Differences in intracranial atherosclerosis plaque between posterior circulation and anterior circulation on high-resolution magnetic resonance imaging: A systematic review and meta-analysis

OBJECTIVE

The clinical characteristics and mechanisms of stroke caused by anterior circulation atherosclerotic plaques (ACAPs) and posterior circulation atherosclerotic plaques (PCAPs) are distinct. We aimed to compare the differences in vulnerability, morphology, and distribution between ACAPs and PCAPs based on hign-resolution magnetic resonance imaging (HR-MRI).

MATERIALS AND METHODS

The PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang database were retrieved from inception through May 2023. Meta-analysis was performed by R 4.2.1 software. The quality of the literature was assessed by the Agency for Healthcare Research and Quality (AHRQ). Subgroup analysis was conducted to explore the heterogeneity of the pooled results.

RESULTS

There were a total of 13 articles, including 1194 ACAPs and 1037 PCAPs. The pooled estimates demonstrated that the incidence of intraplaque hemorrhage in the PCAPs was higher (OR 1.72, 95%CI 1.35-2.18). The plaque length (SMD 0.23, 95%CI 0.06-0.39) and remodeling index (SMD 0.29, 95%CI 0.14-0.44) of PCAPs were larger than those in ACAPs. However, there were no evident differences in significant enhancement or stenosis degree between the two groups.

CONCLUSION

There were more unstable features in PCAPs, highlighting an elevated risk of recurrent ischemic stroke in the posterior circulation. Furthermore, PCAPs were prone to developing penetrating artery disease due to their wider distribution. Nevertheless, posterior circulation arteries exhibited a greater propensity for outward remodeling, which may lead treatment team to miss the optimal intervention stage by being overlooked on angiographic detection.

High-resolution MRI vessel wall enhancement in moyamoya disease: risk factors and clinical outcomes

OBJECTIVES

Intracranial vessel wall enhancement (VWE) on high-resolution magnetic resonance imaging (HRMRI) is associated with the progression and poor prognosis of moyamoya disease (MMD). This study assessed potential risk factors for VWE in MMD.

METHODS

We evaluated MMD patients using HRMRI and traditional angiography examinations. The participants were divided into VWE and non-VWE groups based on HRMRI. Logistic regression was performed to compare the risk factors for VWE in MMD. The incidence of cerebrovascular events of the different subgroups according to risk factors was compared using Kaplan-Meier survival and Cox regression.

RESULTS

We included 283 MMD patients, 84 of whom had VWE on HRMRI. The VWE group had higher modified Rankin Scale scores at admission (p = 0.014) and a higher incidence of ischaemia and haemorrhage (p = 0.002) than did the non-VWE group. Risk factors for VWE included the ring finger protein 213 (RNF213) p.R4810K variant (odds ratio [OR] 2.01, 95% confidence interval [CI] 1.08-3.76, p = 0.028), hyperhomocysteinaemia (HHcy) (OR 5.08, 95% CI 2.34-11.05, p < 0.001), and smoking history (OR 3.49, 95% CI 1.08-11.31, p = 0.037). During the follow-up of 63.9 ± 13.2 months (median 65 months), 18 recurrent stroke events occurred. Cox regression showed that VWE and the RNF213 p.R4810K variant were risk factors for stroke.

CONCLUSION

The RNF213 p.R4810K variant is strongly associated with VWE and poor prognosis in MMD. HHcy and smoking are independent risk factors for VWE.

CLINICAL RELEVANCE STATEMENT

Vessel wall enhancement in moyamoya disease is closely associated with poor prognosis, especially related to the ring finger protein 213 p.R4810K variant, hyperhomocysteinaemia, and smoking, providing crucial risk assessment information for the clinic.

KEY POINTS

• The baseline presence of vessel wall enhancement is significantly associated with poor prognosis in moyamoya disease. • The ring finger protein 213 p.R4810K variant is strongly associated with vessel wall enhancement and poor prognosis in moyamoya disease. • Hyperhomocysteinaemia and smoking are independent risk factors for vessel wall enhancement in moyamoya disease.

Plaque enhancement predicts recurrence in acute ischemic stroke patients with large artery intracranial atherosclerosis

BACKGROUND

The association between the degree of plaque enhancement and ischemic brain stroke recurrence remains unclear. We aimed to establish models to predict plaque enhancement and stroke recurrence.

METHODS

Seventy-eight participants with acute ischemic brain stroke due to intracranial arterial stenosis were recruited and divided into high enhancement (HE) and non-HE groups. The relationship between imaging characteristics (degree of stenosis, minimal lumen area, intraplaque hemorrhage, and plaque burden) and the degree of plaque contrast enhancement was analyzed. Inflammatory cytokine expression was examined by flow cytometry. Independent predictors of stroke recurrence were investigated via multivariate Cox proportional hazards regression analysis. Nomogram was used to construct a prediction model. Harrell's concordance indices (c-indices) and calibration curves were used to assess the discrimination of the nomogram. A risk prediction nomogram for prognosis was constructed.

RESULTS

Thirty-three participants were assigned to the HE group and 45 to the non-HE group. The degree of stenosis and plaque burden in the HE group was higher than that in the non-HE group (P<0.05). Multiple linear regression analysis showed the degree of stenosis was associated with HE (β=0.513; P=0.000). After adjusting for confounding factors, age (HR=1.115; 95%CI=1.034-1.203, P=0.005) and HE plaques (HR=10.457; 95%CI=1.176-93.018; P=0.035) were independent risk factors of stroke recurrence, whereas cytokine levels were not statistically significant between two group.

CONCLUSIONS

HE of intracranial atherosclerosis plaques is an independent factor for ischemic brain stroke recurrence.

A Non-Linear Role of Hyperlipidemia on Progression of Intracranial Atherosclerotic Plaques and Acute Downstream Ischemic Events

AIM

Intracranial atherosclerotic stenosis (ICAS) is the leading cause of ischemic stroke worldwide. Hyperlipidemia is a major contributor to atherosclerosis. However, the effect of hyperlipidemia on the evolution of intracranial atherosclerotic plaques and downstream ischemic episodes remains unclear. In this study, we aimed to assess the radiological features of ICAS plaques and to explore the relationship between hyperlipidemia and plaque progression.

METHODS

We included people with ICAS (≥50% stenosis) undergoing high-resolution magnetic resonance imaging. The culprit plaque was defined as the sole, or in case of multiple stenosis, the narrowest plaque on the intracranial artery responsible for acute ischemic stroke. Demographic, clinical data, plaque features on MRI, and lipid parameters were compared between culprit and non-culprit plaques. Plaque enhancement was graded as Grade 0, 1 and 2 by comparing to the adjacent normal vessel wall and pituitary funnel after contrast enhancement on T1-weighted sequences.

RESULTS

162 patients were included (mean age 57.7±12.1 years, male 61.6%), 110 of whom were identified as culprit plaque with an ipsilateral acute stroke. High-grade enhancement was the most prominent MRI feature of the culpable plaque (Grade-2: OR 6.539, 95%CI 1.706-23.707, p=0.006). LDL cholesterol was significantly associated with overall acute ischemic stroke caused by culprit plaque. After stratification by enhancement grading LDL was independently associated with ischemic events in Grade-1 enhancement plaques (OR 6.778, 95%CI 2.122-21.649, p=0.001). In patients with Grade-2 enhancement plaques, however, LDL was not associated with ischemic event; in contrast, Neutrophil/Lymphocyte ratio was independently associated with ischemic events caused by Grade-2 enhancement plaques (OR 2.188, 95%CI 1.209-3.961, p=0.010).

CONCLUSIONS

LDL was related with ischemia events in intermediate stage of intracranial atherosclerotic plaque progression, an excellent period for intensive lipid-lowering treatment. In advanced stage, inflammatory agents maybe the main contributor to ischemic events.

Distinguishing Intracranial Diabetes-Related Atherosclerotic Plaques: A High-Resolution Magnetic Resonance Imaging-Based Radiomics Study

INTRODUCTION

Diabetes markedly affects the formation and development of intracranial atherosclerosis. The study was aimed at evaluating whether radiomics features can help distinguish plaques primarily associated with diabetes.

MATERIALS AND METHODS

We retrospectively analyzed patients who were admitted to our center because of acute ischemic stroke due to intracranial atherosclerosis between 2016 and 2022. Clinical data, blood biomarkers, conventional plaque features, and plaque radiomics features were collected for all patients. Odds ratios (ORs) with 95% confidence intervals (CIs) were determined from logistic regression models. The receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) were used to describe diagnostic performance. The DeLong test was used to compare differences between models.

RESULTS

Overall, 157 patients (115 men; mean age, 58.7 ± 10.7 years) were enrolled. Multivariate logistic regression analysis showed that plaque length (OR: 1.17; 95% CI: 1.07-1.28) and area (OR: 1.13; 95% CI: 1.02-1.24) were independently associated with diabetes. On combining plaque length and area as a conventional model, the AUCs of the training and validation cohorts for identifying diabetes patients were 0.789 and 0.720, respectively. On combining radiomics features on T1WI and contrast-enhanced T1WI sequences, a better diagnostic value was obtained in the training and validation cohorts (AUC: 0.889 and 0.861). The DeLong test showed the model combining radiomics and conventional plaque features performed better than the conventional model in both cohorts (p < 0.05).

CONCLUSIONS

The use of radiomics features of intracranial plaques on high-resolution magnetic resonance imaging can effectively distinguish culprit plaques with diabetes as the primary pathological cause, which will provide new avenues of research into plaque formation and precise treatment.

Effect of Mid-Basilar Artery Angle and Plaque Characteristics on Pontine Infarction in Patients with Basilar Artery Plaque

AIMS

The basilar artery (BA) geometry and plaque characteristics may play an important role in the development of atherosclerosis. This study was performed to explore the relationship between the mid-BA angle and plaque characteristics and its effect on pontine infarction using high-resolution magnetic resonance imaging and three-dimensional time-of-flight magnetic resonance angiography.

METHODS

In total, 77 patients with BA plaques were included in this study. According to the presence of acute pontine infarction on diffusion-weighted imaging, the patients were divided into a pontine infarction group and pontine non-infarction group. The mid-BA angle, plaque burden, stenosis ratio, positive remodeling, and intraplaque hemorrhage were evaluated to investigate their effects on stroke.

RESULTS

The pontine infarction group had a greater plaque burden, stenosis ratio, positive remodeling, and mid-BA angle than the pontine non-infarction group. The correlation between the plaque burden and mid-BA angle was the highest (r=0.441, P＜0.001). Multivariate logistic regression analysis showed that the plaque burden (odds ratio, 1.164; 95% confidence interval, 1.093-1.241; P＜0.001) was an independent risk factor for pontine infarction.

CONCLUSION

The mid-BA angle may increase the incidence of pontine infarction by increasing the plaque burden.

Study protocol of Branch Atheromatous Disease-related stroke (BAD-study): a multicenter prospective cohort study

BACKGROUND

As a meaningful subtype of ischemic stroke in Asians, Branch atheromatous disease (BAD)-related stroke is associated with high early neurological deterioration (END) and disability, but is understudied and without recommended therapy. The mechanism of END still remains unclear. Branch atheromatous disease-related stroke study (BAD-study) therefore aims to investigate demographic, clinical and radiological features, and prognosis of BAD-related stroke in Chinese patients.

METHODS/DESIGN

BAD-study is a nationwide, multicenter, consecutive, prospective, observational cohort study enrolling patients aged 18-80 years with BAD-related stroke within 72 h after symptom onset. Initial clinical data, laboratory tests, and imaging data are collected via structured case report form, and follow-ups will be performed at 7 days, 30 days, 90 days, 6 months and 12 months after enrollment. The primary outcome is the score on modified Rankin Scale at 90-day follow-up with single-blinded assessment. Secondary outcomes include END within 7 days, and National institute of health stroke scale score, Barthel index, cerebrovascular events, major bleeding complications, and all-cause mortality during 90-day follow-up. Characteristics of penetrating and parent artery will be assessed by high-resolution magnetic resonance imaging combined with other imaging techniques.

DISCUSSION

BAD-study can provide demographic, clinical, radiological, and prognostic characteristics of BAD-related stroke, and thereby potentially figure out the vascular mechanism of early neurological deterioration and optimize therapy strategy with the aid of advanced imaging technique. Baseline data and evidence will also be generated for randomized controlled trials on BAD-related stroke in the future.

[Imaging of retinoblastoma : Current state-of-the-art and future prospects]

BACKGROUND

Retinoblastoma is the most common malignant eye tumor in children and is associated with tumor predisposition syndrome (RB1 mutation) in up to 40% of cases. Imaging is an important part of the diagnostic workup of children with retinoblastoma both during the initial diagnosis and follow-up.

OBJECTIVES

The goal of this review is to present the current state-of-the-art regarding imaging of children with retinoblastoma, including technical background and diagnostic clues with a brief discussion of future prospects. In addition, we summarize the general clinical diagnostic workup and therapeutic options.

MATERIALS AND METHODS

Review of the literature and our own experience in the imaging of retinoblastoma.

CONCLUSION

High-resolution magnetic resonance imaging (MRI) is the imaging modality of choice in children with retinoblastoma for diagnosis (estimation of diagnosis/differential diagnosis, evaluation of local and intracranial tumor extension) and during follow-up. Despite the characteristic calcifications, computed tomography (CT) examinations are no longer indicated in these patients. Due to the high association with tumor predisposition syndrome, genetic counselling is recommended.

Imaging features of adult moyamoya disease patients with anterior intracerebral hemorrhage based on high-resolution magnetic resonance imaging

This study aimed to identify the high-resolution magnetic resonance imaging (HRMRI) features of moyamoya disease (MMD) patients with anterior intracerebral hemorrhage (ICH) and attempted to reveal potential mechanisms of anterior ICH. Eligible adult MMD patients were consecutively included, and the morphological features of lenticulostriate arteries (LSAs), vessel wall structure of terminal internal carotid artery (ICA) and periventricular anastomosis were evaluated by HRMRI. 78 MMD patients containing 21 patients with anterior ICH, 31 ischemic patients and 26 asymptomatic patients were included. The mean value of total length of LSAs in anterior ICH group (90.79 ± 37.00 mm) was distinctively lower (p < 0.001) compared with either ischemic group (138.04 ± 46.01 mm) or asymptomatic group (170.50 ± 39.18 mm). Lumen area of terminal ICA was significantly larger (p < 0.001) in hemorrhagic group (4.33 ± 2.02 mm²) compared with ischemic group (2.29 ± 1.17 mm²) or asymptomatic group (3.00 ± 1.34 mm²). Multivariate analysis revealed the total length of LSAs (OR 0.689, 95%CI, 0.565-0.840; p < 0.001) and lumen area of terminal ICA (OR 2.085, 95%, 1.214-3.582; p = 0.008) were significantly associated with anterior ICH. Coexistence of reduced LSAs and relatively preserved lumen area of terminal ICA with an AUC of 0.901 (95%CI, 0.812-0.990) could be a potential predictor of anterior ICH in MMD patients.

Identification of high-risk intracranial plaques with 3D high-resolution magnetic resonance imaging-based radiomics and machine learning

BACKGROUND

Identifying high-risk intracranial plaques is significant for the treatment and prevention of stroke.

OBJECTIVE

To develop a high-risk plaque model using three-dimensional (3D) high-resolution magnetic resonance imaging (HRMRI) based radiomics features and machine learning.

METHODS

136 patients with documented symptomatic intracranial artery stenosis and available HRMRI data were included. Among these patients, 136 and 92 plaques were identified as symptomatic and asymptomatic plaques, respectively. A conventional model was developed by recording and quantifying the radiological plaque characteristics. Radiomics features from T1-weighted images (T1WI) and contrast-enhanced T1WI (CE-T1WI) were used to construct a high-risk plaque model with linear support vector classification (linear SVC). The radiological and radiomics features were combined to build a combined model. Receiver operating characteristic (ROC) curves were used to evaluate these models.

RESULTS

Plaque length, burden, and enhancement were independently associated with clinical symptoms and were included in the conventional model, which had an AUC of 0.853 vs. 0.837 in the training and test sets. While the radiomics and the combined model showed an improved AUC: 0.923 vs. 0.925 for the training sets and 0.906 vs. 0.903 in the test sets. Both the radiomics model (p = 0.024, p = 0.018) and combined model (p = 0.042, p = 0.049) outperformed the conventional model in the two sets, whereas the performance of the combined model was not significantly different from that of the radiomics model in the two sets (p = 0.583 and p = 0.606).

CONCLUSION

The radiomics model based on 3D HRMRI can accurately differentiate symptomatic from asymptomatic intracranial arterial plaques and significantly outperforms the conventional model.

Predicting Stenosis Aggravation in Follow-Up High-Resolution Magnetic Resonance Images of Patients with Intracranial Atherosclerosis

BACKGROUND

High-resolution magnetic resonance imaging (HRMRI) can provide information on the histopathological characteristics of intracranial atherosclerotic lesions causing arterial stenosis; however, its clinical application in intracranial atherosclerosis lacks standardization for predicting stenosis. Therefore, this study investigated the characteristics of HRMRI that can predict progression based on comparisons of follow-up HRMRI.

METHODS

We retrospectively enrolled patients who underwent HRMRI within 7 days of symptom onset to evaluate the characteristics associated with intracranial stenotic lesions. Among them, patients diagnosed with severe stenosis due to atherosclerosis and who underwent follow-up HRMRI 12-24 months after initial HRMRI were included in the final study. We analyzed distinct features, such as stenosis aggravation, the presence of initial plaque enhancement, increment of plaque enhancement, the existence of both eccentric and concentric plaques, and the presence of initial intraplaque hematoma on initial and follow-up HRMRI.

RESULTS

Among 442 patients who underwent HRMRI for severe stenosis due to atherosclerosis, 35 underwent follow-up HRMRI 12-24 months later. Patients with stenosis aggravation showed a higher incidence of plaque enhancement (87.5% vs. 3.7%, p < 0.001) and the presence of both concentric and eccentric plaques (75.0% vs. 11.1%; p = 0.001). The area under the curve for the increment of plaque enhancement was 0.92 (95% confidence interval [CI] 0.78-1.00, p ≤ 0.001), while that for the presence of both concentric and eccentric plaques was 0.82 (95% CI 0.63-1.00, p < 0.007).

CONCLUSIONS

The presence of both concentric and eccentric plaques and an increase in plaque enhancement were the strongest predictors of aggravation of intracranial artery stenosis.

Brain structural changes in patients with cardio-facio-cutaneous syndrome: effects of BRAF gene mutation and epilepsy on brain development. A case-control study by quantitative magnetic resonance imaging

PURPOSE

To evaluate the brain volumetric changes caused by BRAF gene mutation in non-epileptic CFC patients and the influence of the age of epilepsy onset on brain development in 2 cohorts of epileptic CFC patients.

METHODS

We enrolled CFC patients carrying BRAF gene mutations without epilepsy (4 patients) and with epilepsy (16 patients). CFC epileptic patients were divided into two cohorts based on the age of seizure onset: early-age onset (7 children) and late-age onset (9 adolescents). All three cohorts of patients underwent 3D FSPGR T1-weighted imaging to assess supratentorial and infratentorial brain volumes. Moreover, for each compartment, gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) volumes were measured. All measurements were compared with those of age-matched controls without neuroimaging abnormalities.

RESULTS

All CFC patients showed supratentorial and infratentorial WM reduction and supratentorial ventricular enlargement (p < 0.01). However, patients with early age of epilepsy onset, compared with the other two cohorts of CFC patients, showed both GM and a more pronounced WM volume reduction (p < 0.01).

CONCLUSION

In non-epileptic CFC children, we demonstrated WM volumetric reduction suggesting a direct effect of BRAF gene mutation on brain development. Nevertheless, in CFC epileptic patients, the age of epilepsy onset may contribute to brain atrophy. Brain atrophy in CFC patients, in part due to the natural history of the disease, may be worsened by epilepsy when it begins in the early ages because of interference with brain growth at that critical age of development.

Characteristics of symptomatic plaque on high-resolution magnetic resonance imaging and its relationship with the occurrence and recurrence of ischemic stroke

BACKGROUND

Atherosclerosis is the most common cause of ischemia stroke. Computed tomographic angiography (CTA) and digital subtraction angiography (DSA) are used to evaluate the degree of lumen stenosis. However, these examinations are invasive and can only reveal mild to moderate stenosis. High-resolution magnetic resonance imaging (HRMRI) seems a more intuitive way to show the pathological changes of vascular wall. Hence, we conducted a systematic retrospective study to determine the characteristics of symptomatic plaques in patients with intracranial atherosclerosis on HRMRI and their association with the occurrence and recurrence of ischemic stroke events.

METHODS

The PubMed database was searched for relevant studies reported from January 31, 2010, to October 31, 2020.

RESULTS

We selected 14 clinical outcome studies. We found that plaque enhancement and positive remodeling on HRMRI indicate symptomatic plaques. Besides, intraplaque hemorrhage and positive remodeling index are closely related to the occurrence of stroke. However, it is still controversial whether the initial enhancement of plaque and the occurrence and recurrence of stroke are related. There is also no significant correlation between vascular stenosis and symptomatic plaque or the occurrence and recurrence of ischemic stroke.

CONCLUSION

High-resolution magnetic resonance imaging can be used as an assessment tool to predict the risk of stroke onset and recurrence in patients with atherosclerosis, but further research is also needed.

Vertebral Artery Dissecting Aneurysm Causing Central Tapia's Syndrome: A Case Report

The central type of Tapia’s syndrome is an extremely rare presentation, characterized by unilateral paralysis of the vagal and hypoglossal nerves, contralateral hemiparesis, or hemihypesthesia. This report describes a case of a middle-aged patient who developed central Tapia’s syndrome due to a right vertebral artery dissecting aneurysm (VADA). The patient complained about swallowing difficulty and odynophagia. Right vocal cord paralysis, mild tongue deviation to the right side, left hypesthesia, and decreased temperature sensation with left hemiparesis were observed in neurologic exams. A right VADA and compression of the medulla oblongata due to the VADA were diagnosed on magnetic resonance imaging. Endovascular flow diversion of the right VADA was performed. After 1 year, all neurological symptoms and vocal cord paralysis were nearly resolved, but left hypesthesia remained with decreased nociception. We present and discuss how a VADA caused those symptoms and propose endovascular flow diversion as a treatment option.

Radiomic Model for Distinguishing Dissecting Aneurysms from Complicated Saccular Aneurysms on high-Resolution Magnetic Resonance Imaging

OBJECTIVE

To build radiomic model in differentiating dissecting aneurysm (DA) from complicated saccular aneurysm (SA) based on high-resolution magnetic resonance imaging (HR-MRI) through machine-learning algorithm.

METHODS

Overall, 851 radiomic features from 77 cases were retrospectively analyzed, and the ElasticNet algorithm was used to build the radiomic model. A clinico-radiological model using clinical features and conventional MRI findings was also built. An integrated model was then built by incorporating the radiomic model and clinico-radiological model. The diagnostic abilities of these models were evaluated using leave one out cross validation and quantified using the receiver operating characteristic (ROC) analysis. The diagnostic performance of radiologists was also evaluated for comparison.

RESULTS

Five features were used to form the radiomic model, which yielded an area under the ROC curve (AUC) of 0.912 (95 % CI 0.846-0.976), sensitivity of 0.852, and specificity of 0.861. The radiomic model achieved a better diagnostic performance than the clinico-radiological model (AUC=0.743, 95 % CI 0.623-0.862), integrated model (AUC=0.888, 95 % CI 0.811-0.965), and even many radiologists.

CONCLUSION

Radiomic features derived from HR-MRI can reliably be used to build a radiomic model for effectively differentiating between DA and complicated SA, and it can provide an objective basis for the selection of clinical treatment plan.

Association between type 2 diabetes mellitus, especially recently uncontrolled glycemia, and intracranial plaque characteristics: A high-resolution magnetic resonance imaging study

AIMS/INTRODUCTION

Type 2 diabetes mellitus is a specific risk factor for intracranial atherosclerosis. The purpose of this study was to investigate the relationship between type 2 diabetes mellitus, especially uncontrolled glycemia, and intracranial plaque characteristics using high-resolution magnetic resonance imaging.

MATERIALS AND METHODS

A total of 263 patients (182 men; mean age 62.6 ± 11.5 years) with intracranial atherosclerotic plaques detected on high-resolution magnetic resonance imaging from December 2017 to March 2019 were included in this study. Patients were divided into different groups: (i) patients with and without type 2 diabetes mellitus; (ii) diabetes patients with uncontrolled glycemia (glycated hemoglobin level ≥7.0%) and controlled glycemia; and (iii), diabetes patients with diabetes duration of <5, 5-10 and >10 years. Comparisons of plaque features between groups were made, respectively.

RESULTS

Type 2 diabetes mellitus was diagnosed in 118 patients (44.9%). Diabetes patients had a significantly greater prevalence of enhanced plaque, greater maximum plaque length, maximum wall thickness and more severe luminal stenosis than non-diabetes patients. Compared with diabetes patients with controlled glycemia, those with uncontrolled glycemia had a significantly greater prevalence of enhanced plaque and greater maximum plaque length (all P < 0.05). There were no significant differences in plaque features among patients with different durations of type 2 diabetes mellitus. Uncontrolled glycemia was an independent factor for plaque enhancement after adjustment for potential confounding factors (odds ratio 5.690; 95% confidence interval 1.748-18.526; P = 0.004).

CONCLUSIONS

Type 2 diabetes mellitus is closely related to intracranial plaque enhancement and burden. Recently uncontrolled glycemia might play an important role in the development of enhanced plaque.

Association of lateral rectus muscle volume and ocular motility with the abducens nerve in Duane's retraction syndrome

PURPOSE

To investigate the relationship between ocular motility and lateral rectus (LR) muscle volume according to the presence or absence of the abducens nerve in patients with Duane's retraction syndrome (DRS) using high-resolution magnetic resonance imaging (MRI).

METHODS

A total of 54 unilateral DRS patients were divided into two groups according to high-resolution MRI findings: DRS without an abducens nerve on the affected side (absent CN6 group, n = 45) and DRS with symmetric abducens nerves on both sides (present CN6 group, n = 9). Ocular motility was measured by image analysis based on nine gaze photographs. LR volume was measured on T2-weighted coronal MRI of the orbit, and the ratio of paretic/normal side (P/N) LR volume was investigated. Association of the abducens nerve with various parameters including ocular motility, LR volume, and ratios of P/N LR volume were determined.

RESULTS

LR volume was smaller in the affected eye than the non-affected eye in both groups. In the present CN6 group, abducens nerve diameter and the ratio of P/N LR volume showed a positive correlation. A smaller LR volume and more limitation of abduction in the affected eye were predictive of an absent abducens nerve in DRS.

CONCLUSIONS

LR muscle hypoplasia was apparent in the affected eye of DRS patients. Abducens nerve diameter positively correlated with the ratio of P/N LR volume in the present CN6 group. Graphical abstract.

Late delayed radiation-induced cerebral Arteriopathy by high-resolution magnetic resonance imaging: a case report

Background

Radiation therapy can cause cerebral arteriopahty, resulting in ischemic stroke. We document late-delayed cerebral arteriopathy by high-resolution magnetic resonance imaging (HR-MRI) in a middle aged man who had cranial irradiation 19 years earlier.

Case presentation

A 45-year-old man was diagnosed with frontal lobe glioma 19 years ago and was treated with radiation after surgical resection. He was admitted to our hospital with an acute cerebral infarction in November 8, 2017. Traditional MRI examination and HR-MRI (sagittal, reconstruction of coronal and axial) were performed at admission. He was treated with prednisone (30 mg/day) and clinical symptoms disappeared after 3 months by telephone follow-up. Our patient complained of dizziness and blurred vision and traditional MRI examination indicated acute ischemic stroke in temporal lobe and occipital lobe and microbleeds. In order to define the exact mechanism of stroke, blood tests, auto-immune screening and thrombophilia were performed and results were normal. Electrocardiography and echocardiography were negative and cardiogenic cerebral embolism was excluded. In cerebrospinal fluid (CSF) examination, level of albumin and IgG were elevated. HR-MRI showed vessel wall thickening in T1-weighted imaging, narrow lumen in proton density imaging and vessel wall concentric enhancement in contrast-enhanced T1- weighted imaging. Combined with radiotherapy history, the patient was diagnosed with radioactive vasculitis.

Conclusion

Radiation-induced cerebrovascular damages could be a lasting progress, which we cannot ignore. HR-MRI can provide sensitive and accurate diagnostic assessment of radiation-induced arteritis and may be a useful tool for the screening of causes of cryptogenic stroke.

A Comparative Study of High-Resolution Chemical-Shift-Eliminated Magnetic Resonance Imaging of Finger Specimens with Microcomputed Tomography

Objective:

High-resolution images of finger joints with chemical-shift elimination can be obtained using an interleaved water-fat (IWF) sequence. This study assessed IWF imaging of finger joints in the delineation of bone structures by comparing images of cadaver fingers with those of microcomputed tomography (CT) that served as a standard reference.

Materials and Methods:

IWF images with spatial resolution of 176 µ × 176 µ × 300 µ were obtained from the distal and proximal interphalangeal joints of two cadaver finger specimens using a custom-built radiofrequency receive coil at 1.5T. Regular three-dimensional gradient-echo (GRE) images were also acquired with similar parameters and compared with the IWF images to evaluate the effects of chemical shift. Micro-CT scans were obtained and served as the standard reference. The image data were reviewed by two experienced musculoskeletal radiologists in consensus. The delineation of normal joint structures and abnormalities in the finger specimens as revealed by the magnetic resonance imaging (MRI) and micro-CT images were compared. The IWF and regular GRE images were assigned scores 0–3 for the depiction of apparent marginal bone defects, with zero being the same in appearance to the micro-CT image and three as having minimal resemblance to it. Statistical analysis of the scoring results was conducted to compare the two MRI techniques.

Results:

The high-resolution IWF images provided accurate delineation of bone and calcified structures as seen in micro-CT. The thickness of subchondral bone was depicted similarly on the IWF water + fat and the micro-CT images but not on the regular GRE images. The regular GRE sequence showed false marginal bone defects not observed with IWF and micro-CT. In addition, the IWF water-only images facilitated the identification of bone cyst by revealing its water content.

Conclusion:

High-resolution IWF imaging should be useful for the early diagnosis and treatment assessment of arthritis and should also benefit basic research in the pathophysiology of the disease.

Vascular Morphology has No Direct Relationship with Atherosclerotic Plaque Burden in Patients with Symptomatic Middle Cerebral Artery Stenosis

BACKGROUND

The vascular morphology and the characteristics of atherosclerotic plaques in the middle cerebral artery (MCA) have not been fully studied with high-resolution magnetic resonance imaging (HR-MRI).

OBJECTIVE

HR-MRI was applied to investigate vascular morphology and atherosclerotic plaque in patients with symptomatic MCA stenosis.

MATERIALS AND METHODS

A total of 343 patients with symptomatic MCA stenosis were enrolled in this study. All the patients were examined by HR-MRI to analyze the morphology of MCA and the M1 segment (MCA-M1), the characteristics and the location of the plaques.

RESULTS

The proportion of L-shaped MCA-M1 decreased, while the proportion of S-shaped MCAM1 increased with age. The anterior plaques were the most common in all the patients. The superior plaques were relatively common in patients with L-shaped and U-shaped MCA-M1, while the inferior plaques were relatively common in patients with inverted U-shaped and S-shaped MCAM1. Among all the plaques, the majority were isointense or heterogeneous. The MCA-M1 morphology had no direct relationship with the common risk factors of atherosclerosis and the clinical outcomes of the patients after 12 months of follow up.

CONCLUSION

The morphology of MCA-M1 is not directly related to the plaque burden or the degree of stenosis in patients with symptomatic MCA stenosis. The morphology of MCA-M1 is not associated with the risk factors of atherosclerosis, or the clinical outcomes of the patients.

Morphologic characteristics of severe basilar artery atherosclerotic stenosis on 3D high-resolution MRI

Background

Two-dimensional high-resolution MRI (2D HRMRI) faces many technical challenges for fully assessing morphologic characteristics of inherent tortuous basilar arteries. Our aim was to investigate remodeling mechanisms and plaque distribution in symptomatic patients with basilar artery stenosis on three-dimensional (3D) HRMRI.

Methods

Forty-six consecutive patients with symptomatic basilar artery atherosclerotic stenosis on MRA (70–99%) were enrolled. The remodeling index (RI) was the ratio of vessel area at the maximal-lumen-narrowing (MLN) site to reference vessel area. RI ≥ 1.05 was defined as positive remodeling (PR), RI ≤ 0.95 as negative remodeling (NR), and 0.95 < RI < 1.05 as intermediate remodeling (IR). The remodeling patterns were divided into two groups (PR and non-PR [NR and IR]). The cross-sectional and longitudinal distribution of BA plaques were evaluated.

Results

Two patients were excluded because of poor-quality images. Images of 44 patients were available for measurements. PR was found in 23 (52.3%) patients, and non-PR in 21 (47.7%) patients. At the MLN sites, vessel area, wall area, plaque size and percentage of plaque burden of PR group were significantly greater than non-PR group (p < .001). Most plaques (90.9%) of the 44 patients were located at the dorsal, left and right walls. For the longitudinal distribution of plaque, 8 (18.2%) and 36 (81.8%) plaques were located in BA proximal and distal to AICA, respectively. Most plaques (68.2%) were eccentrically distributed.

Conclusions

3D HRMRI with postprocessing multiple planar reconstruction is able to evaluate the remodeling pattern and plaque distribution of basilar artery atherosclerotic stenosis, which might be used to guide intracranial intervention.

Feasibility of High-Resolution 3-Dimensional Sampling Perfection with Application-Optimized Contrast Using Different Flip Angle Evolution Imaging for the Preoperative Detection of Parasinus Meningioma: A Pilot Study Compared with Contrast-Enhanced Magnetic Resonance Venography

OBJECTIVES

To prospectively evaluate the diagnostic value of 3.0 Tesla magnetic resonance 3-dimensional sampling perfection with application-optimized contrast using different flip angle evolution (3D-SPACE) in the detection of sinus wall invasion and sinus patency in parasinus meningiomas.

METHODS

In this study, 28 patients with suspected meningiomas adjacent to the venous sinus underwent conventional magnetic resonance imaging, contrast-enhanced magnetic resonance venography, and 3D-SPACE scans. We collected patient charts and surgical reports for demographic details, histologic analysis, and neurologic performance preoperatively and postoperatively. Images obtained by each technique were assessed independently by 2 neurosurgeons for characteristics of sinus infiltration, wall invasion, lumen patency, and collateral veins.

RESULTS

The blood flow signal inside the lumen and collateral veins were depressed and presented as black, contrasting well with the sinus wall on 3D-SPACE imaging. When the curved-planar reconstruction images were combined, it was intuitive and accurate to detect the extent of sinus wall invasion by meningioma and also to detect lumen patency. An intratumoral "false lumen" was shown to maintain the blood flow inside the sinus at a totally invaded lesion. Moreover, collateral veins enveloped in a meningioma with their confluence points of the venous sinus were easily observed on 3D-SPACE images.

CONCLUSION

With an integrative presentation of parasinus meningioma, wall invasion, lumen patency, and collateral veins, high-resolution 3D-SPACE imaging provides a reliable technique to accurately assess venous sinus invasion preoperatively.

Prediction of Intracranial Arterial Stenosis Progression in Patients with Moyamoya Vasculopathy: Contrast-Enhanced High-Resolution Magnetic Resonance Vessel Wall Imaging

OBJECTIVE

Moyamoya vasculopathy (MMV) is characterized by progressive stenosis of the intracranial arteries. MMV currently has no curative treatments, and cerebral ischemia and hemorrhage are the major outcomes. Evaluation of the stroke risk of each patient resulting from the progression of intracranial arterial stenosis is clinically important.

METHODS

We prospectively reviewed patients with intracranial arterial stenosis and already diagnosed MMV. High-resolution magnetic resonance imaging using contrast agent is the novel vessel wall imaging (VWI) technique for directly evaluating vascular walls and intracranial artery disease. All patients underwent high-resolution vessel wall imaging and magnetic resonance angiography at the time of registration, and they underwent follow-up magnetic resonance angiography. The Fisher exact test was used to assess associations between the degrees of wall enhancement and between stable and progressive intracranial arterial stenosis.

RESULTS

A total of 24 patients (17 female; mean age, 36.1 ± 16.8 years; range 3-67 years) with MMV were consecutively recruited to this study. Progression of stenosis was shown in 6 lesions (66.6%) on strong enhancement, 2 lesions (12.5%) on mild enhancement, and 1 lesion (4.3%) on lack of enhancement. Arterial vessel wall enhancement in MMV patients correlated closely with progression of intracranial arterial stenosis (P = 0.002).

CONCLUSIONS

Arterial vessel wall enhancement in MMV patients was closely related to progression of intracranial arterial stenosis. Strong enhancement of the intracranial vessel wall was associated with intracranial arterial stenosis progression, and lack of enhancement correlated with the stability of intracranial arterial stenosis.

High resolution magnetic resonance imaging in pathogenesis diagnosis of single lenticulostriate infarction with nonstenotic middle cerebral artery, a retrospective study

Background

It is usually difficult to identify stroke pathogenesis for single lenticulostriate infarction with nonstenotic middle cerebral artery (MCA). Our aim is to differentiate the two pathogeneses, non-branch atheromatous small vessel disease and branch atheromatous disease (BAD) by high-resolution magnetic resonance imaging (HR-MRI).

Methods

Thirty-two single lenticulostriate infarction patients with nonstenotic MCA admitted to the China-Japan Friendship Hospital from December 2014 to August 2017 were enrolled for retrospective analysis. National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS), atherosclerotic risk factors, imaging features, and the characteristic of MCA vessel wall in HR-MRI were evaluated.

Results

MCA plaques were detected in 15(46.9%) patients which implied BAD and 8 of 15 (53.3%) patients had plaques location in upper dorsal side of the vessel wall. Patients with HR-MRI identified plaques had a significantly larger infarction lesion length (1.95 ± 0.86 cm versus 1.38 ± 0.55 cm; P = 0.031) and larger lesion volume (2.95 ± 3.94 cm³ versus 0.90 ± 0.94 cm³; P = 0.027) than patients without plaques. Patients with HR-MRI identified plaques had a significant higher percentage of proximal lesions than patients without plaques (P = 0.055). However, according to the location of MCA plaques, there were no significant differences in terms of imaging features, NIHSS and mRS.

Conclusion

We demonstrated high frequency of MCA atheromatous plaques visualized in single lenticulostriate infarction patients with nonstenotic MCA by using HR-MRI. Patients with HR-MRI identified plaque presented larger infarction lesions and more proximal lesions than patients without plaque, which were consistent with imaging features of BAD. HR-MRI is an important and effective tool for identifying stroke etiology in patients with nonstenotic MCA.

The association between the ring finger protein 213 gene R4810K variant and intracranial major artery stenosis/occlusion in the Han Chinese population and high-resolution magnetic resonance imaging findings

BACKGROUND AND PURPOSE:

The ring finger protein 213 (RNF213) gene R4810K variant, a susceptibility locus for moyamoya disease (MMD), has recently been identified to be associated with intracranial major artery stenosis/occlusion (ICASO) without satisfying the diagnostic criteria of MMD in the Japanese population. However, further studies are needed to determine whether this variant is associated with ICASO in other populations and whether R4810K variant-related ICASO could be categorized as MMD. The aim of this study is to elucidate whether the R4810K variant was associated with ICASO among the Han Chinese population and potential histopathology of R4810K variant-related ICASO.

MATERIALS AND METHODS:

We conducted a case–control study to evaluate association and performed high-resolution (HR) magnetic resonance imaging (MRI) to investigate arterial wall feature of ICASO. The R4810K variant was genotyped in 114 ICASO patients and 268 controls. Then, patients with R4810K variant-related ICASO were subjected to HR MRI examination and presumptively diagnosed based on the characteristics thus observed.

STATISTICAL ANALYSIS:

The relationship between R4810K variant and ICASO was evaluated by Fisher's exact test with odds ratios (OR) and 95% confidence interval (CI).

RESULTS:

The R4810K variant was associated with ICASO and increased the risk for ICASO (P < 0.01; OR: 20.2; 95% CI: 2.5–163.11). Presumptive MMD was diagnosed in all female patients with R4810K variant. However, presumptive intracranial atherosclerotic stenosis was diagnosed in one of three males harboring this variant.

CONCLUSIONS:

The R4810K variant is a genetic risk factor for ICASO among the Han Chinese population and that R4810K variant-related ICASO should be identified as MMD in female but not uncertain in male patients.

Value of high resolution magnetic resonance imaging in preoperative staging of rectal cancer

AIM

To assess the value of conventional magnetic resonance imaging (MRI) combined with high resolution MRI (HR-MRI) in preoperative T and N staging of rectal cancer by comparing with pathological staging.

METHODS

The clinical data of 84 patients with primary rectal cancer who were admitted to Tianjin Haibin People's Hospital from January 2017 to October 2017 and underwent conventional MRI and HR-MRI preoperatively and pathological examination postoperatively were collected. The consistency and correlation were analyzed between preoperative T and N staging by conventional MRI and HR-MRI and pathological T and N staging. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of conventional MRI combined with HR-MRI in diagnosing T and N stages were calculated.

RESULTS

There was a strong consistency between preoperative T and N staging by conventional MRI and HR-MRI and pathological T and N staging (κ = 0.691, P = 0.000), and the correlation rate was 84.52% (71/84). The accuracy, sensitivity, and specificity of conventional MRI and HR-MRI were 93.15%, 87.44%, and 92.36% for preoperative T1 staging, 91.23%, 86.19%, and 95.42% for preoperative T2 staging, 93.15%, 87.44%, and 92.36% for preoperative T3 staging, and 95.24%, 100.00%, and 77.78% for preoperative T4 staging. The accuracy, sensitivity, and specificity of conventional MRI combined with HR-MRI for preoperative N staging were 93.15%, 87.44%, and 92.36%, respectively. Using postoperative pathological results as the "gold standard", the accuracy, specificity, and sensitivity of conventional MRI combined with HR-MRI in predicting mesorectal invasion before surgery were 93.15%, 87.44%, and 92.36%, respectively.

CONCLUSION

Conventional MRI combined with HR-MRI has high diagnostic value in preoperative evaluation of T and N stages and mesangial invasion in patients with rectal cancer, which can provide a reliable reference for the clinical planning of surgical procedures.

Clinical Significance of Circumferential Aneurysmal Wall Enhancement in Symptomatic Patients with Unruptured Intracranial Aneurysms: a High-resolution MRI Study

BACKGROUND AND PURPOSE

The estimates on the risk of rupture of intracranial aneurysms remain a controversial topic. Circumferential aneurysmal wall enhancement (CAWE) on vessel wall magnetic resonance imaging (MRI) has been described in unstable aneurysms. Sentinel headaches and third nerve palsy are possible symptoms prior to the rupture of intracranial aneurysms. In this study, we aimed to demonstrate that CAWE could be associated with these symptoms.

METHODS

We performed a retrospective analysis of consecutive symptomatic or asymptomatic patients with unruptured intracranial aneurysms who were examined by high-resolution MRI from October 2014 to November 2016. Two experienced neurovascular radiologists read the images independently and determined whether there was CAWE of the unruptured intracranial aneurysms. Then, we compared variable factors between patients with and without symptoms through univariate comparison and multivariable logistic regression analyses.

RESULTS

A total of 45 unruptured intracranial aneurysms were detected in 37 patients. The agreement between 2 experienced readers for CAWE was good (kappa = 0.82; 95% confidence interval 0.66-0.99). CAWE of unruptured intracranial aneurysm was more frequently observed in symptomatic than in asymptomatic patients (16/23, 69.6% versus 6/22, 27.3%, respectively, P < 0.05). The CAWE was the only independent factor associated with symptoms in the multivariable logistic regression analysis (odds ratio 5.17; 95% confidence interval 1.30-20.52; P = 0.02).

CONCLUSIONS

Our study demonstrates that CAWE correlated with sentinel headaches and third nerve palsy caused by unruptured aneurysms, and this may be an additional clue to distinguish the cause of these symptoms.

M2 segment dissection of middle cerebral artery diagnosed using high-resolution magnetic resonance imaging

Middle cerebral artery (MCA) dissection is a rare cause of ischemic stroke, especially in the M2 or M3 segments. Diagnosis of intracranial artery dissection remains challenging. We herein report a case of M2 segment dissection of the MCA with typical features of an intimal flap and intramural hematoma diagnosed using high-resolution 3T magnetic resonance imaging. This imaging technique might be a more effective noninvasive method by which to diagnose M2 segment dissection of the MCA than either computed tomography angiography or digital subtraction angiography.

Spontaneous and Unruptured Chronic Intracranial Artery Dissection : High-resolution Magnetic Resonance Imaging Findings

PURPOSE

The aim of this article is to present high-resolution magnetic resonance imaging (HR-MRI) findings of chronic stage spontaneous and unruptured intracranial artery dissection (ICAD).

MATERIAL AND METHODS

From March 2012 to April 2016 a total of 29 patients (15 male and14 female, age range 37-68 years) with chronic stage spontaneous and unruptured ICAD (vertebral artery 27, posterior inferior cerebellar artery 1 and middle cerebral artery 1) were retrospectively enrolled. Patients underwent HR-MRI more than 2 months (median interval 564 days, range 69-391 days) after symptom onset and were diagnosed at symptom onset or at the first imaging acquisition, which included luminal angiography and/or HR-MRI with clinical information. The HR-MRI findings were evaluated against those of luminal angiography on the basis of the lumen wall morphology, including thickening, contrast enhancement and residual dissection.

RESULTS

The HR-MRI findings were classified into complete normalization (normal lumen and wall with or without mild enhancement, n = 6), complete normalization with minimal wall changes (focal wall thickening with enhancement but normal luminal angiography, n = 8), incomplete normalization (focal wall thickening with enhancement with dilatation and stenosis on luminal angiography, n = 4), dissecting aneurysm (fusiform aneurysm with residual dissection findings, n = 8) and occlusion (small outer arterial diameter with diffuse contrast enhancement, n = 3).

CONCLUSION

The use of HR-MRI can demonstrate the distinguishing morphological features of chronic stage of spontaneous and unruptured ICAD as complete normalization, complete normalization with minimal wall changes, incomplete normalization, dissecting aneurysm and occlusion.

More Precise Imaging Analysis and Diagnosis of Moyamoya Disease and Moyamoya Syndrome Using High-Resolution Magnetic Resonance Imaging

BACKGROUND

The diagnosis of moyamoya disease (MMD) is often uncertain. Moyamoya syndrome (MMS) is often misdiagnosed as MMD. High-resolution magnetic resonance imaging (HR-MRI) enables vessel wall assessment to obtain more precise diagnoses. The aim of this study was to determine the true etiologies of arterial steno-occlusion in patients with an angiographic diagnosis of MMD or MMS using HR-MRI.

METHODS

HR-MRI was performed in 21 adult patients with angiographically proven MMD or MMS. A definite diagnosis was based on the HR-MRI findings. The diagnoses made via the 2 different imaging technologies were compared, and significant findings were analyzed.

RESULTS

A total of 21 patients were enrolled, including 7 patients with angiographically proven MMD and 14 patients with angiographically proven MMS. Among the 7 patients with MMD, HR-MRI confirmed the diagnosis of MMD in 6; the remaining patient was considered to have atherosclerosis in the bilateral distal internal carotid arteries (ICAs) and the left middle cerebral artery. Among the 14 patients with MMS, HR-MRI confirmed MMD in 6 patients (including 2 patients with unilateral MMD), atherosclerosis in 5 patients (including 3 patients with bilateral atherosclerosis and 2 with unilateral atherosclerosis), arterial dissection of the left ICA in 1 patient, and MMD in the left cerebral hemisphere with atherosclerosis in the right hemisphere in 2 patients.

CONCLUSIONS

Differentiating MMD from MMS is difficult in certain situations, and HR-MRI may help provide a more in-depth understanding of MMD and MMS, thereby achieving a more reliable diagnosis.

Wall enhancement on high-resolution magnetic resonance imaging may predict an unsteady state of an intracranial saccular aneurysm

INTRODUCTION

The aneurysm wall has been reported to play a critical role in the formation, development, and even rupture of an aneurysm. We used high-resolution magnetic resonance imaging (HRMRI) to investigate the aneurysm wall in an effort to identify evidence of inflammation invasion and define its relationship with aneurysm behavior.

METHODS

Patients with intracranial aneurysms who were prospectively evaluated using HRMRI between July 2013 and June 2014 were enrolled in this study. The aneurysm's wall enhancement and evidence of inflammation invasion were determined. In addition, the relationship between aneurysm wall enhancement and aneurysm size and symptoms, including ruptured aneurysms, giant unruputred intracranial aneurysms (UIAs) presenting as mass effect, progressively growing aneurysms, and aneurysms associated with neurological symptoms, was statistically analyzed.

RESULTS

Twenty-five patients with 30 aneurysms were available for the current study. Fourteen aneurysms showed wall enhancement, including 6 ruptured and 8 unruptured aneurysms. Evidence of inflammation was identified directly through histological studies and indirectly through intraoperative investigations and clinical courses. The statistical analysis indicated no significant correlation between aneurysm wall enhancement and aneurysm size. However, there was a strong correlation between wall enhancement and aneurysm symptoms, with a kappa value of 0.86 (95 % CI 0.68-1).

CONCLUSIONS

Aneurysm wall enhancement on HRMRI might be a sign of inflammatory change. Symptomatic aneurysms exhibited wall enhancement on HRMRI. Wall enhancement had a high consistent correlation of symptomatic aneurysms. Therefore, wall enhancement on HRMRI might predict an unsteady state of an intracranial saccular aneurysm.

Reproducibility of high-resolution MRI for the middle cerebral artery plaque at 3T

PURPOSE

To assess the reproducibility of HR-MRI for the identification of MCA atherosclerotic plaque components and quantification of stenosis.

MATERIALS AND METHODS

Seventy-three consecutive subjects who initially had ischemic stroke or asymptomatic MCA stenosis (>50%) were enrolled in the study. All subjects were scanned using 3.0T MRI. Two independent readers reviewed all images and one reader reevaluated all images four weeks later. The tissue components of plaques were analyzed qualitatively and the vessels were quantitative measured.

RESULTS

HR-MRI displayed the artery wall and lumen clearly. The intra-observer reproducibility was excellent for the identification of plaques (kappa [κ]=0.96; 95% CI: 0.83-1.04) and contrast enhancement (κ=0.89; 0.78-0.95); it was substantial for intra-plaque hemorrhage (κ=0.79; 0.57-0.96) and the fibrous cap (κ=0.65; 0.42-0.86). The inter-observer reproducibility was excellent for plaques (κ=0.92; 0.73-1.06), substantial for contrast enhancement (κ=0.80; 0.65-0.93), intra-plaque hemorrhage (κ=0.68; 0.47-0.92) and moderate for the fibrous cap (κ=0.58; 0.44-0.79). Both intra-observer and inter-observer reproducibility were excellent for quantitative vessel, lumen and wall measurements with intraclass correlation coefficients ranging from 0.91 to 0.97 and 0.87 to 0.96, respectively. However, vessel and wall areas and the intervals defined by the Bland-Altman plots were wide in comparison to the mean.

CONCLUSIONS

The identification of MCA atherosclerotic plaque components and the quantification of vessel and lumen measurements are reproducible. The reproducibility is overall acceptable. HR-MRI may provide a useful tool for clinical risk evaluation in MCA atherosclerosis.