Distributed quantitative evaluation of 3D patient specific arterial models

In this paper we describe a new system for the 3D reconstruction and distribution on the net of models for vessels structures. The system is specifically designed to support measurements of medical interest. We describe 2D and 3D segmentation methods implemented and the procedure used to build interactive VRML97 models. The experimental section presents a comparison between segmentation methods, and a first application to surgical planning for endovascular repair of Abdominal Aortic Aneurysms

Catheter insertion simulation with co-registered direct volume rendering and haptic feedback

We have developed an experimental catheter insertion simulation system supporting head-tracked stereoscopic viewing of volumetric anatomic reconstructions registered with direct haptic 3D interaction. The system takes as input data acquired with standard medical imaging modalities and regards it as a visual and haptic environment whose parameters are interactively defined using look-up tables. The system's display, positioned like a surgical table, provide a realistic impression of looking down at the patient. Measuring head motion via a six degrees-of-freedom head tracker, good positions to observe the anatomy and identify the catheter insertion point are quickly established with simple head motion. By generating appropriate stereoscopic images and co-registering physical and virtual spaces beforehand, volumes appear at fixed physical positions and it is possible to control catheter insertion via direct interaction with a PHANToM haptic device. During the insertion procedure, the system provides perception of the effort of penetration and deviation inside the traversed tissues. Semi-transparent volumetric rendering augment the sensory feedback with the visual indication of the inserted catheter position inside the body.96-9

Catheter insertion simulation with combined visual and haptic feedback

We have developed an experimental catheter insertion system supporting head-tracked stereoscopic viewing of volumetric reconstruction registered with direct haptic 3D interaction. The system takes as input patient data acquired with standard medical imaging modalities and regards it as a visual and haptic environment whose parameters are defined using look-up tables. By means of a mirror, the screen seems to be positioned like a surgical table providing the impression of looking down at the patient in a natural way. Co-registering physical and virtual spaces beforehand means that the patient appears at a fixed physical positionj on the surgical table and inside the workspace of the PHANToM device which controls catheter insertion. During the insertion procedure the system provides perception of the force of penetration and positional deviation of the inserted catheter

Web based 3D quantitative measurements of abdominal aortic aneurysms

We tested a novel approach for the quantitative remote analysis of abdominal aortic aneurysms by reconstructing their 3D geometry and topological structure (i.e. centereline path) and put them on the web as VRML97 models including specialized code enabling the user to perform guided inspection and measurements useful for surgical planning

Reconstruction and web distribution of measurable arterial models

In this paper a novel framework for the segmentation, 3D reconstruction and web distribution of vessel structures specifically tailored to the assessment of abdominal aortic aneurysms for endovascular surgery planning is presented. Deformable models are used for segmentation, while VRML97 and ECMA scripting are used to obtain models that are not only viewable from any VRML97 enabled browser, but that also allow users to perform, directly from standard web browsers, guided measurements of geometrical parameters, relevant to surgical planning.79-93Pubblicat

Primary mesenteric liposarcoma. Report of a case

Primary mesenteric liposarcomas are very rare neoplasms. The authors report a case of mesenteric liposarcoma recently observed. The patient presented with a history of dyspeptic syndrome, meteorism and abdominal pain associated with a change in bowel habit and constipation. On physical examination there was a large, well-circumscribed, abdominal mass. Computed tomography revealed an abdominal, dishomogeneous, low-density mass. Surgical excision with a tumour-free margin was achieved. The histologic appearances were those of a well-differentiated liposarcoma (atypical lipomatous tumour). The patient is alive and disease-free 33 months after the surgery. Primary mesenteric liposarcoma is often resectable and requires aggressivesurgical management; in consideration of the high risk of tumour recurrence, the treatment of choice is a wide surgical excisio

Physical human lumen carotid reconstruction: life-size models by rapid prototyping

Poster of SPIE Conference held in San Diego - CA, USA, 10/15 FebruaryRapid Prototyping (RP) is a technique used in industry for manufacturing prototypes. Its capability to physically reproduce geometrical complex shapes is getting increasing interest in many fields of medicine. In the field of vascular surgery, replicas of artery lumen have utility in complex cases or when standard imaging is felt to be equivocal. Replicas can also facilitate experimental studies of computational vascular fluid-dynamics permitting in-vitro reproductions of blood flow in living subjects before and after surgery. The VIrtual VAscular (VIVA) project at CRS4, developed a system able to process three-dimensional (3D) datasets extracted from a Computer Tomography (CT) apparatus, visualize them, reconstruct the geometry of arteries of specific patients, and simulate blood flow in them. In our work, the applicability of RP techniques to VIVA’s real size replicas of an autoptic carotid vessel lumen is presented and an overview of the RP based system developed is provided. The techniques used in our prototype are discussed and experimental results for the creation of a human carotid lumen replica are analysed. We discuss in detail the pipeline of the manufacturing process: 3D geometric reconstruction from segmented points, geometry tessellation, STL (Stereo Lithography format) conversion. Moreover we illustrate some technical details of the specific RP technique called Fused Deposition Modelling (FDM), used to build the lumen replicas, the materials used for prototypes, throughput time and costs of the FDM models realized. The system is totally based on open-source software. This enables us to control each step of the pipeline, from data acquisition to STL export file. In this context, we present main sources of error encountered during all manufacturing process stages

Internet Patient Records: new techniques

Reviewer: Grohol, John M[This item is a preserved copy and is not necessarily the most recent version. To view the current item, visit http://www.jmir.org/2001/1/e8/ ] Background: The ease by which the Internet is able to distribute information to geographically-distant users on a wide variety of computers makes it an obvious candidate for a technological solution for electronic patient record systems. Indeed, second-generation Internet technologies such as the ones described in this article - XML (eXtensible Markup Language), XSL (eXtensible Style Language), DOM (Document Object Model), CSS (Cascading Style Sheet), JavaScript, and JavaBeans - may significantly reduce the complexity of the development of distributed healthcare systems. Objective: The demonstration of an experimental Electronic Patient Record (EPR) system built from those technologies that can support viewing of medical imaging exams and graphically-rich clinical reporting tools, while conforming to the newly emerging XML standard for digital documents. In particular, we aim to promote rapid prototyping of new reports by clinical specialists. Methods: We have built a prototype EPR client, InfoDOM, that runs in both the popular web browsers. In this second version it receives each EPR as an XML record served via the secure SSL (Secure Socket Layer) protocol. JavaBean software components manipulate the XML to store it and then to transform it into a variety of useful clinical views. First a web page summary for the patient is produced. From that web page other JavaBeans can be launched. In particular, we have developed a medical imaging exam Viewer and a clinical Reporter bean parameterized appropriately for the particular patient and exam in question. Both present particular views of the XML data. The Viewer reads image sequences from a patient-specified network URL on a PACS (Picture Archiving and Communications System) server and presents them in a user-controllable animated sequence, while the Reporter provides a configurable anatomical map of the site of the pathology, from which individual "reportlets" can be launched. The specification of these reportlets is achieved using standard HTML forms and thus may conceivably be authored by clinical specialists. A generic JavaScript library has been written that allows the seamless incorporation of such contributions into the InfoDOM client. In conjunction with another JavaBean, that library renders graphically-enhanced reporting tools that read and write content to and from the XML data-structure, ready for resubmission to the EPR server. Results: We demonstrate the InfoDOM experimental EPR system that is currently being adapted for test-bed use in three hospitals in Cagliari, Italy. For this we are working with specialists in neurology, radiology, and epilepsy. Conclusions: Early indications are that the rapid prototyping of reports afforded by our EPR system can assist communication between clinical specialists and our system developers. We are now experimenting with new technologies that may provide services to the kind of XML EPR client described here