Bernhard Preim

Bernhard Preim
Otto-von-Guericke-Universität Magdeburg | OvGU · Department of Simulation and Graphics (ISG)

Phd, Computer Science
Thinking about virtual reality in medical training and about narrative visualization in medicine for broad audiences.

About

672
Publications
140,067
Reads
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6,476
Citations
Introduction
My research is focussed on medical visualization, visual analytics and virtual reality for diagnosis, treatment planning and medical education. Examples relate to VR for liver surgery training and cognitive rehabilitation, visual analytics of medical cohort data involving medical image data. High-dimensional medical volume data, e.g. blood flow measurements are also a focus of my work. Recently we started to design narrative medical visualizations for broad audiences.
Additional affiliations
March 2003 - present
Otto-von-Guericke-Universität Magdeburg
July 2000 - January 2003
Universität Bremen
Position
  • Wissenschaftlicher Assistent
January 1999 - February 2003
MEVIS Bremen
Position
  • Universität Bremen
Education
April 1994 - January 1999
Otto-von-Guericke-Universität Magdeburg
Field of study
  • Computer Graphics

Publications

Publications (672)
Article
Full-text available
Understanding the hemodynamics of blood flow in vascular pathologies such as intracranial aneurysms is essential for both their diagnosis and treatment. Computational Fluid Dynamics (CFD) simulations of blood flow based on patient-individual data are performed to better understand aneurysm initiation and progression and more recently, for predictin...
Article
Full-text available
This survey provides an overview of perceptually motivated techniques for the visualization of medical image data, including physics-based lighting techniques as well as illustrative rendering that incorporate spatial depth and shape cues. Additionally, we discuss evaluations that were conducted in order to study the perceptual effects of these vis...
Article
Full-text available
This survey provides an overview of visualization and interaction techniques developed for anatomy education. Besides individual techniques, the integration into virtual anatomy systems is considered. Web-based systems play a crucial role to enable learning independently at any time and space. We consider the educational background, the underlying...
Article
We describe visual analytics solutions aiming to support public health professionals, and thus, preventive measures. Prevention aims at advocating behaviour and policy changes likely to improve human health. Public health strives to limit the outbreak of acute diseases as well as the reduction of chronic diseases and injuries. For this purpose, dat...
Conference Paper
Full-text available
Virtual reality (VR) has been used in many medical training systems for surgical procedures. However, the current systems are limited due to inadequate interactions, restricted possibilities of patient data visualization, and collaboration. We propose a collaborative VR system for laparoscopic liver surgical planning and simulation. Medical image d...
Article
Background: For prediction of many types of clinical outcome, the skeletal muscle mass can be used as an independent biomarker. Manual segmentation of the skeletal muscles is time-consuming, therefore we present a deeplearning-based approach for the identification of muscle mass at the L3 level in clinical routine computed tomographic (CT) data....
Article
This paper explores narrative techniques combined with medical visualizations to tell data-driven stories about diseases for a general audience. The field of medical illustration uses narrative visualization through hand-crafted techniques to promote health literacy. However, data-driven narrative visualization has rarely been applied to medical da...
Article
7T TOF MRI scans provide high resolution images of intracranial vasculature. When segmented, the Circle of Willis is detailed and thus opens up new possibilities, in research but also in education. We propose a segmentation pipeline for the Circle ofWillis, and introduce a prototype that enables exploration of not just the entire Circle of Willis,...
Article
Training clipping of intracranial aneurysms is challenging due to less frequent interventions because of minimalinvasive methods, ethical aspects regarding cadaver training and consumption of resources when using 3D printed models. By proposing an immersive virtual reality training system, we make use of increased motivation, engagement and realism...
Article
In contrast to unstructured meshes, structured meshes yield faster simulation results for bio-medical simulations, but are very time-consuming to create. A preprocessing step in the generation of structured meshes is the manual construction of a blockstructure approximating the vessel. Here, we present an automatic centerline calculation and blocks...
Article
Full-text available
To exploit the potential of virtual reality (VR) in medicine, the input devices must be selected carefully due to their different benefits. In this work, input devices for common interaction tasks in medical VR planning and training are compared. Depending on the specific purpose, different requirements exist. Therefore, an appropriate trade-off be...
Article
Full-text available
Objectives 4D flow MRI enables quantitative assessment of helical flow. We sought to generate normal values and elucidate changes of helical flow (duration, volume, length, velocities and rotational direction) and flow jet (displacement, flow angle) as well as wall shear stress (WSS). Methods We assessed the temporal helical existence ( TH EX ), m...
Chapter
Rupture risk analysis of intracranial aneurysms is important for treatment decisions. Morphological parameters like size, diameter or aspect ratio are used to capture the relevant aspects of the aneurysm shape and predict the rupture of intracranial aneurysms. Automatic calculation of these parameters is cumbersome, whereas manual measurements are...
Chapter
Cerebral aneurysms represent an essential problem in neuroradiology. In clinical practice, they are frequently diagnosed and treated based on digital subtraction angiography (DSA) which provides an impression of the blood flow dynamics. In contrast, computational hemodynamics enables precise quantification of flow-related properties based on a pati...
Article
Full-text available
Purpose To create an accurate 3D reconstruction of the vascular trees, it is necessary to know the exact geometrical parameters of the angiographic imaging system. Many previous studies used vascular structures to estimate the system’s exact geometry. However, utilizing interventional devices and their relative features may be less challenging, as...
Article
Full-text available
Numerous studies assess intracranial aneurysm rupture risk based on morphological and hemodynamic parameter analysis in addition to clinical information such as aneurysm localization, age, and sex. However, intracranial aneurysms mostly occur with a saccular shape located either lateral to the parent artery or at a bifurcation. In contrast, fusifor...
Article
Full-text available
Purpose Intracranial aneurysms can be treated micro-surgically. This procedure involves an appropriate head position of the patient and a proper craniotomy. These steps enable a proper access, facilitating the subsequent steps. To train the access planning process, we propose a VR-based training system. Method We designed and implemented an immers...
Article
Full-text available
We present the framework GUCCI (Guided Cardiac Cohort Investigation), which provides a guided visual analytics workflow to analyze cohort-based measured blood flow data in the aorta. In the past, many specialized techniques have been developed for the visual exploration of such data sets for a better understanding of the influence of morphological...
Article
Full-text available
Purpose The treatment of intracranial arteriovenous malformations (AVM) is challenging due to their complex anatomy. For this vessel pathology, arteries are directly linked to veins without a capillary bed in between. For endovascular treatment, embolization is carried out, where the arteries that supply the AVM are consecutively blocked. A virtual...
Conference Paper
Full-text available
Four-dimensional phase-contrast magnetic resonance imaging (4D PC-MRI) allows for a non-invasive acquisition of time-resolved blood flow measurements, providing a valuable aid to clinicians and researchers seeking a better understanding of the interrelation between pathologies of the cardiovascular system and changes in blood flow patterns. Such re...
Conference Paper
We present an approach for computing camera animations composed of optimal views to support the visual exploration of blood flow data using cerebral aneurysms as major example. Medical researchers are interested in hemodynamic parameters and vessel wall characteristics. The time-dependent character of blood flow data complicates the visual analysis...
Conference Paper
Full-text available
Current blood vessel rendering usually depicts solely the surface of vascular structures and does not visualize any interior structures. While this approach is suitable for most applications, certain cardiovascular diseases, such as aortic dissection would benefit from a more comprehensive visualization. In this work, we investigate different shadi...
Conference Paper
Purpose: Three-dimensional (3D) models of the liver are reported to improve preoperative planning in hepatobiliary surgery. These models can be presented as 3D-PDFs, 3D-printed models or with a recently developed immersive virtual reality (VR) application as a 3D VR model. To date, the quality, feasibility and surgeons’ preference of these 3D prese...
Article
Full-text available
The medical domain has been an inspiring application area in visualization research for many years already, but many open challenges remain. The driving forces of medical visualization research have been strengthened by novel developments, for example, in deep learning, the advent of affordable VR technology, and the need to provide medical visuali...
Article
Full-text available
Purpose Intracranial aneurysms are local dilations of brain vessels. Their rupture, as well as their treatment, is associated with high risk of morbidity and mortality. In this work, we propose shape indices for aneurysm ostia for the rupture risk assessment of intracranial aneurysms. Methods We analyzed 84 middle cerebral artery bifurcation aneur...
Preprint
Full-text available
Narrative visualization aims to communicate scientific results to a general audience and garners significant attention in various applications. Merging exploratory and explanatory visualization could effectively support a non-expert understanding of scientific processes. Medical research results, e.g., mechanisms of the healthy human body, explanat...
Conference Paper
Introduction/Purpose Interventional treatment of arteriovenous malformations (AVMs) using liquid embolics is challenging especially in larger AVMs with multiple feeding arteries. Premature occlusion of the draining vein(s) may lead to fatal AVM rupture and sequential occlusion of different feeding arteries is associated with the risks of incomplete...
Conference Paper
Introduction/Purpose Counseling of patients harboring unruptured intracranial aneurysms (UIAs) has remained challenging despite the availability of several risk scores assessing the aneurysm rupture risk for individual patients. However, besides aneurysm size and simple morphological features no advanced hemodynamic or geometric factors have been u...
Conference Paper
Introduction/Purpose Blebs of intracranial aneurysms are clear bulges or outpouchings of the aneurysms wall. Since irregularly shaped aneurysms, i.e. aneurysms with lobulated shapes including one or multiple blebs are associated with a higher rupture risk, bleb occurrence is important for aneurysm treatment planning. Hence, an automatic computer-ba...
Article
Full-text available
We present an analysis tool for subgroup identification in medical research based on feature analysis. Our use case is intracranial aneurysms. In the tool, an aneurysm-of-interest’s most similar aneurysms within a database are found. Similarity is defined via user-selected parameters, which can be entirely arbitrary. Different interactive outputs a...
Article
Background and objective: MeshCNN is a recently proposed Deep Learning framework that drew attention due to its direct operation on irregular, non-uniform 3D meshes. It outperformed state-of-the-art methods in classification and segmentation tasks of popular benchmarking datasets. The medical domain provides a large amount of complex 3D surface mo...
Article
Full-text available
Interdisciplinary exchange of medical datasets between clinicians and engineers is essential for clinical research. Due to the Data Protection Act, which preserves the rights of patients, full anonymization is necessary before any exchange can take place. Due to the continuous improvement of image quality of tomographic datasets, anonymization of p...
Article
Full-text available
Background: Preoperative three-dimensional (3D) reconstructions for liver surgery planning have been shown to be effective in reduction of blood loss and operation time. However, the role of the 'presentation modality' is not well investigated. We present the first study to compare 3D PDFs, 3D printed models (PR) and virtual reality (VR) 3D models...
Article
We developed a virtual road crossing assessment tool called iVRoad - immersive Virtual Road, which allows to put the patient into realistic road crossing situations and to record various parameters that can be used to quantify unilateral spatial neglect. We present a study with 18 stroke patients in which we evaluate our system with respect to usab...
Article
We qualitatively compare three image segmentation techniques (filter and threshold-based segmentation, texture-based clustering and deep learning) for histologic images of intracranial aneurysms. Due to remodeling of the vessel wall and aneurysm formation, the tissue is highly diverse. Only the deep learning segmentation provided semantic informati...
Article
Surgical planning software is a key component in the treatment of tumor diseases. However, desktop-based systems provide only limited visualization and interaction opportunities. Moreover, collaborative planning among members of a surgical team is only possible to a limited extent. In this work, a collaborative virtual reality (VR) environment to a...
Article
Full-text available
Aortic dissection is a life-threatening vascular disease characterized by abrupt formation of a new flow channel (false lumen) within the aortic wall. Survivors of the acute phase remain at high risk for late complications, such as aneurysm formation, rupture, and death. Morphologic features of aortic dissection determine not only treatment strateg...
Conference Paper
Full-text available
Rupture risk assessment is a key to devise patient-specific treatment plans of cerebral aneurysms. To understand and predict the development of aneurysms and other vascular diseases over time, both hemodynamic flow patterns and their effect on the vessel surface need to be analyzed. Flow structures close to the vessel wall often correlate directly...
Article
Full-text available
Purpose For the status evaluation of intracranial aneurysms (IAs), morphological and hemodynamic parameters can provide valuable information. For their extraction, a separation of the aneurysm sac from its parent vessel is required that yields the neck curve and the ostium. However, manual and subjective neck curve and ostium definitions might lead...
Poster
Objective - For rupture risk assessment of intracranial aneurysms, a multitude of approaches have been postulated. However, the amount of potential predictive factors is not applicable in clinical practice and they are rejected in favor of the more practical PHASES Score. For the subgroup of multiple intracranial aneurysms (MIA), the PHASES Score m...
Article
We present Aneulysis, a system to improve risk assessment and treatment planning of cerebral aneurysms. Aneurysm growth, rupture and treatment success depend on the interplay of vascular morphology and hemodynamics. Blood flow simulations can obtain the patient-specific hemodynamics. However, analyzing the time-dependent, multi-attribute data is ti...
Article
Vascular structures are assessed, e.g., in tumor surgery to understand the influence of a planned resection on the vascular supply and venous drainage. The understanding of complex branching vascular structures may benefit from immersive virtual reality (VR) visualization. Therefore, the estimation of distance, depth and shape information is a cruc...
Article
Full-text available
The exploration of large‐scale conflicts, as well as their causes and effects, is an important aspect of socio‐political analysis. Since event data related to major conflicts are usually obtained from different sources, researchers developed a semi‐automatic matching algorithm to integrate event data of different origins into one comprehensive data...
Article
Full-text available
Purpose Three-dimensional (3D) surgical planning is widely accepted in liver surgery. Currently, the 3D reconstructions are usually presented as 3D PDF data on regular monitors. 3D-printed liver models are sometimes used for education and planning. Methods We developed an immersive virtual reality (VR) application that enables the presentation of...
Chapter
Recent progress in VR and AR hardware enables a wide range of educational applications. Anatomy education, where the complex spatial relations of the human anatomy need to be imagined, may benefit from the immersive experience. Also the integration of virtual information and real information, e.g., muscles and bone overlaid on the user’s body, are...
Article
We present a system to visualize multiple time-dependent scalar fields defined on 3D surfaces as they arise from numerical simulations. Domain experts want to understand correlations between multiple scalar fields to verify underlying processes. However, existing visualization techniques require high exploration effort to perceive temporal changes...
Article
Full-text available
Purpose The treatment of cerebral aneurysms shifted from microsurgical to endovascular therapy. But for some difficult aneurysm configurations, e.g. wide neck aneurysms, microsurgical clipping is better suited. From this combination of limited interventions and the complexity of these cases, the need for improved training possibilities for young ne...
Article
Full-text available
Background and Objective: We present a fully automated method for the quantification of knee alignment from full-leg radiographs. Methods: A state-of-the-art object detector, YOLOv4, was trained to locate regions of interests in full-leg radiographs for the hip joint, knee, and ankle. Residual neural networks were trained to regress landmark coordi...
Article
Full-text available
Purpose For the evaluation and rupture risk assessment of intracranial aneurysms, clinical, morphological and hemodynamic parameters are analyzed. The reliability of intracranial hemodynamic simulations strongly depends on the underlying models. Due to the missing information about the intracranial vessel wall, the patient-specific wall thickness i...
Conference Paper
Preoperative planning for liver surgery is a critical procedure to assess a potential resection and it supports surgeons to define the affected vessels and resection volume. Traditional surgical planning systems are widely used to support the planning with the usage of desktop-based 3D and 2D visualizations. However, desktop-based systems offer lim...
Preprint
Full-text available
We present a Virtual and Augmented Reality multiuser prototype of a learning environment for liver anatomy education. Our system supports various training scenarios ranging from small learning groups to classroom-size education, where students and teachers can participate in virtual reality, augmented reality, or via desktop PCs. In an iterative de...
Chapter
Full-text available
This work aims at a deep learning-based prediction of wall shear stresses (WSS) for intracranial aneurysms. Based on real patient cases, we created artificial surface models of bifurcation aneurysms. After simulation and WSS extraction, these models were used for training a deep neural network. The trained neural network for 3D mesh segmentation wa...
Chapter
Arteriovenous malformations in the brain are abnormal connections between cerebral arteries and veins without the capillary system. They might rupture with fatal consequences. Their treatment is highly patient-specific and includes careful analysis of the vessels' configuration. We present an application that visualizes the blood flow after differe...
Article
Full-text available
Introduction A multitude of approaches have been postulated for assessing the risk of intracranial aneurysm rupture. However, the amount of potential predictive factors is not applicable in clinical practice and they are rejected in favor of the more practical PHASES score. For the subgroup of multiple intracranial aneurysms (MIAs), the PHASES scor...
Preprint
Full-text available
We introduce a Virtual Reality (VR) one-on-one tutoring system to support anatomy education. A student uses a fully immersive VR headset to explore the anatomy of the base of the human skull. A teacher guides the student by using the semi-immersive zSpace. Both systems are connected via network and each action is synchronized between both systems....