Ultrasound Aids Early Diagnosis of Juvenile Inflammatory Arthritis

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From Medscape Medical News: Ultrasound Aids Early Diagnosis of Juvenile

Inflammatory Arthritis

http://www.medscape.com/viewarticle/742220

Lara C. Pullen, PhD

May 5, 2011 (Chicago, Illinois)

Ultrasound is more sensitive than physical examination and may detect early

disease that is not evident on physical examination, according to Vick

Panghaal, MD, from Albert Einstein Medical College in Bronx, New York, who

presented the results of his research here at the American Roentgen Ray

Society (ARRS) 2011 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 explained. 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

session and spoke to Medscape Medical News about 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 explained to Medscape Medical News 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.

Dr. Panghaal and Dr. Schreibman have disclosed no relevant financial

relationships.

American Roentgen Ray Society (ARRS) 2011 Annual Meeting: Abstract 194.

Presented May 5, 2011.