Publications by authors named "Andrij Abramyuk"

While intravenous thrombolysis (IVT) in ischemic stroke can be safely applied in telestroke networks within 3 h from symptom onset, there is a lack of evidence for safety in the expanded 3- to 4. 5-h time window. We assessed the safety and short-term efficacy of IVT in acute ischemic stroke (AIS) in the expanded time window delivered through a hub-and-spoke telestroke network.

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Purpose:  We sought to determine the diagnostic agreement between the revised ultrasonography approach by the German Society of Ultrasound in Medicine (DEGUM) and the established Society of Radiologists in Ultrasound (SRU) consensus criteria for the grading of carotid artery disease.

Materials And Methods:  Post-hoc analysis of a prospective multicenter study, in which patients underwent ultrasonography and digital subtraction angiography (DSA) of carotid arteries for validation of the DEGUM approach. According to DEGUM and SRU ultrasonography criteria, carotid arteries were independently categorized into clinically relevant NASCET strata (normal, mild [1-49 %], moderate [50-69 %], severe [70-99 %], occlusion).

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Background: This study investigated the noninvasive assessment of tumor vascularization with clinical F-18-fluorodeoxyglucose positron emission tomography/computed tomography and contrast-enhanced computed tomography ([18F]FDG-PET/CT and CE-CT) in experimental human xenograft tumors with modifiable vascularization and compared results to histology. Tumor xenografts with modifiable vascularization were established in 71 athymic nude rats by subcutaneous transplantation of human non-small-cell lung cancer (NSCLC) cells. Four different groups were transplanted with two different tumor cell lines (either A549 or H1299) alone or tumors co-transplanted with rat glomerular endothelial (RGE) cells, the latter to increase vascularization.

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Purpose:  The German Society of Ultrasound in Medicine (DEGUM) recently revised its multiparametric criteria for duplex ultrasonography (DUS) grading of internal carotid artery (ICA) disease. We determined the diagnostic accuracy of the revised DEGUM criteria for ultrasonography grading of ICA disease in a prospective multicenter study.

Materials And Methods:  We evaluated consecutive patients who underwent digital subtraction angiography of the extracranial carotid arteries at four tertiary care hospitals.

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Introduction: The study aimed to compare efficacy and safety of aspiration thrombectomy (AT) to stentriever thrombectomy (SRT) in patients with basilar artery (BA) occlusion (BAO).

Methods: We retrospectively included patients with the following characteristics: acute BAO or occlusion of the intracranial vertebral artery (ICVA) and endovascular therapy (EVT) with stentriever (SRT) or aspiration thrombectomy (AT). Additional extra- but not intracranial EVT and intravenous thrombolysis (IVT) were allowed.

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Purpose: Clinically successful endovascular therapy (EVT) in ischemic stroke requires reliable noninvasive pretherapeutic selection criteria. We investigated the association of imaging parameters including CT angiographic collaterals and degree of reperfusion with clinical outcome after EVT.

Methods: In our database, we identified 93 patients with large vessel occlusion in the anterior circulation treated with EVT.

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Background: The Stroke Eastern Saxony Network (SOS-NET) provides telecare for acute stroke patients. Stroke neurologists recommend intravenous thrombolysis based on clinical assessment and cerebral computed tomography (CT) evaluation using Alberta Stroke Program Early CT score (ASPECTS). We sought to assess whether ASPECTS misinterpretation by stroke neurologists was associated with thrombolysis-related symptomatic intracranial hemorrhage (sICH).

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Purpose: To explore in a prospective trial the prognostic value of hypoxia imaging before and during radiochemotherapy in patients with locally advanced head and neck cancer.

Patients And Methods: Twenty-five patients with stage III/IV head and neck cancer were investigated with [(18)F]-fluoromisonidazole (FMISO) PET/CT at four time points during radiochemotherapy (baseline, 8-10 Gy, 18-20 Gy,50-60 Gy). FMISO PET/CT image parameters were extracted including maximum-tumour-to-background (TBR(max)) and thresholded volume at different TBR ratios.

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It is obvious that FDG-PET has added value to CT, but there is still insufficient data to define the role of FDG-PET/CT in clinical practice. Usually data are gathered from multiple sources and in consequence the information obtained is heterogeneous and not always comparable between patients. To alleviate this lack of data, we attempted to investigate the differences in staging and therapeutic intent as compared with conventional staging in non small cell lung cancer (NSCLC) patients scheduled for RT after adding FDG-PET/CT to conventional staging in 104 included subjects.

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Purpose: Our study aimed to explore the optimal timing as well as the most appropriate prognostic parameter of (18)F-fluorodeoxyglucose positron emission tomography (FDG PET) during chemoradiotherapy (CRT) for an early prediction of outcome for patients with head and neck squamous cell carcinoma (HNSCC).

Methods: Serial PET data (before and three times during CRT) of 37 patients with advanced stage HNSCC, receiving combined CRT between 2005 and 2009, were evaluated. The maximum standardized uptake value (SUV(max)), the average SUV (SUV(mean)) and the gross tumour volume determined by FDG PET (GTV PET), based on a source to background algorithm, were analysed.

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This study specifies the basic principles to selectively kill p53-deficient cells (H1299, FaDu) by taxol and to protect p53 wild type cells (A549) by the prior administration of structurally related flavonoids (apigenin, genistein, and quercetin). Cytotoxic and cytostatic properties of flavonoids were investigated in vitro by flow cytometry and were compared to known anticancer drugs (cisplatin, doxorubicin, etoposide). It was confirmed that doxorubicin induced growth arrest and protected A549 cells from taxol while simultaneously killing or blocking H1299 and FaDu cancer cells.

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In our comment some essential issues concerning determination of arterial input function (AIF), cardiac and respiratory related motion artifacts, contrast agent application and compartmental model fitting done by Cao et al., 2009 are discussed.

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Background: Recently published data show some controversy concerning the impact of [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in predicting head and neck tumors (HNT) outcome. Assessment of tumor blood supply parameters using dynamic contrast-enhanced CT (DCE-CT) may deliver additional information concerning this important question.

Purpose: To evaluate the contribution of DCE-CT implemented in pretherapeutic FDG-PET/CT protocol for prognosis prediction in patients with HNT.

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Objective: The goal of this study was to investigate the local tumor blood supply parameters relative tumor blood volume (rTBV) and transfer coefficient (K(trans)) measurable with dynamic contrast enhanced computed tomography (DCE-CT) in patients with non-small-cell lung cancer (NSCLC) scheduled for radiation therapy (RT).

Materials And Methods: rTBV and K(trans) were measured before RT in 31 patients with clinically inoperable NSCLC (Stages I-III), which received (n=19) or did not receive (n=12) induction chemotherapy (IChT). Possible links between rTBV and K(trans) and time-to-progression (TTP), overall survival (OS) and maximum standardized uptake value (SUV(max)) from fluorodeoxyglucose positron emission tomography as well as histology were analyzed.

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Purpose: To assess possible consequences for radiotherapy (RT) planning, e.g., reduction of treatment volume by a decreased tumour volume in Fluor-18-fluoro-deoxy-glucose-Positron emission tomography (FDG-PET) based on a close-meshed evaluation of FDG uptake in primary head and neck cancer (HNC) during RT.

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Purpose: To assess kinetics of elimination of different sized microspheres (MS) from the blood pool and tendency of their distribution in parenchymal organs of intact nude rats.

Materials And Methods: A mixture of 1 microm and 3 microm MS in phosphate-buffered saline was injected intravenously into eight rats under intraperitoneal anaesthesia. Blood samples were collected before, just after and in 2, 5 and 10 min after MS injection.

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Purpose: The aim of our study was to develop a method for the fusion of images received after repeated staining of the same sample taking into account spatial differences between the images.

Material And Methods: A method of objective fusion performance was investigated on the images receiving during multistep staining of the xenograft tumour cross-sections.

Results: It was shown that several images receiving from different steps of staining procedures may be successfully fused by fluorescent marking of slide position with Trout red blood cells before analysis.

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Purpose: To assess DOTATOC-affine somatostatin receptor expression in advanced prostate cancer and its bone metastases with regard to DOTATOC-mediated receptor therapies, using a Ga-68-DOTATOC PET/CT.

Procedures: Twenty consecutive patients with advanced prostate cancer underwent bone scintigraphy, followed by Ga-68-DOTATOC PET/CT within 3 weeks. Through side-by-side comparison with bone scintigraphy, the number of visible bone metastases on PET was determined.

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Background And Purpose: Local failure is a significant issue following radiotherapy (RT) for patients with non-small cell lung cancer (NSCLC). The aim of this study was to find out whether FDG-PET/CT is capable to predict tumor relapse location in patients with NSCLC, in particular to determine high risk tumors' subvolumes responsible for local failure.

Material And Methods: Ten patients with locoregional relapse of NSCLC underwent FDG-PET/CT before, during, and in the 4-12 months following curative chemoradiotherapy (ChRT, 66 Gy) using a combined PET/CT scanner.

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