The 7th International Conference on Medical Imaging and Computer Assisted Intervention, MICCAI 2004, was held in Saint-Malo, Brittany, France at the “Palais du Grand Large” conference center, September 26–29, 2004. The p- posaltohostMICCAI2004wasstronglyencouragedandsupportedbyIRISA, Rennes. IRISA is a publicly funded national research laboratory with a sta? of 370,including150full-timeresearchscientistsorteachingresearchscientistsand 115 postgraduate students. INRIA, the CNRS, and the University of Rennes 1 are all partners in this mixed research unit, and all three organizations were helpful in supporting MICCAI. MICCAI has become a premier international conference with in-depth - pers on the multidisciplinary ?elds of medical image computing, comput- assisted intervention and medical robotics. The conference brings together cl- icians, biological scientists, computer scientists, engineers, physicists and other researchers and o?ers them a forum to exchange ideas in these exciting and rapidly growing ?elds. The impact of MICCAI increases each year and the quality and quantity of submitted papers this year was very impressive. We received a record 516 full submissions (8 pages in length) and 101 short communications (2 pages) from 36 di?erent countries and 5 continents (see ?gures below). All submissions were reviewed by up to 4 external reviewers from the Scienti?c Review C- mittee and a primary reviewer from the Program Committee. All reviews were then considered by the MICCAI 2004 Program Committee, resulting in the acceptance of 235 full papers and 33 short communications.