Chrisochoides, Alumni Memorial Distinguished Associate Professor of Computer Science, is working on geometric and numerical algorithms and software for Image Guided Neurosurgery which is a common therapeutic intervention in the treatment of brain tumors. Survival rate and quality of life for a patient greatly depend on the accuracy and precision of tumor resection, which can be significantly improved by utilizing pre-operative brain scans as an aid in decision making during the procedure. However, during the course of intervention the areas of interest may dislocate due to brain shift/deformation, and thus invalidate existing pre-operative brain images. Chrisochoides’ group in the Parallel Experimental Systems Lab (PESLab) at William and Mary use intra-operative MRI and many clusters of computers to track brain deformation.
“William and Mary is proud of the interdisciplinary research that our faculty do,” commented Carl Strikwerda, Dean of Arts and Sciences at the College. “Professor Chrisochoides is one of our distinguished scientists doing cutting edge research bringing together information science and medicine.”
In November of 2005 Chrisochoides’ group with their colleagues at Harvard Medical School were the first team of doctors and scientists to complete in real-time the alignment of pre- and intra-operative brain images using landmark tracking across the entire brain and present the results to neurosurgeons at BWH during the tumor resection procedure.
"This work would not be possible without the generous support of the National Science Foundation (NSF), and more specifically without the vision, hard work and tenacity of Dr. Frederica Darema, Senior Science andTechnology Advisor at NSF." Chrisochoides said.
NSF has funded Chrisochoides with more than $2 million during the past seven years he has been at William and Mary.
“Progress made in this very difficult problem is a result of a large scale collaboration and involves a group of Neurosurgeons lead by Dr. Peter Black and Dr. Alexandra Golby, a group of Radiologists lead by Dr. Ron Kikinis and Dr. Simon Warfield at Brigham and Women's Hospital (BWH), Boston, MA, and an INRIA (Sophia-Antipolis), France team including Dr. Oliver Clatz and lead by Professor Nicholas Ayache – all part of a large interdisciplinary team put together during the last 14 years by Dr. Ferenc Jolesz and Dr. Ron Kikinis at Harvard Medical School,” Chrisochoides said.
He added that “the Guggenheim fellowship will help us to set the foundation for the next step which require, one, the use of the web and many supercomputers around the country to improve the accuracy of current results, two, widen the use of our work, through the web, from other hospitals in US and around the world, and three, train the next generation of researchers that can carry out a noble objective—better and more affordable health care for all.”
“This Fellowship means quite a lot to my research,” said Chrisochoides. “The Fellowship is in medicine and health, not computer science as one would expect, and it will open many more opportunities for our project.” Chrisochoides added that he will use the Fellowship to establish a new Center for Real-Time Computing at William and Mary and design three new courses on Medical Image Analysis at the college. He also hopes to find time for writing the first book on parallel mesh generation. “Parallel mesh generation is critical for real-time medical image analysis,” he added.
Chrisochoides is the fourth professor to receive the John Simon Guggenheim Memorial Foundation Fellowship while on faculty at the College of William and Mary. Past William and Mary fellows are Professors James Axtel (History), Barbara King (Anthropology), and Talbot Taylor (English).
The Foundation notes that since 1925 it has granted over $256 million in Fellowships to more than 16,250 individuals. Fellowship decisions are based on recommendations from hundreds of expert advisors and are approved by the Foundation’s Board of Trustees, which includes six members who are themselves past Fellows of the Foundation – Joel Conarroe, Joyce Carol Oates, Richard A. Rifkind, Charles Ryskamp, Ellen Taaffe Zwilich, and Edward Hirsch.
The full list of 2007 Fellows may be viewed at http://www.gf.org
The preoperative imaging shown here contains information essential to the surgeon (including the tumor, visible in green); but it cannot be used during the operation, unless it is updated to account for the tumor's shifting location.Andriy Fedorov is demonstrating the potential for just this kind of solution. A Ph.D. student of Prof. Nikos Chrisochoides, Andriy has worked for two years putting together a sequence of processes involving an algorithm that registers the pre-surgical MRI image to images taken during the surgery.
Andriy’s research project is titled, Near-Real-Time Nonrigid Registration for Image Guided Neurosurgery Using Commodity and Grid Computing. At the College’s sixth annual Graduate Research Symposium, held in March 2007, his project won the Award for Excellence in Scholarship in the Natural and Computational Sciences.
In Andriy’s research scenario, the surgery takes place within a “double-doughnut” MRI configuration that allows scanning while still providing the surgeon access to the brain cavity. “Speed is a key factor,” Andriy notes. “We have to be able to take new images during surgery, register them to the pre-surgical image, and return updated information to the surgeon as quickly as possible.”
Because MRI images are digital, it’s possible to compare and manipulate the data mathematically. “To register the images we applied an existing algorithm, which we tweaked to improve speed and, in the long run, its accuracy,” said Andriy. “Our requirements for the full registration sequence are accuracy, robustness, and computational feasibility.”
During his first year into the project, Andriy Fedorov developed a tool that constructs the tesselation of the brain from an MRI image. Such tesselation, also known as “mesh,” enables biomechanical modeling of brain deformation for MRI registration. Last year, Andriy Fedorov and his fellow student Andriy Kot, worked together and successfully delivered the implementation of registration, which computes the result here at W&M and sends it to the surgeons at Brigham and Women’s Hospital (BWH) in Boston in less than 5 minutes. For the first time the computation of such complexity was completed within the time constraints of the surgery. Since then, the implementation has been used routinely at BWH.
Andriy emphasizes that this result was made possible by a dedicated team effort. In addition to his colleagues in the Parallel Experimental Systems Lab in the Computer Science Department, the team includes world-recognized experts from around the globe. Medical image processing expertise comes from Olivier Clatz from INRIA Sophia-Antipolis, France, Computational Radiology Lab led by Simon K. Warfield and the Surgical Planning Lab led by Ron Kikinis, at Children’s Hospital and BWH respectively. Neurosurgeons Alexandra Golby and Peter Black at BWH, where the open MRI scanner is located, are also contributing to the investigation. This work is part of a very large interdisciplinary team put together during the last 14 years by Ferenc Jolesz at Harvard Medical School.
Tetrahedral mesh, shown as a wireframe, is the basis for the biomechanical model used to approximate overall brain deformation (shown by the colored arrows).
“I'm delighted to hear the news about Eric. I can't imagine a more deserving individual,” said Phil Kearns, chair of William and Mary’s computer science department and Koskinen’s honors thesis advisor. “He always impressed me as being an intense computer scientist, but one who was well-rounded. This is significant because the intensity and the well-roundedness are often mutually exclusive. He was one of those students who make taking a salary for being a faculty member at W&M seem like larceny.”
Established in 2001, the Gates Cambridge Scholar program enables outstanding graduate students from outside the United Kingdom to study at Cambridge. According to the Web site, the scholars are chosen based on their intellectual ability, leadership capacity and desire to use their knowledge to contribute to society throughout the world by providing service to their communities and applying their talents and knowledge to improve the lives of others.
A native of Allendale, N.J., Koskinen graduated from William and Mary with a double major in computer science and physics. He said he has nothing but fond memories of William and Mary, where he played in a small pop/rock band and met many of his closest friends, including his wife.
Spring/Summer 2007