Clinical Neuroradiology最新文献

Purpose: In acute ischemic stroke with large-vessel occlusion (LVO), collateral assessment with single-phase computed tomography angiography (CTA) might underestimate pial collateral supply in a considerable proportion of patients. We aimed to compare time-resolved magnetic resonance imaging (MRI)-based quantitative collateral mapping to conventional collateral imaging with CTA.

Methods: This retrospective single-center study covering a period of 6 years (2012-2018) included drip-and-ship LVO patients who underwent MR imaging after initial imaging evaluation with CT. For MRI-based collateral assessment, T2*-weighted time series from perfusion-weighted imaging (PWI) were processed to compute a quantitative collateral vessel index (CVI_PWI) based on the magnitude of signal variance across the entire acquisition time. CTA-based collateral scores (Tan and Maas) and CVI_PWI were investigated in terms of inter-modality associations between collateral measures, as well as their relationships with stroke severity, infarct volume and early functional outcome.

Results: The final analysis included n = 56 patients (n = 31 female, mean age 69.9 ± 14.21 years). No significant relationship was found between MR-based quantitative collateral supply (CVI_PWI) and CT-based collateral scores (r = -0.00057, p = 0.502 and r = -0.124, p = 0.797). In contrast to CVI_PWI, CTA-based collateral scores showed no significant relationship with clinical stroke severity and infarct volume. While MR-based CVI_PWI was independently associated with favorable early functional outcome in multivariate analysis (OR 1.075, 95% CI 1.001-1.153, p = 0.046), CTA-based collateral scores were not significantly associated with outcome.

Conclusions: Since collateral scores based on single-phase CTA do not accurately reflect infarct progression and might underestimate pial collateralization in a relevant proportion of patients, they are not associated with early functional outcome in LVO patients. In contrast, CVI_PWI represents a robust imaging parameter of collateral supply and is independently associated with functional outcome.

Purpose: To evaluate a novel flow-independent sequence (Relaxation-Enhanced Angiography without Contrast and Triggering (REACT)) for imaging of the extracranial arteries in acute ischemic stroke (AIS) at 1.5 T.

Methods: This retrospective single-center study included 47 AIS patients who received REACT (scan time: 3:01 min) and contrast-enhanced MRA (CE-MRA) of the extracranial arteries at 1.5 T in clinical routine. Two radiologists assessed scans for proximal internal carotid artery (ICA) stenosis, stated their diagnostic confidence and rated the image quality of cervical arteries, impact of artifacts and image noise. Apparent signal- and contrast-to-noise ratios (aSNR/aCNR) were measured for the common carotid artery and ICA.

Results: REACT achieved a sensitivity of 95.0% and a specificity of 97.3% for ICA stenoses in high agreement with CE-MRA (κ = 0.83) with equal diagnostic confidence (p = 0.22). Image quality was rated higher for CE-MRA at the aortic arch (p = 0.002) and vertebral arteries (p < 0.001), whereas REACT provided superior results for the extracranial ICA (p = 0.008). Both sequences were only slightly affected by artifacts (p = 0.60), while image noise was more pronounced in CE-MRA (p < 0.001) in line with higher aSNR (p < 0.001) and aCNR (p < 0.001) values in REACT for all vessels.

Conclusion: Given its good diagnostic performance while yielding comparable image quality and scan time to CE-MRA, REACT may be suitable for the imaging of the extracranial arteries in acute ischemic stroke at 1.5 T.

Introduction: Rescue intracranial stenting is necessary to provide sufficient recanalization after mechanical thrombectomy (MT) in patients with acute large vessel occlusions (LVO) due to an underlying intracranial atherosclerotic disease (ICAD). The CREDO heal is a novel stent that provides a potentially lower thrombogenicity due to surface modification. We present the first multicentric experience with the CREDO heal for acute rescue stenting.

Methods: Data of 81 patients who underwent rescue stenting after MT at 12 centers in Germany and Spain were prospectively collected and retrospectively evaluated.

Results: Final mTICI 2b‑3 was reached in 95.1% after median two MT maneuvers and stenting. Four periprocedural complications resulted in clinical deterioration (4.9%). Intraparenchymal hemorrhage occurred in one patient (1.2%) and functional independence at FU was reached by 42% of the patients. Most interventions were performed under Gp IIb/IIIa inhibitors.

Conclusion: CREDO heal was effective and safe in our case series. However, more data is needed to define the optimal antithrombotic regime. The use under single antiplatelet medication is not supported by our study.

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.

Background: Stent assisted coiling technique have shown to be an effective and safe endovascular strategy for wide neck bifurcation aneurysms in achieving greater packing, allowing the closure of the aneurysm and preserving the parent arteries, compared to simple coiling.

Material and methods: We conducted a retrospective analysis of 79 patients with cerebral aneurysms treated using 'Y'-configuration double Neuroform® stent-assisted coiling at our center from July 2009 to July 2022.

Results: Of the 79 patients, 76% (60/79) were incidental unruptured cerebral aneurysm and 24% were patients treated for aneurysm recanalization of a previous ruptured aneurysm (19/79). The most frequent locations were anterior communicating artery (AComA) 44.3% (35/79) and middle cerebral artery (MCA) 32.9% (26/79). We found a complete and almost complete aneurysm occlusion (Raymond-Roy occlusion classification (RROC) 1 and 2): in 100% (79/79) in the angiography after procedure, in 97.6% (42/43) at the first follow-up at 6-8 months and 100% (57/57) at the first 1-2 years of follow-up. No mortality related to treatment was detected. We registered 2.5% (2/79) major ipsilateral strokes, one due to acute in stent thrombosis (patient had a mRS: 0 in follow up at 90 days) and a spinal anterior artery occlusion (patient had a mRS: 3 in follow up at 90 days).

Conclusion: The 'Y' stent-assisted coiling technique with double Neuroform® is a safe and effective technique for the treatment of wide-neck bifurcation aneurysms, with high rates of complete occlusion, preserving the permeability of the afferent and efferent arteries and low rate of complications.