HR-VW MRI Research Articles

Characteristics of culprit intracranial plaque without substantial stenosis in ischemic stroke using three-dimensional high-resolution vessel wall magnetic resonance imaging.

We aim to analyze the difference in quantitative features between culprit and non-culprit intracranial plaque without substantial stenosis using three-dimensional high-resolution vessel wall MRI (3D hr-vw-MRI). The patients with cerebral ischemic symptoms of the unilateral anterior circulation were recruited who had non-stenotic intracranial atherosclerosis (<50%) confirmed by computed tomographic angiographic (CTA) or magnetic resonance angiography (MRA). All patients underwent 3D hr-vw MRI within 1 month after symptom onset. 3D hr-vw-MRI characteristics, including wall thickness, plaque burden, enhancement ratio, plaque volume and intraplaque hemorrhage, and histogram features were analyzed based on T2-, precontrast T1-, and post-contrast T1-weighted images. Univariate and multivariate logistic regression analysis were used to identify key determinates differentiating culprit and non-culprit plaques and to calculate the odds ratios (ORs) with 95% confidence intervals (CIs). A total of 150 plaques were identified, of which 133 plaques (97 culprit and 36 non-culprit) were in the middle cerebral artery, three plaques (all culprit) were in the anterior cerebral artery (ACA) and 14 (11 culprit and three non-culprit) were in the internal carotid artery (ICA). Of all the quantitative parameters analyzed, plaque volume, maximum wall thickness, minimum wall thickness, plaque burden, enhancement ratio, coefficient of variation of the most stenotic site, enhancement ratio of whole culprit plaque in culprit plaques were significantly higher than those in non-culprit plaques. Multivariate logistic regression analysis found that plaque volume [OR, 1.527 (95% CI, 1.231-1.894); P < 0.001] and enhancement ratio of whole plaque [OR, 1.095 (95% CI, 1.021-1.175); P = 0.011] were significantly associated with culprit plaque. The combination of the two features obtained a better diagnostic efficacy for culprit plaque with sensitivity and specificity (0.910 and 0.897, respectively) than each of the two parameters alone. 3D hr-vw MRI features of intracranial atherosclerotic plaques provided potential values over prediction of ischemic stroke patients with non-stenotic arteries. The plaque volume and enhancement ratio of whole plaque of stenosis site were found to be effective predictive parameters.

Predictors of improvement for patients with CNS vasculitis stenoses: A high-resolution vessel wall MRI follow-up study

PurposeTo investigate the predictors of the improvement for patients with isolated intracranial vasculitis stenoses using high-resolution vessel wall magnetic resonance imaging (HR VW-MRI). MethodsWe retrospectively reviewed data from consecutive patients with confirmed intracranial vasculitis under the same conventional conservative treatment based on a prospectively established HR VW-MRI database between December 2016 and December 2020. According to the changes between the degree of stenosis at baseline compared to follow-up MR angiography, the patients were divided into an improvement group and a non-improvement group. A multivariate analysis was performed to identify the predictive factors associated with the improvement of stenoses secondary to intracranial vasculitis. ResultsOverall, 41 patients (mean age 32.0 ± 10.1 years, 16 females) with isolated intracranial vasculitis stenoses were included (41.5 % [17/41] in the improvement group, and 58.5 % [24/41] were in the non-improvement group). The degree of wall enhancement on follow-up imaging was significantly reduced compared with that on the baseline imaging in the improvement group (P = 0.004). The multivariate analysis showed that the degree of enhancement (OR, 0.219, 95 % CI, 0.054 to 0.881; P = 0.033) at baseline was an independent predictive factor associated with the improvement in the intracranial vasculitis stenoses. ConclusionsIn patients with isolated intracranial vasculitis stenoses, the less enhancement the vessel wall was, the more likely the degree of stenosis would be reduced by conventional conservative therapy.

Microsurgical treatment of posterior inferior cerebellar aneurysms based on angioarchitecture supplemented by high-resolution vessel wall MRI: a case series report

BackgroundSurgical treatment of posterior inferior cerebellar artery (PICA) aneurysms is challenging because many are nonsaccular and atherosclerotic. We report our tailored approach to PICA aneurysms, which is based on angioarchitecture...

High-Resolution Vessel Wall MRI of Endovascularly Treated Intracranial Aneurysms.

(1) Background: The aim of this study was to determine the frequency and the pattern of post-procedural intracranial aneurysm contrast enhancement on high-resolution vessel wall magnetic resonance imaging (HR-VW MRI). We investigated the possible association between this imaging finding and factors such as time elapsed since embolization or aneurysm occlusion grade on baseline and follow-up imaging. (2) Methods: Consecutive patients presenting for follow-up after endovascular treatment of intracranial aneurysms were included. HR-VW MRI was acquired and interpreted independently by two radiologists. (3) Results: This study included 40 aneurysms in 39 patients. Contrast enhancement was detected in 30 (75%) aneurysms. It was peripheral in 12 (30.0%), central in 9 (22.5%), and both peripheral and central in 9 (22.5%) aneurysms. The statistical analysis did not reveal any relationship between follow-up period and the presence of contrast enhancement (p = 0.277). There were no statistically significant differences in the frequency of contrast enhancement between aneurysms with total occlusion and those with remnant flow on follow-up MR angiography (p = 0.850) nor between aneurysms with different interval changes in the aneurysm occlusion grade (p = 0.536). Multivariate analysis did not demonstrate aneurysm size, ruptured aneurysm status, nor initial complete aneurysm occlusion to be a predictor of contrast enhancement (p = 0.080). (4) Conclusions: Post-procedural aneurysm contrast enhancement is a common imaging finding on HR-VW MRI. The clinical utility of this imaging finding, especially in the prediction of aneurysm recurrence, seems limited. The results of our study do not support routine use of HR-VW MRI in the follow-up of patients after endovascular treatment of intracranial aneurysms.

High-Resolution Vessel Wall Magnetic Resonance Imaging of Small Unruptured Intracranial Aneurysms.

Background: We decided to investigate whether aneurysm wall enhancement (AWE) on high-resolution vessel wall magnetic resonance imaging (HR VW-MRI) coexists with the conventional risk factors for aneurysm rupture. Methods: We performed HR VW-MRI in 46 patients with 64 unruptured small intracranial aneurysms. Patient demographics and clinical characteristics were recorded. The PHASES score was calculated for each aneurysm. Results: Of the 64 aneurysms, 15 (23.4%) showed wall enhancement on post-contrast HR VW-MRI. Aneurysms with wall enhancement had significantly larger size (p = 0.001), higher dome-to-neck ratio (p = 0.024), and a more irregular shape (p = 0.003) than aneurysms without wall enhancement. The proportion of aneurysms with wall enhancement was significantly higher in older patients (p = 0.011), and those with a history of prior aneurysmal SAH. The mean PHASES score was significantly higher in aneurysms with wall enhancement (p < 0.000). The multivariate logistic regression analysis revealed that aneurysm irregularity and the PHASES score are independently associated with the presence of AWE. Conclusions: Aneurysm wall enhancement on HR VW-MRI coexists with the conventional risk factors for aneurysm rupture.

Significance of aneurysm wall enhancement on high-resolution vessel wall magnetic resonance imaging in clinical management of patients with intracranial aneurysms.

The prevalence of intracranial aneurysms is estimated to be around 3% in the general population. Although these are often incidental findings, they potentially carry the risk of rupture, with all of the devastating consequences of SAH. Several risk factors of aneurysm rupture have been identified, including aneurysm size, irregular shape, and location. Although it is widely accepted that the risk of rupture increases with size, small aneurysms remain the cause of a significant percentage of aneurysmal SAH. Up to 30% of patients with acute aneurysmal SAH have multiple aneurysms. Determining the site of rupture in these patients can be challenging, given that the results of imaging studies and clinical symptoms are sometimes inconclusive. It would be extremely useful to identify new imaging biomarkers of aneurysm instability which could have an impact on patient management and qualification for treatment. High-resolution vessel wall magnetic resonance imaging (HR-VW MRI) opens up new possibilities for improved characterisation of intracranial vasculature. One of the most promising clinical applications of this new imaging tool is the evaluation of intracranial aneurysms. Aneurysm wall enhancement (AWE) on HR-VW MRI is believed to be a marker for wall inflammation and, potentially, for aneurysm instability. In this article, we summarise the published literature on AWE with special emphasis on its use in determining the site of rupture in the setting of acute SAH in patients with multiple aneurysms, as well as its role in identifying unruptured aneurysms which are at the greatest risk of rupture. More and larger studies are needed to definitively establish the role of AWE on HR-VW MRI in the diagnostic workup of patients with intracranial aneurysms.

Intimal flap detected by three-dimensional curved multiplanar reconstruction image in isolated posterior inferior cerebellar artery dissection: a report of two cases

BackgroundSpontaneous isolated posterior inferior cerebellar artery (PICA) dissection has been reported more frequently since high-resolution vessel wall magnetic resonance imaging (HR vw-MRI) was introduced to the field. The intimal flap or double lumen, which is commonly reported to be a direct sign of the dissection, is not easily detectable on HR vw-MRI because the size of the PICA is very small and tortuous.Case presentationTwo patients with posterior circulation ischemic stroke due to spontaneous isolated PICA dissection underwent HR vw-MRI. The curved multiplanar reconstruction image reconstructed using three-dimensional (3D) HR vw-MRI (3D curved MPR imaging) is helpful to observe tortuous blood vessels such as the PICA because it can visualize the entire vessel course in a single plane. In this report, routine HR vw-MRI revealed only an intramural hematoma in both patients. However, 3D curved MPR imaging discovered the intimal flap which was not observed on the routine HR vw-MRI. Therefore, these two patients were diagnosed with spontaneous isolated PICA dissection due to the intimal flap that was observed on the 3D curved MPR image.ConclusionHR vw-MRI is useful for the early diagnosis of isolated PICA dissection. Furthermore, we believe that 3D curved MPR imaging could improve the possibility of diagnosing the dissection early because it can easily confirm direct signs such as an intimal flap or double lumen.

High-resolution vessel wall magnetic resonance imaging of carotid and intracranial vessels.

Carotid and intracranial imaging play an essential role in the comprehensive evaluation and prevention for stroke patients. High-resolution vessel wall magnetic resonance imaging (HR VW-MRI) has be...