Objectives To compare ultrasound (US) with magnetic resonance imaging (MRI), which was taken as a “gold standard” for detection of fifth metatarsophalangeal joint synovitis and erosions in patients diagnosed with RA (ACR).
Methods Patients in Institute “Niska Banja” (n=44) with RA (ACR criteria dg) with clinical symptoms in both fifth metatarsophalangeal joints (n=88). 99% of women, mean age 55,1 and disease duration 6,3 years, included in our study. Ultrasonographicaly, using Esoate- My Lab 60 system, equipped with 10-13 MHz probe, have been visualised both fifth metatarsophalangeal joints, and then were reffered for MRI of the same joints on Arthroscen type M (0,2 T) machine. US was developed as the first method, and interpreted by one investigator, and then the other researcher, regardless of previous results of US findings, interpreted the MRI findings. The percentage of compatibility between methods, as well as sensitivity and specificity of US compared to the MRI as a “gold standard”, were examined by using a statistical methods.
Results Compared with the MRI, as a gold standard, US in detection of fifth metatarsal joint synovitis has 92,86% sensitivity and specificity of 100%. US in detection of fifth metatarsal joint erosion has a sensitivity of 72,73%, and 81,82% specificity. The percentage of compatibility between US and MRI, as golden standard methods, was statistically significant. As for the detection of synovitis, according to Cochen kappa test compatibility was highly statistically significant: kappa test 0,904 (p<0,0001). When it comes to erosions, compatibility was smaller but still statistically significant: kappa test 0,545 (p=0,01).
Conclusions US is sensitive method in fifth metatarsophalangeal joint pathology detection, when it comes to detection of synovitis and erosions in patients with RA, compared with MRI as gold standard. Nevertheless, this study shows that further development of US examination techniques and the use of higher frequency probes is necessary, specially in detection of metatarsophalangeal joints erosive changes.
Disclosure of Interest None Declared