Ultrasound's crisis of confidence follows a familiar pattern

Over the years, we've had the privilege of checking the vital signs of many imaging modalities. Diagnostic Imaging served as a witness to the rise and fall of digital subtraction angiography and reported the PET crisis of the mid-1990s.

Everyone with a stake in PET called us to defend the modality after learning the working title of our story was "Is PET dead?". It would have been a snappy headline, if it had been true. Fortunately, for our many callers, PET was still alive. Life support was no longer needed after Congress intervened to assure Medicare reimbursement and PET/CT fused anatomy with PET's physiological images. Coincidence detection, a method for performing PET on SPECT cameras, was a passing fad.

PET/CT has become nuclear medicine's flagship modality. Medicare now pays for most of its applications in oncology, including staging and measuring responses to therapy. Clinical trials have shown it to be more specific than coronary artery CT for diagnosing myocardial infarction, and micro-PET has gained respect for preclinical drug testing.

Mammography was the next modality to appear on the critical care list. Poor reimbursement and mammography's relative lack of status in the hierarchy of imaging modalities scared residents away from specializing in breast imaging. Advocates worried that future generations of radiologists might not be willing to perform the procedures.

That was in 1999. In 2007, mammographers still complain about poor payment and a lack of respect, but residents continue to join the subspecialty for the satisfaction of providing an essential service associated with women's health. Investigational breast imaging technologies, including computer-assisted diagnosis, abound because of huge federal subsidies for research and development. Mammography is alive and kicking.

Now, diagnostic ultrasound has taken a turn for the worse. Recent trends suggest that radiologists who specialize in ultrasound have many good reasons for their anxiety, especially considering the robust health of digital x-ray, MRI, and CT, modalities with which ultrasound often competes.

The central issue for ultrasound is not its survival, however, but the place of radiologists themselves in its future. Diagnostic ultrasound's miniaturization and its rapid spread to physicians throughout the healthcare enterprise reflect its overall vitality.

Rather, radiology's long-standing leadership over diagnostic ultrasound may be picked apart subspecialty by subspecialty, as more physicians apply it in practice and experiment with it in the laboratory. To maintain their influence, radiology's ultrasound specialists must take the lead in the pursuit of quality ultrasound practice. This can be achieved through their knowledgeable and impartial support of facility accreditation programs, physician practice competency criteria, and hospital credentialing policies.

Ultrasound research also needs help. Radiology's advocates for ultrasound should heed the advice of Dr. Stanley Baum, former radiology director of the Hospital of the University of Pennsylvania. Baum argues persuasively that the specialists who do the research for any given modality are destined to own the clinical practice of that modality.

Radiologists need to become more disciplined in designing and executing ultrasound clinical trials, if they hope to retain control of the modality. Multicenter clinical trials aiming at a consensus on scientifically valid specific applications are needed to demonstrate that radiologists are serious about conducting serious ultrasound science.

As with PET and mammography, radiology's continued stewardship of ultrasound requires ingenuity and hard work. We look forward to reporting about its changing condition.