ARDMS May 13, 2011

Advances in Ultrasound in Spotlight at USC Session

A revolution in health care is nearing maturity after a long adolescence, and one of the coming out parties is being staged in Columbia at the first World Congress on Ultrasound in Medical Education.
“We’re hoping this World Congress is a tipping point in understanding the power of ultrasound as a clinical tool,” said Dr. Richard Hoppmann, dean of the University of South Carolina School of Medicine.
Ultrasound has been around for decades, though its use as a diagnostic tool during physical exams was limited. Technological advances, especially in the past decade, now have the potential to turn handheld ultrasound devices into the stethoscopes of the 21st century.
Hoppmann recognized the trend years ago, and the USC School of Medicine has been one of the leaders in incorporating ultrasound into medical school curriculum. That history prompted leaders of the movement to pick Columbia for the first major international conference on ultrasound use in medical education.
Hundreds of medical professionals from the United States and the world began a three-day conference at the Columbia Metropolitan Convention Center. As if to prove the international importance of the event, three of the first five speakers were early proponents of ultrasound in medicine from France, Germany and Italy.
Dr. Daniel Lichtenstein of France began using ultrasound as a general diagnostic tool in 1986 and is credited with being the first to refer to ultrasound as the stethoscope of the future. But only in recent years has the medical community begun to understand his point.
“With ultrasound, diagnosis takes 20 seconds, but it took 20 years to be accepted,” Lichtenstein said during his presentation on this history of clinical ultrasound.
He noted that there were skeptics when the stethoscope was first introduced in the early 1800s. Everything new takes a while to catch on, but ultrasound as a clinical tool has begun to explode.
Dozens of companies that make ultrasound-related devices - including lifelike torsos used to help teach ultrasound techniques - lined the exhibit hall. Recent television advertisements touting GE’s portable Vscan ultrasound device are another indication of mainstream medical acceptance of the technology.
Ultrasound uses sound waves that bounce off solid tissues, allowing physicians to see beneath the skin and examine the heart, lungs, other organs and blood vessels. A stethoscope allows a physician to hear what sounds like a heart murmur. An ultrasound device lets the physician look directly at the heart tissue to get a better idea of what’s wrong.
Ultrasound devices used to be prohibitively expensive for general practice physicians and too bulky to easily move from room to room in hospitals. Now, handheld ultrasounds about the size of a smartphone cost less than $8,000.
“I’m used to a huge system on wheels,” said Jim Kreiner, who helps manage the radiology and ultrasound program for Palmetto Health Heart Hospital and is sonography instructor at Midlands Tech. “To now go to something where it’s feasible for a physician to carry one around in his pocket is amazing.”
USC medical students began using the new generation of hand-held ultrasound devices in their training last year, putting them out front in a field that has the potential to change the profession. Other schools on the lead wave include Ohio State, the University of California and Wayne State in Detroit.
Ultrasound proponents say the technology not only can lead to better health care, but to less costly health care. “Clinicians using ultrasound can make critical health care decisions at the point of need, at the point of care,” Hoppmann said.
For instance, Hoppmann said, an emergency room physician who suspects bleeding in a patient’s abdomen might try several diagnostic tools before pinpointing the problem. But with an ultrasound device in the emergency room, the physician could spot the problem and bypass the other time-consuming and costly diagnostic tools.
Simple physical exams with ultrasound also can spot problems early and hold off more serious consequences. A ruptured aortic artery almost always leads to death. An ultrasound scan of the aortic artery could uncover a weakening early enough to prevent the rupture.
Another beauty of ultrasound is the image produced can be shown to patients. Emotions have overcome prospective parents viewing babies in utero for decades. But ultrasound images also can work as a scare tactic to prompt patients with heart disease to take their medicine or stick to their exercise program, Hoppmann said.
“Ultrasound is not a replacement for a physical exam; it’s a complement to a physical exam,” Hoppmann said. “That’s why it’s important to make sure ultrasound use is taught correctly.”
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Article written by staff at thestate..com and adapted for the purposes of this newsletter.

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Ultrasound Aids Early Diagnosis of Juvenile Inflammatory Arthritis

Ultrasound is more sensitive than physical examination and may detect early disease that is not evident on physical examination, according to Vick Panghaal, MD, who presented the results of his research at the American Roentgen Ray Society (ARRS) Annual Meeting.

Dr. Panghaal began his presentation by noting that there is an increased interest in the use of sonography to evaluate juvenile inflammatory arthritis (JIA). This is because early detection and treatment may prevent and/or delay adverse outcomes such as joint damage and disability. JIA is a potentially debilitating disease of early childhood that may carry with it significant physical, psychological, and financial costs, Dr. Panghaal noted.

At this time, pediatric rheumatologists rely on physical examination to diagnose JIA. Dr. Panghaal's research team compared the results of ultrasound of the knees and ankles of children with known JIA with observations from physical examination by a pediatric rheumatologist.

Patients were examined initially and then given a follow-up physical examination 2 to 5 months later to allow for confirmation of subclinical disease. "We felt that the initial physical exam was not good enough for a gold standard," Dr. Panghaal said. The goal of the study was to see whether ultrasound could improve on the gold standard of physical examination.

The study included 84 joints in 19 patients (8 boys and 11 girls) with active disease. Active disease was defined as nonbony swelling, demonstrable effusion, or limitation of motion with either pain on motion or tenderness. Sonographic imaging was done on 3 planes for the knees and 1 plane for the ankle.

Sixty-five of the examined joints were concordant for both sonography and physical examination. Of the joints that were active on ultrasound and inactive on physical examination, 5 went on to develop clinically evident disease on follow-up, 1 was lost to follow-up, and 8 had only mild increased vascularity on ultrasound. Of the joints that were inactive on ultrasound and active on physical examination, 4 had subtalar involvement and 1 had no explanation.

Dr. Panghaal concluded by stating that sensitivity with the physical examination was not very high, and ultrasound was able to identify subclinical disease in joints that were not identified by physical examination. Mild increased joint vascularity, as imaged by the ultrasound, was not specific for JIA, and did not appear to correlate with disease activity. The researchers also found that ultrasound is very poor at diagnosing subtalar disease. Therefore, in situations where patients are clinically active, but ultrasound is negative, subtalar disease should be considered.

The study was limited by the fact that the imagers and clinicians were not blinded to the diagnosis of JIA. Dr. Panghaal concluded his presentation by stating: "We don't think that ultrasound is a good screening test for every patient."

Ken L. Schreibman, PhD, MD, professor of radiology at the University of Wisconsin School of Medicine & Public Health in Madison, cochaired the study. He explained that physicians need to be aware that although physical examination is their gold standard, it is not as sensitive for detecting JIA as they would like.

Although Dr. Schreibman acknowledged that ultrasound may not be appropriate for every patient, he noted that, "We can expect to see more physicians who treat patients with JIA - especially patients early in the course of disease - will be turning to ultrasound more and more to help them make this diagnosis early. Radiology needs to be able to provide these services."

Dr. Schreibman said that, "These exams need to be performed with a high-end ultrasound unit and specifically with high frequency transducers." He added that for this purpose, there is no need to penetrate deep into the tissue. Instead, what is required is a high frequency that provides a high resolution of the relatively shallow structures. There will be some joint surfaces, however, that remain inaccessible to ultrasound imaging, he cautioned.

View the article online
Article written by staff at medscape.com and adapted for the purposes of this newsletter.

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Combined Ultrasound and Pre-Operative MRI Cost Effective for Evaluating Rotator Cuff Tears

While ultrasound is usually viewed as more cost effective, MRI is most often used to evaluate the rotator cuff. When performing a cost utility analysis, utilizing an ultrasound as the initial imaging test for rotator cuff tear, along with pre-operative MRI to identify alternative and concurrent diagnoses, can be a very effective hybrid imaging strategy, according to research being presented at the 2011 American Roentgen Ray Society's (ARRS) annual meeting.

The study, performed at Duke University Medical Center in Durham, NC and Rush University Medical Center in Chicago, IL, utilized three evaluation techniques: the use of ultrasound alone, MRI alone, and a hybrid strategy of ultrasound for all patients followed by MRI for those patients who required surgery.

"Several meta-analyses in the literature have found that ultrasound and MRI have similar accuracies for the evaluation of rotator cuff tears. Ultrasound is a cheaper imaging modality, yet MRI is much more frequently used for rotator cuff evaluation," said Robert Lee Suber, MD, lead author of the study. "The reasons for the preference of MRI may be related to the possibility of identifying alternative and/or concurrent diagnoses with MRI as well as surgeon preference for anatomic imaging prior to surgery," said Suber.

"One of the imaging strategies we studied was an initial screening test with ultrasound. All those patients who required surgery or failed conservative treatment would then have an MRI. We found this to be more cost effective than everyone undergoing MRI as the initial evaluation," he said.

"There are cutoff values for accuracy of ultrasound and/or MRI where this combined imaging strategy is no longer cost effective over MRI alone. Additionally, as the prevalence (pre-test probability) for rotator cuff tear increases, this combined imaging strategy decreases in cost savings over MRI alone," said Suber.

"Our research shows that in populations with a lower pre-test probability of rotator cuff tear (e.g. patients seeing family practice physicians as opposed to a shoulder specialist surgeon) it may be more cost effective to initially to obtain an ultrasound. Then if the patient needs to have surgery, they can get an MRI," he said.