Technology may hold the key to unlocking mysteries surrounding a painful urologic condition that affects hundreds of thousands of women in the United States.
A study by researchers at the University of Oklahoma Health Sciences Center and OMRF found the use of contrast-enhanced magnetic resonance imaging can lead to better diagnosis and ultimately more effective treatment for patients with interstitial cystitis.
Interstitial cystitis, also known as bladder pain syndrome, is marked by pain and a sense that one needs to urinate urgently and often.
“For those with more severe symptoms, it’s like having a urinary tract infection that won’t go away,” said principal investigator Robert Hurst, Ph.D., professor and director of Basic Research at the OU College of Medicine’s Department of Urology. “Fortunately, the symptoms tend to wax and wane so most sufferers do not experience the highest level of pain and discomfort continuously.”
However, some with interstitial cystitis experience ongoing discomfort, which can greatly impact quality of life.
“Interstitial cystitis is rough on marriages. Sex often becomes painful. Divorce is common, and many sufferers sink into depression,” Hurst said.
The condition is medically challenging, too, because it may have several causes and is often mistaken for urinary tract infection when there is no infection. In addition, diagnosis currently is complicated because patients may have a wide range of symptoms, physical exam findings and clinical test results.
Hurst said one hypothesis is that interstitial cystitis is caused by a “leaky bladder,” for example, a bladder with a wall that is permeable to urine solutes. While urine is mostly water, about five percent of it consists of a variety of chemical compounds including urea, uric acid, sodium, potassium, calcium, ammonia and magnesium. The theory is that in some patients with interstitial cystitis those compounds make their way into and through the bladder wall.
To test the theory, OU and OMRF researchers utilized contrast-enhanced magnetic resonance imaging with the contrast agent administered directly into the bladder of a small group of patients. They then compared the bladders of those with interstitial cystitis to those of study participants who do not have it.
“While non-contrast MRI can differentiate normal tissue from diseased tissue, sometimes a contrast agent can be used to further differentiate these changes. In the interstitial cystitis patients, the MRI contrast agent was found to be taken up into the bladder wall, indicating permeability alterations,” said Rheal Towner, Ph.D., associate member and director of the Advanced Magnetic Resonance Center at OMRF.
Towner led the imaging effort along with Dee Wu, Ph.D., research associate professor and chief of Technology Applications and Translational Research in the OU Department of Radiological Sciences.
“In essence, with a contrast medium in the bladder, it’s possible to actually watch the contrast pass into the bladder wall. In comparison, the normal bladder is impervious to it,” Hurst explained.
Towner said the contrast-enhanced MRI method developed by the OU/OMRF team potentially could provide a new and effective way to diagnose interstitial cystitis/bladder pain syndrome.
“There currently is no other diagnostic method for this syndrome,” Towner said.
The team believes their method also could spare patients unnecessary diagnostic testing and help expedite diagnosis.
“For the first time, it is possible to determine if a patient has a leaky bladder or not. This also will greatly facilitate clinical trials of therapies by better defining patient groups,” Hurst said.
Because the disorder varies greatly from patient to patient, one treatment may not work for everyone. However, the ability to distinguish those with bladder permeability from those without it provides a way to better identify patients who may benefit from potential treatments.
Also assisting in the research were: Amy Wisniewski, Ph.D., associate professor of Urology and director of Clinical Research; Abbas Shobeiri, M.D., professor, OU Department of Obstetrics and Gynecology; and Chris Aston, Ph.D., with OU’s Biomedical and Behavioral Methodology Core.
The study was funded by a grant from the National Institutes of Health, National Institute of Diabetes and Kidney Diseases (grant number P20DK097799).