氢质子MR波谱及双回波同反相位成像评价腰椎骨质疏松的研究

为探究氢质子MR波谱(MRS)的脂肪分数(FF)、脂水比(LWR)及双回波同反相位信号比值(SIR)与腰椎定量CT(QCT)骨矿物质密度(BMD)的相关性,并评估MRS、双回波同反相位成像对腰椎骨质减低及骨质疏松的诊断价值,本研究对因腰腿痛就诊的120名患者资料进行了回顾性分析,根据QCT分类标准将患者分为正常组、骨量减少组和骨质疏松组。所行MRI检查包括MRS和双回波同反相位成像,测量腰2~4椎体FF、LWR及双回波同反相位SIR。结果发现,FF、LWR、SIR与BMD呈负相关;FF、LWR与SIR呈正相关。FF、LWR、SIR、BMD在骨量正常组、骨量减少组和骨质疏松组任意两组间差异均有显著性(P<0.001)。本研究表明MRS及双回波同反相位成像可通过无创无辐射检测骨髓脂肪组织而间接反映骨代谢情况。     

Stochastic Komatu–Loewner evolutions and BMD domain constant

For Komatu–Loewner equation on a standard slit domain, we randomize the Jordan arc in a manner similar to that of Schramm (2000) to find the SDEs satisfied by the induced motion $\xi \left(t\right)$ on $?\mathbb{H}$ and the slit motion $\mathbf{s}\left(t\right)$. The diffusion coefficient $\alpha$ and drift coefficient $b$ of such SDEs are homogeneous functions.Next with solutions of such SDEs, we study the corresponding stochastic Komatu–Loewner evolution, denoted as ${\mathrm{SKLE}}_{\alpha ,b}$. We introduce a function $b_{\mathrm{<font\; color="red">BMD</font>}}$ measuring the discrepancy of a standard slit domain from $\mathbb{H}$ relative to BMD. We show that ${\mathrm{SKLE}}_{\sqrt{6},?b_{\mathrm{<font\; color="red">BMD</font>}}}$ enjoys a locality property.     

Osteoporosis detection in postmenopausal women using axial transmission multi-frequency bone ultrasonometer: Clinical findings

The objective of this study was to evaluate if the Bone UltraSonic Scanner (BUSS) can detect osteoporosis in postmenopausal women. BUSS is an axial transmission multi-frequency ultrasonometer for acquisition of wave propagation profiles along the proximal anterior tibia. We derived 10 diagnostically significant BUSS parameters that were then compared with the DXA spine T-score, which was used in this study as the “gold standard” for the assessment of osteoporosis (T-score <−2.5). BUSS wave parameters were studied in 331 postmenopausal women examined by 9 trained operators at 3 clinical sites with use of 3 devices. The efficiency of each BUSS parameter in osteoporosis detection was assessed using a receiver operating characteristic curve analysis. Area under the curve (AUC) for each of 10 parameters ranged from 58.1% to 70.2%. Using these parameters a linear classifier was derived which provided at its output 83.0% AUC, 87.7% sensitivity and 63.2% specificity to DXA-identified osteoporosis. The results of this study confirm BUSS’s capability to detect osteoporosis in postmenopausal women.     

超声背散射法评价松质骨状况的研究

超声背散射法评价松质骨状况及诊断骨质疏松症是近年来医学超声领域内的研究热点之一,现已取得了显著的进展。本文将介绍近年来超声背散射法及其参量评价松质骨状况的研究进展,并分析超声背散射相关参量频谱质心偏移量（SCS）和平均骨小梁间距（TbSp）与骨矿密度（BMD）的相关性。研究结果表明,超声背散射参量与BMD有较高的相关性。最后提出了将来研究中需要努力的方向。     

Bone microarchitecture evaluated by histomorphometry

The increasing use of densitometric devices for assessing bone fragility has progressively strengthened the assumption that mass is the most important property determining bone mechanical competence. Nevertheless, structure and microarchitecture are relevant aspects of bone strength. The study of microarchitecture is based on the measure of width, number, and separation of trabeculae as well as on their spatial organization. There are several methods to assess bone architecture, particularly at the trabecular level. In particular, histomorphometry, based on the use of optical microscopy and on the principles of quantitative histology and stereology, evaluates microarchitecture two-dimensionally, even if these measures appear well correlated to the three-dimensional structure and properties of bone. In addition, new computerized methods allow the acquisition of more sophisticated measurements by means of a digitizer have been introduced to integrate the use of the microscope. These methods supply information on trabecular width as well as on its distribution and on the organization of the trabeculae in the marrow space.

Microarchitecture seems to be a determinant of bone fragility independent of bone density and it is important for understanding the mechanisms of bone fragility as well as the action of the drugs used to prevent osteoporotic fractures. Several in vivo studies (on animals and humans) can provide an additional interpretation for the anti-fracture effect of such drugs. For instance, bisphosphonates and parathyroid hormone seem to preserve or even improve microarchitecture. The challenge for the future will be to evaluate bone quality in vivo with the same or better resolution and accuracy than the invasive methods used today.