Introducing CAVASS a Computer Assisted Visualization and Ana

Introducing CAVASS: a Computer Assisted Visualization and

Analysis Software System

George Grevera*ab, Jayaram Udupa b, Dewey Odhner b, Ying Zhuge b, Andre Souza b, Tad Iwanaga b,

and Shipra Mishra b

a Department of Mathematics and Computer Science, Saint Joseph’s University, 5600 City Avenue,

Philadelphia, PA 19131;

b Medical Image Processing Group (MIPG), Department of Radiology, University of Pennsylvania,

423 Guardian Drive, 4th Floor Blockley Hall, Philadelphia, PA 19104-6021

*ggrevera@aa7e2cf8770bf78a65295458; phone 1 610 660-1535; fax 1 610 660-3082; aa7e2cf8770bf78a65295458/~ggrevera

ABSTRACT

The Medical Image Processing Group (MIPG) at the University of Pennsylvania has been developing (and distributing with source code) medical image analysis and visualization software systems for a long period of time. Our most recent system, 3DVIEWNIX, was first released in 1993. Since that time, a number of significant advancements have taken place with regard to computer platforms and operating systems, networking capability, the rise of parallel processing standards, and the development of open source toolkits. The development of CAVASS by our group is the next generation of 3DVIEWNIX. CAVASS will be freely available, open source, and is integrated with toolkits such as ITK and VTK. CAVASS runs on Windows, Unix, and Linux but shares a single code base. Rather than requiring expensive multiprocessor systems, it seamlessly provides for parallel processing via inexpensive COWs (Cluster of Workstations) for more time consuming algorithms. Most importantly, CAVASS is directed at the visualization, processing, and analysis of 3D and higher dimensional medical imagery, so support for DICOM data and the efficient implementation of algorithms is given paramount importance.

Keywords: visualization, 3D imaging, software systems, image analysis

1. INTRODUCTION

Software development for 3D CAVA (Computer Aided Visualization and Analysis) in our group started in the 1970s. In 1980, we brought out the first ever such package for medical 3D CAVA [1]. This software worked on a Data General minicomputer, which drove a Comtal image display frame buffer. In 1982, we brought out a significantly expanded version of this software package [2]. In spite of its high machine and display device dependency, this package was distributed to over 150 sites with source code worldwide long before the term “open source” was coined. This package was also incorporated into the General Electric CT/T 8800 scanner [3]. We subsequently developed a more advanced package [4] for the GE 9800 CT scanner. GE distributed widely these on-the-scanner packages. Earlier, we implemented DISPLAY and DISPLAY82 at the Mayo Clinic whose investigators used these packages until they started developing the Analyze system [5] around 1984-85.

Around 1987, we started the development of a Unix-workstation-based software system named 3DVIEWNX [6] which was based on standard C programming language and a graphical user interface library developed by us based on X Windows. It also incorporated a multidimensional generalization [7] of the 2D DICOM image representation standards. This issue of the need to handle a multidimensional vectorial image as a single entity and also to handle non-image structure information such as surfaces is only now being looked into by the standards committees related to DICOM. These issues were addressed in 3DVIEWNIX in the early stage of its design during 1987-1990. 3DVIEWNIX has incorporated numerous advanced 3D (and higher dimensional) CAVA operations including various methods of interpolation, filtering, segmentation, registration, algebraic and morphological operations, visualization methods for surfaces and volumes, interactive structure editing and manipulation, and scene intensity and structure-based quantitative analysis. Its binary version is available freely via Internet and has been used by 100s of sites, and the source-code-

version has been distributed to more than 180 sites worldwide to date. We continue to maintain, distribute, and develop 3DVIEWNIX by incorporating into it all functions that we find useful after rigorously testing them in one or more of our on-going applications. About 60-person years of work has gone into 3DVIEWNIX so far. Its design has stood the test of time and of over 15 applications pursued by us since its release.

Since the time 3DVIEWNIX was first released (1993), a number of significant developments have occurred. Most significantly, PC platforms (and the Windows OS) have gained in capability accompanied by precipitous price reductions. They have supplanted traditional Unix-based workstations as the scientific workstations of choice. Second, network connectivity (speed) has greatly increased. Third, viable parallel processing standards have been developed and are now freely available for all popular platforms and operating systems. Fourth, platform independent windowing APIs, some of which maintain the native look and feel, have been defined and implemented. And finally, toolkits such as ITK and VTK have been developed and are freely available. Although not complete applications in themselves, these toolkits provide a breadth of techniques and can be employed as building blocks of applications.

2. METHODS

CAVASS is an open source system written entirely in C/C++ and is based on our years of experience with 3DVIEWNIX. It encompasses four groups of operations: image processing (including region of interest, interpolation, filtering, segmentation, registration, morphological operations, and algebraic operations), analysis (various methods for extracting quantitative information), visualization (including slice, reslice, maximum intensity projection, surface rendering, and volume rendering), and manipulation (for surgical planning and …… 此处隐藏：30127字，全部文档内容请下载后查看。喜欢就下载吧 ……