High-resolution Magnetic Imaging Research Articles

MPIGAN: An end-to-end deep based generative framework for high-resolution magnetic particle imaging reconstruction.

Magnetic particle imaging (MPI) is a recently developed, non-invasive in vivo imaging technique to map the spatial distribution of superparamagnetic iron oxide nanoparticles (SPIONs) in animal tissues with high sensitivity and speed. It is a challenge to reconstruct images directly from the received signals of MPI device due to the complex physical behavior of the nanoparticles. System matrix and X-space are two commonly used MPI reconstruction methods, where the former is extremely time-consuming and the latter usually produces blurry images. Currently, we proposed an end-to-end machine learning framework to reconstruct high-resolution MPI images from 1-D voltage signals directly and efficiently. The proposed framework, which we termed "MPIGAN", was trained on a large MPI simulation dataset containing 291597 pairs of high-resolution 2-D phantom images and each image's corresponding voltage signals, so that it was able to accurately capture the nonlinear relationship between the spatial distribution of SPIONs and the received voltage signal, and realized high-resolution MPI image reconstruction. Experiment results showed that, MPIGAN exhibited remarkable abilities in high-resolution MPI image reconstruction. MPIGAN outperformed the traditional methods of system matrix and X-space in recovering the fine-scale structure of magnetic nanoparticles' spatial distribution and achieving enhanced reconstruction performance in both visual effects and quantitative assessments. Moreover, even when the received signals were severely contaminated with noise, MPIGAN could still generate high-quality MPI images. Our study provides a promising AI solution for end-to-end, efficient, and high-resolution magnetic particle imaging reconstruction.

Relationship between the intravascular enhancement sign on three-dimensional T1-weighted turbo spin echo and intraluminal thrombus in middle cerebral artery atherosclerosis

PurposeTo investigate the association between the intravascular enhancement sign (IVES) and intraluminal thrombus (ILT) detected by high-resolution magnetic resonance vessel wall imaging (HR-VWI) in patients with middle cerebral artery (MCA) atherosclerosis. MethodThe data of patients who underwent HR-VWI between May 2021 and May 2023, including clinical information, the number of IVES vessels, stenosis degree, ILT, plaque features on 3D T1-weighted turbo spin echo sequences, and signal intensity ratio (SIR) on 3D time-of-flight magnetic resonance angiography, were retrospectively analyzed. Correlation and logistic regression analyses were performed. ResultsA total of 194 MCA plaques were identified in 132 patients (103 [53 %] on the left). Atherosclerosis with, relative to without, ILT was associated with a higher incidence of ischemic events, higher plaque enhancement and stenosis degrees, more vessels with IVES, and lower remodeling ratio, lumen area, wall area, total vessel area, and SIR. Multivariate logistic regression analysis showed significant and independent associations of the number of IVES vessels (OR = 1.089; 95 % CI [1.013–1.170]; P = 0.020) and SIR (OR = 0.007; 95 % CI [0.0004–0.124]; P < 0.001) with ILT. The number of vessels with the IVES (AUC = 0.81, 95 % CI [0.75–0.87]; P < 0.001) and SIR (AUC = 0.88, 95 % CI [0.82–0.94]; P < 0.001) sufficiently diagnosed ILT, and the AUC of the combination of the IVES and SIR was 0.89 (95 % CI [0.84–0.94]; P < 0.001). ConclusionThe number of IVES vessels and SIR are independent risk factors for ILT. They may provide new monitoring targets for stroke prevention in patients with atherosclerotic stenosis.

High-resolution magnetic resonance vessel wall imaging provides new insights into Moyamoya disease.

Moyamoya disease (MMD) is a rare condition that affects the blood vessels of the central nervous system. This cerebrovascular disease is characterized by progressive narrowing and blockage of the internal carotid, middle cerebral, and anterior cerebral arteries, which results in the formation of a compensatory fragile vascular network. Currently, digital subtraction angiography (DSA) is considered the gold standard in diagnosing MMD. However, this diagnostic technique is invasive and may not be suitable for all patients. Hence, non-invasive imaging methods such as computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are often used. However, these methods may have less reliable diagnostic results. Therefore, High-Resolution Magnetic Resonance Vessel Wall Imaging (HR-VWI) has emerged as the most accurate method for observing and analyzing arterial wall structure. It enhances the resolution of arterial walls and enables quantitative and qualitative analysis of plaque, facilitating the identification of atherosclerotic lesions, vascular entrapment, myofibrillar dysplasia, moyamoya vasculopathy, and other related conditions. Consequently, HR-VWI provides a new and more reliable evaluation criterion for diagnosing vascular lesions in patients with Moyamoya disease.

Association between high-resolution magnetic resonance vessel wall imaging characteristics and recurrent stroke in patients with intracranial atherosclerotic steno-occlusive disease: A prospective multicenter study.

High-resolution magnetic resonance vessel wall imaging (HRMR-VWI) is a promising technique for identifying intracranial vulnerable plaques beyond lumen narrowing. However, the association between HRMR-VWI characteristics and recurrent stroke remains uncertain. This study aimed to investigate the association between HRMR-VWI characteristics and recurrent ipsilateral stroke in patients with symptomatic intracranial atherosclerotic steno-occlusive disease (ICAS). This multicenter, observational study recruited first-ever acute ischemic stroke patients attributed to ICAS (>50% stenosis or occlusion) within 7 days after onset. Participants were assessed by multiparametric magnetic resonance imaging (MRI) including diffusion-weighted imaging, three-dimension time-of-flight magnetic resonance angiography, and three-dimensional T1-weighted HRMR-VWI. The patients were recommended to receive best medical therapy and were systematically followed up for 12 months. The association between HRMR-VWI characteristics and the time to recurrent ipsilateral stroke was investigated by univariable and multivariable analysis. Two hundred and fifty-five consecutive patients were enrolled from 15 centers. The cumulative 12 month ipsilateral recurrence incidence was 4.1% (95% confidence interval (CI): 1.6-6.6%). Patients with recurrent ipsilateral stroke exhibited higher rates of intraplaque hemorrhage (IPH) (30.0% vs 6.5%) and eccentric plaque (90.0% vs 48.2%), and lower occurrence of occlusive thrombus (10.0% vs 23.7%). Plaque length (5.69 ± 2.21 mm vs 6.67 ± 4.16 mm), plaque burden (78.40 ± 7.37% vs 78.22 ± 8.32%), degree of stenosis (60.25 ± 18.95% vs 67.50% ± 22.09%) and remodeling index (1.07 ± 0.27 vs 1.03 ± 0.35) on HRMR-VWI did not differ between patients with and without recurrent ipsilateral stroke. In the multivariable Cox regression analysis, IPH (hazard ratio: 6.64, 95% CI: 1.23-35.8, p = 0.028) was significantly associated with recurrent ipsilateral stroke after adjustment.Conclusions:Our results suggest intraplaque hemorrhage (IPH) is significantly associated with recurrent ipsilateral stroke and has potential value in the selection of patients for aggressive treatment strategies. Data from this study are available and can be accessed upon request.

Plaque characteristics associated with failure of primary balloon angioplasty for intracranial atherosclerotic stenosis: a retrospective study

BackgroundPrimary balloon angioplasty (PBA) is an alternative treatment approach for intracranial atherosclerotic stenosis (ICAS); however, its efficacy may be compromised by arterial dissection or early elastic recoil after balloon dilation....

Association of systemic inflammatory response index and plaque characteristics with the severity and recurrence of cerebral ischemic events

AimWe aimed to investigate the relationship between systemic inflammatory response index (SIRI) and intracranial plaque features, as well as the risk factors related to the severity and recurrence of cerebral ischemic events. MethodsWe enrolled 170 patients with cerebral ischemic events. Baseline demographic characteristics and laboratory indicators were collected from all participants. All patients were assessed by high-resolution magnetic resonance vessel wall imaging for culprit plaque characteristics and intracranial atherosclerotic burden. Outpatient or telephone follow-up were conducted at 1, 3, and 6 months after discharge. ResultsSIRI levels were significantly associated with the enhanced plaque number (r = 0.205, p = 0.007), total plaque stenosis score (r = 0.178, p = 0.020), total plaque enhancement score (r = 0.222, p = 0.004), intraplaque hemorrhage (F = 5.630, p = 0.004), and plaque surface irregularity (F = 3.986, p = 0.021). Higher SIRI levels (OR = 1.892), total plaque enhancement score (OR = 1.392), intraplaque hemorrhage (OR = 3.370) and plaque surface irregularity (OR = 2.846) were independent risk factors for moderate-severe stroke, and these variables were significantly positively correlated with NIHSS (P < 0.05 for all). In addition, higher age (HR = 1.063, P = 0.015), higher SIRI levels (HR = 2.003, P < 0.001), and intraplaque hemorrhage (HR = 4.482, P = 0.008) were independently associated with recurrent stroke. ConclusionsHigher SIRI levels may have adverse effects on the vulnerability and burden of intracranial plaques, and links to the severity and recurrence of ischemic events. Therefore, SIRI may provide important supplementary information for evaluating intracranial plaque stability and risk stratification of patients.

High resolution magnetic field imaging probe with two rows of TMR sensors for small defects inspection

It is still a challenging problem to detect small defects for eddy current array probes, which requires the probes to possess excellent sensitivity, as well as high spatial resolution. This paper presents a novel high-resolution magnetic field imaging probe with two rows of tunneling magnetoresistance (TMR) array sensors. The bare die sensors are integrated on a printed circuit board by golden wire bonding technology. The two rows of sensors are placed staggered with each other. The data of the two arrays are merged into a matrix, in which way the image pixel pitch is increased to 0.25 mm. The probe employs a differential scheme to suppress the noise, so as to detect the weak signal of small defects. To highlight the weak defect indications, feature extraction and segmentation algorithms are developed. The experimental results confirm that the proposed method can inspect a small defect with dimensions 1 mm (length) × 0.1 mm (width) × 0.1 mm (depth) on a stainless-steel sample.

Application Progress of High-Resolution Magnetic Resonance Vascular Wall Imaging in Intracranial Arterial Dissection

Application Progress of High-Resolution Magnetic Resonance Vascular Wall Imaging in Intracranial Arterial Dissection

Risk prediction of CISS classification in endovascular treatment of basilar artery stenosis

ObjectiveTo investigate the incidence of ischemic stroke complications after endovascular treatment for basilar artery stenosis used preoperative high-resolution magnetic resonance vascular wall imaging (HRMR/VWI) and diffusion-weighted imaging (DWI). MethodsThe clinical data of 47 patients with severe symptomatic basilar artery stenosis (stenosis rate ≥70 %) treated with endovascular therapy at the Neuro-interventional Center from December 2017 to December 2021 were retrospectively analyzed. High-resolution magnetic resonance angiography (HRMR VWI) and DWI were used to evaluate the location of atherosclerotic plaque at basilar artery stenosis and the distribution of cerebral infarction lesions in all patients before surgery.According to the CISS classification system for ischemic stroke, patients were divided into a perforation group and a hypoperfusion group, and the general situation, plaque distribution, and incidence of ischemic stroke complications 7 days after endovascular treatment in the two groups were analyzed. ResultsThere was no significant difference in baseline data between the two groups. After 7 days of intravascular treatment, the incidence of ischemic stroke was higher in the perforation group (20.0 %) than in the hypoperfusion group (0.0 %), and the difference was statistically significant (P = 0.027). A significant association was found between the perforation group and the hypoperfusion group for the incidence of ischemic stroke at 7 days (P = 0.003, OR = 2.347; 95 % CI = 2.056–4.268). There were a higher proportion of ventral plaques (74.1 %) and a lower proportion of dorsal plaques (33.3 %) in the hypoperfusion group, which were 15.0 % and 90.0 % in the perforation group, respectively (χ2 = 16.045, P < 0.001; χ2 = 15.092, P < 0.001). There was no significant difference in the proportion of left and right plaques between the two groups. ConclusionsThe risk of ischemic stroke is greater in patients with perforator artery obstruction undergoing endovascular therapy, and lower in patients with hypoperfusion/embolus removal.

Morning blood pressure surge and intracranial atherosclerotic plaque characteristics: a high-resolution magnetic resonance vessel wall imaging study.

To investigate the relationship between morning blood pressure surge (MBPS) and intracranial atherosclerotic plaque burden and vulnerability. A total of 267 ischaemic stroke patients were retrospectively analysed. Sleep-trough and prewaking MBPS were calculated from ambulatory blood pressure monitoring (ABPM). Plaque characteristics, including intraplaque haemorrhage (IPH), maximum wall thickness (max WT), and stenosis degree, were obtained from high-resolution MR vessel wall imaging (HR-vwMRI). Linear and logistic regression were used to detect the association. Subjects with the top tertile of sleep-trough MBPS (≥15.1 mmHg) had a lower prevalence (9.1% vs. 19.6%, P = .029) of severe stenosis (≥70%) than others. Subjects within the top tertile of prewaking MBPS (≥7.6 mmHg) had a lower percentage of IPH (27.3% vs. 40.4%, P = .035) than others. After adjusting for stroke risk factors (age, sex, diabetes, hyperlipidaemia, hyperhomocysteinaemia, smoking, and family stroke history) and 24-h mean systolic blood pressure, 10 mmHg sleep-trough MBPS increment was associated with 0.07mm max WT reduction, and the top tertile MBPS group was associated with a lower chance of severe stenosis (odd ratio = 0.407, 95% CI, 0.175-0.950). Additionally, an increased prewaking MBPS is associated with a lower incidence of IPH, with OR = 0.531 (95% CI, 0.296-0.952). Subgroup analysis demonstrated that the positive findings could only be seen in non-diabetic subjects. Increment of MBPS is negatively associated with intracranial atherosclerotic plaque burden and vulnerability, and this relationship remains significant in the non-diabetic subgroup. This study provided evidence that MBPS was associated with the intracranial atherosclerotic plaque burden and vulnerability on HR-vwMRI.

Vessel wall MRI characteristics associated with intraprocedural stent thrombosis during angioplasty for intracranial atherosclerotic stenosis

BackgroundFew studies have so far explored plaque characteristics on high-resolution magnetic resonance vessel wall imaging (HR-VWI) associated with intraprocedural stent thrombosis (IPST) during angioplasty for intracranial atherosclerotic stenosis (ICAS). We...

Imaging investigation of cervicocranial artery dissection by using high resolution magnetic resonance VWI and MRA: qualitative and quantitative analysis at different stages

BackgroundTo explore the value of magnetic resonance angiography (MRA) and high resolution magnetic resonance vessel wall imaging (HRMR-VWI) in cervicocranial artery dissection (CCAD) for the disease diagnosis, course staging and treatment. On the basis of qualitative evaluation, this study also extract the changes of different stages in vessel wall in different vessel segments to identify imaging indicators for the quantitative evaluation of CCAD.MethodsWe retrospectively enrolled 34 patients with CCAD (38branches) with conventional MRA and HRMR-VWI examinations. Two radiologists independently analyzed imaging features of vessel wall and lumen in the different stages, and the typical sign detection of artery dissection were compared between MRA and HRMR-VWI. Then the parameters of vessel wall was quantitatively evaluated by the post-processing software (Vesselmass, Leiden University Medical Center, Leiden, The Netherlands.ResultsHRMR-VWI revealed typical sign detection of artery dissection in all patients in the acute and subacute stage. Among them, the intimal flap/double lumen sign ditection were more common than the MRA, there was significant difference (P = 0.012). MRA revealed typical sign detection of artery dissection in more than half the patients, and the detection was no significant difference at the chronic stage between MRA and HRMR-VWI (P = 1.000/1.000/0.761). In the acute and subacute stage, the typical sign detection of intramural hematoma and Grade II enhancement revealed by HR-MRI was higher than the observations in the chronic stage (P = 0.000/0.000/0.016), while there was no significant difference by MRA (P = 0.902). The values of wall thickness, relative signal intensity of vessel wall enhancement, relative signal intensity of intramural hematoma (IMH), and percentage of stenosis in CCAD decreased from acute to subacute and then to chronic stages. Each quantitative parameter in patients with CCAD in the early stages (i.e., acute and subacute stages) was significantly different from that in patients with CCAD in the recovered group at chronic stage (P < 0.05). Wall thickness and relative signal intensity of vessel wall enhancement in patients with CCAD in the early stages were not significantly different from those in patients with CCAD in the incompletely recovered group at chronic stage (P > 0.05).ConclusionsAs the only noninvasive imaging technology, HRMR-VWI displays the structure of the vessel wall in vivo, showing not only excellent performance in the early diagnosis of CCAD, but also describing the changes of different stages in the qualitative and quantitative characteristics of vessel wall. It also helps to guide the diseasediagnosis, course staging and treatment of CCAD. Although the diagnostic efficacy of MRA was not as good as HRMR-VWI, it should be the first choice of method for routine examination in evaluating CCAD, especially at the chronic stage of CCAD.

Prediction of Stroke Onset Time With Combined Fast High-Resolution Magnetic Resonance Spectroscopic and Quantitative T2 Mapping.

The purpose of this work is to develop a multispectral imaging approach that combines fast high-resolution 3D magnetic resonance spectroscopic imaging (MRSI) and fast quantitative T2 mapping to capture the multifactorial biochemical changes within stroke lesions and evaluate its potentials for stroke onset time prediction. Special imaging sequences combining fast trajectories and sparse sampling were used to obtain whole-brain maps of both neurometabolites (2.0 × 3.0 × 3.0 mm3) and quantitative T2 values (1.9 × 1.9 × 3.0 mm3) within a 9-minute scan. Participants with ischemic stroke at hyperacute (0-24 h, n = 23) or acute (24 h-7d, n = 33) phase were recruited in this study. Lesion N-acetylaspartate (NAA), lactate, choline, creatine, and T2 signals were compared between groups and correlated with patient symptomatic duration. Bayesian regression analyses were employed to compare the predictive models of symptomatic duration using multispectral signals. In both groups, increased T2 and lactate levels, as well as decreased NAA and choline levels were detected within the lesion (all p < 0.001). Changes in T2, NAA, choline, and creatine signals were correlated with symptomatic duration for all patients (all p < 0.005). Predictive models of stroke onset time combining signals from MRSI and T2 mapping achieved the best performance (hyperacute: R2 = 0.438; all: R2 = 0.548). The proposed multispectral imaging approach provides a combination of biomarkers that index early pathological changes after stroke in a clinical-feasible time and improves the assessment of the duration of cerebral infarction. Developing accurate and efficient neuroimaging techniques to provide sensitive biomarkers for prediction of stroke onset time is of great importance for maximizing the proportion of patients eligible for therapeutic intervention. The proposed method provides a clinically feasible tool for the assessment of symptom onset time post ischemic stroke, which will help guide time-sensitive clinical management.

Association of plaque characteristics with long-term stroke recurrence in patients with intracranial atherosclerotic disease: a 3D high-resolution MRI-based cohort study

ObjectivesTo evaluate the predictive ability of plaque characteristics for long-term stroke recurrence among patients with symptomatic intracranial atherosclerotic disease (ICAD).MethodsThis cohort study included 132 patients with acute ischemic stroke (AIS) attributed to ICAD who were recruited between July 2017 and December 2020 and followed until stroke recurrence or December 2021. Plaque surface irregularity, degree of stenosis, plaque burden, remodeling ratio, enhancement ratio, and intraplaque hemorrhage were assessed with 3-dimensional high-resolution magnetic resonance vessel wall imaging (3D HR-MRI). Data were analyzed using Cox models, receiver operating characteristic (ROC) curves, and Kaplan–Meier survival analysis.ResultsOf the 132 patients, during a median follow-up of 2.8 years, stroke recurrence occurred in 35 patients. The multivariable-adjusted hazard ratio (95% confidence interval) of stroke recurrence was 3.15 (1.34–7.42) per 10% increase in plaque burden and 2.17 (1.27–3.70) for enhancement ratio. The area under the curve (AUC) to predict stroke recurrence was 0.725 (95% CI 0.629–0.822) for plaque burden, 0.692 (95% CI 0.593–0.792) for enhancement ratio, and only 0.595 (95% CI 0.492–0.699) for the Essen stroke risk score. The Kaplan–Meier survival analysis further demonstrated significant differences in survival of free recurrent stroke between patients with plaque burden or enhancement ratio below and above the optimum cut-offs (both p < 0.001).ConclusionHigher plaque burden and enhancement ratio are independent risk factors for long-term stroke recurrence among patients with symptomatic ICAD, and valuable imaging markers for predicting and stratifying risk of stroke recurrence.Clinical relevance statementIn patients with symptomatic ICAD, the results of this high-resolution magnetic resonance vessel wall imaging study have potential implications for optimal management of intracranial plaques and secondary prevention of stroke recurrence based on plaque burden and enhancement ratio.Key Points• Identification of intracranial plaque characteristics responsible for stroke recurrence is essential to preventing stroke recurrence in patients with symptomatic intracranial atherosclerotic disease.• Higher plaque burden and enhancement ratio are independent risk factors for stroke recurrence.• Plaque burden and enhancement ratio are valuable imaging markers in the prediction and stratification of the risk of stroke recurrence.

Application of high-resolution magnetic resonance vessel wall image in the treatment of M1 segment stenosis of middle cerebral artery

To investigate the application of high-resolution magnetic resonance vessel wall image (HRMR-VWI) in treating middle cerebral artery (MCA) M1 segment stenosis. We retrospectively analyzed preoperative clinical data, imaging data, preoperative evaluation, stent procedure, and postoperative complications in 35 patients with atherosclerotic stenosis of the MCA M1 segment. And the 30-day postoperative mortality and disability and the 12-month restenosis were followed up. There were 21 males and 14 females, with a median age of 55 and a median duration of 1 month from onset to stenting. DSA confirmed that the stenosis locates in the M1 segment, with a stenosis degree of (75.00±17.15) %, a stenosis length of (4.34±1.51) mm, and a blood vessel diameter of (2.25±0.42) mm. After the operation, there was 1 case of death after a craniotomy to remove hematoma+decompression due to reperfusion hemorrhage. There were two technical complications during the procedure (1 case of asymptomatic occlusion of the A1 segment due to the covering of stent at the initial part of A1, 1 case of intraparenchymal hematoma in the temporal lobe due to penetrating distal small blood vessel with guide wire). HRMR-VWI is of great value in observing plaques' location, morphology, and stability. It can improve the safety and effectiveness of stenting treatment of MCA M1 segment stenosis.

Harmonic dependence of thermal magnetic particle imaging

Advances in instrumentation and tracer materials are still required to enable sensitive, accurate, and localized in situ 3D temperature monitoring by magnetic particle imaging (MPI). We have developed a high-resolution magnetic particle imaging instrument and implemented a low-noise multi-harmonic lock-in detection method to observe and quantify temperature variations in iron oxide nanoparticle tracers using the harmonic ratio method for determining temperature. Using isolated harmonics for MPI and temperature imaging revealed an apparent dependence of imaging resolution on harmonic number. Thus, we present experimental and simulation studies to quantify the imaging resolution dependence on temperature and harmonic number, and directly validate the fundamental origin of MPI imaging resolution on harmonic number based on the concept of a harmonic point-spread-function.

High-Resolution Magnetic Imaging Probe With Staggered Sensor Arrays for Small Defects Inspection

High-Resolution Magnetic Imaging Probe With Staggered Sensor Arrays for Small Defects Inspection

Association of intravascular enhancement sign on 3D-T1W TSE with collateral status in middle cerebral artery occlusion stroke

ObjectiveThe significance of the intravascular enhancement sign (IVES) on high-resolution magnetic resonance vascular wall imaging (HR-VWI) remains unclear. This study aimed to investigate the correlation between the IVES and collateral assessment derived from digital subtraction angiography (DSA). MethodA total of 75 patients with occlusion of the first segment of the middle cerebral artery (MCA) who underwent HR-VWI and DSA examinations at our research institution between November 2016 and February 2023 were included. The number of vessels with IVES, IVES-Alberta Stroke Program Early Computed Tomography Score (ASPECTS), American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) collateral grade, and DSA collateral blood flow grade were retrospectively evaluated. Correlations between these indicators were assessed using Spearman's correlation. ResultsInterrater agreement was good for the assessment of HR-VWI and DSA indicators. After adjustments for age, degree of wall enhancement, and hypertension, a multivariable ordinal logistic regression model identified both the number of IVES vessels (OR = 1.37; 95%CI [1.06–1.78]; P = 0.017) and IVES-ASPECTS (OR = 2.00; 95%CI [1.03–3.87]; P = 0.041) as independent predictors of ischemic stroke. In the patient group with acute ischemic stroke, we found weak correlations between the number of IVES vessels and the ASITN/SIR collateral grade (rho = −0.35; P = 0.002) and between the IVES-ASPECTS and ASITN/SIR collateral grade (rho = −0.27; P = 0.02). Moreover, there were strong correlations between the number of IVES vessels and the DSA collateral blood flow grade (rho = −0.74; P < 0.001) and between the IVES-ASPECTS and the DSA collateral blood flow grade (rho = −0.65; P < 0.001). The number of IVES vessels correlated strongly with the IVES-ASPECTS (rho = 0.92, P < 0.001). ConclusionWe find that the IVES is closely associated with sluggish collateral blood flow, which further confirms the hemodynamic mechanism underlying the IVES in MCA occlusion.

The diagnostic performance of high-resolution magnetic resonance-vessel wall imaging in differentiating atherosclerosis-associated moyamoya vasculopathy from moyamoya disease.

To evaluate the diagnostic performance of high-resolution magnetic resonance-vessel wall imaging (HRMR-VWI) in differentiating moyamoya disease (MMD) from atherosclerosis-associated moyamoya vasculopathy (AS-MMV) and investigate an accurate approach for the differential diagnosis. Adult patients who were diagnosed as MMD or AS-MMV and underwent HRMR-VWI were retrospectively included. The three vessel wall features (outer diameter (OD), remodeling index (RI), and pattern of vessel wall thickening) of middle cerebral artery (MCA) in identifying MMD from AS-MMV were assessed and compared. Furthermore, subgroup analysis stratified by degree of luminal stenosis was performed and the cutoff values of different vessel wall features in differentiating MMD from AS-MMV were also calculated. A total of 265 patients (160 cases of MMD and 105 AS-MMV) were included. Patients with AS-MMV had greater OD and RI and were more likely to exhibit eccentric thickening of vessel wall compared to those with MMD (all p < 0.001). The ROC analysis showed that the AUC value of OD was greater than that of RI (0.912 vs. 0.889, p = 0.007) in differentiating MMD from AS-MMV, and their corresponding cutoff values were 1.77 mm and 0.27, respectively. And the AUC value of pattern of vessel wall thickening was 0.786 in non-occluded patients. With the increase of lumen stenosis, the discrimination power of the three indicators enhanced correspondingly. HRMR-VWI is valuable in distinguishing MMD from AS-MMV. The OD of MCA has better diagnostic performance in differentiating AS-MMV from MMD compared to RI and pattern of vessel wall thickening. The outer diameter of the involved artery proved to be both accurate and convenient in distinguishing atherosclerosis-associated moyamoya vasculopathy from moyamoya disease and may provide a quantitative reference for clinical diagnosis. High-resolution magnetic resonance-vessel wall imaging is valuable in distinguishing atherosclerosis-associated moyamoya vasculopathy from moyamoya disease. Compared to remodeling index and pattern of vessel wall thickening, outer diameter is more accurate in differentiating atherosclerosis-associated moyamoya vasculopathy from moyamoya disease. With the increase of lumen stenosis, the discrimination power of outer diameter, remodeling index, and pattern of vessel wall thickening enhanced correspondingly.

Calcification circumference, area, and location are associated with carotid stent expansion rate: high-resolution magnetic resonance vessel wall imaging study.

The plaque imaging findings associated with the stent expansion rate (SER) of the carotid artery are not well known. The purpose of this study was to investigate the imaging findings associated with SER. It was a retrospective investigation. Based on the kind of carotid stents used, retrospective data from 89 patients who had carotid artery stenting (CAS) for atherosclerotic carotid stenosis were gathered and divided into two groups: open-cell stents and closed-cell stents. Patients underwent preoperative carotid high-resolution magnetic resonance vessel wall imaging (HR-VWI). Use HR-VWI to quantitatively evaluate carotid wall thickness and plaque components. Calculate SER using digital subtraction angiography (DSA). All patients' baseline and HR-VWI imaging features were retrospectively analyzed. Simple and multivariable linear regression analysis was used to determine the imaging findings associated with SER of open-cell and closed-cell stents. A total of 89 patients (mean age, 70±8 years; 69 men) were included in the final analysis. Among 89 patients, 35 patients were treated with open-cell stents. Fifty-four patients were treated with closed-cell stents. In the open-cell stents group, the Maximum single-slice calcification circumference score, maximum wall thickness (WTmax), and total calcification location score with P<0.10 in the simple linear regression analysis were included in the multivariable linear regression analysis. The results of the multivariable linear regression revealed that only the Maximum single-slice calcification circumference score (β=-9.35; 95% CI: -18.15 to -0.56; P=0.03) was associated with SER of open-cell stents. In the closed-cell stents group, the Maximum single-slice calcification circumference score, WTmax, maximum area percentage of calcification, calcification volume, and total calcification location score with P<0.10 in the simple linear regression analysis were included in the multivariable linear regression analysis. The results of the multivariable linear regression revealed that the Maximum area percentage of calcification (β=-0.67; 95% CI: -1.29 to -0.05; P=0.03), Maximum single-slice calcification circumference score (β=-8.43; 95% CI: -13.36 to -3.49; P=0.001) and total calcification location score (β=-0.37; 95% CI: -1.08 to 0.09; P=0.02) were associated with SER of closed-cell stents. Calcified plaques are associated with SER of the carotid artery. Calcification circumference correlates with SER of open-cell stents. Calcification circumference, calcification area, and calcification location are related to SER of closed-cell stents, which may provide a new consideration for clinicians when choosing carotid artery stents.