Microgravity shoulder scan makes ultrasound history

While exploration of Mars and Saturn accounts for most of the news from outer space these days, astronauts aboard the International Space Station have quietly published the results of a shoulder ultrasound exam performed in zero gravity.

The first medical research paper ever submitted from the International Space Station was published in the February edition of Radiology.

Study coauthor Dr. Marnix van Holsbeeck, division director of musculoskeletal radiology at Henry Ford Hospital in Detroit, assisted in the project. His experience with remote-guided ultrasound began (and continues) with professional sports teams. During Detroit Red Wing hockey games, for example, van Holsbeeck has remotely guided the athletic trainer to quickly triage injured players.

Astronauts risk musculoskeletal injury because prolonged spaceflight results in a reduction in bone, muscle, and tendon mass-about 2% per month. Their shoulders are particularly vulnerable to injury, due to strenuous physical work during spacewalks and limited upper body and arm mobility in spacesuits.

Van Holsbeeck and Dr. Scott A. Dulchavsky, a surgeon at Henry Ford who had worked in the space industry, trained Dr. Ashot E. Sargsyan, the remote sonologist, in musculoskeletal ultrasound. Sargsyan, a radiologist with Wylie Laboratories in Houston, had extensive experience in abdominal ultrasound but none in joints, van Holsbeeck said.

On board the space station, Science Officer E. Michael Fincke and Commander Gennady Palalka performed full unilateral shoulder musculoskeletal exams on each other. They included transverse and longitudinal views of the biceps and supraspinatus tendons and the articular cartilage surface. The exams were initiated with the probe positioned at the distal end of the clavicle in a longitudinal attitude. Sargsyan "steered" the probe with voice commands.

Each exam took less than 15 minutes to perform. The Houston team reported that the real-time video and still frames provided excellent-quality detail to exclude subtle shoulder injury.

This research has direct implications for the fields of emergency, rural, and remote medicine, van Holsbeeck said. Emergency crews can, for example, place a transducer on a patient's abdomen, while the remote expert determines whether there is fluid present. Patients with penetrating injury to the chest can be checked for pericardial effusion or tamponade, and pneumothorax can be diagnosed in an ambulance for a faster triage. More immediately, van Holsbeeck is using this technology to virtually connect the sprawling facilities of the Henry Ford complex.

In a related development, investigators at Stony Brook University on Long Island, NY, have developed an ultrasound-based device that can diagnose bone loss in space. The scanning confocal acoustic diagnostic system (SCAD) will help physicians on the ground determine the rate of bone loss and severity of injuries sustained in space, as well as appropriate recovery planning, said Dr. Yi-Xian Qin, an associate team leader of NASA's National Space Biomedical Research Institute.

Compared with FDA-approved quantitative ultrasound technology clinically available for diagnosing osteoporosis, SCAD provides an image-based assessment of bone strength in a region of interest. The device can increase ultrasound's accuracy and reduce noise from soft tissue by providing real-time mapping of the bone.

Researchers anticipate that SCAD could help physicians in several clinical fields improve the early diagnosis of conditions such as osteopenia and osteoporosis, which are difficult to diagnose during their initial stages.