|
|
||||||||
Special Reports |
1 From the National Aeronautics and Space Administration, Johnson Space Center, Houston, Tex (E.M.F., G.P.); Texas Diagnostic Imaging, Dallas, Tex (D.L.); Departments of Radiology (M.v.H.) and Surgery (K.M., S.A.D.), Henry Ford Hospital, 2799 W Grand Blvd, Detroit, MI 48202; and Wyle Laboratories, Houston, Tex (A.E.S., D.R.H., D.M., S.L.M.). Received September 30, 2004; revision requested October 12; revision received October 14; accepted October 15. Supported by NASA Flight Grant NNJ04HB07A and the National Space Biomedical Research Institute Grant SMS00301. Address correspondence to S.A.D. (e-mail: sdulcha1@hfhs.org).
| ABSTRACT |
|---|
|
|
|---|
Supplemental material: radiology.rsnajnls.org/cgi/content/full/2342041680/DC1
© RSNA, 2004
| INTRODUCTION |
|---|
|
|
|---|
Some alterations in musculoskeletal integrity take place during prolonged exposure to microgravity, despite the generally successful exercise countermeasures (5). Insidious reduction in bone, muscle, and tendon mass that has been observed during spaceflight may heighten the risk of musculoskeletal injury. In addition, strenuous physical work during spacewalks, combined with upper body and arm motion constrained by the current spacesuits, further raises the likelihood of shoulder injury.
The assessment of musculoskeletal integrity is difficult in space because of limited medical training of the crew and a lack of radiographic and magnetic resonance imaging capabilities on either the transport vehicles or the ISS (6,7). However, a multipurpose diagnostic ultrasonographic (US) system is available within the Human Research Facility (HRF) of the ISS. We evaluated the ability of a nonphysician astronaut operator to perform shoulder US by using remote guidance techniques. This report documents the first shoulder US examination ever performed in microgravity of spaceflight.
| Astronaut Training |
|---|
|
|
|---|
Astronaut crewmembers attended a 2.5-hour US familiarization session approximately 4 months before this evaluation to include a brief didactic presentation on the basics of US examination and the experiment-specific principles of remote guidance. The crewmembers also participated in a hands-on US session in the Payload Development Laboratory at the Johnson Space Center, Houston, Tex, where they performed abdominal and musculoskeletal US on a human subject via remote guidance from an experienced sonologist (A.S. and D.L., with 15 and 10 years of experience in musculoskeletal US, respectively). The hands-on sessions were designed to closely simulate in-orbit experiments. Real-time US images were transmitted to the remote sonologist, who guided the astronauts through the necessary positioning, probe placement and manipulation, and equipment adjustments to obtain optimal images. Identical remote-guidance "cue cards" were available to the guiding experienced sonologist on the ground and the operator onboard. The cards included keyboard prompts, anatomic reference points, and other essential information to increase remote guidance efficiency.
| Imaging, Evaluation, and Communication |
|---|
|
|
|---|
The astronauts were asked to develop specific restraining techniques for both the subject and the operator, which would allow access to the upper arm and shoulder area, provide stability for the examination, allow unrestricted use of the keyboard, and help avoid operator hand fatigue.
The astronaut US operator completed a 1-hour computer-based US "refresher" course by using the Onboard Proficiency Enhancement (OPE) compact disk developed by the evaluation team 1 week before the US session. Information regarding OPE navigation, time on task, and query responses was stored on the ISS computer and was downlinked to the evaluation team before the US session to allow the team to refine the procedure or highlight certain procedural components to facilitate the upcoming US evaluations.
The US session was completed during scheduled Ku-band (video) and S-band (voice) communications. Dynamic US video was routed through the ISS communications system to the Telescience Center at the Johnson Space Center, where the ground-based experienced sonologist viewed the video output from the US machine with near real-time (1.6-second delay) conditions. Two-way audio communication with the US operator was used to guide US probe placement and adjust US device settings.
A full unilateral shoulder musculoskeletal examination was conducted, which included transverse and longitudinal views of the biceps and supraspinatus tendons and the articular cartilage surface. The examination was initiated with the probe positioned at the distal end of the clavicle in a longitudinal attitude. The probe was "steered" with remote experienced sonologist voice commands to achieve the desired images. After acquisition of the four views of the shoulder area, the subject and operator aboard the ISS switched roles, and the examination was repeated.
Examination completeness was evaluated initially by the ground-based experienced musculoskeletal sonologist by viewing the real-time downlinked US video stream. Full-resolution US frames were saved during the examination and were downlinked to the Telescience Center at a later time. These images were subsequently reviewed by an outside musculoskeletal US specialist (M.v.H.) to verify the diagnostic quality of the examination and the ability to exclude injury on the resultant images.
| Findings |
|---|
|
|
|---|
|
|
|
|
|
| DISCUSSION |
|---|
|
|
|---|
US is currently used in many trauma centers to diagnose abdominal injury (8,9). The technique has been shown to be accurate and sensitive in the identification of intraabdominal hemorrhage, even when performed by nonradiologists or nonphysicians (10). NASA investigators have similarly demonstrated that US can be used by nonphysicians to diagnose thoracic injury or bone fracture. The performance of US examinations and interpretation of images for the detection of abdominal bleeding or long-bone fracture do not require extensive training. Conversely, musculoskeletal US is substantially more complex and requires specialized expertise during both data acquisition and image interpretation.
Basic ultrasonic imaging has been completed on both U.S. and Russian spacecraft (5,11,12). NASA investigators have demonstrated a wide array of diagnostic US applications in microgravity experiments on animal models and human volunteers during parabolic flight on KC-135 aircraft. Results of these investigations suggest that the sensitivity and specificity of these US applications are not degraded in microgravity and may even be enhanced in certain circumstances. More comprehensive US examinations (eg, abdominal, musculoskeletal, and cardiac) require considerably more operator experience to perform and interpret autonomously. Since extensive US training with frequent refresher practice is not feasible in many situations, including remote medicine or the space program, alternative paradigms of US examination are required for this application.
Remote US guidance by experienced sonologists virtually couples a modestly trained US operator with a remote sonologist. The US operator is trained in basic US operation and gross requirements of the US examination. The operator places the US probe in a predetermined and familiar starting point (aided by topologic reference cue cards), and the video stream from the US device is split between the on-site monitor and a remote location, where it is viewed by the experienced sonologist. Optimal probe position and device settings are guided with voice commands from the remote sonologist to obtain the necessary US images.
The remote guidance paradigm substantially reduces initial and refresher operator training requirements and allows experienced sonologist input during the conduct of the examination. We combined remote guidance with a focused review of complex US to complete the shoulder musculoskeletal examinations. The unique software used for OPE evaluation in this project streamlined equipment setup and subject and operator positioning and facilitated the successful completion of the complex US tasks by means of remote guidance. This "just-in-time" training approach allowed preflight and in-flight training time to be reduced substantially. The OPE program was constructed in modules that allow future HRF refinements or equipment alterations to be modified electronically as required. The program also can be used as a framework for other complex tasks that require focused skills or complex instructions. The self-reporting feature of the program allowed the experienced sonologists on the ground to assess operator familiarity with the procedures to better prepare for and conduct the session.
The evaluation of shoulder integrity with the use of US is the standard of care at many institutions and is used by professional athletic teams to evaluate injuries to athletes. Astronaut crewmembers may be at risk of shoulder injury during long-duration spaceflight because of decreases in muscle and tendon mass and exertion during space walks. The extravehicular activity suits that are worn constrain upper body and arm movement. Construction requirements on the ISS and future exploratory missions involving extravehicular activities can increase strain on the shoulder joint. A reliable method for evaluation of shoulder integrity during long-duration space missions would increase medical care capabilities for this operationally relevant concern.
Shoulder musculoskeletal US was performed rapidly and accurately by the two astronaut crewmembers aboard the ISS. The average time to perform the examination was less than 15 minutes. The conduct of the examination was not appreciably different than similar examinations in a terrestrial environment and was aided by innovative restraint techniques developed by the crewmembers (Movie 4, radiology.rsnajnls.org/cgi/content/full/2342041680/DC1). The quality of the near real-time US video transmitted to the Telescience Center was very good and could be used to exclude substantial shoulder musculoskeletal injury. Still US images were obtained during the examination and were downlinked to the team afterward. These high-fidelity images were of excellent diagnostic quality and could be used to exclude subtle changes in shoulder integrity.
The ability of the ISS crew to perform complex US tasks aboard the ISS supports the hypothesis that a nonphysician crewmember with modest training in US can perform high-fidelity diagnostic-quality examinations when directed by a ground-based experienced sonologist. The images acquired by the astronaut in this study were of excellent content and quality, and in a "real" medical scenario, they would have provided essential information to guide clinical decision making. There were no discernible differences between the US examinations performed in orbit and those performed in standard terrestrial conditions when the images were evaluated by the experienced sonologists involved in this trial.
The optimal training of crewmembers for the ISS and later exploration-class missions is still being defined. This initial US experience suggests that limited training, combined with onboard proficiency enhancement and directed remote guidance, may be an effective technique for performing complex tasks. The examination was conducted within a strictly limited time frame, which would probably be the case in most terrestrial situations, such as in some remote and most military settings.
The unique constraints imposed by the space environment require the development of detailed training, diagnostic, and therapeutic strategies. Although some of the aerospace procedures currently investigated by NASA are appropriate only for the space environment, many other spaceflight-derived techniques are readily transferable to the Earth, including rural, military, and emergency medical care. The remotely guided US concept, with crew medical officers or comparably trained first responders as operators, is an important and clinically relevant advancement in space medicine, with profound ramifications for emergency or clinical medicine (Audio 1, radiology.rsnajnls.org/cgi/content/full/2342041680/DC1).
| FOOTNOTES |
|---|
Author contributions: Guarantor of integrity of entire study, S.A.D.; study concepts and design, all authors; literature research, S.A.D. M.v.H.; data acquisition and analysis/interpretation, all authors; manuscript preparation and definition of intellectual content, all authors; manuscript editing, S.A.D., K.M.; manuscript revision/review and manuscript final version approval, all authors
| REFERENCES |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
K. Cole Sonography's Expansion Into Space Journal of Diagnostic Medical Sonography, November 1, 2008; 24(6): 380 - 387. [Abstract] [PDF] |
||||
![]() |
S. Rao, L. van Holsbeeck, J. L. Musial, A. Parker, J. A. Bouffard, P. Bridge, M. Jackson, and S. A. Dulchavsky A Pilot Study of Comprehensive Ultrasound Education at the Wayne State University School of Medicine: A Pioneer Year Review J. Ultrasound Med., May 1, 2008; 27(5): 745 - 749. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. H. Thrall Teleradiology * Part I. History and Clinical Applications Radiology, June 1, 2007; 243(3): 613 - 617. [Full Text] [PDF] |
||||
![]() |
V. Popov, D. Popov, I. Kacar, and R. D. Harris The Feasibility of Real-Time Transmission of Sonographic Images from a Remote Location over Low-Bandwidth Internet Links: A Pilot Study Am. J. Roentgenol., March 1, 2007; 188(3): W219 - W222. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. P. Finn, R. Saleh, S. Thesen, S. G. Ruehm, M. H. Lee, J. Grinstead, J. S. Child, and G. Laub MR Imaging with Remote Control: Feasibility Study in Cardiovascular Disease Radiology, November 1, 2006; 241(2): 528 - 537. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. B. Wolbarst and W. R. Hendee Evolving and Experimental Technologies in Medical Imaging Radiology, January 1, 2006; 238(1): 16 - 39. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| RADIOLOGY | RADIOGRAPHICS | RSNA JOURNALS ONLINE |