Progess in specific computer-assisted techniques (digital imaging , computer-aided diagnosis, image-guided surgery, MEMS, etc.) combined with computer-assisted integration tools offers a valuable complement to or replacement for existing procedures in healthcare. Physicians are now employing PACS and telemedicine systems as enabling infrastructures to improve quality of and access to healthcare. Tools based on CAD and CAS facilitate completely new paths in patient care. To ensure that CARS tools benefit the patient, collaboration between various disciplines, specifically radiology, surgery, engineering, informatics, and healthcare management, is a critical factor. A multidisciplinary congress like CARS is a step in the desired direction of knowledge sharing and crossover education. It provides the necessary cooperative framework for advancing the development and application of modern computer-assisted technologies in healthcare.

This volume once again comprises the papers presented at the 17th International Congress of Computer Assisted Radiology and Surgery that was held in London between 25 and 28 June 2003. After many years of research and development in the application of computer and communication technology in radiology and surgery, progress in these endeavours has finally come to fruition: PACS is at the forefront and has achieved a high level of acceptance in clinical settings. This can be observed in many small and large scale PACS realisations. In recent times, however, the traditional focus of PACS medical workstation design directed towards radiology is shifting to other clinical disciplines, specifically surgery. In the vision expressed by H.K. Huang in the Prelude of these CARS proceedings, PACS based imaging informatics is providing the foundation for image assisted applications, not only for computer assisted diagnosis, but even more so in surgery. In this year's CARS, this is reflected in a large increase (32% as compared to CARS 2002) in the number of abstracts submitted for themes relating to computer assisted surgery (CAS). It can be expected that CAS will proceed in its development to reach, in the not too distant future, the level of maturity and acceptance of PACS and thereby will enhance the effectiveness of physicians and the welfare of patients.

Almost 500 paper and poster contributions from more than 30 countries had to be evaluated for CARS 2004. In addition to the traditional CARS themes and topics, emphasis has been given to developments such as IHE, Surgical Workflow and PACS, Operation Room of the Future, and Strategic Thinking. In special congress sessions, partner societies such as SPIE and SCAR have joined these endeavours to assist in achieving progress in these fields. While the increased reliance on multi-source information is proceeding at a rapid rate, it is interesting to note that the basis for the greater part of medical decision making is still medical imaging. This may change as genomics and proteomics fulfil more of their potential, but it is estimated that more than half of current hospital visits result in imaging studies. In that respect, it is true that "the more things change, the more they stay the same" (Alphonse Karr, 1849) and that medical imaging is the cornerstone of the field. This focus on medical imaging is evident throughout the CARS conference, with sessions dedicated to Medical Imaging (MI) itself, Image Processing and Display (IPD), Image Guided Radiological Therapy (IGRT), Image Guided Therapy (IGT), and separate symposia on Computer Aided Diagnosis (based on imaging) and both Cardiovascular and Maxillofacial Imaging. Still, it is up to you, the engineers, scientists, clinicians, and related personnel participating in CARS, to ensure that innovation in technology and procedures is not developed just for the sake of change, but instead to achieve progress and thereby provide better patient care.

New developments in computer assisted medical tools have improved medical workflow considerably. Advances in medical imaging, healthcare networking, surgical robotics and instrumentation and other imaging based technologies contribute towards a more flexible computer assisted medicine. With the advent of the electronic medical record (EMR) and suitable access management, collaboration between all healthcare parties, including the patient, also becomes possible. Progress in specific computer assisted techniques (e.g. digital imaging, computer aided diagnosis, image guided surgery, MEMS, etc.) combined with computer assisted integration tools (e.g. PACS, EMR, middleware, Internet, telemedicine, etc.) offers a valuable complement to or replacement for existing procedures in healthcare. Physicians are now employing PACS and telemedicine systems as enabling infrastructures for improving quality of and access to healthcare. Tools based on CAD and CAS facilitate completely new paths in patient care. To reflect this development, the depth and spectrum of topics included in this year's CARS Proceedings have been expanded to include all aspects of modern IT in radiology and surgery. In addition to the traditional CARS topics, special emphasis is also been given to endoluminal surgery, cardiovascular imaging, the electronic medical record and bio-intelligence. CARS 2001 is the first volume to be published simultaneously in print and on the web. Buyers of the book will have access to this web edition of CARS 2001 proceedings at no additional charge.

The fifth international Conference in Medical Image Computing and Computer Assisted Intervention (MICCAI 2002) was held in Tokyo from September 25th to 28th, 2002. This was the first time that the conference was held in Asia since its foundation in 1998. The objective of the conference is to offer clinicians and scientists the opportunity to collaboratively create and explore the new medical field. Specifically, MICCAI offers a forum for the discussion of the state of art in computer-assisted interentions, medical robotics, and image processing among experts from multi-disciplinary professions, including but not limited to clinical doctors, computer scientists, and mechanical and biomedical engineers. The expectations of society are very high; the advancement of medicine will depend on computer and device technology in coming decades, as they did in the last decades. We received 321 manuscripts, of which 41 were chosen for oral presentation and 143 for poster presentation. Each paper has been included in these proceedings in eight-page full paper format, without any differentiation between oral and poster papers. Adherence to this full paper format, along with the increased number of manuscripts, surpassing all our expectations, has led us to issue two proceedings volumes for the first time in MICCAI’s history. Keeping to a single volume by assigning fewer pages to each paper was certainly an option for us considering our budget constraints. However, we decided to increase the volume to offer authors maximum opportunity to argue the state of art in their work and to initiate constructive discussions among the MICCAI audience.

The 6th International Conference on Medical Imaging and Computer-Assisted Intervention,MICCAI2003,washeldinMontr ́ eal,Qu ́ ebec,CanadaattheF- rmont Queen Elizabeth Hotel during November 15–18, 2003. This was the ?rst time the conference had been held in Canada. The proposal to host MICCAI 2003 originated from discussions within the Ontario Consortium for Ima- guided Therapy and Surgery, a multi-institutional research consortium that was supported by the Government of Ontario through the Ontario Ministry of E- erprise, Opportunity and Innovation. The objective of the conference was to o?er clinicians and scientists a - rum within which to exchange ideas in this exciting and rapidly growing ?eld. MICCAI 2003 encompassed the state of the art in computer-assisted interv- tions, medical robotics, and medical-image processing, attracting experts from numerous multidisciplinary professions that included clinicians and surgeons, computer scientists, medical physicists, and mechanical, electrical and biome- cal engineers. The quality and quantity of submitted papers were most impressive. For MICCAI 2003 we received a record 499 full submissions and 100 short c- munications. All full submissions, of 8 pages each, were reviewed by up to 5 reviewers, and the 2-page contributions were assessed by a small subcomm- tee of the Scienti?c Review Committee. All reviews were then considered by the MICCAI 2003 Program Committee, resulting in the acceptance of 206 full papers and 25 short communications. The normal mode of presentation at MICCAI 2003 was as a poster; in addition, 49 papers were chosen for oral presentation.