Osteoporosis is a common metabolic skeletal disorder characterized by decreased bone mass and deteriorated bone structure, leading to increased susceptibility to fractures. With aging population, osteoporotic fracture...Osteoporosis is a common metabolic skeletal disorder characterized by decreased bone mass and deteriorated bone structure, leading to increased susceptibility to fractures. With aging population, osteoporotic fractures are of global health and socioeconomic importance. The three-dimensional microstructural information of the common osteoporosis-related fracture sites, including vertebra, femoral neck and distal radius, is a key for fully understanding osteoporosis pathogenesis and predicting the fracture risk. Low vertebral bone mineral density(BMD) is correlated with increased fracture of the spine. Vertebral BMD decreases from cervical to lumbar spine, with the lowest BMD at the third lumbar vertebra. Trabecular bone mass of the vertebrae is much lower than that of the peripheral bone. Cancellous bone of the vertebral body has a complex heterogeneous three-dimensional microstructure, with lower bone volume in the central and anterior superior regions. Trabecular bone quality is a key element to maintain the vertebral strength. The increased fragility of osteoporotic femoral neck is attributed to low cancellous bone volume and high compact porosity. Compared with age-matched controls, increased cortical porosity is observed at the femoral neck in osteoporoticfracture patients. Distal radius demonstrates spatial inhomogeneous characteristic in cortical microstructure. The medial region of the distal radius displays the highest cortical porosity compared with the lateral, anterior and posterior regions. Bone strength of the distal radius is mainly determined by cortical porosity, which deteriorates with advancing age.展开更多
背景股骨头坏死患者常处于青壮年,如果不及时治疗,会快速进展,发生股骨头的塌陷,严重影响工作生活,最终需要接受全髋关节置换。目的观察早期股骨头坏死标本不同区域微观结构,研究其内部结构变化规律,为早期股骨头坏死的治疗提供指导。...背景股骨头坏死患者常处于青壮年,如果不及时治疗,会快速进展,发生股骨头的塌陷,严重影响工作生活,最终需要接受全髋关节置换。目的观察早期股骨头坏死标本不同区域微观结构,研究其内部结构变化规律,为早期股骨头坏死的治疗提供指导。方法收集2019年3月-2020年1月因股骨头坏死于解放军总医院第一医学中心行全髋关节置换术患者的10个股骨头标本,其中女性5例,男性5例,年龄41~66岁,平均52岁。术前起病时间3~24个月,平均9.5个月。根据改良的国际骨循环研究学会(ARCO)分期标准,放射学分期均为Ⅱ期。将骨坏死标本沿冠状位切成厚约2 mm切片,采用micro-CT、高精度X线检查、病理学等方法研究股骨头坏死不同区域内部结构变化规律。结果通过micro-CT及病理切片染色发现早中期股骨头坏死标本软骨下骨正常的屏障作用减退或消失,部分区域有新生血管侵入,坏死区骨小梁结构完整性消失,骨小梁表面新生骨较少,且存在大量空骨陷窝。硬化区骨小梁数量和厚度均明显增加,新生类骨质较多,硬化区成骨相对于坏死区和正常区更为活跃。骨计量参数统计分析显示硬化区骨矿密度(bone mineral density,BMD)(mg/cc)(202.83±38.95 vs 79.00±24.50和102.12±17.44)、骨体积分数(bone volume fraction,BV/TV)(50.35%±7.40%vs 29.14%±8.80%和33.68%±5.70%)相对于坏死区和正常区明显增加(P均<0.05)。同时坏死修复反应区血管面积也较坏死区和正常区明显增加(P<0.05)。结论早中期股骨头坏死已发生软骨下骨屏障作用减退。坏死区保留死骨,改变成骨方式,对于早中期骨坏死的治疗及塌陷的预防具有积极意义。展开更多
Ultrasonic backscatter signals from cancellous bone are sensitive to the microstructure of trabecular bone,and thus enable the feasibility to extract microstructural information of trabecular bone.The mean trabecular ...Ultrasonic backscatter signals from cancellous bone are sensitive to the microstructure of trabecular bone,and thus enable the feasibility to extract microstructural information of trabecular bone.The mean trabecular bone spacing(MTBS)is an important parameter for characterizing bone microstructure.This paper proposes an MTBS estimation method based on the combination of Hilbert transform and fundamental frequency estimation(CHF). The CHF was verified with ultrasonic backscatter signals from simulations and in vitro measurements at a central frequency of 5MHz.The CHF method was compared with the simplified inverse filter tracking(SIFT)method,Simons' Quadratic Transformation(QT)method,Singular Spectrum Analysis(SSA)method,and Spectral Autocorrelation(SAC)method.Monte-Carlo simulations were performed by varying the MTBS,signal-to-noise ratio(SNR),standard deviation of regular spacing(SDRS),amplitude ratio of diffuse scattering to regular scattering(Ad)and frequency dependent attenuation(nBUA).The simulation results showed that the CHF method had a better performance in MTBS estimation under almost all the examination conditions except for SNR.The estimation percentage correct(EPC)was greater than 90% when the MTBS was in the range of 0.4to 1.4mm.In the in vitro measurements,the estimated EPC by the CHF method was91.25±7.81%(mean±standard deviation).A significant correlation was observed for the CHF-estimated MTBS and micro-computed tomography(μ-CT)-measured values(R^2=0.75,p<0.01).These results demonstrate that the CHF method is anti-interference for MTBS estimation and can be used to estimate trabecular bone spacing.展开更多
The study aimed to examine changes in trabecular bone microstructure （TBMS） during the period of 5 weeks after the injury in a rat model of spinal cord injury （SCI）. Eight-week-old male Wistar rats underwent surgi...The study aimed to examine changes in trabecular bone microstructure （TBMS） during the period of 5 weeks after the injury in a rat model of spinal cord injury （SCI）. Eight-week-old male Wistar rats underwent surgical transection of the lower thoracic spinal cord （SCI, n = 16） or sham operation （SHAM, n = 14）. TBMS （tissue volume, bone volume, bone volume fraction, trabecular thickness, width, number, separation, connectivity density, and trabecular bone pattern factor）, assessed using a micro-computed tomography, was deteriorated 1, 3 and 5 weeks after SCI. In addition, both bone mass and serum biochemical parameters were determined. Dry bone weight, ash weight, bone mineral content （BMC）, and BMC/tissue-volume were significantly lower in the SCI group than in the SHAM group throughout the experimental period. Serum inorganic phosphate and alkaline phosphatase levels were significantly lower in the SCI group than in the SHAM group 1 week after the surgery. SCI resulted in rapid deterioration of both bone mass and microstructure. These changes appeared as early as 1 week after SCI. Based on the authors＇ results, it should be noted that in SCI patients, interventions for preventing bone loss should start as soon as possible after the injury.展开更多
文摘Osteoporosis is a common metabolic skeletal disorder characterized by decreased bone mass and deteriorated bone structure, leading to increased susceptibility to fractures. With aging population, osteoporotic fractures are of global health and socioeconomic importance. The three-dimensional microstructural information of the common osteoporosis-related fracture sites, including vertebra, femoral neck and distal radius, is a key for fully understanding osteoporosis pathogenesis and predicting the fracture risk. Low vertebral bone mineral density(BMD) is correlated with increased fracture of the spine. Vertebral BMD decreases from cervical to lumbar spine, with the lowest BMD at the third lumbar vertebra. Trabecular bone mass of the vertebrae is much lower than that of the peripheral bone. Cancellous bone of the vertebral body has a complex heterogeneous three-dimensional microstructure, with lower bone volume in the central and anterior superior regions. Trabecular bone quality is a key element to maintain the vertebral strength. The increased fragility of osteoporotic femoral neck is attributed to low cancellous bone volume and high compact porosity. Compared with age-matched controls, increased cortical porosity is observed at the femoral neck in osteoporoticfracture patients. Distal radius demonstrates spatial inhomogeneous characteristic in cortical microstructure. The medial region of the distal radius displays the highest cortical porosity compared with the lateral, anterior and posterior regions. Bone strength of the distal radius is mainly determined by cortical porosity, which deteriorates with advancing age.
文摘背景股骨头坏死患者常处于青壮年,如果不及时治疗,会快速进展,发生股骨头的塌陷,严重影响工作生活,最终需要接受全髋关节置换。目的观察早期股骨头坏死标本不同区域微观结构,研究其内部结构变化规律,为早期股骨头坏死的治疗提供指导。方法收集2019年3月-2020年1月因股骨头坏死于解放军总医院第一医学中心行全髋关节置换术患者的10个股骨头标本,其中女性5例,男性5例,年龄41~66岁,平均52岁。术前起病时间3~24个月,平均9.5个月。根据改良的国际骨循环研究学会(ARCO)分期标准,放射学分期均为Ⅱ期。将骨坏死标本沿冠状位切成厚约2 mm切片,采用micro-CT、高精度X线检查、病理学等方法研究股骨头坏死不同区域内部结构变化规律。结果通过micro-CT及病理切片染色发现早中期股骨头坏死标本软骨下骨正常的屏障作用减退或消失,部分区域有新生血管侵入,坏死区骨小梁结构完整性消失,骨小梁表面新生骨较少,且存在大量空骨陷窝。硬化区骨小梁数量和厚度均明显增加,新生类骨质较多,硬化区成骨相对于坏死区和正常区更为活跃。骨计量参数统计分析显示硬化区骨矿密度(bone mineral density,BMD)(mg/cc)(202.83±38.95 vs 79.00±24.50和102.12±17.44)、骨体积分数(bone volume fraction,BV/TV)(50.35%±7.40%vs 29.14%±8.80%和33.68%±5.70%)相对于坏死区和正常区明显增加(P均<0.05)。同时坏死修复反应区血管面积也较坏死区和正常区明显增加(P<0.05)。结论早中期股骨头坏死已发生软骨下骨屏障作用减退。坏死区保留死骨,改变成骨方式,对于早中期骨坏死的治疗及塌陷的预防具有积极意义。
基金supported by the NSFC(11327405,11504057&11525416)
文摘Ultrasonic backscatter signals from cancellous bone are sensitive to the microstructure of trabecular bone,and thus enable the feasibility to extract microstructural information of trabecular bone.The mean trabecular bone spacing(MTBS)is an important parameter for characterizing bone microstructure.This paper proposes an MTBS estimation method based on the combination of Hilbert transform and fundamental frequency estimation(CHF). The CHF was verified with ultrasonic backscatter signals from simulations and in vitro measurements at a central frequency of 5MHz.The CHF method was compared with the simplified inverse filter tracking(SIFT)method,Simons' Quadratic Transformation(QT)method,Singular Spectrum Analysis(SSA)method,and Spectral Autocorrelation(SAC)method.Monte-Carlo simulations were performed by varying the MTBS,signal-to-noise ratio(SNR),standard deviation of regular spacing(SDRS),amplitude ratio of diffuse scattering to regular scattering(Ad)and frequency dependent attenuation(nBUA).The simulation results showed that the CHF method had a better performance in MTBS estimation under almost all the examination conditions except for SNR.The estimation percentage correct(EPC)was greater than 90% when the MTBS was in the range of 0.4to 1.4mm.In the in vitro measurements,the estimated EPC by the CHF method was91.25±7.81%(mean±standard deviation).A significant correlation was observed for the CHF-estimated MTBS and micro-computed tomography(μ-CT)-measured values(R^2=0.75,p<0.01).These results demonstrate that the CHF method is anti-interference for MTBS estimation and can be used to estimate trabecular bone spacing.
文摘The study aimed to examine changes in trabecular bone microstructure （TBMS） during the period of 5 weeks after the injury in a rat model of spinal cord injury （SCI）. Eight-week-old male Wistar rats underwent surgical transection of the lower thoracic spinal cord （SCI, n = 16） or sham operation （SHAM, n = 14）. TBMS （tissue volume, bone volume, bone volume fraction, trabecular thickness, width, number, separation, connectivity density, and trabecular bone pattern factor）, assessed using a micro-computed tomography, was deteriorated 1, 3 and 5 weeks after SCI. In addition, both bone mass and serum biochemical parameters were determined. Dry bone weight, ash weight, bone mineral content （BMC）, and BMC/tissue-volume were significantly lower in the SCI group than in the SHAM group throughout the experimental period. Serum inorganic phosphate and alkaline phosphatase levels were significantly lower in the SCI group than in the SHAM group 1 week after the surgery. SCI resulted in rapid deterioration of both bone mass and microstructure. These changes appeared as early as 1 week after SCI. Based on the authors＇ results, it should be noted that in SCI patients, interventions for preventing bone loss should start as soon as possible after the injury.
