Objective To review imaging use in the diagnosis of thoracolumbar burst fractures and to determine the diagnostic va-lue of different imaging methods. Methods One hundred and fourteen patients with 120 thoracolumbar b...Objective To review imaging use in the diagnosis of thoracolumbar burst fractures and to determine the diagnostic va-lue of different imaging methods. Methods One hundred and fourteen patients with 120 thoracolumbar burst fractures were retrospectively reviewed. Pl-ain radiographs were available in all cases; CT scans and MRI were obtained in 96 and 74 cases, respectively. Results A total of 27 burst fractures were misdiagnosed as other types of fractures on radiographs alone, and accounted for 22.5% of all fractures. The results indicated that plain radiographs often fail to delineate the pathological features of thor-acolumbar burst fractures, leading to delay in diagnosis. Conclusion In regard to thoracolumbar injury diagnosis, burst fractures should be differentiated from compression frac-tures. CT should be routinely indicated and MRI examination, when necessary, may be simultaneously considered.展开更多
Review of X-ray dark-field imaging under development is presented. Its goal is its application to clinical diagnosis of organs that have been invisible by the ordinary techniques. In order to clinically visualize tiss...Review of X-ray dark-field imaging under development is presented. Its goal is its application to clinical diagnosis of organs that have been invisible by the ordinary techniques. In order to clinically visualize tissues in detail one needs high contrast and high spatial resolution say ～50 μm. This X-ray optics comprises a Bragg asymmetric monochro-collimator and a Bragg case or a Laue case filter with capability of analyzing angle in a parallel position. Their diffraction index is 4,4,0 and the X-ray energy 35 keV (λ= 0.0354 nm). The filter has 0.6 mm thickness in the Bragg case or 1.075 mm or 2.15 mm thickness in the Laue case. Under this condition only the refracted X-rays from object can transmit through the filter while the beam that may receive absorption and/or phase change will not. Soft tissues at human joints thus taken show high contrast images so that the DFI is promising for clinical diagnosis. Preliminary X-ray absorption images of another clinical candidates of ear bones are also shown.展开更多
Pilot biomechanical design of biomaterials for artificial nucleus prosthesiswas carried out based on the 3D finite-element method. Two 3D models of lumbar intervertebral discrespectively with a real human nucleus and ...Pilot biomechanical design of biomaterials for artificial nucleus prosthesiswas carried out based on the 3D finite-element method. Two 3D models of lumbar intervertebral discrespectively with a real human nucleus and with the nucleus removed were developed and validatedusing published experimental and clinical data. Then the models with a stainless steel nucleusprosthesis implanted and with polymer nucleus prostheses of various properties implanted were usedfor the 3D finite-element biomechanical analysis. All the above simulation and analysis were carriedout for the L4/L5 disc under a human worst--daily compression load of 2000 N. The results show thatthe polymer materials with Young's modulus of elasticity E = 0.1-100 MPa and Poisson's ratio v=0.35-0.5 are suitable to produce artificial nucleus prosthesis in view of biomechanicalconsideration.展开更多
Objective: To detect the effect of hBMP-2 transfected rMSCs on bone repair and the capability of the new biomaterial in enhancing bone repair. Methods: Auto-rMSCs were cultured and transfected with hBMP-2 by liposome....Objective: To detect the effect of hBMP-2 transfected rMSCs on bone repair and the capability of the new biomaterial in enhancing bone repair. Methods: Auto-rMSCs were cultured and transfected with hBMP-2 by liposome. All the transfected and un-transfected riSCs were attached to Allo-DBMs. These new biomaterials were implanted in muscle bags and segmental radius defects of the New Zealand white rabbits, and some controlled material groups were established for comparison. All the biomaterials and the controlled materials were assessed by gross observation, radiographical and histological methods. Results: The osteoblasts could be seen in the biomaterials with transfected rMSCs, which have been implanted in muscle bags. There was no sign of bone formation in the biomaterials with untransfected rMSCs and the single DBM groups. With the segmental bone defects, all the transfected, untransfected and single DBM biomaterials could work, but the healing of the biomaterial with transfected hBMP-2 was the fastest and most effective. Conclusion: Delivery of rMSCs with transfected hBMP-2 genemay generate osteo.morphogenesis and promote skeletal repair in vivo.展开更多
文摘Objective To review imaging use in the diagnosis of thoracolumbar burst fractures and to determine the diagnostic va-lue of different imaging methods. Methods One hundred and fourteen patients with 120 thoracolumbar burst fractures were retrospectively reviewed. Pl-ain radiographs were available in all cases; CT scans and MRI were obtained in 96 and 74 cases, respectively. Results A total of 27 burst fractures were misdiagnosed as other types of fractures on radiographs alone, and accounted for 22.5% of all fractures. The results indicated that plain radiographs often fail to delineate the pathological features of thor-acolumbar burst fractures, leading to delay in diagnosis. Conclusion In regard to thoracolumbar injury diagnosis, burst fractures should be differentiated from compression frac-tures. CT should be routinely indicated and MRI examination, when necessary, may be simultaneously considered.
文摘Review of X-ray dark-field imaging under development is presented. Its goal is its application to clinical diagnosis of organs that have been invisible by the ordinary techniques. In order to clinically visualize tissues in detail one needs high contrast and high spatial resolution say ～50 μm. This X-ray optics comprises a Bragg asymmetric monochro-collimator and a Bragg case or a Laue case filter with capability of analyzing angle in a parallel position. Their diffraction index is 4,4,0 and the X-ray energy 35 keV (λ= 0.0354 nm). The filter has 0.6 mm thickness in the Bragg case or 1.075 mm or 2.15 mm thickness in the Laue case. Under this condition only the refracted X-rays from object can transmit through the filter while the beam that may receive absorption and/or phase change will not. Soft tissues at human joints thus taken show high contrast images so that the DFI is promising for clinical diagnosis. Preliminary X-ray absorption images of another clinical candidates of ear bones are also shown.
文摘Pilot biomechanical design of biomaterials for artificial nucleus prosthesiswas carried out based on the 3D finite-element method. Two 3D models of lumbar intervertebral discrespectively with a real human nucleus and with the nucleus removed were developed and validatedusing published experimental and clinical data. Then the models with a stainless steel nucleusprosthesis implanted and with polymer nucleus prostheses of various properties implanted were usedfor the 3D finite-element biomechanical analysis. All the above simulation and analysis were carriedout for the L4/L5 disc under a human worst--daily compression load of 2000 N. The results show thatthe polymer materials with Young's modulus of elasticity E = 0.1-100 MPa and Poisson's ratio v=0.35-0.5 are suitable to produce artificial nucleus prosthesis in view of biomechanicalconsideration.
文摘Objective: To detect the effect of hBMP-2 transfected rMSCs on bone repair and the capability of the new biomaterial in enhancing bone repair. Methods: Auto-rMSCs were cultured and transfected with hBMP-2 by liposome. All the transfected and un-transfected riSCs were attached to Allo-DBMs. These new biomaterials were implanted in muscle bags and segmental radius defects of the New Zealand white rabbits, and some controlled material groups were established for comparison. All the biomaterials and the controlled materials were assessed by gross observation, radiographical and histological methods. Results: The osteoblasts could be seen in the biomaterials with transfected rMSCs, which have been implanted in muscle bags. There was no sign of bone formation in the biomaterials with untransfected rMSCs and the single DBM groups. With the segmental bone defects, all the transfected, untransfected and single DBM biomaterials could work, but the healing of the biomaterial with transfected hBMP-2 was the fastest and most effective. Conclusion: Delivery of rMSCs with transfected hBMP-2 genemay generate osteo.morphogenesis and promote skeletal repair in vivo.
