Key points are not available for this paper at this time.
It is certainly an unexpected honor to receive the inaugural PASSOR (Physiatric Association of Spine, Sports, and Occupational Rehabilitation) Legacy Award. First and foremost I would like to extend my gratitude to the American Academy of Physical Medicine and Rehabilitation (AAPM 1: 64-75.) Most importantly with respect to MSK US, a portion of the sound is also reflected at the interface. This reflected sound can be detected by the transducer, which then functions as a receiver. Through computer-intensive, high-speed processing, the US machine can map the intensity and location of these reflected “echoes,” producing the 2-dimensional black and white (B-mode) image depicted on the screen when performing MSK US. These acoustic interfaces occur throughout the body. Some interfaces are dramatic, such as the interface between the supraspinatus tendon and underlying humeral head. Others are more subtle, such as the interface between 2 adjacent collagen bundles within the supraspinatus tendon. It is the sensitivity of MSK US to these subtle interfaces that results in the high-resolution capabilities of modern-day US machines. One further comment regarding US physics is warranted as it pertains to image quality, as well as a limitation of MSK US. All physiatrists should recognize the relationship among scanning frequency, resolution, and penetration depth. Superficial structures such as the finger flexor tendons are imaged using high-frequency transducers (>10 MHz). High-frequency sound waves provide submillimetric resolution but can penetrate only a short distance into the body. On the contrary, lower-frequency transducers (<6 MHz) are used to image deeper structures in the body, such as the hip joint. Lower frequencies penetrate deeper into the body but sacrifice resolution. Consequently, a basic premise of MSK US imaging is that the imager chooses the transducer that will provide the highest frequency (and best resolution) that will penetrate to the target depth. Modern-day US machines provide significant advantages that have brought MSK US to the forefront of diagnostic imaging. As previously stated, high-frequency transducers provide submillimetric resolution equivalent or superior to currently available magnetic resonance imaging (MRI) scanners. Unlike MRI or computed tomography, MSK US also offers the capability of performing dynamic imaging. Clinicians can palpate under the transducer (ie, sonopalpation) to visualize the structures localizing to a patient's complaints. In addition, dynamic US facilitates the investigation of symptomatic pops, clicks, and snaps that plague so many of our patients. Finally, US can be used to precisely guide needles to target areas for interventional procedures. Compared with other advanced imaging modalities, US facilitates left-right (ie, symptomatic versus asymptomatic side) comparisons, is relatively cost effective as a diagnostic modality, and is readily accessible. The installation of a modern MRI machine requires a crane to place the machine into a specially shielded area, whereas current US machines are essentially “plug and play.” Finally, US imparts no radiation to the operator or patient, produces no side effects, and has no contraindications. So, how did MSK US work its way into the field of physiatry? Certainly, physiatrists have a long history with US technology. By the time Dr. Frank Krusen (Figure 2) established the Department of PM&R at the Mayo Clinic in 1936, physiatrists had already been using therapeutic US for many years (Incidentally, Dr. Krusen also coined the term “physiatrist” to replace the previously used term “physical therapy doctor”). Dr. Frank Krusen founded the Mayo Clinic Department of PM&R in 1936 and coined the term “physiatrist” to describe physicians specializing in PM&R. (Image courtesy of the Mayo Clinic.) By the early 1950s, the field of PM&R was rapidly expanding, and several important events occurred with respect to the continued development of US in our field. First, Dr. Justus Lehmann arrived at the Mayo Clinic to study under Dr. Krusen. As we are all well aware, Dr. Lehmann subsequently established himself as an international authority on the use of therapeutic modalities in physical medicine, particularly with respect to US. During this same period, Disraeli Kobak, MD (Figure 3), and 23 other physiatrists met at the American Congress of Physical Medicine and Rehabilitation in Denver, Colorado, to discuss the need for an organization that could promote education, research, patient care, and advocacy with respect to US. This group of physiatrists subsequently formed the American Institute of Ultrasound in Medicine (AIUM), for which Dr. Kobak served as first president until his death a few years later. The AIUM continued to thrive, and we'll come back to this organization later in our discussion. Dr. Disraeli Kobak was a founding member of the AIUM and served as the organization's first president. (Image courtesy of the American Institute for Ultrasound in Medicine.) Throughout the 1950s and into the 1970s, physiatrists continued to focus on the therapeutic aspects of US. During this same time period, the first diagnostic US machines were produced. These machines were large, expensive, and generated low-resolution images with large acquisition times (Figure 4). Nonetheless, diagnostic US applications in obstetrics/gynecology, gastroenterology, and cardiology continued to slowly expand. During the 1980s, computer engineering advances eventually resulted in the development of real-time US imaging capability, as well as reduced machine size and dramatically improved resolution. Clinicians and imagers began to explore the utility of diagnostic US to image the MSK system, initially focusing their attention on the rotator cuff. Dr. Jeffrey Crass and colleagues at the University of Minnesota eventually published the first paper 1 in the United States describing the use of diagnostic US for a MSK application. These authors' seminal paper demonstrated the diagnostic utility of MSK US to evaluate the rotator cuff when compared with a surgical gold standard. Early model US machine. (Image courtesy of the American Institute for Ultrasound in Medicine.) In the early 1990s, MSK US was introduced to physiatry by Dr. Scott Primack (Figure 5). In 1991 Dr. Primack completed his PM&R residency training at the Rehabilitation Institute of Chicago and came across an article published by Dr. Douglas Harryman et al 2 in which functional outcome after rotator cuff repair was correlated with cuff integrity as determined by US examination. As a physiatrist, Dr. Primack was intrigued by the use of US to determine structure and function, so much so that he subsequently completed a 6-month fellowship with Dr. Harryman and colleagues at the University of Washington in Seattle. Dr. Scott Primack was the first physiatrist in the United States to receive formal training in MSK US. During this time, Dr. Primack became proficient in MSK US and later integrated it into his Colorado practice. Dr. Primack quickly recognized the potential for MSK US in physiatry and began to educate physiatrists about this emerging technology. He directed the first course on MSK US—focusing on the shoulder—at the AAPM&R Annual Assembly in 1995. As a testament to how long ago this occurred, PASSOR still held closed, ticketed meetings at that time. As a senior resident in PM&R at Mayo Clinic, I was speaking at the PASSOR meeting, but, admittedly “snuck out” to attend Dr. Primack's course. Attendance was “modest.” Dr. Primack's enthusiasm remained unaffected, and he subsequently authored the first article pertaining to MSK US completed by a American physiatrist, titled “Musculoskeletal Ultrasound: A Clinician's Perspective,” published in the Radiologic Clinics of North America in 1999 3. Although I was first introduced to MSK US at Dr. Primack's course in 1995, I admittedly did not recognize its potential at that time. My interest increased after I noticed several US vendors in the exhibit hall of the American College of Sports Medicine Meeting in 2000. I started reading the literature to get a better sense of where the technology might fit into my practice. The pivotal point in my career with respect to MSK US came in 2002, when I was volunteering in the Olympic Poly-Clinic at the Salt Lake City Olympics. (As an aside, I have to give credit to Dr. Stuart Willick, who recruited me to the medical team.) While working in the clinic, I had regular exposure to an US machine. I witnessed MSK US's powerful combination of high-resolution and dynamic imaging as the on-site radiologist scanned athletes in the clinic. At that time, I decided that I had to integrate MSK US into my practice for the benefit of my patients. By the end of 2003, I had convinced the Mayo Clinic Sports Medicine Center Co-Directors Drs. Edward Laskowski (incidentally a founding member of PASSOR) and Michael Stuart to purchase a portable US machine. It wasn't much to look at, but it did offer high resolution at the right price. In February 2004, I completed my first MSK US course with Dr. Levon Nazarian at Thomas University in Dr. Nazarian is a MSK US a and my After Dr. I to the of the and to diagnostic and interventional MSK US. By the AIUM that organization founded by physiatrists more years had recognized the dramatically increased interest in MSK US and held its first course on MSK US in Dr. Nazarian me to at this and more physiatrists my best this The with respect to MSK US had started in physiatry. A few later at the Annual Assembly in several MSK US and in the The the academy its inaugural MSK US at the Annual Assembly in directed by Dr. from the Rehabilitation Institute of In and in with the I directed the first MSK US course to held at the Mayo Clinic in physiatrists this which in high the of physiatrists that use MSK US in their is rapidly are by multiple such as the the American College of the American Academy of and and the American for Sports The of physiatric pertaining to MSK US is also as by published such as Dr. article First for At this Annual Assembly in the MSK US was for the in a to Dr. there are and to MSK US (and many that are MSK and 2 resident on MSK US by Dr. from physiatrists are with respect to MSK US advocacy and in such as the American for Sports and American Academy of and MSK US has arrived in the field of physiatry. I have integrated MSK US into my practice as a clinical problem-solving MSK US can be used to or a clinical diagnosis (eg, a rotator cuff in patient (eg, the between and of and and provide real-time for therapeutic (eg, like to clinical to the clinical of MSK US in to my practice as well as some of the previously advantages of MSK US. A patient with of after some was in and of and to in physical a rotator cuff with a in rotator which was initially to be After in physical was to for tendon After the patient and the we completed a diagnostic US of which a tendon and demonstrated that the was adjacent to the tendon (Figure By using we determined that the patient was not the but the with a symptomatic rotator cuff and to an and of the in resolution after (Figure US image of the tendon a large supraspinatus adjacent and to a tendon. The patient was to the = greater = = = = US a into the of the patient's for and from is a who with right after of also of the and stiffness. a as well as an were for The primary clinical was the of the there was a or by a diagnostic MSK US to the of the with but no of or on dynamic scanning (Figure The patient eventually after a short of and a rehabilitation of the patient's symptomatic right tendon at the with a of the patient's asymptomatic and of the right by with = = This is to the resolution available on modern-day US machines. This right patient had a and are not for the and with The and of his a the He was to an to and MRI was He was to for diagnostic US of the to or the Although the patient did not with his the MSK US until we completed an course we the of his the After diagnostic scanning demonstrated a of the an but with (Figure were to determine the or of a within the but we the patient's to this US of a of the at the of the that the in and a the of which is with = = This the dynamic capabilities of MSK US, as well as the of US and This with a 6-month history of right He had several but did not the of his current with to the point of being to long or to the tendons in the as well as a of the tendons tendon to or the were and MRI only a greater location of an tendon. He was for a of his tendons and the of the as well as a dynamic his and within the his clinical and tendon or in the a superior He was with tendon and subsequently surgical of the and of the superior After completion of his rehabilitation the patient was to At this point in our discussion, it should be that MSK US is a powerful clinical problem-solving tool that can patient I of more 2 physiatrists who have already integrated MSK US into their As by the increased for MSK US education, it is to that many more physiatrists are in MSK US to their of US's recent reduced and It is that these are not to physiatry. MSK US is rapidly among primary medicine and US is currently of the of the imaging and a large portion of this is to the of to MSK US As clinical applications for MSK US continue to we can increased use among is to the potential role of and of such as for the of tendon and other tissue US are being that will provide of tissue physiatrists to but regions of tendons, ligaments, and other imaging will more image of and promote the development of more interventional procedures. As we look into the we with respect to MSK US. First, we the future of MSK US in PM&R. MSK US a that will and eventually or will it to such that only a of physiatrists with interest and training will use MSK will it such that MSK US is into residency training and all physiatrists basic in diagnostic and interventional MSK This is for to and we as physiatrists should this later. we the future of MSK US in we provide the and training to this of the we practice to that this technology is applied with high of My is that all physiatrists should use MSK US for patient This not that all physiatrists should MSK US. physiatrists should US into their MSK of they the For all physiatrists should that multiple a recent article by and that MSK US can be used to evaluate the for rotator cuff with equal to In addition, physiatrists should as demonstrated by et al use of MSK US in place of more MRI would of of each Finally, all physiatrists should that US MRI scanning that the diagnostic utility is These and many that MSK US is currently in physiatry as well as in other in which evaluate and with MSK At the current time, there is no or to training in MSK US in the United the and to MSK US but not I have for in MSK US First, you regular to an US machine. will not get at MSK US until you get to a machine. you or your practice would purchase a machine. For to MSK US, I would a portable machine the will you to the machine and practice. Most modern portable machines are high and offer and some used machines can be on the at cost you should initiate a a body on which to practice, such as the the purchase and of the many MSK US available and that (eg, of you are with on to the a few you will have a large of MSK US you should attend or more MSK US that offer On this the is that I started using MSK US more years there has been a significant in the of each As previously our academy has to by MSK at the Annual In addition, the AAPM&R will its first advanced MSK US on the in This course will be by my Dr. and me. will also continue to offer our diagnostic and interventional MSK US course at Mayo Clinic in with the currently for Finally, and you practice, practice, practice. should and (ie, US and you have to for to will dramatically your The need to practice is to my comment pertaining to the need to regular to an US machine. you have you practice. you practice, be US into your clinical is to practice need to determine should be with MSK US, it should be and should should be as MSK US rapidly we the and of this powerful technology in the of patient is a between what be and what be this with respect to MSK US will clinical and to emerge. For we previously and published our for (ie, what be after the need for a to this in subsequently demonstrated that the was more the used that US should be the in (ie, what be MSK US should be several have published for the of the MSK US at at and of at should use these training and practice to that the of the are Finally, there is the This is the of MSK US practice. there is no or practice available for MSK US. I that are to the to MSK US will patient and for In this the AIUM that same organization founded by has been for US for many years and is currently practice for MSK US. Although a has not been MSK US is physiatrists will be to for through the As a to this the AIUM has completed a the to the MSK US in with multiple the respect to there is currently no by which physiatrists can be to MSK US. Certainly, our academy to a but the for this would need to come from academy The American for Diagnostic is the organization that in (eg, and also has for The is currently the for in MSK US. this would be to this is several years into the future at can we about the past, present, and future of MSK US in physiatry? First, come a long from the of therapeutic US by Drs. Krusen and to the founding of the AIUM by Dr. Kobak and to the of MSK US to physiatry by Dr. and to the of MSK US into physiatric practice the as we have MSK US is to I this will continue to not only within the field of physiatry but also within other medical that evaluate and with musculoskeletal as demonstrated in my MSK US is an powerful clinical problem-solving MSK US has an of my practice, as well as the of physiatrists like who use US to patient physiatrists are to be of MSK US. in and focus on the high-resolution and dynamic capabilities of MSK US. I that use of this technology patient care, and as and Mayo have at the Mayo Clinic, the of the patient come Finally, with this powerful technology an to the education, research, and advocacy to be of MSK US in the and I would like to thank the PASSOR, Dr. Michael Lupinacci and the Dr. Scott and all the physiatrist today that are to promote MSK US in our field. to have received this
Jay Smith (2010) studied this question.