Real-time three-dimensional ultrasound user interface for TIPS planning Poster No.: C-2024 Congress: ECR 2015 Type: Scientific Exhibit Authors: C. F. Cuijpers 1, C. Klink 2, E. Varga 2, P. J. Stappers 1, Y. Song 1 ; 1 2 Delft/NL, Rotterdam/NL Keywords: DOI: Interventional vascular, Liver, Ultrasound, Computer Applications-3D, Puncture, Computer Applications-Detection, diagnosis, Cirrhosis, Hypertension 10.1594/ecr2015/C-2024 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 6
Aims and objectives The transjugular intrahepatic portosystemic shunt (TIPS) procedure is one of the most technically challenging procedures in interventional radiology [1]. During the TIPS procedure, a shunt is created in the liver to decrease the high blood pressure for patients with portal hypertension [2]. Especially the intrahepatic puncture is a challenging part of the procedure [3]. During this critical step, the interventional radiologists (IRs) desire to gain access to the portal vein and intend to puncture from the hepatic vein, through the liver, into the portal vein. After this step, a shunt can be placed between the hepatic vein and portal vein to bypass blood from the liver into the systemic circulation. Limited information is available from the image guidance systems to perform the intrahepatic puncture [4-5]. Before the procedure, IRs first plan their actions on CT [6-7] and develop a mental representation (mental model) of the anatomy, the puncture and other aspects [8]. During the intraoperative part of the TIPS procedure, mainly fluoroscopy is used to guide the IRs [9]. However, three-dimensional, real-time information about the anatomy and instruments is limited [4-5]. Therefore, IRs often rely on their mental model and own skills to complete the procedure [8,10]. IRs mainly have to proceed through trial and error when performing the puncture [4], multiple needle passes are frequently needed and these can cause complications [9]. The above shows the need for additional support from the image guidance system, but also from a good planning aid. A proper planning user interface (UI) might help IRs to provide the desired support. Currently, such a planning-ui is unavailable: IRs can now solely scroll through CT or other pre-operative images [6-7] and have to imagine and remember planned actions [6]. In our study, we introduce a UI using three-dimensional ultrasound (3D US) information for planning the puncture. 3D US is a promising modality to provide appropriate guidance [11]. A US planning-ui might help, by: 1. visualizing what can be expected and what options are feasible to puncture the portal vein. With the planning-ui, IRs can see and interact with the patient's anatomy and possible puncture trajectories in 3D. This could help IRs to get familiar with the anatomy, anatomical constraints, risks, puncture possibilities and anatomical distances before the procedure. Based on that information, IRs are able to set concrete expectations and select a desired puncture trajectory. 2. generating optimal 2D US planes for the intrahepatic puncture. With the planning-ui IRs can select 2D planes which will show all the information needed by the performing IR to gain access to the PV, such as the anatomy, the puncture line and target point. The planes can be visualized during the intrahepatic puncture in real-time. Page 2 of 6
The aim of this study is to assess the usability of the UI which concerns the planning of an intrahepatic puncture. Methods and materials From an acquired 3D US dataset, a 3D US based UI was designed (figure 1): 1) on the right, the 3D view of the segmented hepatic and portal vein images are visualized; 2) on the left, a 2D axial section plane is visualized. The mouse allows IRs to scroll through the dataset in the axial direction and to zoom or rotate the segmented images. The mouse also allows IRs to select the preferred target point/area in the portal vein (figure 1) and the preferred hepatic vein to target from (figure 2). Based on the selection, the system calculates and presents three possible puncture trajectories (figure 3). It also shows accompanying distances, such as the distance between the exit point in the hepatic vein and the entry point in the portal vein. The IRs are able to study the different trajectory options and to select a suitable one. After selecting one, IRs can view the chosen trajectory in the longitudinal and cross section of the veins and in the 3D US image. Five IRs were asked to use the planning-ui and to plan and select a desired trajectory, view the created planes and provide feedback. Images for this section: Fig. 1: The design of the planning-ui: showing an example of a selected target point and -area in the portal vein. Page 3 of 6
Fig. 2: An example of the planning-ui in which a desired branch of the hepatic vein is selected. Fig. 3: An example of an optimal needle trajectory, which the system has created based on the selections Page 4 of 6
Results All participating IRs said they were seriously interested in the planning-ui. Three participants already expressed their desire to clinically test the UI: "I would also like to, at the proper time, to put it into practice". IRs mainly appreciated: 1. The possibility to view and interact with 3D digital information. IRs said it made it easier to understand the anatomy, distances, possibilities and constraints and to select the proper trajectory and stent. 2. The UI's potential to generate 2D planes which could make the current procedure less invasive and complex. The main critiques given was that: 1. IRs found it difficult to spatially orientate the different planes within the patient's body. They recommended to add more support to spatially orientate. Examples given to do so were the availability of CT images and a representation of the US probe in relation to the patient's body. 2. IRs were not satisfied with the available US dataset and the proposed trajectory options. It was expressed that the dataset did not properly visualize the portal vein and the proposed trajectories were sometimes unsuitable. An IR said that for an optimal trajectory the systems should know the anatomy of the veins. Two others said that the trajectory should allow IRs to creates a smooth and spacious intrahepatic curve with the needle. Conclusion The test showed that the UI provides valuable 3D visualization support to plan the intrahepatic TIPS puncture. Although a prototype, all IRs were seriously interested in the UI. The possibility to view and interact with 3D digital information which is currently mentally constructed based on CT was highly appreciated. In addition, the presented 2D US images which can be used during the procedure were greatly valued as well. Design improvements based on the feedback and elaborate testing are needed to further improve the UI. Personal information Page 5 of 6
CF Cuijpers, Department of Design Engineering, Delft University of Technology, Industrial Design Engineering, Delft, the Netherlands, c.f.cuijpers@tudelft.nl; C Klink, Department of Interventional Radiology, Erasmus Medical Centre, Rotterdam, the Netherlands; E Varga, Department of Biomedical Imaging Group, Erasmus Medical Centre, Rotterdam, the Netherlands; PJ Stappers, Department of Industrial Design, Delft University of Technology, Industrial Design Engineering, Delft, the Netherlands, Y Song, Department of Design Engineering, Delft University of Technology, Industrial Design Engineering, Delft, the Netherlands. References [1] Funaki B (2008) Transjugular Intrahepatic Portosystemic Shunt. Seminars in interventional radiology, 1:168-174. [2] Goykhman Y, Ben-Haim M, Rosen G, et al. (2010) Transjugular intrahepatic portosystemic shunt: current indications, patient selection and results. IMAJ 12:687-91. [3] Owen A., Stanley A., Vijayananthan A, Moss J. (2009) The transjugular intrahepatic portosystemic shunt (TIPS). Clinical radiology 64:664-74. [4] Cuijpers CF, Moelker A, Varga E, Stappers PJ, Freudenthal A (2012) Improving image guidance in interventional radiology: the lack of information during a transjugular intrahepatic shunt procedure, EAM, Germany. [5] Krajina A, Lojik M, Chovanec V, Raupach J, Hulek P (2002) Wedged Hepatic Venography for Targeting the Portal Vein During TIPS: Comparison of Carbon Dioxide and Iodinated Contrast Agents, Cardiovasc Interv Rad 25. [6] Scanlon T, Ryu RK, (2008) Portal vein imaging and access for transjugular intrahepatic portosystemic shunts, Tech Vasc Interv Radiol 11, 217-224. [7] Ferral H, Bolbao JI (2005) The difficult transjugular intrahepatic portosystemic shunt: alternative techniques and "Tips" to successful shunt creation, Seminars in interventional radiology, 22(4). [8] Varga E, Pattynama PMT, Freudenthal A (2012) Manipulation of mental models of anatomy in interventional radiology and its consequences for design of human-computer interaction. Cognition, Technology & Work. [9] Adamus R, Pfister M, Loose RWR (2009) Enhancing transjugular intrahepatic portosystemic shunt puncture by using three-dimensional path planning based on the back projection of two twodimensional portographs. Radiology 251:543-7. [10] Jalote-Parmar A (2009), Workflow driven decision support systems: a case of an intra-operative visualization system for surgeons, Thesis, Technical university of Delft, Delft. [11] Cuijpers CF, Klink C, Stappers PJ, Freudenthal A (2013) Comparing image guidance systems to improve complex navigation in medicine, IFAC, USA. Page 6 of 6