Purpose To investigate the application value of MRI in distinguishing Association Research Circulation Osseous(ARCO)stage II and IIIA of osteonecrosis of the femoral head.Materials and Methods A total of 48 patients with ARCO stage II/IIIA non-traumatic osteonecrosis of the femoral head in the Fourth Medical Center of Chinese PLA General Hospital from October 2022 to September 2023 were retrospectively included,with a total of 75 hips.The hips were divided into ARCO stage II group(26 hips)and stage IIIA group(49 hips)based on CT.The MRI findings(including irregular articular surface of femoral head,similar closed-loop shape of necrotic-viable interface,fibrous granulation tissue and cystic change in necrotic area,perinecrotic bone marrow edema,articular effusion and synovitis)were compared between the two groups,and the diagnostic efficiencies were evaluated.Results Irregular articular surface of femoral head,cystic change and fibrous granulation tissue in necrotic area and synovitis were more common in stage IIIA group than in stage II group,the range of bone marrow edema was larger than that in stage II group,the grade of articular effusion was larger than that in stage II group,and similar closed-loop shape of the necrotic-viable interface was found in stage II group,but no such sign was found in stage IIIA group,with statistical difference of all the above(χ2/Z=-5.727-54.764,all P<0.001).The area under the curve of irregular articular surface of femoral head,bone marrow edema,synovitis,articular effusion,fibrous granulation tissue in necrotic area,cystic change in the necrotic area,and similar closed-loop shape of the necrotic-viable interface in distinguishing ARCO stage II and IIIA were 0.931,0.891,0.845,0.799,0.772,0.724 and 0.692,respectively.The diagnostic efficiency of irregular articular surface of femoral head was not statistically significant with bone marrow edema and synovitis(both P>0.05),and higher than articular effusion,fibrous granulation tissue in necrotic area,cystic change in necrotic area,and similar closed-loop shape of the necrotic-viable interface(Z=2.054,2.711,4.182,4.003,all P<0.05).Conclusion MRI is helpful to distinguish ARCO stage II from stage IIIA of osteonecrosis of the femoral head.The diagnostic efficiencies of irregular articular surface of femoral head,bone marrow edema and synovitis are higher.

Purpose To investigate the application value of MRI in distinguishing Association Research Circulation Osseous(ARCO)stage II and IIIA of osteonecrosis of the femoral head.Materials and Methods A total of 48 patients with ARCO stage II/IIIA non-traumatic osteonecrosis of the femoral head in the Fourth Medical Center of Chinese PLA General Hospital from October 2022 to September 2023 were retrospectively included,with a total of 75 hips.The hips were divided into ARCO stage II group(26 hips)and stage IIIA group(49 hips)based on CT.The MRI findings(including irregular articular surface of femoral head,similar closed-loop shape of necrotic-viable interface,fibrous granulation tissue and cystic change in necrotic area,perinecrotic bone marrow edema,articular effusion and synovitis)were compared between the two groups,and the diagnostic efficiencies were evaluated.Results Irregular articular surface of femoral head,cystic change and fibrous granulation tissue in necrotic area and synovitis were more common in stage IIIA group than in stage II group,the range of bone marrow edema was larger than that in stage II group,the grade of articular effusion was larger than that in stage II group,and similar closed-loop shape of the necrotic-viable interface was found in stage II group,but no such sign was found in stage IIIA group,with statistical difference of all the above(χ2/Z=-5.727-54.764,all P<0.001).The area under the curve of irregular articular surface of femoral head,bone marrow edema,synovitis,articular effusion,fibrous granulation tissue in necrotic area,cystic change in the necrotic area,and similar closed-loop shape of the necrotic-viable interface in distinguishing ARCO stage II and IIIA were 0.931,0.891,0.845,0.799,0.772,0.724 and 0.692,respectively.The diagnostic efficiency of irregular articular surface of femoral head was not statistically significant with bone marrow edema and synovitis(both P>0.05),and higher than articular effusion,fibrous granulation tissue in necrotic area,cystic change in necrotic area,and similar closed-loop shape of the necrotic-viable interface(Z=2.054,2.711,4.182,4.003,all P<0.05).Conclusion MRI is helpful to distinguish ARCO stage II from stage IIIA of osteonecrosis of the femoral head.The diagnostic efficiencies of irregular articular surface of femoral head,bone marrow edema and synovitis are higher.

The accurate assessment of burn injuries is complex and difficult. The emergence of some new skin imaging techniques, such as hyperspectral imaging, unilateral magnetic resonance imaging, laser Doppler perfusion imaging, etc., has made great progress in research on burn injury assessment. With the continuous progress of imaging technology and medical imaging, medical imaging technologies such as digital radiography, computed tomography, magnetic resonance imaging, and ultrasonography, and so on, have played an important role in burn injury assessment. However, there are still relatively few research reports on burn injury imaging, which may be due to the fact that the imaging techniques and diagnostic experience used for burn injury assessment are not yet fully popular in some medical institutions, and the imaging manifestations related to burns are complex and lack of specificity. This article mainly reviews the application research progress of various imaging techniques in the assessment of burn injury in recent years, aiming to explore the application value of various imaging techniques in burn injury assessment.