Clinical Neuroradiology最新文献

Background & purpose: Non-stenotic (< 50%) carotid plaques are increasingly recognized as a potential mechanism for ischemic stroke. We assessed the prevalence of such plaques in patients with low-risk neurologic events and evidence of DWI (Diffusion Weighted Imaging)-positive ischemia.

Methods: This is a post-hoc exploratory analysis from the DOUBT study, a prospective, observational, multicenter study of patients with low-risk transient or persistent minor focal neurological symptoms. Patients who had baseline CT angiography (CTA) and an MRI within 8 days of their event were included in the study. We aimed to assess the prevalence of non-stenotic carotid disease in patients with versus without DWI-positive events, and in patients with ipsilateral DWI-positive events. A carotid-level analysis with univariable logistic regression analysis was performed to assess whether any of the assessed plaque features were associated with ipsilateral stroke.

Results: Of the 334 patients (mean age 62.7 years, 50.4% females) with available vascular neuroimaging, 153 (45.9%) had non-stenotic carotid plaques (≤50% stenosis), 174 (52.1%) had no stenosis and 7 (2.1%) patients had >50% stenosis. Of those with non-stenotic carotid plaques, 31/153 (20.3%) had evidence of DWI-positive ischemia, approximately half (15/31; 48.4%) of which was in the territory of the carotid plaque. Amongst patients with DWI-positive ischemia, non-stenotic plaques were significantly more common on the side of DWI-positive lesions [31/49 (63.3%) versus 18/49(36.7%)]. Presence of non-stenotic plaque was a risk marker for DWI-positive events (RR 1.4, 95% CI 1.1-1.8, p 0.012). On matched analysis, non-stenotic plaques were more likely on the side of DWI+ ischemia (odds ratio 1.14, 95% CI 0.36-3.70, McNemar's p value 0.80). Plaque features, including hypodensity, irregularity and greater plaque thickness were significantly associated with a higher likelihood of ipsilateral DWI+ ischemia.

Conclusion: In patients with low-risk transient or persistent neurologic events, non-stenotic carotid plaques are more common in patients with DWI-positive ischemia. Plaque features like hypodense and irregular plaque were more common with DWI-positive changes in the territory of the affected carotid.

Purpose: This study aimed to characterize spinal cord microstructure in healthy subjects using high angular resolution diffusion imaging (HARDI) and tractography.

Methods: Forty-nine healthy subjects (18-50 years, divided into 2 age groups) were included in a prospective study. HARDI of the cervical spinal cord were acquired using a 3T MRI scanner with: 64 directions, b‑value: 1000s/mm², reduced field-of-view (zonally magnified oblique multi-slice), and opposed phase-encoding directions. Distortions were corrected using the FSL software package. Fiber tracking was performed using a deterministic approach with DSI-Studio software. Tensor metrics-fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD)-and tractography statistics were then extracted, at each spine level, and after grey-white matter segmentation.

Results: The microstructural organization of the spinal cord differed between upper and lower cervical spine levels: FA, and AD significantly decreased (p < 0.001); and RD significantly increased (p < 0.05) in lower levels, demonstrating changes in axonal density and myelinated fibers according to a cranio-caudal axis. FA, MD, AD, and RD values were significantly higher in spinal cord white matter (p < 0.0001), compared to grey matter. Age was not associated with a significant change in FA, while there is for MD, AD and RD (p < 0.05). Spinal cord tractography may provide information on the architectural organization of fibers and spinal tracts.

Conclusion: This study proposes a database in cervical spinal cord HARDI, allowing to study the microstructural organization of the spinal cord in healthy subjects, and providing a foundation for comparison with patients presenting spinal cord pathologies.

Background: The Hyperdense Middle Cerebral Artery Sign (HMCAS) is an early marker of acute MCA occlusion on non-contrast CT (NCCT), which has been linked with stroke type and thrombus composition.

Aims: To assess the prognostic value of HMCAS in M1 occlusion patients treated with endovascular thrombectomy and explore its predictive value across different patients.

Methods: Patients with M1 occlusion were selected from the ANGEL-ACT registry, which comprised 1793 individuals. Cohorts were divided based on the presence of HMCAS. The primary outcome was functional independence (mRS 0-2) at 90 days. Secondary outcomes included excellent outcome (mRS 0-1), good functional outcome (mRS 0-3), modified first pass effect (mFPE), successful recanalization, intracranial hemorrhage, and 90-day mortality. Propensity score matching (PSM) was employed to adjust for confounders, with 96 patients in each matched group. Subgroup analysis was performed to determine whether the effect of HMCAS on clinical outcomes differed between groups.

Results: Among 714 acute M1 occlusion patients, 96 (13.4%) had HMCAS. PSM analysis showed that HMCAS was independently associated with mFPE (OR: 1.97, 95% CI: 1.04-3.75, p = 0.038) but had no significant effects on other clinical outcomes. There was a significant association between HMCAS and functional independence for patients who underwent direct thrombectomy but not for patients who underwent bridging therapy (P for interaction = 0.033).

Conclusion: This study indicates that in patients with acute M1 occlusion undergoing EVT, HMCAS on pretreatment NCCT is not significantly associated with functional independence but is linked to a higher first-pass recanalization rate. Its clinical impact on outcomes depends on whether intravenous thrombolysis is administered before thrombectomy.

Introduction: Although stentrievers (SRs) are widely used for mechanical thrombectomy (MT), the impact of device dimensions on optimizing reperfusion outcomes in high clot burden cases is unclear. Our study aimed to investigate the effect of SR size on angiographic and clinical outcomes in patients with acute terminal internal cerebral artery (TICA) occlusion.

Methods: We analyzed ROSSETTI registry data to compare technical and clinical outcomes of TICA occlusion patients treated with MT without rescue therapy, according to SR diameter and length: 6 × 41-50 mm, 6 × 20-40 mm, and <6 × 20-50 mm. The first-pass effect (FPE) was defined as achieving a TICI2c‑3 after a single pass.

Results: We included 491 patients, 240 (41.5%) in 6 × 41-50 group, 117 (20.2%) in 6 × 20-40 group, and 134 (23.2%) in < 6 × 20-50 group. The MT procedure time for the 6 × 41-50 group was shorter, but the FPE rate was similar across all groups. The highest final mTICI 2c‑3 rate was in 6 × 41-50 group (81.2%), compared to 6 × 20-40 group (68.4%) and 4-6 × 20-50 group (72.4%) (p = 0.016). Distal catheter use was associated with final mTICI 0-2b (62% of patients). Clinical outcomes were similar between the groups. Larger diameter and longer length of the SR, as well as not using an intermediate catheter, were independent predictors of final mTICI 2c‑3. The use of 6 × 41-50 SRs (OR 1.64, 95% CI 1.06-2.52; p = 0.024) and distal catheter use (OR 0.62, 95%CI 0.40-0.96; p = 0.034) were independent predictors of final mTICI 2c‑3.

Conclusions: Use of longer and larger SRs in acute intracranial TICA occlusion improves final reperfusion rate.

Purpose: This study aimed to investigate the factors influencing favourable clinical outcomes in idiopathic intracranial hypertension (IIH) patients with venous sinus stenosis (VSS) who received stenting treatment.

Methods: In this prospective cohort study, we analyzed a total of 172 IIH patients with VSS treated with venous sinus stenting. Clinical outcomes were categorized as either "complete resolved" or "improved". We employed multivariable logistic regression modeling to identify independent factors associated with the clinical outcomes. The predictive accuracy of the model was assessed using receiver operating characteristic (ROC) analysis.

Results: Out of the total cohort, 126 patients exhibited asymptomatic clinical outcomes, while 46 patients showed improved clinical outcomes. Patients with asymptomatic clinical outcomes demonstrated notably lower preoperative BMI (26.8 kg/m² versus 28.7 kg/m², P = 0.013). In multivariate analysis, preoperative BMI (odds ratio [OR] = 1.108, 95% confidence interval [CI] = 1.009-1.216) was an independent factor of complete resolution of the symptoms. In the receiver operating characteristic (ROC) analysis, the identified cut-off BMI for the highest sensitivity (0.5) and specificity (0.754) was determined to be 29.3 kg/m².

Conclusion: Lower BMI may be associated with the complete resolution of symptoms in IIH patients with VSS who received venous sinus stenting treatment.

Background and purpose: So-called contrast-induced encephalopathy (CIE) is a rare but worrying condition occurring after cerebral angiography or neuroendovascular interventions using iodine contrast media. This study aimed to compare cerebral iodine concentrations in patients suspected of having CIE after endovascular procedures to those in matched controls.

Methods: This is a retrospective monocentric study of 25 suspected CIE patients in a tertiary care teaching hospital diagnosed from June 2017 to February 2024. Cerebral multispectral computed tomography (CT) iodine mean concentrations were measured and compared with 1:1 matched controls using the CT constructor's workstation in the whole brain and in specific regions of interest (ROIs) corresponding to a vascular territory downstream of the procedure. Concentration values were compared with paired samples t‑test.

Results: During the study period, 1097 patients underwent aneurysm embolization and 137 arteriovenous malformation (AVM) embolization procedures. So-called CIE was suspected in 25 patients after aneurysm or AVM embolization (2%). Mean iodine concentrations in the procedure vascular territory ROIs were higher in suspected CIE cases (mean 543 ± 147 µg/cm³) compared to matched controls (mean 463 ± 141 µg/cm³; p = 0.01). Whole brain mean iodine concentrations were modestly higher in CIE patients compared to controls across all subgroups, without reaching statistical significance.

Conclusions: CIE may be associated with modest increase in CT iodine concentration in the procedure vascular territory after neurointerventional procedures. The underlying pathophysiology of this condition remains uncertain and merits further investigation.

Key messages: Contrast-induced encephalopathy (CIE) is known as a rare neurologic condition following iodine contrast media use in neuroendovascular interventions, with unclear pathophysiology.

What this study adds: This study provides evidence that suspected CIE is associated with higher cerebral iodine concentrations in affected vascular territories, a novel quantifiable change. Implications for research, practice, or policy: These findings suggest the potential for iodine concentration monitoring to refine CIE diagnosis and prevention strategies in clinical practice.

Purpose: This systematic review and meta-analysis aimed to systematically evaluate and enhance the understanding of optimal management strategies for serpentine aneurysms.

Methods: A systematic search was conducted in Medline, Scopus, and Cochrane databases up to July 8, 2024, using relevant keywords. Studies included were case series, prospective or retrospective cohorts, or randomized controlled trials with data on clinical and angiographic outcomes of intracranial serpentine aneurysms. Data extraction and quality assessment were performed independently by two authors. Statistical analysis was conducted using R, with pooled estimates under a random-effects model.

Results: Ten studies comprising 70 patients with 71 serpentine aneurysms were included. The majority (92.9%) were giant aneurysms. The overall rate of procedure-related complications was 33%, morbidity was 13%, and mortality was 13%. Good neurological outcomes were achieved in 76% of cases. For unruptured aneurysms, the complication rate was 34%, while no complications were observed in ruptured aneurysms. Comparative analysis between ruptured and unruptured aneurysms showed no significant differences in outcomes or complications. The technical success rate was 91%. Reconstructive methods showed a slightly higher rate of good neurological outcomes (77%) compared to deconstructive methods (70%), though complication rates were similar.

Conclusion: Both reconstructive and deconstructive endovascular treatments for serpentine aneurysms are effective, with high rates of good neurological outcomes and acceptable complication rates.

Background: Maximum wall shear stress (maxWSS) points of unruptured cerebral aneurysms (UCAs) may cause wall remodeling leading to rupture. We characterized maxWSS points and their inherent intra-aneurysmal flow structures in a sizable cohort of saccular UCAs using four-dimensional (4D) flow magnetic resonance imaging (MRI).

Methods: After contrast administration, 50 saccular UCAs were subjected to 4D flow MRI using a 1.5 T MRI scanner. Post-processing of obtained data was performed using commercially available software. The maxWSS points and maxWSS values were evaluated. The maxWSS values were statistically compared between aneurysm groups.

Results: The maxWSS point was located on the aneurysm apex in 9 (18.0%), body in 2 (4.0%), and neck in 39 (78.0%) UCAs. The inherent intra-aneurysmal flow structure of the maxWSS point was an inflow zone in 34 (68.0%) UCAs, an inflow jet in 8 (16.0%), and an impingement zone in 8 (16.0%). The maxWSS point on the neck had significantly higher maxWSS values than those points on the other wall areas (P = 0.008). The maxWSS values of the maxWSS points on the apex and on the impingement zone were not significantly different compared with those of the other maxWSS points.

Conclusion: The maxWSS points existed preferentially on the aneurysmal neck adjacent to the inflow zone with higher maxWSS values. The maxWSS points existed occasionally on the aneurysmal apex adjacent to the impingement zone. 4D flow MRI may be helpful to discriminate saccular UCAs with higher-risk maxWSS points that can cause wall remodeling leading to rupture.

Purpose: Supratentorial (ST) ependymoma subgroups are defined by two different fusions with different prognoses. Astroblastomas, MN1-altered, have ependymal-like histopathologic features and represent a differential diagnosis in children. We hypothesized that ZFTA-fused ependymoma and YAP1-fused ependymoma on the one hand, and astroblastoma, MN1-altered, on the other hand, show different MRI characteristics.

Methods: We retrospectively analyzed the preoperative imaging of 45 patients with ST ependymoma or astroblastoma between January 2000 and September 2020, blinded to histomolecular grouping. Several characteristics, such as location, tumor volume, calcifications, solid/cystic component, and signal enhancement or diffusion were evaluated. We compared imaging characteristics according to their molecular subtype (ZFTA-fused, YAP1-fused, and astroblastoma, MN1-altered).

Results: Thirty-nine patients were classified as having an ependymoma, 35 with a ZFTA fusion and four with a YAP1 fusion, and six as having an astroblastoma, MN1-altered. YAP1-fused ependymomas were more likely to involve at least 3 lobes than ZFTA-fused ependymomas. Astroblastomas were located in the frontal lobe in 100% of the tumors versus 49% of the ependymomas. Cerebral blood flow by arterial spin labeling was higher in astroblastomas than in ependymomas. There were no differences in the other characteristics between the molecular groups. All the tumors showed common features: intra-axial extra-ventricular tumors, very frequent contrast enhancement (39/43, 91%), a cystic/necrotic component (41/45, 91%), restricted diffusion (32/36, 89%), calcifications (15/18, 83%), and peri-tumoral edema (38/44, 86%).

Conclusion: The distinction between ST ependymoma subtypes and astroblastomas can be guided by several imaging features. These tumors share common imaging features that may help to differentiate ST ependymomas and astroblastomas from other pediatric ST tumors.

Purpose: The clinical importance and management of vasospasm as a complication during endovascular stroke treatment (EVT) has not been well studied. We sought to investigate the effect of adding nimodipine to the guiding catheter flush (GCF) to prevent vasospasm during EVT.

Methods: This is a single-center retrospective analysis including patients with EVT (stent-retriever and/or distal aspiration) treated for anterior or posterior circulation intracranial vessel occlusion from January 2018 to June 2023. Exclusion criteria were intracranial or extracranial stenosis, intra-arterial alteplase, patient age over 80 years. Study groups were patients with (nimo+) and without (nimo-) nimodipine in the GCF. They were compared for occurrence of vasospasm as primary endpoint and clinical outcome in univariate analysis.

Results: 477 patients were included in the analysis (nimo+ n = 94 vs. nimo- n = 383). Nimo+ patients experienced less vasospasm during EVT (e.g. vasospasm in target vessel n (%): nimo- = 113 (29.6) vs. nimo+ = 9 (9.6), p < 0.001; extracranial vasospasm, n (%): nimo- = 68 (17.8) vs. nimo+ = 7 (7.4), p = 0.017). Patients of the two study groups had a comparable clinical outcome (90 day mRS, median (IQR): 3 (1-6) for both groups, p = 0.896). In general, patients with anterior circulation target vessel occlusion (TVO) experienced more vasospasm (anterior circ. TVO 38.7% vs. posterior circ. 7.5%, p = 0.006).

Conclusion: Prophylactic adding of nimodipine reduces the risk of vasospasm during EVT without affecting the clinical outcome. Patients with anterior circulation TVO experienced more vasospasm compared to posterior circulation TVO.