Sonographic Astronaut Vertebral
Examination (Spinal Ultrasound)
OpNom: Spinal Ultrasound
This content was provided by Scott A. Dulchavsky, M.D., Ph.D., and is maintained in a database by the ISS Program Science Office.
Sonographic Astronaut Vertebral Examination (Spinal Ultrasound) aims to use ground and space-based studies to characterize spinal changes during and after spaceflight. Ground based pre- and post-flight MRI and high fidelity ultrasound, combined with in-flight ultrasound will be used to characterize and assign a mission health risk to microgravity-associated spinal alterations for back pain and potential injury. This research will determine the accuracy of MRI and musculoskeletal ultrasound in characterizing the anatomy of the vertebral unit and develop novel imaging and training methodologies.
Scott A. Dulchavsky, M.D., Ph.D., Henry Ford Hospital, Detroit, MI, United States
Vicky Byrne, M.S., Lockheed Martin, Houston, TX, United States
Douglas Ebert, Ph.D., Wyle Laboratories, Houston, TX, United States
Kathleen M. Garcia, Wyle Laboratories, Houston, TX, United States
Ashot E. Sargsyan, M.D., Wyle Laboratories, Houston, TX, United States
Johnson Space Center, Houston, TX, United States
Henry Ford Health System, Detroit, MI, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
ISS Expedition Duration:
May 2012 – September 2014
Previous ISS Missions
Advanced Diagnostic Ultrasound in Microgravity (ADUM) was conducted during Expeditions 8 through 12. The objective of that experiment was to develop training methodologies to teach non-physician astronauts to perform advanced ultrasound examinations on the International Space Station. An Onboard Proficiency Enhancement educational program was developed to facilitate the examinations.
- The risk of intervertebral disk (IVD) damage due to extended microgravity exposure, launch or landing forces, or other unrealized causes (radiation, nutrition/metabolism, etc.) has been identified as a risk that should be further investigated and addressed for long-duration space missions.
- This proposal will provide real-time data regarding adaptation of the vertebral unit during long-duration spaceflight to capture the progression of IVD changes, assist with the identification of causes of IVD damage, and enhance mission completion, countermeasure development, and astronaut health.
- The ability to assess the crewmember musculoskeletal system is critical to guide countermeasures, provide functional data for high risk or high impact activities, and assess acute injuries which may occur during exploration class spaceflight or return to Earth. This investigation will provide essential data to quantify the risk of spine related complications for crewmembers following long duration microgravity exposure. The procedures developed and verified through this research will provide novel data and capabilities to enhance crew health for long duration space missions.
There has been a long standing observation of increased height in shuttle astronauts and long-duration crewmembers after exposure to microgravity. Height measurements conducted on orbit and immediately on post-flight have consistently shown an up to 3% increase; however, the exact mechanism is unclear. Proposed causes include alteration and redistribution of postural muscle tone, gravitational unloading of the intervertebral discs, and an increase in disc water content/composition. Back pain is a frequent medical complaint during early adaption to reduced gravity conditions; fortunately, this has not been reported as an appreciable impediment to completion of mission objectives. The mechanisms of back pain, which is reported to be more pronounced in early days of space missions, are likely associated with the elongation of the spinal column, including the postural adaptations of its shape in free-floating and forced positions aboard the spacecraft. Quantification and characterization of these changes has relevance to the well-being of crewmembers as well as to Soyuz landing safety concerns if spinal elongation results in an overly tight fit in the personal Kazbek seat liner. Additionally, spinal elongation may contribute to changes in volume and compliance of the spinal canal, which could have a direct effect on cerebrospinal fluid hydrodynamics. This research teams combines experts in musculoskeletal (MSK) ultrasound at Henry Ford Health Systems (HFHS) and space medical experts at Wyle in an investigation that uses ultrasound to characterize spaceflight-associated changes in the lumbar and cervical spine. The focus of this study is the in-flight comparison of lumber and cervical spine dimensions measured with musculoskeletal ultrasound as compared to pre and post flight MRI and ultrasound. The study will couple MRI examinations with ultrasound imagery to enhance accuracy and reduce training requirements. This study will provide operationally relevant data to optimize crew health and guide countermeasure development. This research will determine the accuracy of MRI and musculoskeletal ultrasound in characterizing the anatomy of the vertebral unit (disc, musculature, facets, and ligaments) to provide essential information to address operational issues associated with spinal changes during spaceflight.
This project will provide longitudinal, real-time data regarding adaptation of the vertebral unit during long-duration spaceflight that will contribute to countermeasure development, astronaut health, and mission completion. The ability to assess crewmembers’ musculoskeletal systems is critical to guide countermeasures, provide functional data for high risk or high impact activities, and assess acute injuries which may occur during exploration class spaceflight or during return to Earth. This project will provide essential data and methods to quantify the risk of spine related complications for crewmembers following long duration spaceflight exposure. Astronaut-performed ultrasound examinations on the ISS have demonstrated that diagnostic quality images can be obtained with targeted training; the procedures developed and verified through this investigation will provide novel capabilities to enhance crew health for long duration space missions.
The American Institute of Ultrasound in Medicine issued the following statement on April 6, 2009 concerning non-operative, spinal and paraspinal ultrasound: “There is insufficient evidence in the peer-reviewed medical literature establishing the value of nonoperative spinal/paraspinal ultrasound in adults. Therefore, the AIUM states that, at this time, the use of non-operative spinal/paraspinal ultrasound in adults (for study of intervertebral discs, facet joints and capsules, central nerves and fascial edema, and other subtle paraspinous abnormalities), for screening, diagnostic evaluation, including pain or radiculopathy syndromes, and for monitoring of therapy has no proven clinical utility. Nonoperative spinal/paraspinal ultrasound in adults should be considered investigational. The AIUM urges investigators to perform properly designed research projects to evaluate the efficacy of these diagnostic spinal ultrasound examinations”. There has been no pressing need for the use of ultrasound in spinal examination of adults in the standard clinical setting due to the availability of advanced imaging in developed nations and the common agreement that MRI imaging is the preferred method of spinal characterization. Prior to the ground breaking research conducted during the ADUM experiment and working with the ISS lab, there were no peer reviewed journal articles on the use of lung ultrasound for the detection of pneumothorax in clinical evaluation; X-ray and clinical evaluation were the standard. During the ADUM investigation, this investigative team introduced clinical evidence that ultrasound could be used for detection of normal lung function and for the detection of pneumothorax. Today, ultrasound is used for pre-hospital clinics and emergency room settings worldwide.
In the austere environment of the ISS, this investigation seeks to provide evidence-based information to expand the role of ultrasound into the realm of spinal evaluation and will significantly contribute to medical care on Earth in settings where there is limited access to advanced imaging such as MRI.
Six long-duration crewmember subjects are required for this experiment. In-flight scanning sessions are planned on flight day 30 (FD30) ± 15 days, FD90 ± 15 days, and FD150 ± 15 days. Both an operator and a subject are required for the ultrasound scans along with real-time video downlink to enable remote guidance by ground experts.
In-fight cervical and lumbosacral ultrasound scan sessions will be performed at FD30 (±15), FD90 (±15), and FD150 (±15). Up to 7 days prior to the scanning sessions, ultrasound operators will be asked to view Spinal Ultrasound Experiment Review software materials and participate in a short teleconference with members of the experimental team. These planning sessions are expected to be shorter for subsequent scans with the same operator.
Each in-flight session will consist of experiment set-up, subject data collection, and data transfer. The scanning sessions are requested as early as possible in the morning and prior to any exercise activity, particularly any that produces axial loading. The ultrasound images to be collected include the cervical and lumbar spine and surrounding tissues; ECG will be collected as part of the ultrasound exam. Cabin video will be set up slightly above and to the side of the crew for viewing of the optimal angle of the ultrasound probe position in relationship to the subject’s body. It is preferred that both the cervical and the lumbar data be collected at the same time, but measurements can be taken in separate sessions if required to meet scheduling constraints.
The crewmember subject will be restrained supine on the CMRS in order to maintain a stationary position for the majority of the exam; one prone viewing position will also be used. The operator will use a combination of Spinal Ultrasound Experiment Review software and remote guidance to allow the operator to perform a comprehensive evaluation of the cervical and lumbosacral vertebral units for the assessment of alterations in intervertebral disc (IVD) spacing, ligaments, and other structural and functional relationships secondary to prolonged microgravity. The in-flight procedures will be designed to obtain ultrasound images which correspond to pre- and post-flight data sets.