The Diagnosis Value Of Ultrasound On The Animal Model Of The Earlier Period Rheumatoid Arthritis

[Objective] 1. Applying high-frequency ultrasound, we observed the early period changes on the animal model of rheumatoid arthritis, in order to explore the early period ultrasonographic features and diagnosis theory of human rheumatoid arthritis.2. Using pathology as the gold standard and compared with magnetic resonance imaging, we evaluated the value that high-frequency ultrasound used for the early diagnosis of rheumatoid arthritis.[Methods] 18 rabbits were randomly divided into three groups, and of the total,12 rabbits were induced rheumatoid arthritis model via injection ovalbumin, others were the normal control. Applying high-frequency ultrasound and MRI, we observed fluidify of suprapatellar bursa, synovium, cartilage and subchondral cortical bone of condyles of femur of the bilateral articular genu of all rabbits at the 4th week and 8th week. All rabbits were killed by aeroembolism, pathological sections were employed to observed synovium and cartilage of bilateral articular genu.[Results] At the 4th weekend, bilateral articular genu intracavitary of the model group rabbits were administered with drug, after 24 hours, rabbits came into the acute phase of rheumatoid arthritis and appeared arthrocele, skin temperature increased, limitation of activity, and circumference of articular genu which compared with control group was significantly increased (p<0.05). Compared with control group, fluidify of suprapatellar bursa were significantly increased and synovium were thickening (p<0.05) in the ultrasound sonogram. Model group rabbits entered into the earlier period rheumatoid arthritis at the 8th week. The ultrasound sonogram of model group which compared with the control group manifested that fluidify of suprapatellar bursa were increasing (p<0.05) and synovium were thickening distinctly (p<0.05) and papillary hyperplasia protruded into the capsular space, but the cartilage and cortical bone were no significant changes(p>0.05). The diagnose accordance rate of ultrasound and MRI respectively which were used to detect fluidify of suprapatellar bursa and synovium at the acute phase and the earlier period of rheumatoid arthritis was higher and no significant difference. The diagnose accordance rate of fluidify of suprapatellar bursa respectively was 100%(10/10),100 %(11/11),The diagnose accordance rate of synovium of suprapatellar bursa respectively was77.8%(7/9),80%(8/10).[Conclusion] 1. High-frequency ultrasound can discover the lesions on the acute and early stage of the rheumatoid arthritis, which mainly shows that fluidify of suprapatellar bursa were significantly increased and synovium were thickening distinctly in the ultrasound sonogram. There is a coincidence between ultrasound sonogram and light microscopy pathological changes about early period RA, moreover ultrasound sonogram is consistent with MRI too. Therefore, high-frequency ultrasound maybe a promising method on the examination early period RA, which in combination with other imagings are expected to increase the rate of early diagnosis on RA.2. Because of hyperacoustic limitation, high-frequency ultrasound is not satisfied on the observation of cartilage and bone cortex, the expectation in this area should come from further research.