Advanced Computer Imaging Tech Tapped to Reconstruct Bladder

Researchers have used images from cameras attached to long, flexible instruments called endoscopes and then advanced computer imaging technology to create a three-dimensional computer reconstruction of a patient’s bladder.

With this fusion of medicine and engineering, doctors could develop organ maps, better prepare for operations and detect early cancer recurrences.

With endoscopes but without the computer imaging technology, the way doctors examine the bladder for tumors or stones is like exploring the contours of a cave with a flashlight, as they find it sometimes difficult to orient the location of masses within the bladder’s blood vessel-lined walls.

However, bladder cancer has among the highest recurrence rates of any cancer. From 50 percent to 70 percent of tumors return after removal, according to Joseph Liao, an associate professor of urology at the Standford University School of Medicine and co-senior author on a paper published in Biomedical Optics Express.

Being able to see each patient’s bladder as a three-dimensional model could improve surgical planning and monitor cancer recurrence.

“The beauty of this project is that we can take data that doctors are already collecting,” Audrey Bowden, assistant professor in Stanford’s Department of Electrical Engineering and co-senior author on the paper, was quoted as saying in a news release.

Endoscopy of the bladder, called cystoscopy, is an integral part of cancer management, according to Liao. One of the technique’s advantages is that doctors don’t have to buy new hardware or modify their techniques significantly. Through the use of advanced computer vision algorithms, the team reconstructed the shape and internal appearance of a bladder using the video footage from a routine cystoscopy, which would ordinarily have been discarded or not recorded in the first place.

To test the accuracy of their reconstruction, the team created a model based on endoscopy images taken in a 3D-printed bladder, known as a tissue phantom. Because the details of the tissue phantom are known, the researchers compared their rendering to the real thing and found they matched with few errors.

“Sometimes you don’t have a sense – where was I in the bladder?” Liao said. Seeing a three-dimensional rendering of an organ before operating, like having a map before embarking on a trip, could make the procedure easier for doctors. Other potential applications include using the 3D reconstruction as a visual medical record.

Although the team developed the technique for the bladder, it could be applied to other hollow organs where doctors routinely perform endoscopy, including the stomach or colon. “We were the first group to achieve complete 3D bladder models using standard clinical equipment, which makes this research ripe for rapid translation to clinical practice,” said Kristin Lurie, lead author on the paper, a recent PhD graduate and postdoctoral fellow at Stanford, and a current software engineer at Google, a subsidiary of Alphabet Inc.

This technique is the first of its kind and still has room for improvement, the researchers said. Primarily, the three-dimensional models tend to flatten out bumps on the bladder wall, including tumors. With the model alone, this may make tumors harder to spot. The team is now working to advance the realism, in shape and detail, of the models. (PNA/Xinhua)
RMA/SSC