Ivana Galinovic | Charité - Universitätsmedizin Berlin / Charité Medical University Berlin (original) (raw)

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Papers by Ivana Galinovic

Frontiers in Neurology

Brain arteries are routinely imaged in the clinical setting by various modalities, e.g., time-of-... more Brain arteries are routinely imaged in the clinical setting by various modalities, e.g., time-of-flight magnetic resonance angiography (TOF-MRA). These imaging techniques have great potential for the diagnosis of cerebrovascular disease, disease progression, and response to treatment. Currently, however, only qualitative assessment is implemented in clinical applications, relying on visual inspection. While manual or semi-automated approaches for quantification exist, such solutions are impractical in the clinical setting as they are time-consuming, involve too many processing steps, and/or neglect image intensity information. In this study, we present a deep learning-based solution for the anatomical labeling of intracranial arteries that utilizes complete information from 3D TOF-MRA images. We adapted and trained a state-of-the-art multi-scale Unet architecture using imaging data of 242 patients with cerebrovascular disease to distinguish 24 arterial segments. The proposed model u...

EuroIntervention

BACKGROUND New ischaemic brain lesions on magnetic resonance imaging (MRI) are reported in up to ... more BACKGROUND New ischaemic brain lesions on magnetic resonance imaging (MRI) are reported in up to 86% of patients after transcatheter edge-to-edge repair of the mitral valve (TEER-MV). Knowledge of the exact procedural step(s) that carry the highest risk for cerebral embolisation may help to further improve the procedure. AIMS The aim of this study was to identify the procedural step(s) that are associated with an increased risk of cerebral embolisation during TEER-MV with the MitraClip system. Furthermore, the risk of overt stroke and silent brain ischaemia after TEER-MV was assessed. METHODS In this prospective, pre-specified observational study, all patients underwent continuous transcranial Doppler examination during TEER-MV to detect microembolic signals (MES). MES were assigned to specific procedural steps: (1) transseptal puncture and placement of the guide, (2) advancing and adjustment of the clip in the left atrium, (3) device interaction with the MV, and (4) removal of the clip delivery system and the guide. Neurological examination using the National Institutes of Health Stroke Scale (NIHSS) and cerebral MRI were performed before and after TEER-MV. RESULTS Fifty-four patients were included. The number of MES differed significantly between the procedural steps with the highest numbers observed during device interaction with the MV. Mild neurological deterioration (NIHSS ≤3) occurred in 9/54 patients. New ischaemic lesions were detected in 21/24 patients who underwent MRI. Larger infarct volume was significantly associated with neurological deterioration. CONCLUSIONS Cerebral embolisation is immanent to TEER-MV and predominantly occurs during device interaction with the MV. Improvements to the procedure may focus on this procedural step.

Frontiers in artificial intelligence, May 2, 2022

Transient ischemic attack (TIA) is defined as focal neurological deficit caused by ischemia resol... more Transient ischemic attack (TIA) is defined as focal neurological deficit caused by ischemia resolving within 24 hours. In a secondary analysis of a large monocentric cohort of 446 TIA patients, we explored the frequency and determinants of diffusion-weighted imaging (DWI) lesions on high-resolution magnetic resonance imaging. Overall, 240 (54%) of all TIA patients presented with DWI lesions. These patients had higher National Institute of Health Stroke Scale and ABCD2 scores and presented more frequently with vessel occlusion and perfusion deficits, but had similar functional outcome at 3 months. Taken together, high-resolution DWI provides evidence of ischemic brain injury in the majority of TIA patients. ANN NEUROL 2019

International Journal of Stroke, 2020

Here we provide three datasets with VSI measurements (vessel size and vessel density) as well as ... more Here we provide three datasets with VSI measurements (vessel size and vessel density) as well as relative tissue perfusion meassurements (rCBV and rCBF) in selected regions of interest (lesion, perilesional space, mirrored lesion) - these datesets were used for mixed-model analyses of variance in our manuscript entitled 'Changes in vascular morphology and cerebral perfusion in sub-acute ischemic stroke - a multiparametric MRI study' Patient demographics and related data are not publicly available as this may compromise patient privacy, this data however can be shared upon request.

Stroke, 2016

Introduction: Patients with unknown time from stroke onset, e.g. in wake-up stroke, are not eligi... more Introduction: Patients with unknown time from stroke onset, e.g. in wake-up stroke, are not eligible for thrombolyic treatment. Relative signal intensities (rSI) of DWI and FLAIR MRI are biomarkers for eligibility for thrombolysis, but have shown heterogeneous results to date. We investigated if the addition of available clinical parameters improves the prediction of the thrombolysis time window in patients with acute stroke. Hypothesis: Inclusion of clinical parameters improves the prediction of the thrombolysis time window by quantitative MRI biomarkers Methods: Patients from two centers with proven stroke and stroke-onset <12 hours were included in a retrospective design. The DWI lesion was segmented and overlaid on ADC and FLAIR maps. rSI mean and standard deviation (std) were calculated: mean VOI value/mean value of the unaffected hemisphere. Prediction of the thrombolysis time window was evaluated by the area-under-the-curve (AUC) of receiver-operating-characteristic (ROC) ...

Copyright information:Taken from "The biennial cycle of respiratory syncy... more Copyright information:Taken from "The biennial cycle of respiratory syncytial virus outbreaks in Croatia"http://www.virologyj.com/content/5/1/18Virology Journal 2008;5():18-18.Published online 28 Jan 2008PMCID:PMC2267449.

Clinical Neuroradiology, 2021

Purpose Cerebral neoplasms of various histological origins may show comparable appearances on con... more Purpose Cerebral neoplasms of various histological origins may show comparable appearances on conventional Magnetic Resonance Imaging (MRI). Vessel size imaging (VSI) is an MRI technique that enables noninvasive assessment of microvasculature by providing quantitative estimates of microvessel size and density. In this study, we evaluated the potential of VSI to differentiate between brain tumor types based on their microvascular morphology. Methods Using a clinical 3T MRI scanner, VSI was performed on 25 patients with cerebral neoplasms, 10 with glioblastoma multiforme (GBM), 8 with primary CNS lymphoma (PCNSL) and 7 with cerebral lung cancer metastasis (MLC). Following the postprocessing of VSI maps, mean vessel diameter (vessel size index, vsi) and microvessel density (Q) were compared across tumors, peritumoral areas, and healthy tissues. Results The MLC tumors have larger and less dense microvasculature compared to PCNSLs in terms of vsi and Q (p = 0.0004 and p

ArXiv, 2020

Anonymization and data sharing are crucial for privacy protection and acquisition of large datase... more Anonymization and data sharing are crucial for privacy protection and acquisition of large datasets for medical image analysis. This is a big challenge, especially for neuroimaging. Here, the brain's unique structure allows for re-identification and thus requires non-conventional anonymization. Generative adversarial networks (GANs) have the potential to provide anonymous images while preserving predictive properties. Analyzing brain vessel segmentation as a use case, we trained 3 GANs on time-of-flight (TOF) magnetic resonance angiography (MRA) patches for image-label generation: 1) Deep convolutional GAN, 2) Wasserstein-GAN with gradient penalty (WGAN-GP) and 3) WGAN-GP with spectral normalization (WGAN-GP-SN). The generated image-labels from each GAN were used to train a U-net for segmentation and tested on real data. Moreover, we applied our synthetic patches using transfer learning on a second dataset. For an increasing number of up to 15 patients we evaluated the model per...

International Journal of Stroke, 2021

Background Fluid-attenuated inversion recovery (FLAIR) sequences have gained a role to guide trea... more Background Fluid-attenuated inversion recovery (FLAIR) sequences have gained a role to guide treatment of patients with unknown time of stroke symptom onset. Evolution of signal intensities in FLAIR is associated with time since stroke onset with continuous linear increases. Aims Estimating symptom onset during night-sleep in patients from the WAKE-UP trial based on relative signal intensities FLAIR (FLAIR-rSI) from acute stroke lesions an independent dataset (PRE-FLAIR study). Methods FLAIR-rSI was quantified in stroke lesions in PRE-FLAIR and WAKE-UP. The PRE-FLAIR study was a multicenter observational trial establishing FLAIR as a surrogate parameter for time since stroke onset. WAKE-UP was a randomized controlled trial that revealed a benefit for alteplase in patients selected based on a DWI-FLAIR mismatch. Stroke onset times were recorded in PRE-FLAIR and used to fit a linear regression model with FLAIR-rSI, adjusted for patient age and lesion volume. The model was applied to F...

BJR|case reports, 2021

Total perfusion-diffusion mismatch is a well-recognised phenomenon in patients with acute ischaem... more Total perfusion-diffusion mismatch is a well-recognised phenomenon in patients with acute ischaemic stroke. We describe a case of total perfusion-diffusion mismatch detected using an emerging contrast-agent-free perfusion imaging technique in a young patient with acute cerebellar stroke.

Frontiers in Artificial Intelligence, 2020

American Journal of Neuroradiology, 2015

Stroke, 2010

Background and Purpose— After acute ischemic stroke, the proportion of patients with detectable l... more Background and Purpose— After acute ischemic stroke, the proportion of patients with detectable lesions on fluid-attenuated inversion recovery (FLAIR) MRI sequences increases over time. We investigated whether thrombolysis was less effective in FLAIR-positive versus -negative patients. Methods— In this single-center hospital-based study, all consecutive patients with ischemic stroke who underwent an MRI before and 24 hours after thrombolysis between May 2008 and October 2009 were included. Patients were included if exact time of onset was known and thrombolysis was performed within 3 hours up until August 2008 and within 4.5 hours from September 2008 on. Blinded to time of symptom onset, 3 raters independently judged the visibility of lesions on FLAIR. Lesion volumes on diffusion-weighted imaging as well as National Institutes of Health Stroke Scale before and 1 day after thrombolysis were determined. Results— Of 51 patients (25 females, mean age 71, median National Institutes of He...

Stroke, 2009

Background and Purpose— It has recently been proposed that fluid-attenuated inversion recovery (F... more Background and Purpose— It has recently been proposed that fluid-attenuated inversion recovery (FLAIR) imaging may serve as a surrogate marker for time of symptom onset after stroke. We assessed the hypothesis that FLAIR imaging could be used to decide if an MRI was performed within 4.5 hours from symptom onset or later. Methods— All consecutive patients with presumed stroke who underwent an MRI within 12 hours after known symptom onset were included regardless of stroke subtype and severity between May 2008 and May 2009. Blinded to time of symptom onset, 2 raters judged the visibility of lesions on FLAIR. Apparent diffusion coefficient values, lesion volume on diffusion-weighted imaging, and relative signal intensity of FLAIR lesions were determined. Results— In 94 consecutive patients with stroke, we found that median time from symptom onset for FLAIR-positive patients (189 minutes; interquartile range, 110 to 369 minutes) was significantly longer compared with FLAIR-negative pati...

Stroke, 2013

Background and Purpose— The so-called smoking-thrombolysis paradox of an improved outcome after t... more Background and Purpose— The so-called smoking-thrombolysis paradox of an improved outcome after thrombolysis was first described in smokers with myocardial infarction. We investigated whether reperfusion rates and clinical outcome differ between smokers and nonsmokers with ischemic stroke after intravenous tissue plasminogen activator. Methods— Consecutive acute ischemic stroke patients, who had magnetic resonance imaging before and 1 day after thrombolysis, were included for analysis. All of the patients received intravenous tissue plasminogen activator within 4.5 hours. Reperfusion was defined as a 75% reduction in perfusion deficit (mean transit time >6 s) after thrombolysis compared with baseline. Magnetic resonance angiography was used to evaluate arterial stenosis and occlusion. Functional outcome was assessed 3 months after stroke using the modified Rankin Score. Results— Of 148 patients, 21.6% were smokers (n=32). Smokers were younger (median, 61 years [ SD , 9.4 years] v...