Kyla Kent had just finished conducting CT scans of bones in a 10-year-old boy’s forearm and lower leg. Walking him back to the waiting room, she asked how he wanted to explain the images to his mom.
The detailed view provided by the CT machine, a high-resolution peripheral quantitative computed tomography scanner called XtremeCT II, is giving Stanford scientists unusually precise information about the toll of chronic diseases on children’s bones. But young research participants are often more excited about the images’ gee-whiz factor. Kent could sense the boy’s mental wheels turning.
“Mom, here’s what happened,” the boy said. “From a single cell, a very small wizard was born. And he goes inside my arm—it doesn’t hurt, I just felt a little pinch—and while he’s in there, he takes a picture of the inside of my bone with his iPhone 6s camera!”
Kent, telling the story, stopped and chuckled. “I could not have come up with that explanation on my own,” she said. Kent is the technical director of the Stanford Assessment of Bone and Muscle Across the Ages Center, or SAMBA Center, a multidisciplinary research effort to document and find ways to improve bone health over the life span.
The work, much of which focuses on kids, is led by Mary Leonard, MD, professor of pediatrics and of medicine and the center’s founding director. Many chronic childhood diseases, including diabetes, chronic kidney disease, inflammatory bowel disease, congenital heart defects, and childhood cancer, take a silent toll on patients’ bones. Leonard and her team want to help patients maximize their bone health in childhood and reduce their risk for osteoporosis later on.
One key tool in Leonard’s efforts to do that is the SAMBA Center’s high-resolution CT scanner, the only such machine west of Missouri. It is designed to provide an extremely detailed view of the bone structure inside the arms and legs, and it uses much less radiation than a typical medical CT scanner.
The high-resolution CT is such a new tool that the Stanford team had to begin by creating a normative database of bone scans from healthy children, a process that is still underway. They are also collaborating with other scientists around the world to agree on standardized methods for running the scans.
The team’s work is an example of Stanford Medicine’s focus on precision health, the goal of which is to anticipate and prevent disease in the healthy and precisely diagnose and treat disease in the ill.
The team is also using more traditional methods of assessing bone health, including dual X-ray absorptiometry, or DXA, scans, which provide information about children’s overall bone mass, lean body mass and body composition, as well as hand-grip testing, leg-endurance testing and maximum force generation tests, which measure different elements of limb strength to allow the team to assess how bones and muscles function as a unit.
