Objective To investigate the techniques of lower limbs MRI. Methods 50 patients underwent lower limbs MRI examinations on 1.5T scanner using 4-channel torso coil, in which 28 were femur and 22 were tibia and fibula. Pulse sequences included FSE T2WI and SE T1WI. All FSET2WI were added with fat saturation. FOV is 42cm?42cm. Imaging planes included axial, coronal and saggital views. Slice thickness ranged from 8mm to10mm on axial and 4mm to 5mm on sagital or coronal view. Results Axial view could delineated the anatomical relationship of the lesions. Coronal or sagital view could show the global view and relation to the adjacent structure. Conclusion The proper scan skill, optimized parameters and proper pulse sequences are essential for better delineation of the anatomy of the lower extremities and helpful for the location and the diagnosis.

Objective To prepare the acellular carotid artery of adult pig using biotic enzymes for small-diameter vascular tissue-engineering scaffold.Methods Carotid artery of adult pig was removed cells by using Trypsin/EDTA,ribonuclease and desoxyribonuclease.Residual cellular composition was studied with quantitative DNA analysis and the Hematoxylin and Eosin(H&E)staining.Extracellular matrix composition was evaluated with elastin van Gieson's(VG)staining and scanning electron microscopy(SEM).Results Quantitative DNA analysis and H&E staining confirmed that carotid arteries were completely decellularized.Elastin van Gieson's staining demonstrated that elastin morphology appeared unchanged.Scanning electron microscopy examination of the acellular scaffolds revealed a well-oriented porous decellularized structure that maintained natural architecture of the aorta.Conclusion Carotid artery of adult pig rendered acellular with Trypsin/EDTA,ribonuclease and desoxyribonuclease has well-preserved extracellular matrix for vascular scaffold,which can be used as a scaffold for further small-diameter vascular tissue engineering.