with a median of 10.0 (interquartile range, 5.75-21.0) compared with 4.5 (interquartile range, 2.0-8.0) in those with AC-FCA-i. Different from the anterior cases, PC infarct volume did not correlate with higher discharge, maximum, or final FCASS scores (Pearson correlation coefficient [r], 0.25, 0.35, and 0.54). CONCLUSIONS: FCA-i also affects the PC. These cases should be included in future investigations into FCA-i. Although it did not correlate with clinical outcomes in our cohort, the modified FCASS may well serve as a marker for the evolution of the arteriopathy in posterior FCA-i.

MR vessel wall enhancement in a pediatric focal cerebral arteriopathy.

BACKGROUND: Focal cerebral arteriopathy (FCA) is a common cause of childhood arterial ischemic stroke in previously healthy children. Although its mechanisms are poorly understood, recent studies have suggested inflammatory processes. Magnetic resonance vessel wall imaging (VWI) is a potential imaging biomarker of inflammation. CASE DESCRIPTION: We describe the case of a 7-year-old Japanese girl with right hemiplegia and dysarthria for 3 days. Brain MRI showed acute infarct in the left basal ganglia, and MRA and conventional cerebral angiogram detected vascular stenosis in the left distal internal carotid artery, left M1 and A1 segments. VWI revealed marked vessel wall enhancement and thickening in the left carotid artery, M1, and A2 segments. Based on imaging findings, she was diagnosed with acute ischemic stroke caused by FCA. Because VWI findings were thought to suggest vessel wall inflammation, high-dose steroid therapy was administered in addition to neuroprotective care and antithrombotic therapy. Although her clinical symptoms improved immediately, cerebral arteriopathy worsened on MRA a month after the onset. Subsequently, after 3 months of steroid therapy, vessel wall enhancement on VWI decreased, while arterial stenosis partially improved. At the follow-up 9 months after the onset, she had no recurrent stroke, her arteriopathy had stabilized. DISCUSSION: Definitive evidence of inflammatory mechanisms in FCA is limited, and appropriate management and treatment strategies for FCA are undefined. VWI attempts to demonstrate pathologic processes within the vessel wall, and reversible wall enhancement observed in our patient suggested the presence of inflammation. VWI would help in the evaluation of disease activity in FCA. CONCLUSION: VWI may contribute to the appropriate diagnosis and treatment for FCA to reflect active inflammation. Further work is needed to assess the utility of VWI in pediatric FCA.

Clinical improvement of a toddler with COVID-19 focal cerebral arteriopathy possibly due to intra-arterial nimodipine.

Pediatric stroke is considered an infrequent complication of COVID-19. Focal cerebral arteriopathy (FCA) is one of the most common causes of arterial ischemic stroke in a previously healthy child. The present report describes a toddler with FCA most likely induced by SARS-CoV-2 infection who showed significant clinical improvement that may be related to injection of intra-arterial nimodipine. To our knowledge, this is the first reported use of nimodipine in this setting.

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

PURPOSE: 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. METHODS: Patients with ischemic stroke with isolated MCA disease with ≥ 50% luminal narrowing by vascular imaging were enrolled within 2 weeks of onset and underwent high-resolution (3 T) 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 3 months with imaging characteristics were analysed. RESULTS: Of the 36 patients, the mean age was 49.53 ± 15.61 years. 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 3 months. 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. CONCLUSION: High-resolution MRVWI can help in identifying the aetiology of stroke. The HRVWI characteristics in ICAD can help in risk stratification.

Ischemia in intracerebral hemorrhage: A comparative study of small-vessel and large-vessel diseases.

OBJECTIVE: This study aimed to compare effects of cerebral small-vessel disease (cSVD) burden and cerebral artery stenosis (CAS) on acute ischemia in intracerebral hemorrhage (ICH) and their interaction with mean arterial pressure (MAP) change. METHODS: We recruited consecutive patients with acute primary ICH. Brain magnetic resonance imaging and angiography were performed to quantify diffusion-weighted imaging (DWI) lesions, CAS, and cSVD markers, which were calculated for the total cSVD score. Multivariable regression models were adopted to explore their associations by DWI lesions size (<15 vs. ≥15 mm) and median MAP change stratification. RESULTS: Of 305 included patients (mean age 59.5 years, 67.9% males), 77 (25.2%) had DWI lesions (small, 79.2%; large, 20.8%) and 67 (22.0%) had moderate and severe CAS. In multivariable analysis, small DWI lesions were independently associated with higher total cSVD score (odds ratio [OR] 1.81, 95% confidence interval [CI] 1.36-2.41). and large DWI lesions were associated with more severe CAS (OR 2.51, 95% CI 1.17-5.38). This association was modified by MAP change (interaction p = 0.016), with stratified analysis showing an increased risk of large DWI lesions in severe CAS with greater MAP change (≥44 mmHg) (OR 3.48, 95% CI 1.13-10.74) but not with mild MAP change (<44 mmHg) (OR 1.21, 95% CI 0.20-7.34). INTERPRETATION: Total cSVD burden is associated with small DWI lesions, whereas the degree of CAS is associated with large DWI lesions, specifically with greater MAP change, suggesting that large-artery atherosclerosis may be involved in ischemic brain injury, which is different from small-vessel pathogenesis in ICH.

Visit-to-Visit Blood PressureVariations and Hemodynamic Deterioration in Atherosclerotic Major Cerebral ArteryDisease.

OBJECTIVE: Visit-to-visit variations in blood pressure (BP) in patients with atherosclerotic major cerebral artery disease could impair the function of cerebral collaterals, leading to hemodynamic deterioration at follow-up. However, few studies have investigated the relationship between visit-to-visit BP variability and changes in hemodynamic parameters at follow-up. MATERIALS AND METHODS: We evaluated 35 medically treated patients with atherosclerotic internal carotid artery or middle cerebral artery disease with no ischemic episodes during follow-up (mean: 35 ± 20 months); these patients had a three-time visit for positron emission tomography examinations with 15O-gas. Differences in the mean hemispheric values of hemodynamic parameters in the cortical territory of the diseased artery between the first and third examinations (changes at follow-up) were correlated with the coefficient of variation (CoV) in three systolic BP (SBP) values at the three examinations (BP variability during follow-up). RESULTS: CoV values were negatively correlated with changes in oxygen metabolism or cerebral blood flow/cerebral blood volume (CBF/CBV) ratio. In 17 patients with higher CoV values (> group median, 0.072), decreases in CBF, cerebral metabolic rate of oxygen, and CBF/CBV ratio were observed at follow-up; CBV decreased in 18 patients without elevated CoV. A higher CoV was associated with a lack of statin use. CONCLUSION: In patients with atherosclerotic major cerebral artery disease, high visit-to-visit SBP variations during follow-up may be associated with deterioration in cerebral hemodynamics and metabolism.

Letter-to-the Editor: Focal cerebral arteriopathy and acute ischaemic stroke in children: A diagnostic-therapeutical conundrum.

Acute ischaemic stroke (AIS) in children is generally considered an up-to-date and controversial topic because its presents significant peculiarities. Focal cerebral arteriopathies (FCA) are a possible cause of AIS in children characterized by an unilateral lesion of the terminal internal cerebral artery (ICA) and proximal segment (M1) of middle cerebral artery (MCA), leading to subocclusion, occasionally with a typical "striate" pattern and a tendency to stability or regression at follow-up. It is unclear whether in FCA the basic lesion is an inflammatory or a dissective arterial pathology. Herein we report a small series of children (<16 yo) with AIS from a FCA who underwent mechanical thrombectomy (MT). We speculate on the angiographic findings suggesting an aetiology of the lesion, and on indications and limits of the currently available treatments.

Focal Cerebral Arteriopathy in a Young Adult Following SARS-CoV2 Reinfection.

Ten days after SARS-Cov2 reinfection with mild gastrointestinal symptoms and headache that occurred 2 months after an initial infection, a previously healthy 37-year-old woman developed fluctuating facial and upper limb paresthesia and weakness. Diffusion-weighted magnetic resonance imaging revealed ischemic lesions in the right parietal region of different stages within the same vascular territory. A cerebral angiography demonstrated an isolated focal arteriopathy with no other arterial involvement. Focal cerebral arteriopathy is exceedingly rare among adults and most commonly triggered by varicella-zoster virus reactivation. We present a case of focal cerebral arteriopathy in a patient with a recent reinfection with SARS-CoV-2.

Focal Cerebral Arteriopathy of Childhood: Clinical and Imaging Correlates.

Background and Purpose: Focal cerebral arteriopathy (FCA) of childhood with unilateral stenosis of the anterior circulation is reported to account for up to one-quarter of childhood arterial ischemic stroke, with stroke recurrence in 25% of cases. Limited knowledge regarding pathophysiology and outcome results in inconsistent treatment of FCA. Methods: Children with arterial ischemic stroke due to FCA between January 1, 2009, and January 1, 2019, were retrospectively identified at our institution which serves the US Pacific Northwest region. Electronic health record data, including neuroimaging studies, were reviewed, and the Pediatric Stroke Outcome Measure at 1 year was determined as the primary clinical end point. Results: Fifteen children were diagnosed with FCA, accounting for 19% of children with cerebral arteriopathies (n=77). Among children with FCA, the median age at the time of stroke was 6.8 years (Q1­Q3, 1.9­14.0 years). Four (20%) patients had worsening stroke, 3 of whom had concurrent infection. Three (20%) FCA cases were treated with steroids, one of whom had worsening stroke. Median Pediatric Stroke Outcome Measure at 1 year was 1.0 (Q1­Q3, 0.6­2.0). Variability in arteriopathy severity was observed within many patients. Patients with more severe arteriopathy using the Focal Cerebral Arteriopathy Severity Score had larger strokes and were more likely to have worsening stroke. The most common long-term neurological deficit was hemiparesis, which was present in 11 (73%) patients and associated with middle cerebral artery arteriopathy and infarcts. Conclusions: FCA may be less common than previously reported. Neuroimaging in FCA can help identify patients at greater risk for worsening stroke.

A connectome-based approach to assess motor outcome after neonatal arterial ischemic stroke.

OBJECTIVE: Studies of motor outcome after Neonatal Arterial Ischemic Stroke (NAIS) often rely on lesion mapping using MRI. However, clinical measurements indicate that motor deficit can be different than what would solely be anticipated by the lesion extent and location. Because this may be explained by the cortical disconnections between motor areas due to necrosis following the stroke, the investigation of the motor network can help in the understanding of visual inspection and outcome discrepancy. In this study, we propose to examine the structural connectivity between motor areas in NAIS patients compared to healthy controls in order to define the cortical and subcortical connections that can reflect the motor outcome. METHODS: Thirty healthy controls and 32 NAIS patients with and without Cerebral Palsy (CP) underwent MRI acquisition and manual assessment. The connectome of all participants was obtained from T1-weighted and diffusion-weighted imaging. RESULTS: Significant disconnections in the lesioned and contra-lesioned hemispheres of patients were found. Furthermore, significant correlations were detected between the structural connectivity metric of specific motor areas and manuality assessed by the Box and Block Test (BBT) scores in patients. INTERPRETATION: Using the connectivity measures of these links, the BBT score can be estimated using a multiple linear regression model. In addition, the presence or not of CP can also be predicted using the KNN classification algorithm. According to our results, the structural connectome can be an asset in the estimation of gross manual dexterity and can help uncover structural changes between brain regions related to NAIS.

Utility of minimum intensity projection images based on three-dimensional CUBE T1 weighted imaging for evaluating middle cerebral artery stenosis.

OBJECTIVE: This study investigated the diagnostic performance of MinIP images based on three-dimensional variable-flip-angle turbo spin echo T1 weighted imaging (3D CUBE T1WI) from high-resolution vessel wall magnetic resonance imaging for detecting middle cerebral artery (MCA) stenosis. METHODS: A total of 63 consecutive patients were included in this study. MinIP images were reconstructed using 3D CUBE T1WI as the source images. The degree and length of MCA stenosis were measured on MinIP images and were compared with digital subtraction angiography (DSA) as the reference standard. RESULTS: The intra- and interobserver agreement for both the rate and length of MCA stenosis were excellent for the MinIP images. There was also excellent agreement in the degree of MCA stenosis calculated using MinIP images and DSA. MinIP images had a high sensitivity, specificity for diagnosing MCA stenosis. There was a good correlation between the two methods for measuring the rate and length of MCA stenosis. CONCLUSION: MinIP images based on 3D CUBE T1WI are highly consistent with DSA for evaluating the degree and length of MCA stenosis. ADVANCES IN KNOWLEDGE: MinIP images can be produced as a derivative from vessel wall imaging and implemented as an adjunct to vessel wall imaging without extra acquisition time.

Susceptibility-Weighted Imaging in Neurodegenerative Disorders: A Review.

As human life expectancy increases, there is an increased prevalence of neurodegenerative disorders and dementia. There are many ongoing research trials for early diagnosis and management of dementia, and neuroimaging is a critical part of such studies. However, conventional neuroimaging often fails to provide enough diagnostic findings in patients with neurodegenerative disorders. In this context, different MRI sequences are currently under investigation to facilitate the accurate diagnosis of such disorders. Susceptibility-weighted imaging (SWI) is an innovative MRI technique that utilizes "magnitude" and "phase" images to produce an image contrast that is sensitive for the detection of susceptibility differences of the tissues. As many neurodegenerative disorders are associated with accelerated iron deposition and/or microhemorrhages in different parts of the brain, SWI can be applied to detect these diagnostic clues. For instance, in cerebral amyloid angiopathy, SWI can demonstrate cortical microhemorrhages, which are predominantly in the frontal and parietal regions. Or in Parkinson disease, abnormal swallow-tail sign on high-resolution SWI is highly diagnostic. Also, SWI is a useful sequence to detect the low signal intensity of precentral cortices in patients with amyotrophic lateral sclerosis. Being familiar with SWI findings in neurodegenerative disorders is critical for an accurate diagnosis. In this paper, the authors review the technical parameters of SWI, physiologic, and pathologic iron deposition in the brain, and the role of SWI in the evaluation of neurodegenerative disorders in daily practice.

Occlusive Disease and Upright Activity in Acute Ischemic Stroke.

The impact of out-of-bed upright activity on outcomes in ischemic stroke patients with severe extra- and intracranial stenosis or occlusion is unknown. Using ultrasound findings from a cohort recruited to A Very Early Rehabilitation Trial (AVERT) which compared higher dose very early mobilisation (VEM) to usual care (UC), we aimed to explore the association between occlusive disease and 3-month outcomes and occlusive disease-by-mobilisation treatment interactions. Participants with ischemic stroke, with carotid and transcranial Doppler ultrasounds performed ≤1 week after admission, were included in this single centre substudy in Melbourne, Australia. Reports were retrospectively reviewed to determine the degree of stenosis or presence of occlusion in the relevant arterial territory. Stenosis ≥70% extracranial or ≥50% intracranial were classified as severe or occlusion. Overall, 19% (n = 36/191) had occlusive disease in the affected circulation. About 40% (n = 14/36) with occlusive disease and 51% (n = 79/155) without had a 3-month favourable outcome (mRS 0-2) (adjusted OR0.53, CI0.17-1.67). Fourteen percent (n = 5) with occlusive disease and 4% (n = 6) without died by 3 months (adjusted OR2.52, CI0.6-10.7). Fifty percent (n = 11/22) of UC (adjusted OR0.86, CI0.23-3.2) and 21% (n = 3/14) of VEM participants (adjusted OR0.16, CI0.01-2.7) with occlusive disease had a favourable outcome. Almost 30% (n = 4) VEM participants with occlusive disease died (adjusted OR3.99, CI0.69-22.9) compared to 5% (n = 1) UC participants with occlusive disease (adjusted OR0.45, CI0.02-8.6), however numbers were small. No stenosis-by-treatment interactions were found. High quality prospective studies are needed to help guide decision making about when patients with occlusive disease should commence upright activity in acute stroke.

Effects of site, cerebral perfusion and degree of cerebral artery stenosis on cognitive function.

OBJECTIVE: To investigate the effects of site, cerebral perfusion and degree of cerebral artery stenosis (CAS) on cognitive function. METHODS: A total of 57 patients with CAS and 53 controls from January 2019 to December 2019 were included. The former group was further divided into different subgroups according to the site, cerebral perfusion and degree of CAS. A series of neuropsychological tests were performed to evaluate the cognitive domains (such as memory, executive function, psychomotor speed, etc.). Rank sum test, t test, Chi-square test and analysis of variance were used for data analysis. Spearman correlation analysis was used to examine the relationship between the site, cerebral perfusion and degree of CAS and all tests' scores. RESULTS: For patients with CAS who have decreased cerebral perfusion, their global cognitive function, memory, psychomotor speed, executive function and frontal lobe function were significantly impaired (all P < 0.05). There was a significant decrease in global cognitive function, psychomotor speed, memory, executive function and frontal lobe function in patients with anterior circulation stenosis (all P < 0.05). Moderate and severe CAS impaired subjects' global cognitive function, memory, psychomotor speed, executive function and frontal lobe function (all P < 0.05). There was a correlation between the site, cerebral perfusion, the degree of CAS and cognitive function. CONCLUSION: Global cognitive function, memory, psychomotor speed, frontal lobe function and executive function are impaired in patients with CAS, especially in those with anterior circulatory stenosis, moderate to severe stenosis and low cerebral perfusion.See Video Abstract, http://links.lww.com/WNR/A613.

Late-onset cerebral arteriopathy in a patient with incontinentia pigmenti.

BACKGROUND: Incontinentia pigmenti (IP) is an X-linked neurocutaneous disorder that can present with cerebral arteriopathy during early infancy. However, no previous reports have demonstrated arteriopathic manifestations during postinfantile childhood in patients with IP. PATIENT DESCRIPTION: We describe a case of IP in a 2-year-old girl who developed encephalopathic manifestations associated with influenza A infection. She presented diffuse magnetic resonance imaging abnormalities involving the cortices, subcortical white matter, corpus callosum, basal ganglia, and thalami, resembling the findings in early infantile cases reported in the previous literatures. Magnetic resonance angiography demonstrated attenuation of the cerebral arteries. Proinflammatory cytokines and chemokines were upregulated in the cerebrospinal fluid. Left hemiplegia remained following the remission of the arteriopathic manifestations. Genetic analyses revealed a novel type of mutation in the IKBKG gene. CONCLUSION: Our findings indicate that patients with IP can develop destructive cerebral arteriopathy even after early infancy. The similarities in magnetic resonance imaging abnormalities between our patient and the previously reported infantile patients may be explained by the underlying immunologic pathophysiology of IP.

Multiple Cerebrovascular Insults in Pseudoxanthoma Elasticum.

Pseudoxanthoma elasticum (PXE) is a rare systemic genetic disorder and an uncommon cause of ischaemic and haemorrhagic strokes. Its rarity and variable presentation may delay recognition and diagnosis of the primary disorder or associated conditions. Here, we describe a patient of European ancestry diagnosed with PXE in her 20s who presented in her 50s with a haemorrhagic stroke. Subsequent workup additionally revealed clinically silent ischaemic cerebral infarcts, critical stenosis of the right internal carotid artery and intracranial vasculopathy. Though she had some typical vascular risk factors, they were well-controlled. Antiplatelet therapy has traditionally been avoided in PXE due to increased risk of GI (and potentially retinal and cerebral) haemorrhage, but the medical team opted to start aspirin for secondary stroke prevention because she had no history of GI or retinal bleed, and her risk of ischaemic stroke was considered unacceptably high compared with that of clinically significant haemorrhage. Judicious use of antiplatelet therapy may be relatively safe in carefully selected patients. Anticipatory surveillance and management of the numerous manifestations of this potentially debilitating disorder are also important to preserve function and quality of life.

Validation of the focal cerebral arteriopathy severity score (FCASS) in a Swiss cohort: Correlation with infarct volume and outcome.

BACKGROUND: Focal cerebral arteriopathy (FCA), a major cause of childhood arterial ischemic stroke (AIS), can progress and lead to increased infarct size and/or recurrent stroke. Evaluating treatment options depends on the ability to quantify reliably the degree of stenosis in FCA. AIMS: We validated the recently introduced FCA severity score (FCASS) in an independent cohort from the Swiss Neuro-Paediatric Stroke Registry (SNPSR). MATERIALS AND METHODS: We included children with FCA who had MR or CT angiography and a Pediatric Stroke Outcome Measure (PSOM) at 6-months and 2-years post-stroke. A paediatric neuroradiologist applied the FCASS and the modified pediatric Alberta Stroke Program Early Computed Tomography Score (ASPECTS), a measure of infarct volume, to all available imaging. Two senior paediatric stroke neurologists and a neuroradiology fellow independently assigned FCASS scores to test interrater reliability. Pairwise correlations between FCASS, pedASPECTS, and PSOM were examined. RESULTS: Thirty-two children [median (IQR) age = 5.9 (1.8, 9.6), 19 males] were included. The median maximum FCASS score at any time was 9 (IQR 6, 12; range 3, 16). Larger infarct volume scores correlated with both higher maximum FCASS scores and worse post-stroke outcomes, although we found no direct correlation between FCASS and outcomes. Stroke neurologists tended to assign lower FCASS scores than the neuroradiologist, but interrater reliability was predominantly good. CONCLUSIONS: In this independent validation cohort, higher maximum FCASS correlated with greater infarct volume scores that also correlated with worse neurological outcomes. Scoring by non-imaging specialists seems to be valuable, although differences are present.

Acetazolamide-Loaded Dynamic 7T MR Quantitative Susceptibility Mapping in Major Cerebral Artery Steno-Occlusive Disease: Comparison with PET.

BACKGROUND AND PURPOSE: Dynamic changes in cerebrovascular reactivity after acetazolamide administration vary markedly among patients with major cerebral arterial steno-occlusive disease. MR quantitative susceptibility mapping can dynamically quantify the cerebral magnetic susceptibility. The purpose of this study was to determine whether dynamic changes in susceptibility after administration of acetazolamide on 7T quantitative susceptibility mapping are associated with pre-existing states of CBV and the cerebral metabolic rate of oxygen in the cerebral hemispheres with major cerebral arterial steno-occlusive disease. MATERIALS AND METHODS: Sixty-five patients underwent 7T MR imaging at baseline and at 5, 10, 15, and 20 minutes after acetazolamide administration. Differences between the susceptibility of venous structures and surrounding brain tissue were calculated in the quantitative susceptibility mapping images. Susceptibility differences at 5, 10, 15, and 20 minutes after acetazolamide administration relative to baseline were calculated in 97 cerebral hemispheres with major cerebral arterial steno-occlusive disease. CBV and the cerebral metabolic rate of oxygen were also calculated using 15O-gas PET in the resting state. RESULTS: Dynamic changes of susceptibility after acetazolamide administration were classified into 3 patterns: abnormally increasing 5 or 10 minutes after acetazolamide administration; abnormally decreasing within 20 minutes after acetazolamide administration; and remaining unchanged after acetazolamide administration. CBV was significantly greater in the first pattern than in the latter 2. The cerebral metabolic rate of oxygen differed significantly in descending order from the first to middle to last pattern. CONCLUSIONS: Dynamic changes of susceptibility after acetazolamide administration on 7T MR quantitative susceptibility mapping are associated with pre-existing states of CBV and the cerebral metabolic rate of oxygen in major cerebral arterial steno-occlusive disease.