Researchers at the University of Washington (UW) in Seattle are developing a semi-automated method that could provide a more economical, more comfortable and more convenient method for bladder imaging.
Bladder cancer is the fourth most common cancer in men and one of the most expensive cancers to treat from diagnosis to death. After initial diagnosis and surgery, patients must return to the urologist at least yearly for a costly, time-consuming and uncomfortable bladder scan. Tumors recur in more than half of patients.
The proposed system would use the UW's ultrathin laser endoscope, the scanning fiber endoscope (SFE), in combination with software that stitches together images from the scope's path to create a 3D panorama of the bladder interior. Michael Porter, MD, a UW assistant professor of urology, explained, "The SFE is an advance compared to current scopes because of its small size (2 mm compared with 6 mm for traditional flexible scopes). It is also capable of seamlessly incorporating narrow band imaging (NBI) and fluorescence imaging without the need for add on equipment."
The project merges the SFE with mosaicing software being developed by UW researchers to create a 3D image of the bladder that can be stored and manipulated, similar to a 3D reconstruction of a CT scan.
The semi-automated scan could be completed by a nurse or technician, and images could be reviewed by a urologist at a later time, potentially in another city or country.
"This is trying to bring endoscopy to a more digital, modern age," said co-author Eric Seibel, PhD, a UW research associate professor of mechanical engineering. "Currently, video images obtained during cystoscopy are not saved. The ability to save these images reconstructed into a single 3D image has the potential to improve documentation, allow for telemedicine applications, and is a step towards automating cystoscopic examination of the bladder," added Porter.
The UW software checks that no part of the organ was missed, so a nurse or technician could administer the procedure–especially using a small scope that doesn't require anesthesia.
"There's a potential with this technology to semi-automate or fully automate the examination," Porter offered. "It's a few years down the road, at least, but the potential is there."
The current user interface projects the reconstructed organ onto a spherical ball or onto a flat map. The resulting mosaic matches the images to a single pixel of accuracy. Ultimately, the digital display would incorporate all the original frames, so a physician could zoom into an area of interest and observe it from all angles at the highest resolution.
"Essentially, I want to give urologists a Google Earth view of the bladder," added co-author Timothy Soper, PhD, a UW research scientist in mechanical engineering. "As you move the mouse over the 3D surface it would show the individual frame showing exactly where that image came from. So you could have the forest and the trees."
Reviewing the resulting panoramic image would likely require less of the urologist's time than performing a manual inspection.
UW researchers are waiting for FDA safety clearance to test the scope for human bladder scans and pursuing funding options. The next step will ask urologists to compare their experiences of performing a diagnosis from a live video scan of a human bladder with the 3D digital recreation.