Department of Nuclear Medicine, Hamilton Health Sciences, Hamilton, Canada.
Department of Nuclear Medicine, Hamilton Health Sciences, Hamilton, Canada.
J Clin Densitom. 2010 Jan-Mar;13(1):18-23. doi: 10.1016/j.jocd.2009.10.001.
The least significant change (LSC) represents the smallest difference between successive measurements of bone mineral density (BMD) that can be considered to be a real change and not attributable to chance. The LSC is derived from same-day in vivo BMD precision measurements. Our first objective was to determine if the LSC differs between technologists. Our second objective was to determine if patient body size influenced the LSC. Each of 8 technologists measured same-day precision in groups of 30 patients for the lumbar spine and the total trochanter and neck regions of the proximal femur. At the spine, precision ranged from 0.008 to 0.011g/cm(2) and did not differ between technologists. Precision for the total region of the left proximal femur ranged from 0.006 to 0.016g/cm(2) and did differ between technologists. For the trochanter and neck regions, precision ranged from 0.008 to 0.013g/cm(2) for the former and from 0.010 to 0.020g/cm(2) for the latter, again, with inter-technologist differences. The LSC for the lumbar spine increased linearly from 0.022 to 0.031g/cm(2) when body mass index (BMI) increased from 19.5 to 31.3kg/m(2). In contrast, there was no discernable impact of BMI on the LSC for any of the proximal femur regions. The LSC at the spine is determined by the patient, whereas the LSC at the femur is determined by the technologist. Use of a single value for the LSC will lead to misinterpretations of the significance of BMD changes at both the spine and the proximal femur.
最小有意义变化（LSC）代表骨密度（BMD）连续测量值之间的最小差异，可以认为这是真实的变化，而不是偶然的。LSC 是从同日的体内 BMD 精密度测量中得出的。我们的第一个目标是确定技术人员之间的 LSC 是否存在差异。我们的第二个目标是确定患者体型是否会影响 LSC。8 位技术人员中的每位都对 30 位患者的腰椎和股骨近端的总转子和颈部区域进行了同日的精密度测量。在脊柱部位，精密度范围在 0.008 到 0.011g/cm²之间，且技术人员之间没有差异。左侧股骨近端总区域的精密度范围在 0.006 到 0.016g/cm²之间，技术人员之间存在差异。对于转子和颈部区域，前者的精密度范围在 0.008 到 0.013g/cm²之间，后者的精密度范围在 0.010 到 0.020g/cm²之间，技术人员之间也存在差异。当体重指数（BMI）从 19.5 增加到 31.3kg/m²时，腰椎的 LSC 呈线性增加，从 0.022 增加到 0.031g/cm²。相比之下，BMI 对股骨近端任何区域的 LSC 都没有明显的影响。脊柱的 LSC 由患者决定，而股骨的 LSC 由技术人员决定。使用单一的 LSC 值将导致对脊柱和股骨近端 BMD 变化的意义的误解。
