Interventional neuroradiology of stroke, still not dead

Since the National Institute of Neurological Disorders and Stroke trial,intravenous thrombolysis has been gaining wide acceptance as the modality of treatment for acute embolic stroke,with a current therapeutic window of up to 4.5 h.Both imaging[with either magnetic resonance imaging(MRI)or computed tomography(CT)]and interventional techniques(thrombolysis and/or thrombectomy)have since improved and provided us with additional imaging of the penumbra using CT or MRI and more advanced thrombolysis or thrombectomy strategies that have been embraced in many centers dealing with patients with acute cerebral ischemia.These techniques,however,have come under scrutiny due to their accrued healthcare costs and have been questioned following major recent studies.These studies basically showed that interventional techniques were not superior to the traditional intravenous thrombolysis techniques and that penumbra imaging could not determine what patients would benefit from more aggressive(i.e.,interventional)treatment.We discuss this in the light of the latest developments in both diagnostic and interventional neuroradiology and point out why further studies are needed in order to define the right choices for patients with acute stroke.Indeed,these studies were in part conducted with suboptimal patient recruitment strategies and did not always use the latest interventional techniques available today.So,while these studies may have raised some relevant questions,at the same time,definitive answers have not been given,in our opinion.

Microstructural analysis of pineal volume using trueFISP imaging

AIM:To determine the spectrum of pineal microstructures (solid/cystic parts) in a large clinical population using a high-resolution 3D-T2-weighted sequence. METHODS:A total of 347 patients enrolled for cranial magnetic resonance imaging were randomly included in this study. Written informed consent was obtained from all patients. The exclusion criteria were artifacts or mass lesions prohibiting evaluation of the pineal gland in any of the sequences. True-FISP-3D-imaging (1.5-T, isotropic voxel 0.9 mm) was performed in 347 adults (55.4 ± 18.1 years). Pineal gland volume (PGV), cystic volume, and parenchyma volume (cysts exclud- ed) were measured manually. RESULTS:Overall, 40.3% of pineal glands were cystic. The median PGV was 54.6 mm 3 (78.33 ± 89.0 mm 3 ), the median cystic volume was 5.4 mm 3 (15.8 ± 37.2mm 3 ), and the median parenchyma volume was 53.6 mm 3 (71.9 ± 66.7 mm 3 ). In cystic glands, the standard deviation of the PGV was substantially higher than in solid glands (98% vs 58% of the mean). PGV declined with age (r = -0.130, P = 0.016). CONCLUSION:The high interindividual volume variation is mainly related to cysts. Pineal parenchyma volume decreased slightly with age, whereas genderrelated effects appear to be negligible.

脊柱旁肌水-脂肪MRI测量与等长肌力测量的关系

目的基于化学位移编码的水-脂肪MRI衍生的脊髓旁肌肉质子密度脂肪分数(PDFF)已成为肌肉减少、腰痛、损伤和神经肌肉疾病病人的替代标志物。本研究旨在探讨椎旁肌PDFF及横断面面积(CSA)对等长肌力的预测能力。

肝硬化中肝细胞癌的动态对比增强CT成像:根据示踪动力学模型行延迟双期检查方案的可行性

应用双期动态对比增强成像对4例肝细胞癌行CT检查．首先应用初始快速动态成像观察早期强化用以评估灌注情况,其后应用逐渐增加时间间隔的延迟成像来监测随后的组织增强表现以评估组织通透性。利用双人路双室分布参数模型来分析动态对比增强CT影像．分别评估血流量和通透性及血管内外容积分数。结果表明,半透膜分隔的双室模型能恰当地显示肝细胞癌和周围肝硬化组织的增强曲线。与背景肝组织相比,肝细胞癌的强化更早。

Effect of thrombectomy on oedema progression and clinical outcome in patients with a poor collateral profile

Background and purpose The impact of the cerebral collateral circulation on lesion progression and clinical outcome in ischaemic stroke is well established.Moreover,collateral status modifies the effect of endovascular treatment and was therefore used to select patients for therapy in prior trials.The purpose of this study was to quantify the effect of vessel recanalisation on lesion pathophysiology and clinical outcome in patients with a poor collateral profile.Materials and methods 129 patients who had an ischaemic stroke with large vessel occlusion in the anterior circulation and a collateral score(CS)of 0-2 were included.Collateral profile was defined using an established 5-point scoring system in CT angiography.Lesion progression was determined using quantitative lesion water uptake measurements on admission and follow-up CT(FCT),and clinical outcome was assessed using modified Rankin Scale(mRS)scores after 90 days.Results Oedema formation in FCT was significantly lower in patients with vessel recanalisation compared with patients with persistent vessel occlusion(mean 19.5%,95%CI:17%to 22%vs mean 27%,95%CI:25%to 29%;p<0.0001).In a multivariable linear regression analysis,vessel recanalisation was significantly associated with oedema formation in FCT(ß=−7.31,SD=0.015,p<0.0001),adjusted for CS,age and Alberta Stroke Program Early CT Score(ASPECTS).Functional outcome was significantly better in patients following successful recanalisation(mRS at day 90:4.5,IQR:2-6 vs 5,IQR:5-6,p<0.001).Conclusion Although poor collaterals are known to be associated with poor outcome,endovascular recanalisation was still associated with significant oedema reduction and comparably better outcome in this patient group.Patients with poor collaterals should not generally be excluded from thrombectomy.

脑MRI影像组学在预测转移瘤类型中的应用

目的探讨在未知原发病灶的病人中,运用多分类机器学习方法中不同脑转移瘤的MRI影像组学特征预测肿瘤类型的可行性。材料与方法这项单中心回顾性分析纳入189例病人(女101例,男88例;年龄32~85岁,平均61岁)共658幅脑转移瘤的MR影像,包括T1平扫、T1增强与液体衰减反转恢复(FLAIR)序列影像。

Impact of aspiration catheter size on first-pass effect in the combined use of contact aspiration and stent retriever technique

Background and purpose The first-pass effect(FPE),defined as a first-pass Expanded Treatment in Cerebral Ischaemia(eTICI)2c/3 reperfusion,has emerged as a key metric of efficacy in mechanical thrombectomy(MT)for acute ischaemic stroke.The proximal balloon occlusion together with direct thrombus aspiration during stent retriever thrombectomy(PROTECT)-PLUS technique consists in the use of a balloon guide catheter and a combined MT approach involving contact aspiration and a stent retriever.The aim of this study is to assess the effectiveness and safety of the PROTECT-PLUS technique using distal aspiration catheters(DACs)with different inner diameters by comparing the large-bore DAC Catalyst 7 versus the use of medium-bore DACs.Methods Retrospective analysis of a prospectively maintained database of patients treated with PROTECT-PLUS using Catalyst 7,Catalyst 6 or Catalyst 5 with an occlusion of either the terminal carotid artery or the M1 or M2 segments of the middle cerebral artery from 2018 to 2020 in two comprehensive stroke centres.Baseline characteristics and procedural,safety and clinical outcomes were compared between groups.Multivariable logistic regression analysis was performed in order to find independent predictors of FPE.Results We identified 238 consecutive patients treated with PROTECT-PLUS as front-line approach using Catalyst 7(n=86),Catalyst 6(n=78)and Catalyst 5(n=76).The rate of FPE was higher with Catalyst 7(54%)than Catalyst 6(33%,p=0.009)and Catalyst 5(32%,p=0.005),in addition to higher final eTICI 2c/3 reperfusion rates,shorter procedural times,lower need of rescue therapy and fewer procedure-related complications.After multivariable analysis the sole independent factor associated to FPE was the use of Catalyst 7(OR 2.34;95%CI 1.19 to 4.58;p=0.014).Conclusion Further development of combined MT by incorporating larger-bore aspiration catheters is associated with higher reperfusion rates,shorter procedure times,and lower need of rescue therapy while reducing the complication rates.

Successful coil embolization with a basic technique for ruptured posterior tibial artery in a patient with Ehlers-Danlos syndrome type IV: A case report

The surgical management of vascular complication with Ehlers-Danlos Syndrome type IV (EDS-IV) is extremely challenging because of its tissue or organ fragility including arteries. Less traumatic maneuvers and devices have been recommended to perform the endovascular treatment for the vascular lesion of EDS-IV, although the endovascular procedure is less invasive than surgical intervention. We report a 23-year-old man with EDS-IV suffered from left posterior tibial arterial rupture. We performed internal trapping of the ruptured segment using detachable coils with a standard technique via the contralateral femoral artery puncture. The patient was discharged without any complication associated with the endovascular procedure. Embolization by a basic technique, performed with greatest care, is a safe and useful treatment option which we radiologists should try for managing EDS-IV patients.

MR磁敏感加权成像评价轻度认知障碍者的脑内微出血和铁沉积

目的探讨MR磁敏感加权成像是否有助于在基线水平预测认知的下降。材料与方法本项前瞻性研究得到学术审查委员会批准,所有病人均签署知情同意书。

Interdisciplinary management of central nervous system metastasis and neoplastic meningitis:recent developments and future perspectives

The incidence of metastatic disease in the central nervous system(CNS)is rising.According to current estimates,up to a third of adult cancer patients will suffer from CNS metastasis.Clinical evidence-based data from prospective randomized trials are rare,however,because CNS metastasis patients were often excluded from clinical trial participation.The management of CNS metastasis patients is therefore rather ill-defined and an interdisciplinary challenge.Recent basic and translational science data have begun contributing to a more profound understanding of the molecular mechanisms leading to invasion of tumor cells into the CNS.This report reviews advances,challenges,and perspectives in this field.

Neoadjuvant stereotactic radiosurgery for intracerebral metastases of solid tumors(NepoMUC):a phase I dose escalation trial

Background:More than 25%of patients with solid cancers develop intracerebral metastases.Aside of surgery,radia-tion therapy(RT)is a mainstay in the treatment of intracerebral metastases.Postoperative fractionated stereotactic RT(FSRT)to the resection cavity of intracerebral metastases is a treatment of choice to reduce the risk of local recur-rence.However,FSRT has to be delayed until a sufficient wound healing is attained;hence systemic therapy might be postponed.Neoadjuvant stereotactic radiosurgery(SRS)might offer advantages over adjuvant FSRT in terms of better target delineation and an earlier start of systemic chemotherapy.Here,we conducted a study to find the maximum tolerated dose(MTD)of neoadjuvant SRS for intracerebral metastases.Methods:This is a single-center,phase I dose escalation study on neoadjuvant SRS for intracerebral metastases that will be conducted at the Klinikum rechts der Isar Hospital,Technical University of Munich.The rule-based traditional 3+3 design for this trial with 3 dose levels and 4 different cohorts depending on lesion size will be applied.The primary endpoint is the MTD for which no dose-limiting toxicities(DLT)occur.The adverse events of each participant will be evaluated according to the Common Terminology Criteria for Adverse Events(CTCAE)version 5.0 continuously during the study until the first follow-up visit(4-6 weeks after surgery).Secondary endpoints include local control rate,survival,immunological tumor characteristics,quality of life(QoL),CTCAE grade of late clinical,neurological,and neurocognitive toxicities.In addition to the intracerebral metastasis which is treated with neoadjuvant SRS and resection up to four additional intracerebral metastases can be treated with definitive SRS.Depending on the occurrence of DLT up to 72 patients will be enrolled.The recruitment phase will last for 24 months.Discussion:Neoadjuvant SRS for intracerebral metastases offers potential advantages over postoperative SRS to the resection cavity,such as better target volume definition with subsequent higher efficiency of eliminating tumor cells,and lower damage to surrounding healthy tissue,and much-needed systemic chemotherapy could be initiated more rapidly.

Haemorrhage after thrombectomy with adjuvant thrombolysis in unknown onset stroke depends on high early lesion water uptake

Background and purpose In wake-up stroke,CT-based quantitative net water uptake(NWU)might serve as an alternative tool to MRI to guide intravenous thrombolysis with alteplase(IVT).An important complication after IVT is symptomatic intracerebral haemorrhage(sICH).As NWU directly implies ischaemic lesion progression,reflecting blood-brain barrier injury,we hypothesised that NWU predicts sICH in patients who had a ischaemic stroke undergoing thrombectomy with unknown onset.Methods Consecutive analysis of all patients who had unknown onset anterior circulation ischaemic stroke who underwent CT at baseline and endovascular treatment between December 2016 and October 2020.Quantitative NWU was assessed on baseline CT.The primary endpoint was sICH.The association of NWU and other baseline parameters to sICH was investigated using inverse-probability weighting(IPW)analysis.Results A total of 88 patients were included,of which 46 patients(52.3%)received IVT.The median NWU was 10.7%(IQR:5.1–17.7).The proportion of patients with any haemorrhage and sICH were 35.2%and 13.6%.NWU at baseline was significantly higher in patients with sICH(19.1%vs 9.6%,p<0.0001)and the median Alberta Stroke Program Early CT Score(ASPECTS)was lower(5 vs 8,p<0.0001).Following IPW,there was no association between IVT and sICH in unadjusted analysis.However,after adjusting for ASPECTS and NWU,there was a significant association between IVT administration and sICH(14.6%,95%CI:3.3%to 25.6%,p<0.01).Conclusion In patients with ischaemic stroke with unknown onset,the combination of high NWU with IVT is directly linked to higher rates of sICH.Besides ASPECTS for evaluating the extent of the early infarct lesion,quantitative NWU could be used as an imaging biomarker to assess the degree of blood-brain barrier damage in order to predict the risk of sICH in patients with wake up stroke.