| 1. |
- Kreiser, Julian, et al.
(författare)
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A Survey of Flattening-Based Medical Visualization Techniques
- 2018
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Ingår i: Computer Graphics Forum (Proceedings of EuroVis 2018). - : Wiley-Blackwell Publishing Inc.. - 0167-7055. ; 37:3, s. 597-624
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Tidskriftsartikel (refereegranskat)abstract
- In many areas of medicine, visualization research can help with task simplification, abstraction or complexity reduction. A common visualization approach is to facilitate parameterization techniques which flatten a usually 3D object into a 2D plane. Within this state of the art report (STAR), we review such techniques used in medical visualization and investigate how they can be classified with respect to the handled data and the underlying tasks. Many of these techniques are inspired by mesh parameterization algorithms which help to project a triangulation in ℝ3 to a simpler domain in ℝ2. It is often claimed that this makes complex structures easier to understand and compare by humans and machines. Within this STAR we review such flattening techniques which have been developed for the analysis of the following medical entities: the circulation system, the colon, the brain, tumors, and bones. For each of these five application scenarios, we have analyzed the tasks and requirements, and classified the reviewed techniques with respect to a developed coding system. Furthermore, we present guidelines for the future development of flattening techniques in these areas.
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| 2. |
- Kreiser, Julian, et al.
(författare)
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Decision Graph Embedding for High-Resolution Manometry Diagnosis
- 2018
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Ingår i: IEEE Transactions on Visualization and Computer Graphics. - : Institute of Electrical and Electronics Engineers (IEEE). - 1077-2626 .- 1941-0506. ; 24:1, s. 873-882
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Tidskriftsartikel (refereegranskat)abstract
- High-resolution manometry is an imaging modality which enables the categorization of esophageal motility disorders. Spatio-temporal pressure data along the esophagus is acquired using a tubular device and multiple test swallows are performed by the patient. Current approaches visualize these swallows as individual instances, despite the fact that aggregated metrics are relevant in the diagnostic process. Based on the current Chicago Classification, which serves as the gold standard in this area, we introduce a visualization supporting an efficient and correct diagnosis. To reach this goal, we propose a novel decision graph representing the Chicago Classification with workflow optimization in mind. Based on this graph, we are further able to prioritize the different metrics used during diagnosis and can exploit this prioritization in the actual data visualization. Thus, different disorders and their related parameters are directly represented and intuitively influence the appearance of our visualization. Within this paper, we introduce our novel visualization, justify the design decisions, and provide the results of a user study we performed with medical students as well as a domain expert. On top of the presented visualization, we further discuss how to derive a visual signature for individual patients that allows us for the first time to perform an intuitive comparison between subjects, in the form of small multiples.
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| 3. |
- Kreiser, Julian, et al.
(författare)
-
Visually Supporting Multiple Needle Placement in Irreversible Electroporation Interventions
- 2018
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Ingår i: Computer Graphics Forum. - : Wiley-Blackwell Publishing Inc.. - 0167-7055. ; 37:6, s. 59-71
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Tidskriftsartikel (refereegranskat)abstract
- Irreversible electroporation (IRE) is a minimally invasive technique for small tumour ablation. Multiple needles are inserted around the planned treatment zone and, depending on the size, inside as well. An applied electric field triggers instant cell death around this zone. To ensure the correct application of IRE, certain criteria need to be fulfilled. The needles' placement in the tissue has to be parallel, at the same depth, and in a pattern which allows the electric field to effectively destroy the targeted lesions. As multiple needles need to synchronously fulfill these criteria, it is challenging for the surgeon to perform a successful IRE. Therefore, we propose a visualization which exploits intuitive visual coding to support the surgeon when conducting IREs. We consider two scenarios: first, to monitor IRE parameters while inserting needles during laparoscopic surgery; second, to validate IRE parameters in post‐placement scenarios using computed tomography. With the help of an easy to comprehend and lightweight visualization, surgeons are enabled to quickly visually detect what needs to be adjusted. We have evaluated our visualization together with surgeons to investigate the practical use for IRE liver ablations. A quantitative study shows the effectiveness compared to a single 3D view placement method.
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| 4. |
- Kreiser, Julian, et al.
(författare)
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Void Space Surfaces to Convey Depth in Vessel Visualizations
- 2021
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Ingår i: IEEE Transactions on Visualization and Computer Graphics. - : IEEE COMPUTER SOC. - 1077-2626 .- 1941-0506. ; 27:10, s. 3913-3925
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Tidskriftsartikel (refereegranskat)abstract
- To enhance depth perception and thus data comprehension, additional depth cues are often used in 3D visualizations of complex vascular structures. There is a variety of different approaches described in the literature, ranging from chromadepth color coding over depth of field to glyph-based encodings. Unfortunately, the majority of existing approaches suffers from the same problem: As these cues are directly applied to the geometrys surface, the display of additional information on the vessel wall, such as other modalities or derived attributes, is impaired. To overcome this limitation we propose Void Space Surfaces which utilizes empty space in between vessel branches to communicate depth and their relative positioning. This allows us to enhance the depth perception of vascular structures without interfering with the spatial data and potentially superimposed parameter information. With this article, we introduce Void Space Surfaces, describe their technical realization, and show their application to various vessel trees. Moreover, we report the outcome of two user studies which we have conducted in order to evaluate the perceptual impact of Void Space Surfaces compared to existing vessel visualization techniques and discuss expert feedback.
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