Objective To explore the application value of quantitative analysis of tissue diffusion by ultrasound elastography in evaluating the evolution of achilles tendinopathy and indirectly reflecting the feature of tendon biomechanics.Methods Rabbits underwent 0.1 ml (group M) or 0.3 ml (group S)collagenase or 0.2 ml saline (group C) injection.The percentage of area displaying blue (％AREA) in the area of interest was measured by the diffusion quantitative technique of ultrasound elastography at baseline and 1,3,7 and 14 days after model.The achilles tendon was obtained for pathological examination to observe the changes of collagen fibers and tested to measure the maximum tensile load by the universal testing machine.Results (1) The ％AREAs in group M and S at 1,3,7 and 14 days after model were smaller than those in group C (P ＜0.05),and reached its lowest value at 3 days after model.％ AREA in groupSwas significant lower than that in group M at 3 or 7 days after model (P ＜0.05).(2) The maximum tensile loads in group M at 1,3 and 7 days after model were smaller than those in group C (P ＜0.05),but there was no significant difference between group M and C at 14 days after model (P ＞0.05).The maximum tensile load in group S was significant lower than those in group M and C after model (P ＜0.05),and arrived its lowest point at 3 days after model.(3) The ％AREA was positively associated with the maximum tensile load of achilles tendon (r =0.87,P ＜0.001).Conclusions Ultrasound elastography can dynamically monitor the evolution of achilles tendinopathy and reflect the biomechanical state of achilles tendon.

BACKGROUND:The knee joint acts as the body’s largest and most complex joint, which is a commonly seen perplex in patients because of synovium and cartilage diseases. Moreover, clinical physicians are often confused on the ultrasonic diagnosis of synovium and cartilage diseases.
OBJECTIVE: To review the ultrasound misdiagnosed cases of knee cartilage and synovial lesions and to summarize the common misconceptions and discrimination methods.
METHODS: A retrospective analysis was performed in the ultrasound misdiagnosed cases of knee cartilage and synovial lesions reported from 2002 to 2014, and then the common misconceptions and corresponding identification methods were summarized.
RESULTS AND CONCLUSION: High-frequency ultrasound is most likely to have six “mistaken ideas” addressing knee cartilage and synovial lesions: (1) cartilage degeneration; (2) synovial calcification; (3) echo intensity from synovial lesions; (4) blood flow in the synovium; (5) synovial effusion; (6) lesions involving intraarticular structures. High-frequency ultrasound runs through dynamical observation and contrast observation of bilateral knee joint lesions, which is a valuable imaging method for diagnosis of cartilage and synovial diseases based on vigilance at the “mistaken ideas” and mastery of the distinguishing ideas and methods.