Ordering CT scans is part of Dr. Shireen Fatemi’s daily job. As an endocrinologist at Kaiser Permanente Panorama City, she frequently orders the computed tomography scans to determine the cause of severe stomach aches, back pain, diverticulitis, or other ailments.
New technology, though, may soon give those old CT scans a new life. It could one day also be used to determine if a patient has weak bones, a condition called osteoporosis.
“We did research that showed using this new technology, you can get information about a patient’s risk for a fracture without any additional tests or radiation,” Dr. Fatemi said. “This technology has great potential, especially for our patients over 65.”
Dr. Fatemi was one of the authors of research published today in the Journal of Bone and Mineral Research. The research demonstrated that CT scans taken in the past for an unrelated purpose could successfully screen for osteoporosis. The new technology, a semi-automated software-based analysis that uses specialized software, has the potential to allow physicians to check older patients for osteoporosis without a specialized X-ray.
Researchers have applied for funding to complete a pilot study at the Panorama City Medical Center and further test the technology before recommending it for general clinical use. This first study, published today, looked at CT scans taken in the past. The pilot study would examine the feasibility of analyzing CT scans for osteoporosis whenever a CT scan is taken of a patient whose age may put them at risk of osteoporosis.
Osteoporosis increases risk of fractures
Osteoporosis reduces bone strength and causes millions of fractures each year. It typically affects people over the age of 65. Hip fractures are the most serious and costly fractures caused by osteoporosis. Most often, osteoporosis is diagnosed by measuring bone mineral density using dual-energy X-ray absorptiometry (DXA) scans, a specialized type of X-ray used specifically to determine bone density.
However, rates of testing are low.
“Osteoporosis is asymptomatic until you have a fracture,” said Annette Adams, PhD, of Kaiser Permanente Southern California Department of Research & Evaluation, who led the study. “But this is an opportunity to screen patients for osteoporosis without an extra image that exposes the patient to additional radiation. It’s a way of screening people who may have osteoporosis but who don’t know it.”
Researchers analyzed health records
To test the potential of the CT scans, the researchers conducted an analysis of health records of patients ages 65 years and older who were seen at 11 Kaiser Permanente hospitals in Southern California. The patients had undergone abdominal or pelvic CT scans between 2006 and 2014, and a DXA scan within 3 years of the CT scan. They had not experienced a hip fracture before the CT scan was taken.
A total of 1,340 women and 619 men had a first hip fracture during the study period. They were compared to randomly selected subjects without hip fractures. The new technology assessed both bone mineral density and bone strength. Researchers found that the 86 percent of the incidental CT scan provided valid measurements, and identified more patients who later developed fractures.
Technology builds on structural analysis
A professor of mechanical engineering and bioengineering at University of California, Berkeley, Tony Keaveny, PhD, developed the software that allows the CT scans to determine a bone’s density, strength, and risk of fracture. The bone mineral density is the same as what you get from a DXA scan. In addition, the software uses finite element analysis — which is typically used by engineers to assess the integrity of structures such as buildings and bridges and even medical devices — to assess bone strength.
“Working from a patient’s previously taken CT scan, our computer technology starts by isolating the image of a bone, typically the hip because that’s where you get the most severe fractures,” Dr. Keaveny said. “Then, on the computer, we virtually stress the bone, applying bigger and bigger forces until we virtually break the bone, and in that way, we estimate the breaking strength of the bone; the lower your strength, the higher your risk of fracture.”
If it was discovered that someone did have osteoporosis, they would be able to receive prompt care to reduce risk of a fracture, Dr. Fatemi said. The care could include several interventions including medication, taking calcium and vitamin D, regular exercise and avoiding excessive tobacco and alcohol.
Dr. Adams noted that if people don’t know they have osteoporosis, they typically don’t do anything about it.
“This research, though, has shown we may be able to use incidental CT scans to determine who is at risk,” she said. “When you save an older person from a fracture, you may just be saving their life.”