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Current MR methods use T2? relaxation time as a surrogate measure of ligament strength. Currently, a multi-echo voxel-wise least squares fit is the gold standard to create T2? maps; however, the post-processing is time-intensive and serves as a stopgap for clinical use. The study objective was to determine if an alternative method could improve post-processing time without sacrificing fidelity of T2? values for eventual translational use in the clinic. Using a 6 echo FLASH sequence, three different methods were used to determine intact posterior cruciate ligament (PCL) median T2? Two of these methods utilized a voxel-wise method to establish T2? maps: (1) a current “gold standard” method using a voxel-wise 6 echo least-squares fit (6LS) and (2) a voxel-wise 2 echo point T2? determination (2MM). The third method used median ligament signal intensity and a single nonlinear least-squares fit (6LSROI) instead of a voxel-wise basis. The resulting median T2? values of the PCL and computational time were compared. The median T2? values were 42% higher using the 2MM compared to the 6LS method (p<0.0001). However, a strong correlation was found for the median T2? values between the 2MM and 6LS methods (R2=0.80). The median T2? values were not significantly different between the 6LS and 6LSROI methods (p=0.519). Using the 2MM (which provides a regional map) and the 6LSROI (which efficiently provides the median T2? value) methods in tandem would take only minutes of post-processing computational time compared to the 6LS method (~540 min), and hence would facilitate clinical application of T2? maps to predict ligament structural properties as a patient outcome measure. 相似文献
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D. A. H. Murray 《Australian Journal of Entomology》1982,21(2):119-122
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Leonard J. Yamshon 《The Western journal of medicine》1958,89(5):333-334
Frozen shoulder, rare in the young but more easily incurred after age 40, is a result of immobilization from any cause. Atrophy is the first phase, followed by shortening of soft tissues, pain on extension, spasm contractures and adhesions.Mobilization is urgent to prevent contractures. Rotation is the most important exercise, and should be done with the upper arm supported in nearly horizontal extension to prevent the humeral head from impinging on the acromion. From this position the forearm, lifting or pulling down in a forward are against weights and pulleys, restores the rotatory power of the shoulder. 相似文献
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