Publications by authors named "Sophie Ostmeier"

Article Synopsis
  • The study aims to improve prediction of 90-day functional outcomes in ischemic stroke patients using a deep learning model that combines non-contrast CT images and clinical data, potentially aiding healthcare planning and clinical trials.
  • The dataset included 1,335 patients from multiple trials and registries, and the model demonstrated superior accuracy in predicting outcomes compared to models using only imaging or clinical data alone.
  • The fused model achieved a mean absolute error (MAE) of 0.94 for mRS score prediction and an AUC of 0.91 for identifying unfavorable outcomes, indicating it significantly outperforms existing methods.
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Article Synopsis
  • - Over 85 million CT scans are done annually in the US, with a significant portion focused on the abdomen, highlighting a need for efficient interpretation methods due to a shortage of radiologists.
  • - To address this, researchers introduced Merlin, a 3D Vision Language Model (VLM) that uses both electronic health records and radiology reports for training without the need for manual annotations, utilizing a vast clinical dataset of millions of images and codes.
  • - Merlin was evaluated on various tasks, including chronic disease prediction and report generation, showing better performance than current methods, demonstrating its potential to support radiologists in their work.
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Introduction: Distal navigability and imprecise delivery of embolic agents are two limitations encountered during liquid embolization of cerebrospinal lesions. The dual-lumen Scepter Mini balloon (SMB) microcatheter was introduced to overcome these conventional microcatheters' limitations with few small single-center reports suggesting favorable results.

Methods: A series of consecutive patients undergoing SMB-assisted endovascular embolization were extracted from prospectively maintained registries in seven North-American centers (November 2019 to September 2022).

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Background: Outlining acutely infarcted tissue on non-contrast CT is a challenging task for which human inter-reader agreement is limited. We explored two different methods for training a supervised deep learning algorithm: one that used a segmentation defined by majority vote among experts and another that trained randomly on separate individual expert segmentations.

Methods: The data set consisted of 260 non-contrast CT studies in 233 patients with acute ischemic stroke recruited from the multicenter DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3) trial.

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We determined if a convolutional neural network (CNN) deep learning model can accurately segment acute ischemic changes on non-contrast CT compared to neuroradiologists. Non-contrast CT (NCCT) examinations from 232 acute ischemic stroke patients who were enrolled in the DEFUSE 3 trial were included in this study. Three experienced neuroradiologists independently segmented hypodensity that reflected the ischemic core on each scan.

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Performance metrics for medical image segmentation models are used to measure the agreement between the reference annotation and the predicted segmentation. Usually, overlap metrics, such as the Dice, are used as a metric to evaluate the performance of these models in order for results to be comparable. However, there is a mismatch between the distributions of cases and the difficulty level of segmentation tasks in public data sets compared to clinical practice.

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Background: Predicting long-term clinical outcome based on the early acute ischemic stroke information is valuable for prognostication, resource management, clinical trials, and patient expectations. Current methods require subjective decisions about which imaging features to assess and may require time-consuming postprocessing. This study's goal was to predict ordinal 90-day modified Rankin Scale (mRS) score in acute ischemic stroke patients by fusing a Deep Learning model of diffusion-weighted imaging images and clinical information from the acute period.

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Background: Aneurysmal subarachnoid hemorrhage results in significant mortality and disability, which is worsened by the development of delayed cerebral ischemia. Tests to identify patients with delayed cerebral ischemia prospectively are of high interest.

Objective: We created a machine learning system based on clinical variables to predict delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage patients.

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Background: Lymph nodes (LN) are examined in every computed tomography (CT) scan. Until now, an evaluation is only possible based on morphological criteria. With dual-energy CT (DECT) systems, iodine concentration (IC) can be measured which could conduct in an improved diagnostic evaluation of LNs.

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