Diagnostics & Imaging Week National Editor

When we ultimately, inevitably use up this planet and head out to find another, we will have to do more than reach that outer destination and find sources of oxygen, water and food.

We'll have to figure out a way to keep our bones from falling apart.

Yi-Xian Qin, PhD, says that on the Space Station or other outer-space missions, astronauts experience about 1.5% to 2% of bone loss every month and that longer flights will mean a general deterioration and aging of the skeletal structure, leading to much faster overall aging.

Qin is director of the Orthopaedic Bioengineering Research Laboratory at Stony Brook University (Stony Brook, New York). And along with colleagues at Stony Brook and researchers is advanced ultrasound technology to National Space Biomedical Research Institute (NSBRI; Houston), Qin is developing advanced ultrasound technology designed to provide a much more definitive assessment of bone structure and the nature and pace of loss than standard ultrasound scanning, currently used primarily as a screening tool.

Qin told Diagnostics & Imaging Week that the approach has two purposes: to better track how micro-gravity environments impact bone loss in astronauts during long space flights, and to provide a pathway for development of a more precise diagnostic instrument for the benefit of aging earthlings.

A third potential use is therapeutic — faster healing of fractures, whether on space flight, distant planet or home planet.

Qin, also associate team leader for NSBRI's Smart Medical Systems and Technology Team, spoke to D&IW from Las Vegas, where he was a presenter at the recent American Academy of Orthpaedic Surgeons (Rosemont, Illinois) conference, discussing his research concerning how bone senses and responds to biomechanical stimuli in maintaining its structure and remodeling.

Qin terms his new ultrasound system Scanning Confocal Acoustic Navigation (SCAN), and he says it is a large advance because it is able to provide much more information about bone beyond mineral density, namely bone qualities such as strength, structure and stiffness.

The team also is working to develop a small, mobile SCAN device for clinical practice, the mobile scanning instrument "about the size of a shoebox," he explains, that runs off a laptop computer that can image a heel or wrist in about five minutes by means of special algorithms that assess multiple parameters of bone.

Besides working with NASA on the system for use in outer space, Qin says that Stony Brook University's technology transfer department is pursuing commercialization opportunities with device firms.

"SCAN uses non-invasive and non-destructive ultrasound to image bone, and the technology enables us to identify weak regions, as well as make a diagnosis and to assist in healing fractures," he says.

"With confocal scanning, we can increase the resolution and also the accuracy, by the convergence of the ultrasound beam directly into the region of trabecular or sponge bone area and give a better image," and an assessment of bone stiffness.

This is possible, he says, because the quality of bone is a greater predictor of fracture risk than bone density.

Stress-related fractures are a major concern for astronauts during long missions to the moon or in space, Qin says. Fracture rates on space journeys or on the moon or another planet could be frequent due to the effect of much reduced gravity (on the moon, one-sixth of earth's), combined with workload force and the stresses multiplied in heavy spacesuits.

Testing the technology in space will be beneficial to those with osteoporosis or other bone disorders, he says.

Qin is currently conducting evaluations of the diagnostic component of SCAN with small groups at the university volunteering as patients. Also under development is the capability to scan the knee and hip, as well as the spinal cord.

Qin and his team at Stony Brook and the NSBRI also are developing the therapeutic portion of the technology.

He told D&IW that the system, as now conceived, can't be used for the entire skeleton but could be employed locally to accelerate fracture healing by stimulating bone regeneration.

Ultrasound has been used to heal fractures with better accuracy and effectiveness at the fracture site than the current technology.

"We are trying to use ultrasound technology as a way to get an image of the fracture site," explains Qin. "An integrated probe will directly shoot ultrasound into the region of the fracture. We hope this will result in effective acceleration of fracture healing."

Besides offering benefits to an increasing aging population, SCAN technology would have much more capabilities and be smaller, easier, and cheaper to use than current X-ray based bone density measurement machines, Qin says.

The Orthopaedic Bioengineering Research Laboratory at Stony Brook University, part of the Department of Biomedical Engineering, is focused on understanding the micro-nano level mechanisms involved in the control of tissue growth, healing, and homeostasis, especially hard tissue adaptation influenced by the physical environment. The lab examines how these mechanisms can be utilized in the treatment and prevention of diseases.

NSBRI, funded by NASA, is a consortium of institutions studying the health risks related to long-duration spaceflight. The institute's science, technology and education projects take place at more than 60 U.S. institutions.

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