Magnetic Resonance Angiography Scores Research Articles

Predictive value of the hemispheric magnetic resonance angiography score on the development of indirect pial synangiosis after combined revascularization surgery for adult moyamoya disease.

It is difficult to precisely predict indirect bypass development in the context of combined bypass procedures in moyamoya disease (MMD). We aimed to investigate the predictive value of magnetic resonance angiography (MRA) signal intensity in the peripheral portion of the major cerebral arteries for indirect bypass development in adult patients with MMD. We studied 93 hemispheres from 62 adult patients who underwent combined direct and indirect revascularization between 2005 and 2019 and genetic analysis for RNF213 p.R4810K. The signal intensity of the peripheral portion of the major intracranial arteries during preoperative MRA was graded as a hemispheric MRA score (0-3 in the middle cerebral artery and 0-2 in the anterior cerebral and posterior cerebral arteries, with a high score representing low visibility) according to each vessel's visibility. Postoperative bypass development was qualitatively evaluated using MRA, and we evaluated the correlation between preoperative factors, including the hemispheric MRA score and bypass development, using univariate and multivariate analyses. A good indirect bypass was observed in 70% of the hemispheres. Hemispheric MRA scores were significantly higher in hemispheres with good indirect bypass development than in those with poor indirect bypass development (median: 3 vs. 1; p < 0.0001). Multiple logistic regression analysis revealed hemispheric MRA score as an independent predictor of good indirect bypass development (odds ratio, 2.1; 95% confidence interval, 1.3-3.6; p < 0.01). The low hemispheric MRA score (< 2) and wild-type RNF213 predicted poor indirect bypass development with a specificity of 0.92. Hemispheric MRA score was a predictive factor for indirect bypass development in adult patients who underwent a combined bypass procedure for MMD. Predicting poor indirect bypass development may lead to future tailored bypass surgeries for MMD.

Abstract WP247: Potential Predictors for Progression of Adult Moyamoya Disease: A Study From Multicenter Registry

Background and aims: Moyamoya disease refers to a chronic progressive steno-occlusive disease at the distal portion of the internal carotid arteries (ICAs) and compensatory abnormal collateral vessel formation. However, the incidence of progression and its’ related factors in adult moyamoya disease has not been well known. Our study was to investigate the prevalence of progression of steno-occlusion of intracranial vessels and clinical outcome in the patients with adult moyamoya disease. Methods: From Jan 2001 to Jun 2021, we included the patients who was diagnosed with symptomatic or asymptomatic moyamoya disease from moyamoya registries of 4 hospitals in Korea. We excluded patients who did not have any follow-up angiography more than 1 year after baseline angiography [digital subtraction angiography (DSA) or magnetic resonance angiography (MRA)]. We adopted Suzuki’s angiographic staging and MRA score for the analysis. Results: A total of 293 moyamoya patients were included, and mean follow-up period was 92.7 ±52.8 months. Among them, progression of vessel stenosis in DSA and/or MRA was found in 110 patients (37.5%). Recurrent stroke occurred in 39/183 (21.3%) in non-progression group and 40/110 (36.4%) in progression group. Clinical characteristics were not significantly different between two groups. However, previous ischemic stroke history is independently associated with angiographic progression (odds ratio, 3.384 [95% CI, 1.521-7.531]) in multivariable logistic regression analysis. Conclusions: Occlusive arterial status worsened in one-third of the patients with adult moyamoya disease during approximately 8 years of follow-up. Careful neurological and radiological follow-up would be essential to prevent additional stroke occurrence, especially in patients with a history of cerebral infarction.

Risk Factors for Massive Cerebral Infarction in Pediatric Patients With Moyamoya Disease

BackgroundTo explore the risk factors for preoperative massive cerebral infarction (MCI) in pediatric patients with moyamoya disease (MMD). MethodsPediatric patients with MMD treated between 2017 and 2022 were enrolled. Logistic regression analysis was performed to identify risk factors for MCI among the patients, and a nomogram was constructed to identify potential predictors of MCI. Receiver operating characteristic (ROC) curves and areas under the curves were calculated to determine the effects of different risk factors. ResultsThis study included 308 pediatric patients with MMD, including 36 with MCI. The MCI group exhibited an earlier age of onset than the non-MCI group. Significant intergroup differences were observed in familial MMD history, postcirculation involvement, duration from diagnosis to initiation of treatment, Suzuki stage, magnetic resonance angiography (MRA) score, collateral circulation score, and RNF213 p.R4810K variations. Family history, higher MRA score, lower collateral circulation score, and RNF213 p.R4810K variations were substantial risk factors for MCI in pediatric patients with MMD. The nomogram demonstrated excellent discrimination and calibration capabilities. The integrated ROC model, which included all the abovementioned four variables, showed superior diagnostic precision with a sensitivity of 67.86%, specificity of 87.01%, and accuracy of 85.11%. ConclusionsThis study showed that family history, elevated MRA score, reduced collateral circulation score, and RNF213 p.R4810K variations are risk factors for MCI in pediatric patients with MMD. The synthesized model including these variables demonstrated superior predictive efficacy; thus, it can facilitate early identification of at-risk patients and timely initiation of appropriate interventions.

“Transcallosal” periventricular anastomosis in moyamoya disease: the fourth periventricular anastomosis and a potential predictor of hemorrhage

ObjectivesChoroidal anastomosis is a risk factor for hemorrhage in moyamoya disease. One variant of choroidal anastomosis, “transcallosal anastomosis,” originates from the medial posterior choroidal artery, and penetrates the corpus callosum to reconstruct the pericallosal artery. We aimed to investigate the prevalence and the bleeding rate of transcallosal anastomosis using sliding thin-slab maximum intensity projection reformatted from magnetic resonance angiography (MRA). Materials and MethodsThis study included 222 patients. We defined transcallosal anastomosis grades (0-2) and the stenosis of the anterior (ACA, 0-2), middle (MCA, 1-3), and posterior cerebral artery (PCA, 0-2) by MRA scores, independently by two coauthors. ResultsGrade-2 transcallosal anastomosis was detected in 21 patients (9.5 %). There were no correlations of the incidence of transcallosal anastomosis with previous bypass surgery (P = 0.23). Multivariate analysis revealed a significantly higher incidence in hemorrhagic onset and younger age (odds ratio [OR] 3.77, and 0.97). Transcallosal anastomosis had statistically significant correlation with ACA and PCA scores (P = 0.01 and 0.03), but not with MCA scores (P = 0.1). In multivariate analysis, ACA scores 1 and 2 were significantly higher (OR, 15.44 and 11.17), and PCA score 1 was also higher (OR, 3.07), but PCA score 2 was not. Interrater agreement for judgment of transcallosal anastomosis grade was strong (κ = 0.89). Two patients with Grade-2 transcallosal anastomosis had late hemorrhage in the corpus callosum (bleeding rate: 2.5 % per year). ConclusionsTranscallosal anastomosis may be associated with both advanced ACA and moderate PCA stenosis, and cause hemorrhage at the corpus callosum.

Transient ischemic attack after indirect revascularization surgery for pediatric patients with moyamoya disease: A retrospective study of intraoperative blood pressure

BackgroundThis study aimed to investigate the association between intraoperative blood pressure and postoperative transient ischemic attacks (TIAs) in pediatric patients with moyamoya disease after indirect revascularization surgery. MethodsWe retrospectively reviewed the medical records of patients with moyamoya disease younger than 15 years who underwent indirect revascularizations under general anesthesia from 2013 to 2019. Perioperative clinical factors and intraoperative blood pressure data were collected and analyzed. Univariate and multivariable mixed-effect logistic regressions were used to identify predictors of postoperative TIA and symptom progression. ResultsAmong 444 hemispheres in 296 pediatric patients, 70 cases (16%) experienced postoperative TIAs within 2 weeks after surgery, and 34 cases (7.7%) developed postoperative symptom progression. Baseline mean blood pressure (MBP) (adjusted odds ratio, 1.261; 95% confidence interval, 1.037−1.528; P < 0.001), Average mean arterial pressure (MAP) (adjusted odds ratio, 1.137; 95% confidence interval, 1.052−1.228; P = 0.006), and Ipsilateral magnetic resonance angiography (MRA) score (adjusted odds ratio, 1.464; 95% confidence interval, 0.886−2.419; P = 0.012) were statistically significant risk factors for postoperative TIA. Average real variability of MAP (ARV-MAP), which were measures of intraoperative MAP variability (adjusted odds ratio, 4.731; 95% confidence interval, 1.419−15.257; P = 0.003) and maximum MAP declination (MaxD-MAP) (adjusted odds ratio, 1.271; 95% confidence interval, 1.013−1.520; P = 0.010) were statistically significant risk factors for postoperative symptom progression. ConclusionHigher pre-induction baseline blood pressure and ipsilateral MRA score were independent risk factors predicting postoperative TIA in pediatric patients with moyamoya disease after indirect revascularization. The high variability and drastic decline in intraoperative MAP showed predictive value in postoperative symptom progression.

Preoperative Risks of Cerebral Infarction in Pediatric Moyamoya Disease.

In pediatric moyamoya disease, there have been few reports of the risk factors for preoperative cerebral infarction, especially during the waiting period before surgery. The clinical and radiological findings of surgically treated pediatric moyamoya patients were evaluated to analyze the risk factors for cerebral infarction seen from onset to surgery. Between August 2003 and September 2019, 120 hemispheres of 71 patients under 18 years of age with moyamoya disease were surgically treated by direct and indirect bypass procedures. The mean age of all surgical hemispheres at diagnosis was 6.7±3.9 years (6 months–17 years). The potential risk factors for preoperative infarction were examined statistically. Multivariate logistic regression analysis showed that risk factors for infarction at the time of diagnosis were age at diagnosis (odds ratio [OR], 0.68 [95% CI, 0.57–0.82]; P<0.0001) and the magnetic resonance angiography (MRA) score (OR, 2.29 [95% CI, 1.40–3.75]; P=0.001). Univariate analysis showed that risk factors for infarction while waiting for surgery were age at diagnosis (OR, 0.61 [95% CI, 0.46–0.80]; P<0.0001), the MRA score (OR, 1.75 [95% CI, 1.26–2.41]; P=0.0003), and onset of infarction (OR, 40.4 [95% CI, 5.08–322.3]; P<0.0001). Multiple comparisons showed that patients under 4 years of age were at a significantly high risk of infarction at the time of diagnosis and while waiting for surgery. Time from diagnosis to surgery of >2 months was a significant risk factor for infarction while waiting for surgery in patients under 6 years of age. Young age at diagnosis and a high MRA score may be associated with rapid disease progression and result in preoperative infarction. We recommend that surgery be performed within 2 months of diagnosis for the patients under 4 years of age with a high MRA score (>5) and cerebral infarction. Further study is needed to define the optimal timing of surgery.

Prediction of Cerebral Hyperperfusion after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis by Three-Dimensional-Time-of-Flight Magnetic Resonance Angiography in Adult Patients with Moyamoya Disease

Introduction: Superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis is an effective surgical procedure for adult patients with moyamoya disease (MMD) and is known to have the potential to prevent cerebral ischemia and/or hemorrhagic stroke. Cerebral hyperperfusion (CHP) syndrome is one of the serious complications of this procedure that can result in deleterious outcomes, such as delayed intracerebral hemorrhage, but the prediction of CHP before revascularization surgery remains challenging. The present study evaluated the diagnostic value of preoperative three-dimensional (3D)-time-of-flight (TOF) magnetic resonance angiography (MRA) for predicting CHP after STA-MCA anastomosis for MMD. Materials and Methods: The signal intensity of the peripheral portion of the intracranial major arteries, such as the anterior cerebral artery (ACA), MCA, and posterior cerebral artery (PCA) ipsilateral to STA-MCA anastomosis, on preoperative MRA was graded (0–2 in each vessel) according to the ability to visualize each vessel on 97 affected hemispheres in 83 adult MMD patients. Local cerebral blood flow (CBF) at the site of anastomosis was quantitatively measured by N-isopropyl-p-[¹²³I]-iodoamphetamine single-photon emission computed tomography 1 and 7 days after surgery, in addition to the preoperative CBF value at the corresponding area. Then, we investigated the correlation between the preoperative MRA score and the development of CHP. Results: The CHP phenomenon 1 day after STA-MCA anastomosis (local CBF increase over 150% compared with the preoperative value) was evident in 27 patients (27/97 hemispheres; 28%). Among them, 8 (8 hemispheres) developed CHP syndrome. Multivariate analysis revealed that the hemispheric MRA score (0–6), the summed ACA, MCA, and PCA scores for the affected hemisphere, was significantly associated with the development of CHP syndrome (p = 0.011). The hemispheric MRA score was also significantly correlated with the CHP phenomenon, either symptomatic or asymptomatic (p < 0.001). Conclusion: The signal intensity of the intracranial major arteries, including the ACA, MCA, and PCA, on preoperative 3D-TOF MRA may identify adult MMD patients at higher risk for CHP after direct revascularization surgery.

Arterial transit artifacts observed by arterial spin labeling in Moyamoya disease

Objectives: Arterial spin labeling (ASL) is a magnetic resonance imaging (MRI) technique used to assess cerebral perfusion. When tissue perfusion is impaired, such as in Moyamoya disease, a hyperintense band called the arterial transit artifact (ATA) may occur, which interferes with accurate measurements on ASL-MRI. In this study, we evaluated the correlation of ATAs with magnetic resonance angiography (MRA) and single-photon emission computed tomography (SPECT) imaging results in Moyamoya disease. The aim of our study was to elucidate the pathophysiology of ATAs and risk factors for high ATA scores. Materials and Methods: This retrospective study included 28 patients (56 hemispheres) with Moyamoya disease treated at our institution. MRI, MRA, ASL perfusion, and N-isopropyl-[123I] b-iodoamphetamine (123I-IMP) SPECT were performed. In order to semi-quantitatively evaluate the degree of ATA, the ATA scores were measured according to the number of hyperintense signal bands in the cerebral cortex. The relationship between the ATA scores and clinical and radiological factors were analyzed. Results: Regional cerebral blood flow (rCBF) determined with ASL weakly correlated with that determined by 123I-IMP SPECT (ρ=0.31, p=0.027). There was no significant association between the ATA scores and rCBF values determined with 123I-IMP SPECT (p=0.872, 0.745, 0.743 at PLD1000 (post-labeling delay), 1500, and 2000, respectively). However, there was a significant correlation between ATA scores and MRA scores (ρ=0.427 p=0.001; ρ=0.612 p=0.001; ρ=0.563 p=0.001 at PLD1000, 1500, and 2000, respectively). An analysis of patient background characteristics revealed a significantly higher incidence of high ATA scores in female patients, patients with high MRA scores, and patients with a distinguishable ivy sign. A multivariate analysis confirmed that female sex, high MRA score, and presence of an ivy sign were risk factors for high ATA scores. Conclusion: ATA scores were moderately correlated with MRA scores, and presence of an ivy sign was the most predictive factor for high ATA scores. A high ATA score determined using ASL in a patient with Moyamoya disease might suggest an advanced disease stage and a reduction in cerebrovascular reserve capacity.

Study on the risk prediction for cerebral infarction after transient ischemic attack: A STROBE compliant study.

Transient ischemic attack (TIA) is often recurrent, and about one-third of patients will progress to cerebral infarction. Rapidly identifying high-risk patients is pivotal to prevent the development of cerebral infarction. Therefore, this study aimed to evaluate the value of ABCD2 score, ABCD2 score combined with magnetic resonance diffusion weighted imaging (DWI) and intracranial arterial magnetic resonance angiography (MRA) in predicting cerebral infarction after 2 to 30 days of transient ischemic attack (TIA).182 patients with TIA from August 2011 to August 2014 were enrolled as study subjects, and their clinical data, test results of DWI and MRA were collected. The incidence of cerebral infarction was observed at 2 days, 7 days and 30 days after TIA in patients with TIA, through scoring according to the 7-point ABCD2 score method proposed by Johnston. The relationship between ABCD2 score, performances of DWI and MRA and the early incidence of cerebral infarction after TIA was analyzed. The accuracy rating of ABCD2 score and ABCD2 + DWI + MRA score used for predicting the early incidence of cerebral infarction after TIA were compared with each other.The incidence of cerebral infarction after TIA was 19 cases (10.4%) in 2 days, 42 cases (23.1%) in 7 days, 56 cases (30.8%) in 30 days respectively. For the ABCD2 score of incidence of cerebral infarction 2 to 30 days after TIA, that of those with high risk was higher than that with medium risk, and that with the medium risk was higher than that with low risk (P < .05). The area under the curve of ABCD2 + DWI + MRA score and ABCD2 score predicting the incidence of cerebral infarction was: in 2 days: 0.782 and 0.748, in 7 days: 0.839 and 0.801, in 30 days: 0.780 and 0.757, P < .05.Compared with ABCD2 score, ABCD2 score combined with DWI and MRA can further improve the accuracy of prediction for cerebral infarction after TIA.

Predictive factors for acute thrombogenesis occurring immediately after bypass procedure for moyamoya disease.

Extracranial-to-intracranial (EC-IC) bypass surgery is an effective treatment for patients with moyamoya disease and other conditions. Some patients with moyamoya disease have a risk of acute thrombogenesis at the anastomotic site just after bypass surgery. The purpose of this study was to study risk factors of acute thrombogenesis and determine effective countermeasures. This study included 48 patients (66 EC-IC bypass procedures) with moyamoya disease and 52 controls (54 procedures) without moyamoya disease. The development of acute thrombogenesis was compared between the moyamoya disease and control groups. In the moyamoya disease group, clinical and radiological characteristics were assessed with respect to acute thrombogenesis. In the patients with acute thrombogenesis, causes of technical problems were retrospectively examined. The incidence of acute thrombogenesis was significantly higher in the moyamoya disease group than those in the control group. In the moyamoya disease group, acute thrombogenesis was observed in seven patients. In the moyamoya disease group, the magnetic resonance angiography (MRA) scores were significantly higher in patients with acute thrombogenesis than those in the patients without acute thrombogenesis. In the multivariate analysis, the predictive factor of acute thrombogenesis in moyamoya disease was a high MRA score (odds ratio, 2.336; p = 0.009). During EC-IC bypass surgery for moyamoya disease, acute thrombogenesis should be considered to obtain a high patency rate, particularly in patients with high MRA scores. Acute thrombogenesis will not influence morbidity if proper countermeasures are followed; therefore, the prediction and recognition of white thrombus are important for a successful bypass surgery.

Characteristics of Moyamoya Syndrome in Sickle-Cell Disease by Magnetic Resonance Angiography: An Adult-Cohort Study.

Background: Sickle cell disease (SCD) can be complicated by moyamoya syndrome. Brain magnetic resonance angiography (MRA) is a non-invasive method to diagnose this syndrome and, steno-occlusion and moyamoya vessels (MMV) scores have been proposed to evaluate its severity. Previous studies of SCD moyamoya syndrome did not evaluate the severity according to MRA scores. The objective was to assess the characteristics of moyamoya syndrome in an adult cohort of SCD using these MRA scores.Methods: Twenty-five SCD patients with moyamoya syndrome were included using MRA with 3D time of flight technique. We evaluate steno-occlusion score for each hemisphere (range 0–10) from: steno-occlusion severity of internal carotid (ICA) (0–3), anterior cerebral (ACA) (0–3), middle cerebral (MCA) (0–2), and posterior cerebral (PCA) (0–2) arteries. MMV score for each hemisphere (range 0–5) depended from 5 MMV areas: (1) anterior communicating artery (2) basal ganglia (3) ICA/MCA (4) posterior communicating artery/PCA (5) basilar artery.Results: Eight patients (32%) showed unilateral moyamoya syndrome. ICA steno-occlusion was involved in 22 patients (88%), MCA in 23 patients (92%), ACA in 9 patients (36%), and PCA in 3 patients (12%). MMV involved ACoA area in 10 patients (40%), basal ganglia in 13 patients (52%), PCoA/PCA in 10 patients (40%), MCA/ICA in 7 patients (28%), and BA in 1 patient (4%). Steno-occlusion and MMV mean hemisphere scores were 3.4/10 (± 1.42) and 1.6/5 (± 0.71), respectively.Conclusion: Frequent unilateral moyamoya syndrome, uncommon PCA involvement and, moderate steno-occlusion and MMV scores seem to be features of SCD moyamoya syndrome. In future studies, MRA scores could be collected to assess the follow-up in these patients.

Geometrical Complexity of Cortical Microvascularization in Moyamoya Disease

Dilatation of the microvascular diameter is recognized in moyamoya disease and referred to as microvascularization. The purpose of this study was to characterize the cortical microvascularization in moyamoya disease using imaging analysis, and to explore the developmental mechanism of the collateral network around the cortical surface. A total of 20 hemispheric sides of 14 patients with moyamoya disease were included in this study. From the intraoperative images, cortical surface images were extracted, and binary images were subsequently created. Then the ratio of the microvessels of the brain surface (vascular fraction; VF) and the box-counting fractal dimension (Db) values were calculated. The VF and Db values in the moyamoya disease group were then compared with those in atherosclerotic disease and nonischemic disease groups, and assessed in terms of clinical and radiologic factors. VF was significantly higher in the moyamoya disease group compared with the atherosclerotic disease group, and Db was significantly higher in the moyamoya disease group compared with the atherosclerotic disease and nonischemic disease groups. In the moyamoya disease group, VF showed a moderate correlation with magnetic resonance angiography (MRA) score. Moreover, Db was significantly higher in the pediatric patients, in the presence of ischemic symptoms, and in the presence of ivy sign, and Db showed a moderate correlation with MRA score and cerebral blood flow in moyamoya disease. In the patients with moyamoya disease, the cortical microvascularization exhibited increased Db and dilatation of the pial arteries. In moyamoya disease, cortical microvascularization is associated with clinical and radiologic factors. This microvascularization might be a compensatory mechanism in the ischemic condition in moyamoya disease.

Meandering flow void around the splenium in moyamoya disease

Objectives: Meandering flow void around the splenium, which can be recognized on conventional T2-weighted images, implicates collateral flow in the splenial artery in patients with moyamoya disease. In this report, curves of flow voids around the splenium (SFVs) were evaluated in patients with moyamoya disease, and their diagnostic value and pathophysiology were verified.Methods: A total of 65 consecutive patients with moyamoya disease were included in this analysis. The number of SFV curves was counted on each side. The numbers of SFV curves in patients with moyamoya disease was compared with those in the control group. The clinical features of patients with large numbers of flow voids were analyzed.Results: The mean number of SFVs was significantly higher in the moyamoya disease group than in the control group or the atherosclerotic disease group. The cut-off SFV count for a diagnosis of moyamoya disease should be set to 2.25 in consideration of receiver operating characteristic curve analysis. A multivariate logistic analysis of SFV data in moyamoya disease revealed significant differences between the high SFV count group (≥2.25) and the low SFV count group (<2.25) in age, flow voids in the basal ganglia, and magnetic resonance angiography score of the internal carotid artery and anterior cerebral artery.Conclusion: Based on this study, number of SFV curves on conventional T2-weighted imaging could be a useful measurement for confirming a diagnosis of moyamoya disease. Increased number of SFV curves was associated with age and progress of disease.

Vascular remodeling of the circle of Willis in moyamoya disease

Objectives:A positive (outward) remodelling pattern in patients with typical atherosclerotic disease was recognised using magnetic resonance imaging (MRI). In this report, the outer diameter of the circle of Willis was evaluated in patients with moyamoya disease, and its remodelling pattern was verified.Methods:A total of 18 consecutive patients with moyamoya disease were included in this analysis. The diameter of the terminal portion of the internal carotid artery (ICA) (C1), proximal portion of the middle cerebral artery (MCA) (M1) and proximal portion of the anterior cerebral artery (A1) was evaluated using fast imaging employing steady-state acquisition (FIESTA) imaging. The outer diameter was estimated using these images, and compared with the control group, and the correlation with magnetic resonance angiography (MRA) scores was calculated for patients with moyamoya disease.Results:The mean diameter of the moyamoya patient group on FIESTA was significantly lower than that of the control group in the C1, M1 and A1 (P < 0.0001). The M1 diameter on the FIESTA image showed a strong correlation with the moyamoya disease MRA score (y = (0.53x+2.31; R = 0.72), whereas the C1 diameter on the FIESTA image showed only a weak correlation (y = (0.16x+2.47; R = 0.21).Conclusion:We found that the outer diameter of all the vessels around the C1 was generally reduced in patients with moyamoya disease. Diameter of the MCA especially decreases as the disease progresses, similar to the negative (constrictive) remodelling pattern.

Characteristics of brain magnetic resonance images at symptom onset in children with moyamoya disease.

To clarify the characteristics of brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) at symptom onset in patients with childhood moyamoya disease (MD) according to developmental stage. In 26 childhood MD patients who underwent brain MRI and MRA within 3 months from symptom onset, MRA scores and grades and MRI findings from symptomatic hemispheres were summarized according to developmental stage: infancy (0-1 years, three patients), toddlerhood/preschool age (2-5 years, nine patients), school age (6-10 years, seven patients), and adolescence (11-18 years, seven patients). Mean MRA score was 5.6, which was higher in adolescents (6.9). The most common MRA grade was grade 3, particularly in those under 10 years. Acute ischemic infarction presented in 17 patients (65%), was more common in patients below 5 years (83%) and was mainly in a gyral pattern (47%). Most hemorrhagic infarctions occurred in adolescents. Moyamoya vessels in the Sylvian valleys were apparent in 22 patients (85%), which were the most sensitive non-ischemic findings on T2 weighted images. The signal void in the distal internal carotid artery was diminished in 73% and apparent signal voids in basal ganglia were seen in three patients. The ivy sign was positive in 81% on fluid attenuated inversion recovery images and 69% on contrast-enhanced T1-weighted images in 21 and 16 patients, respectively. Brain MRIs and MRAs at symptom onset in childhood MD have characteristic findings, which differ in different developmental stage.

Arterial spin-labeling MR imaging in moyamoya disease compared with clinical assessments and other MR imaging finings

PurposeOur purpose was to identify the causal factors for the perfusion distribution obtained with ASL-MRI by comparing ASL-MRI with clinical information and other MRI findings in moyamoya disease. MethodsSeventy-one patients with moyamoya disease underwent ASL-MRI and other MRI, including fluid-attenuated inversion recovery imaging (FLAIR) and three-dimensional time-of-flight magnetic resonance angiography (MRA) on 3.0-Tesla MRI system. Cerebral blood flow (CBF) values (ASL values) for the cerebral hemispheres (142 sides) were measured on CBF maps generated by ASL-MRI. Relationships between the ASL values and the following 9 factors were assessed: sex, family history, revascularization surgery, age at MR exam, age at onset, the steno-occlusive severity on MRA (MRA score), degree of basal collaterals, degree of leptomeningeal high signal intensity seen on FLAIR, and size of ischemic or hemorrhagic cerebrovascular accident lesion (CVA score). ResultsPatients with a family history had significantly higher ASL values than those without such a history. There were significant negative correlations between ASL values and age at MR exam, MRA score, and CVA score. ConclusionsASL-MRI may have cause-and-effect or mutual associations with family history, current patient age, size of CVA lesion, and intracranial arterial steno-occlusive severity in Moyamoya disease.

Evaluation of the lower limb vasculature before free fibula flap transfer. A prospective blinded comparison between magnetic resonance angiography and digital subtraction angiography

Introduction The aim of this study was to compare magnetic resonance angiography (MRA) with digital subtraction angiography (DSA) in the preoperative assessment of crural arteries and their skin perforators prior to free fibular transfer. Patients and methods Fifteen consecutive patients, scheduled for free vascularized fibular flap transfer, were subjected to DSA as well as MRA of the crural arteries of both legs (n = 30). All DSA and MRA images were assessed randomly, blindly, and independently by two radiologists. Each of the assessors scored the degree of stenosis of various segments on a 5 point scale from 0 (occlusive) to 4 (no stenosis). The Cohen's Kappa coefficient was used to assess the agreement between DSA and MRA scores. In addition, the number of cutaneous perforators were scored and the assessors were asked if they would advise against fibula harvest and transplantation based on the images. Results A Cohen's Kappa of 0.64, indicating "substantial agreement of stenosis severity scores" was found between the two imaging techniques. The sensitivity of MRA to detect a stenosis compared with DSA was 79% (CI 95%:60-91), and a specificity of 98% (CI 95%: 97-99). In 53 out of 60 assessments, advice on suitability for transfer were equal between DSA and MRA. The median number of cutaneous perforators that perfuse the skin overlying the fibula per leg was one for DSA as well as MRA (P = 0.142).Conclusions A substantial agreement in the assessment of stenosis severity was found between DSA and MRA. The results suggest that MRA is a good alternative to DSA in the preoperative planning of free fibula flap transplantation.

Assessment of Moyamoya Disease Using Multidetector Row Computed Tomography

The recent introduction of multidetector row computed tomography (MDCT) scanners has enabled high-resolution 3-dimensional reconstruction. The purpose of this study was to establish a method to evaluate moyamoya disease using computed tomography angiography (CTA), specifically MDCT. Twenty-four patients (48 sides total) with moyamoya disease diagnosed by magnetic resonance angiography (MRA) were evaluated by means of CTA using MDCT by 3 independent observers, and the resulting 144 sides were analyzed. CTA and MRA were compared in terms of the steno-occlusive changes exhibited in each vessel. CTA and MRA scores were assigned on the basis of the severity of occlusive changes in the internal carotid artery, middle cerebral artery, anterior cerebral artery, and posterior cerebral artery. CTA scores were significantly correlated with MRA scores (P < .0001), and the 2 scores were in complete agreement in 57 sides (39.6%). The mean CTA score was significantly lower than the mean MRA score (P < .0001). Compared with CTA, MRA overestimated occlusion in 115 of the 576 vessels assessed. The mean MRA score was significantly higher in the overestimation group than in the good correlation group (P < .0001). CTA had a significantly higher rate of detection of moyamoya-affected vessels (P = .0001). Our data indicate that CTA using MDCT is a more reliable technique than MRA for diagnosing moyamoya disease. The ability to perform CTA quickly is a significant benefit for patients with moyamoya disease, particularly in pediatric and emergency cases.

Brain magnetic resonance angiography-based strategy for stroke reduction in coronary artery bypass grafting

We have been using magnetic resonance angiography (MRA) preoperatively to identify patients at increased risk of stroke in coronary artery bypass grafting (CABG). Based upon the intracranial MRA findings, either the off-pump or the on-pump procedure was selected. We report the results of our MRA-based strategy of CABG in 140 consecutive patients. Intracranial arterial lesions were found in 90 patients (64%). The most affected arteries were internal carotid (48%), followed by vertebral (18%) and middle cerebral (16%). Using the MRA score describing the severity of intracranial atherosclerosis, 35 patients with a score of > or = 5 underwent off-pump, while 105 patients with a score of < 5 underwent on-pump CABG. In the off-pump group, the patient age was older, the incidence of abnormal preoperative brain CT was higher, and the MRA score was higher (6.0+/-1.1 vs. 1.2+/-1.3 points) than in the on-pump groups. Even though the risk was higher in the off-pump group, the clinical outcomes were not significantly different, including the hospital mortality and the incidence of stroke and additional coronary intervention. In conclusion, the brain MRA-based selection of off-pump CABG can contribute to prevention of stroke in neurologically high-risk patients.

Novel Magnetic Resonance Angiography Stage Grading for Moyamoya Disease

Background: Magnetic resonance angiography (MRA) has been acknowledged as a noninvasive diagnostic modality for moyamoya disease. However, in terms of staging of moyamoya disease, conventional angiography is still the gold standard. Therefore, the purpose of this study was to establish MRA grades for moyamoya disease as an alternative to conventional angiography. Methods: Twenty-two patients (44 sides) with moyamoya disease diagnosed by conventional angiography were evaluated by MRA during the past 5 years. MRA scores were assigned based on the severity of occlusive changes of the internal carotid artery, the horizontal portion of the middle cerebral artery, the anterior and the posterior cerebral arteries and the signals of the distal branches of these arteries. Total points ranged from 0 (normal) to 10 (most severe). Results: MRA scores (0–10) were significantly consistent with the conventional angiographic staging. Four grades based on this novel MRA scores correlated well with Suzuki’s stages, with high sensitivity and specificity. Conclusions: These novel MRA grades can be a reliable alternative to conventional staging. By employing these novel MRA grades, the use of conventional angiography can be avoided for the purpose of evaluation of the stages of moyamoya disease.