High-frequency ultrasound is more accurate than bone scintigraphy for the differential diagnosis of early inflammatory arthritis, Turkish researchers have shown.
The study, which appears in the journal Rheumatology International, evaluated different diagnostic strategies in 51 patients with early symptoms of inflammatory arthritis but not fulfilling the American College of Rheumatology (ACR) 1987 criteria for rheumatoid arthritis (RA).
“RA is currently defined according to the ACR criteria, which have been derived from patients with long-term established disease,” explain Ahmet Ozgul (Gulhane Military Medical Academy, Ankara, Turkey) and co-authors. “However, no diagnostic criteria are available to detect the early disease.”
After clinical and laboratory examination, all patients underwent high-frequency ultrasonography of the synovial joints followed by total body bone scanning, with three-phase bone scanning in some patients. They were then followed-up for at least 2 years.
The study authors do not report the numbers of patients diagnosed with RA by each method but instead report concordance with the gold standard, ACR-defined RA during follow-up.
Ultrasonography showed average concordance with the reference group whereas bone scintigraphy was discordant. This was true both for the overall cohort and for the subset of patients who had suffered pain for the last three months.
The authors also report that concordance between bone scintigraphy and ultrasonography in detecting early arthritis was mild in the shoulder, wrist, hand proximal interphalangeal, and foot metatarsophalangeal joints; moderate in the elbow and metacarpophalangeal joints; advanced in knee joints; and discordant in the hand distal interphalangeal joints.
“We think that ultrasound is an important tool in diagnosing early arthritis and directing the treatment of arthritis successfully,” Ozgul and co-authors conclude.
“In this respect, ultrasound should be used to verify the clinical findings, and it may be described as an extension of the physical examination.”