Emerging from the development of single-energy Computed Tomography (CT) and Dual-Energy Computed Tomography, Multi-Energy Computed Tomography (MECT) is a promising tool allowing advanced material and tissue decomposition and thereby enabling the use of multiple contrast materials in preclinical research. The scope of this work was to evaluate whether a usual preclinical micro-CT system is applicable for the decomposition of different materials using MECT together with a matrix-inversion method and how different changes of the measurement-environment affect the results. A matrix-inversion based algorithm to differentiate up to five materials (iodine, iron, barium, gadolinium, residual material) by applying four different acceleration voltages/energy levels was established.
View Article and Find Full Text PDFAim: Here we describe the results of superselective intraarterial application of diagnostic Ga-68-DOTA0,Tyr3-octreotate (Ga-68-DOTATATE) in a series of patients with inoperable WHO grade II meningiomas which were no longer amenable to radiotherapy.
Methods: Four patients with inoperable WHO grade II meningioma underwent systemic venous infusion of Ga-68-DOTATATE followed by PET/CT. Ga-68-DOTATATE application was repeated intraarterially via transfemoral catheterization of vessels supplying the meningioma and another PET/CT was performed.
Biodegradable stents are not established in neurovascular interventions. In this study, mechanical, radiological, and histological characteristics of a stent prototype developed for neurovascular use are presented. The elasticity and brittleness of PLA 96/4, PLDL 70/30, PCL, and PLGA 85/15 and 10/90 polymers in in vitro experiments are first analyzed.
View Article and Find Full Text PDFBackground: Critical hypoperfusion and metabolic derangement are frequently encountered with refractory vasospasm. Endovascular rescue therapies (ERT) have proven beneficial in selected cases. However, angioplasty (AP) and intraarterial lysis (IAL) are measures of last resort and prospective, quantitative results regarding the efficacy (cerebral oxygenation, metabolism) are largely lacking.
View Article and Find Full Text PDFBackground: Timely detection of impending delayed cerebral ischemia after subarachnoid hemorrhage (SAH) is essential to improve outcome, but poses a diagnostic challenge. Retinal vessels as an embryological part of the intracranial vasculature are easily accessible for analysis and may hold the key to a new and non-invasive monitoring technique. This investigation aims to determine the feasibility of standardized retinal vessel analysis (RVA) in the context of SAH.
View Article and Find Full Text PDFObjectives: Interventions such as balloon angioplasty can cause vascular injury leading to platelet activation, thrombus formation, and inflammatory response. This induces vascular smooth muscle cell activation and subsequent re-endothelialization with expression of αvβ3-integrin by endothelial cells and vascular smooth muscle cell. Thus, poly-N-butylcyanoacrylate microbubbles (MBs) targeted to αvβ3-integrin were evaluated for monitoring vascular healing after vessel injury in pigs using molecular ultrasound imaging.
View Article and Find Full Text PDFBackground: Flow control during endovascular stroke treatment with stent-retrievers is crucial for successful revascularization. The standard technique recommended by stent-retriever manufacturers implies obstruction of the respective access catheter by the microcatheter, through which the stent-retriever is delivered. This, in turn, results in reduced aspiration during thrombectomy.
View Article and Find Full Text PDFBackground: Epidemiologic studies identified a 'weekend effect' or 'out-of-hours effect', which implies that procedural and clinical outcomes of patients with stroke, who are admitted out-of-hours, are less favorable than for patients admitted during working-hours.
Objective: To determine (1) whether our procedural times and clinical outcome were affected by an out-of-hours effect and (2) whether the decision in favor of, or against, endovascular stroke treatment (EST) depends on the time of admission.
Methods: Between February 2010 and January 2015, 6412 consecutive patients presenting with symptoms of acute ischemic stroke were evaluated for EST eligibility according to established local protocols and generally accepted consensus criteria, and dichotomized into working-hours and out-of-hours cohorts according to admission times.
Background: The optimal interaction between stent struts and thrombus is crucial for successful revascularization in endovascular stroke therapy with stent retrievers. Deploying the stent retriever by actively pushing it into the thrombus increases the radial force with which the stent struts expand into the thrombus.
Objective: To examine the (APD) technique in an in vitro model and present our clinical experience with this technique.
We present a patient who underwent successful removal of a fully detached platinum coil from the peroneal artery using a Solitaire stent retriever (Covidien, Irvine, CA) that is usually used in endovascular stroke treatment.
View Article and Find Full Text PDFBackground: Rapid recanalization of occluded vessels is crucial for good clinical outcome in acute ischemic stroke. Endovascular treatment is usually performed via a transfemoral approach, but catheterization of the carotid arteries can be problematic in cases of difficult anatomy or vascular pathologies in some cases.
Objective: To describe our experience with a technique involving surgical access to the carotid artery and consecutive transcarotid endovascular thrombectomy in patients with acute stroke.
Introduction: As digital mammography and micro-computed tomography (CT) have been used for evaluation of stents deployed in experimental animal models, we compared the two methods regarding their sensitivity to detect abnormalities in three prototypes of intracranial stents.
Methods: Three different prototypes of intracranial stents (n = 84) were implanted in various animal models. Explanted stents were examined using digital mammography and micro-CT.
Introduction: This study aims to investigate the clinical significance of post-interventional cerebral hyperdensities (PCHD) after endovascular mechanical thrombectomy in acute ischaemic stroke.
Methods: Data of 102 consecutive patients who received post-interventional CT scans within 4.5 h after mechanical thrombectomy were analysed retrospectively.
Background: To assess the efficiency of IIb/IIIa platelet receptor inhibition by abciximab in the prevention of silent embolism during digital subtraction angiography.
Methods: In this randomized, double-blind, prospective study, pre- and postangiographic diffusion-weighted magnetic resonance imaging (DWI) of 184 participants was evaluated for the occurrence of silent embolism.
Results: No significant relationship was found between the patients receiving abciximab before digital subtraction angiography (15 of 90; 16.
The number of publications describing the use of micro-computed tomography (microCT) for preclinical in vivo imaging of small animals has risen considerably within the last few years. The purpose of this review is to familiarize the reader with the basic principles of microCT, to present successful experimental approaches in order of the evaluated organ system, and to highlight limitations that need to be considered when planning microCT-based studies.
View Article and Find Full Text PDFBackground: Gliomatosis cerebri is a rare primary cerebral tumour entity characterized by diffuse infiltrative growth patterns representing a WHO grade III malignancy. The prognosis is dismal and therapeutical options are still controversial. In contrast to other high-grade gliomas, angiogenesis is thought to be absent in gliomatosis cerebri.
View Article and Find Full Text PDFAims And Background: We retrospectively analyzed the impact of different adjuvant chemotherapy regimens in a group of patients treated for glioblastoma compared to patients receiving only postoperative radiotherapy.
Material And Methods: Eighty-six consecutive patients underwent radiotherapy between January 2000 and December 2003: 52 patients received radiotherapy alone, 17 patients radiochemotherapy with low-dose temozolomide (20 mg/m(2)) + cyclooxygenase-2-inhibitors (200 mg), 6 patients radiochemotherapy with high-dose temozolomide (50 mg/m2). Eleven patients, with unfavorable prognostic factors, were treated with imatinib and 55/2.
Image analysis systems are an essential tool in measurements of size of intraparenchymal tumors or lesions in experimental small animal models. Conventional image analysis systems are relatively expensive. We therefore compared the performance of a professional image analysis system with an inexpensive setup by evaluating tumor size in an orthotopic glioma mouse model.
View Article and Find Full Text PDFObjective: Glioma cell migration is determined by a complex interplay between soluble motogens and extracellular matrix components. Several growth factors are thought to be involved in glioma cell migration; however, little is known about their motogenic potency relative to one another.
Methods: Using modified Boyden chamber assays, we compared the chemotactic effects of scatter factor/hepatocyte growth factor (SF/HGF), transforming growth factor (TGF)-alpha, TGF-beta1, TGF-beta2, epidermal growth factor (EGF), fibroblast growth factor (FGF)-1, FGF-2, insulin-like growth factor (IGF)-1, IGF-2, platelet-derived growth factor (PDGF)-AA, PDGF-BB, vascular endothelial growth factor (VEGF), pleiotrophin (PTN), and midkine (MK) in concentrations ranging from 1 pmol/L to 50 nmol/L on three different human glioblastoma cell lines.