February 1, 2007 With MRI or CT scans, clinicians have to identify and extract the anatomy out of cross-sections views of the body. Computer scientists have created a new interactive tool that can examine scans and quickly find hidden organs, such as a kidney or heart, or peel back layers to reveal muscles. Medical physicists will be able to implement the new software at hospitals within a year.
MRI and CT body scans can show every organ, tissue and bone in one image. But picking out just one body part from scans isn't easy.
"Some of the very powerful and accepted medical imaging technologies that are being used to do that today cannot identify and extract just a single piece of anatomy," William Barrett, a computer scientist at Brigham Young University in Provo, Utah, tells DBIS.
Thanks to computer scientists like Barrett, doctors now have a new tool, called Live Surface, that locates and picks out one body part at a time from CT and MRI scans.
"The ultimate goal is to give the end user, the clinician, a powerful tool that will allow them to be in the driver's seat and very quickly extract anatomy of interest from which they can make diagnoses," Barrett tells DBIS. The interactive tool can quickly find hidden organs, like a kidney or heart, and peel back layers to reveal muscles.
Barrett says Live Surface allows the user to simply make a couple of mouse strokes and immediately, the object is identified. Once the doctor chooses an organ -- like a kidney -- to be revealed from a scan, the computer eliminates the parts that are not wanted, like tissue and fat. Then, instantly, out pops a kidney that can be viewed from every angle.
"There's nothing quite like seeing the anatomy in its three-dimensional form. And in fact, it can be a valuable ally to the patient to be able to say, 'This is what the tumor looks like,'" Barrett says -- creating a virtual roadmap to the body. He says medical physicists will be able to implement the Live Surface computer program in hospitals within a year.
BACKGROUND: A new software tool developed by computer scientists at Brigham Young University will allow surgeons to instantly visualize any part of a patient's anatomy by extracting a 3D computer image from an MRI, CT scan, 3D ultrasound, or similar data with just a few clucks of the mouse. Called Live Surface, the software peels away body layers and extracts specific types of tissue, bones, and organs. It can also be used to extract a single actor's performance or inanimate objects from video clips.
HOW IT WORKS: The user identifies the object he wishes to extract by clicking and dragging the mouse, and then identifies those portions of the data that surround the object to extract it from the data. The program does this much more quickly than other similar software tools because it uses a hierarchical algorithm, or set of mathematical rules, that tells toe computer to eliminate irrelevant information in broad, coarse cuts. Once the bulk of unwanted data is gone, the computer can make more refined calculations more quickly. After a surgeon has extracted a 3D image of a person's heart or brain, for example, the image could then be projected onto the patient's body, fitted to create a road map for the surgeon as s/he operates.
BENEFITS: Instead of just showing patients the usual MRI, CT or ultrasound images in a few segmented slices, a physician can now show the patient exactly where the problem is, how big the tumor is, or rotate specific organs to get a view from all angles. Apart from helping radiologists and other physicians analyze patients' anatomy in better detail -- including locating hidden tumors -- the software tool can also help clinicians to better explain what is going on to patients. ABOUT CAT SCANS: CAT (Computerized Axial Tomography) scans are similar to conventional X-ray imaging, but instead of imaging the outline of bones and organs, a CAT scan machine forms a full three-dimensional computer model of the inside of a patient's body. Doctors can even examine the body one narrow slice at a time. The X-ray beam moves all around the patient, scanning from hundreds of different angles, and the computer takes all that information to compile a 3D image of the body.
HOW MRI WORKS: Magnetic resonance imaging uses radiofrequency waves and a strong magnetic field instead of X-rays to provide clear and detailed pictures of internal organs and tissues. These radio waves are directed at protons in hydrogen atoms -- one of the most abundant atoms in the human body, because of the body's high water content. The waves "excite" the protons, and when they "relax," they emit strong radio signals. A computer can turn those signals into a high-contrast image showing differences in the water content and distribution in various bodily tissues.
The American Association of Physicists in Medicine contributed to the information contained in the video portion of this report.
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.