Doctors Take Virtual Reality Tours Inside Patients

Nov. 29, 2000 (Chicago) -- Remember Raquel Welch breathlessly navigating a microscopic space ship through the human body in the cult classic Fantastic Voyage? Well, Raquel is not on board but radiologists are "flying" through the inner ear using high-tech CT scans that offer an inside view of the human anatomy.

Show time was yesterday at an international radiology meeting here. Raleigh F. Johnson Jr., PhD, says his souped up 3D CT seems to erase bone and allows ear specialists to fly through the inner ear "from the brain's point-of-view."

Traditionally, ear specialists use an endoscope -- a type of flexible scope that has a tiny camera mounted on the tip -- to see inside the ear. But to get to the inner ear, anyone using this traditional scope must first pierce part of the skull. Johnson, director of radiological sciences and 3D imaging at the University of Texas Medical Branch at Galveston, says his 3D program gives as good an image as a traditional scope without having to pierce the skull at the temple. He tells WebMD that ear specialists who have seen the program "can almost immediately orient themselves to the image because it is very much like the image they see in their scopes, but without the invasive aspect."

CTs take "pictures" of multiple thin slices of parts of the body, which Johnson's 3D program stacks and processes in a way that creates an enhanced 3D image. His program then allows doctors to create a specific view and "fly through" the area of concern. Johnson says his program navigates through "these very delicate structures that are actually less than one millimeter in diameter and yet we can clearly visualize the structure."

Brian J. Penrod, MD, chief of musculoskeletal radiology at Brooke Army Medical Center, says he is using a similar virtual reality 3D CT to assist orthopaedic surgeons. He tells WebMD that by using the virtual reality programs, he is able to show the orthopaedic surgeons that when they go in to view the inside of a joint, "this is exactly what you will see and this is exactly how it will look."

Virtual reality 3D CT is not new, says Geoffrey D. Rubin, MD, associate professor of radiology at Stanford University School of Medicine. At a previous meeting, they "did a fly through of the sinus. I think that we continue to see a lot of 'gee whiz' images but the real perspective on this work is that it is now five years since we first saw the technology. So, are we making great leaps? Is it improving treatment?"

Rubin says that he has not yet seen evidence of that much anticipated improvement. He cautions against "every year reinventing the wheel." The goal, he says, is to advance treatment. Rubin says the area where the "breakthrough with 3D CT may come is virtual colonoscopy." He says that doctors who do colonoscopy -- in which a scope is inserted into the colon as a screening test for colon cancer -- seem to be those most interested in the technology.

"I think the reason for that is that we can do so much more with 3D CT than one can do with traditional colonoscopy. We can straighten out the colon" which gives the specialists novel perspectives, he says. Additionally, using virtual colonoscopy eliminates the need for sedation and thus may make the procedure more acceptable to patients.

Penrod and Johnson agree that patients may drive acceptance of "virtual reality" imaging because the noninvasive nature is appealing to many patients.

Currently, Johnson says the inner ear program is being used mainly as an educational tool. He says, however, that he is planning a large-scale study to compare the accuracy of the program with more traditional techniques.