The The T <sub> 2 </ Sub> <sup> * </ Sup> Figure (t-<sub> 2 </ Sub> <sup> * </ Sup> Map) Monitoring Articular Cartilage Damage, Clinical And Experimental Study

Objectives:To investigate the clinical significance of a new method,T₂^* map,in patella articular cartilage degeneration.Materials and Methods:Four adult changbai pigs divided into four groups(A,B,C,D). Intraarticular injection of Papain was performed to establish animal models of different stages of cartilage degeneration in the right knees of A,B,C,D groups,MRI scan with T₂^* map in axial plain and the T₂^* values were measured.The T₂^* values were compared within every group.The articular cartilage was pathologically examined(HE and alcican blue stain).105of Osteoarthritis(OA),19 of acute injuried and 25 of healthy volunteers knees were imaged with normal MR sequences and T₂^* map sequences.The patella articular cartilage were divided into 3 parts(superior,middle and inferior).each portion segment(medial,middle and lateral) and each segment were divided into 3 parts(inner,middle and outer).The T₂^* values of each part were measured and compared with each other.Results:Arthritis wsa successfully induced in all 4 right knees with intraarticular injection of Papain. MRI scan with T₂^* map in axial plain and the T₂^* values were measured in animal models of different stages of cartilage and the healthy volunteers,OA patients and actue injuried group.1,healthy volunteers,the T₂^* value among S-M-I parts was not significantly different(p＞0.093) and the T₂^* value of medial,middle and lateral was significantly different.The T₂^* value was up gradually from inner to outer parts.2,In OA patients,the T₂^* value among S-M-I parts was not significantly different(p＞0.097) and the T₂^* value of medial,middle and lateral was significantly different.The T₂^* value was up gradually from inner to outer parts.3,The T₂^* value of In healthy volunteers was lower than the T₂^* value of OA group.4,In actue injuried group,the T₂^* value shows significantly different with the healthy volunteers'.Conclusion:T₂^* map could give a quantitative criteria for abnormal microscopic content of water and the structure change of articular cartilage.T₂^* map is a useful method in detecting the cartilage injury.