RSNA News - February 2005

Radiologists Debate Advantages of Maintaining Musculoskeletal Ultrasound Market

Because of the uniqueness of ultrasound, we are truly respected as consultants for all bone and joint imaging.
—Marnix T. van Holsbeeck, M.D.

(from left to right) Marnix T. van Holsbeeck, M.D., Jon A. Jacobson, M.D., Levon N. Nazarian, M.D., Bruce Forster, M.D., Joseph H. Introcaso, M.D., John McShane, M.D.

Radiologists currently dominate the market in ultrasound (US) imaging for the evaluation and diagnosis of musculoskeletal injuries and other musculoskeletal conditions, but various specialists, including primary care physicians, rheumatologists and podiatrists, are using musculoskeletal US more and more in their practices. As a result, the market share for radiologists is eroding.

In a focus session at RSNA 2004 moderated by Marnix T. van Holsbeeck, M.D., chief of musculoskeletal ultrasound at Henry Ford Hospital in Detroit, five physicians debated the question, "Musculoskeletal Ultrasound: Do We Want to Keep It or Do We Want to Give It Away?" and explored the advantages and disadvantages of using musculoskeletal US in radiologic and clinical practice.

Advantages of Ultrasound

Ultrasound has many practical advantages over MR imaging in the evaluation of musculoskeletal conditions, according to Levon N. Nazarian, M.D., professor of radiology at Thomas Jefferson University in Philadelphia. Those advantages include lower cost, better availability, portability, better acceptance by patients and no contraindications to its use. Ultrasound also has certain imaging advantages over MR imaging, such as real-time capability and better spatial resolution.

"It's quite evident from the literature and my experience that ultrasound is a cost-effective tool for problem-solving and guiding intervention. For many indications, it should be the first-line imaging modality, such as for rotator cuff tears," Dr. Nazarian commented.

A Clinician's Perspective

John McShane, M.D., a clinician and director of the sports medicine fellowship program at Thomas Jefferson University, said that musculoskeletal US is an extremely valuable tool for clinicians, especially for the diagnosis of soft-tissue injuries and to guide injections in joints.

"To make the most of musculoskeletal ultrasound, clinicians need an understanding of anatomy and musculoskeletal pathology and the ability to physically examine the patient in order to direct the scan, unlike MR imaging which does not require the ability to examine the patient," Dr. McShane said. "With ultrasound, you ask the patient where it hurts. This patient interaction enhances the effectiveness of the ultrasound."

The advantages of ultrasound for clinicians include its dynamic nature, the fact that it can be incorporated into the patient's physical exam and its accuracy, which is equal to or better than MR imaging for many things, he said.

Among the disadvantages of US for radiologists are that the scans are difficult to interpret just from static images and it can be time consuming, he added. There are also issues of access to radiologists and interested in performing musculoskeletal US because of low reimbursement levels.

Advantages of MR Imaging

Bruce Forster, M.D., associate professor of radiology at the University of British Columbia, Vancouver, defended the use of MR imaging over US in musculoskeletal imaging, saying MR imaging is more cost-effective than US in some situations, such as knee injuries, because you can avoid arthroscopy. He added that MR imaging offers a "one-stop shop" for the evaluation of multiple musculoskeletal injuries occurring in the same patient at the same time.

"Patients have complex injuries," he explained. "They often have more than just a tendon problem."

Other advantages of MR imaging are that it is less operator-dependent than US in the diagnosis of musculoskeletal conditions, and it provides a more graphic display of images and an extended field of view which allows a better understanding of the patient's pathology, Dr. Forster noted. In addition, the physical exam may be inaccurate and an MR exam may uncover an unsuspected condition.

"There is no question that musculoskeletal ultrasound has its strengths, but I believe MR will remain the primary musculoskeletal assessment technique, other than radiography," he concluded.

Using Both Modalities

Jon A. Jacobson, M.D., associate professor of radiology at the University of Michigan in Ann Arbor, discussed the complementary roles of US and MR imaging and when to perform each type of study.

Radiologists should consider using US to assess soft tissue adjacent to hardware such as metal screws, peripheral nerves, tendon subluxation and muscle hernias, Dr. Jacobson said.

"Both US and MR imaging are useful for evaluating focal tendon abnormalities," he added, "but radiologists should consider using MR imaging if the patient has diffuse joint pain. With regard to the shoulder, US should be considered if the patient has suspected rotator cuff pathology and is over 40 years old; and MR arthrography if the patient is under age 40 and has shoulder pain."

For the evaluation of fluid collections, US may be most appropriate if the collection is superficial, but MR imaging or CT could be used for deep-seated collections, he said.

Economic Aspects

Joseph H. Introcaso, M.D., a radiologist in private practice at Lutheran General Hospital in Park Ridge, Ill., cited data from the Centers for Medicare and Medicaid Services (CMS) showing that while the overall Medicare market for musculoskeletal ultrasound has increased over the last five years at a rate of eight percent per year, radiologists' share of that market has declined from 68 percent in 2000 to 59 percent in 2003.

"The biggest market-share gainers are podiatry, general practice and internal medicine," Dr. Introcaso said.

The cost of ultrasound equipment is no longer much of a barrier to entry into the market, but knowledge is probably the biggest barrier to entry, he commented. "Many clinicians are not comfortable looking at ultrasound images. It is also more difficult for technologists to learn how to do musculoskeletal examinations compared with renal ultrasound or gallbladder ultrasound."

A shortage of ultrasound technologists currently exists and there are many underserved areas around the country, Dr. Introcaso said. He concluded musculoskeletal US represents a market with good growth potential for radiologists, acceptable reimbursement levels and sufficient barriers to market entry by other specialists to protect the market for radiologists.

While some radiologists have said that they prefer using musculoskeletal MR imaging over ultrasound because of the long learning curve and the amount of physician time required to perform US, Dr. Nazarian responded that MR imaging also requires a long learning curve and physicians can train sonographers to do the scanning. He said he believes the real reason radiologists prefer to use musculoskeletal MR imaging is that reimbursement for MR studies is higher than that for US.

Conclusion

So, the question remains—Should radiologists keep musculoskeletal ultrasound or should they give it away?

"If we would give it away, we would see the rest of our practice erode as well," said Dr. van Holsbeeck. "Musculoskeletal ultrasound increases throughput in the orthopedic practices we serve. Because of the respect we gained by letting the surgeons do more and better surgery, we help guarantee referrals for CT and MR imaging in our departments. The growth in the other cross-sectional modalities follows the growth of ultrasound. Because of the uniqueness of ultrasound, we are truly respected as consultants for all bone and joint imaging."