Franck H, Munz M, Scherrer M
Clinic Mayenbad, Bad Waldsee, Germany.
Calcif Tissue Int. 1995 Mar;56(3):192-5. doi: 10.1007/BF00298608.
Dual energy X-ray absorptiometry (DXA) using a single-beam (SB) design is a well-established procedure for measuring bone mineral area density (BMD). Recently, fan beam (FB) techniques have become available to measure BMD. We evaluated the QDR1000 and QDR2000 densitometers with regard to precision and cross-compared values using single beam (SB) and FB techniques. To study the effect of osteoarthritic changes on bone measurement (BMC in g) and bone mineral area density (BMD in g/cm2), both parameters were measured in patients with and without osteophytic calcifications (OC) of the lumbar spine. Precision errors for BMD in vitro over 1 and 6 months using the QDR2000 were 0.4% and 0.6% for SB and 0.5% and 0.7% for the three FB modes. For QDR1000 only SB is available. Using this scan mode, the BMD difference (delta = 0.1%) in vitro between QDR1000 and QDR2000 was not significant. The short-term (same day) reproducibility of BMD in vivo was 0.85% for SB mode and 1.1% for FB scan mode (n = 33). The midterm (1 month) precision errors were 0.9% for SB and 1.5% for FB (n = 11). The spine BMD of 751 patients from our outpatient clinic and department of rheumatology was 1.7% lower with FB than with SB (0.878 +/- 0.137 versus 0.888 +/- 0.146 g/cm2). Lower (1.8%) BMD values were also found in the hip with FB compared to SB (0.805 +/- 0.111 versus 0.821 +/- 0.111 g/cm2). There was a highly significant (P < 0.00001) correlation between SB and FB on the spine (r = 0.99) and hip (r = 0.98) using the QDR2000. Correlations found QDR1000 and QDR2000 were lower on the spine (r = 0.97) and hip (r = 0.93).(ABSTRACT TRUNCATED AT 250 WORDS)
使用单束（SB）设计的双能X线吸收法（DXA）是一种成熟的测量骨矿物质面积密度（BMD）的方法。最近，扇形束（FB）技术已可用于测量BMD。我们使用单束（SB）和FB技术，对QDR1000和QDR2000骨密度仪的精度和交叉比较值进行了评估。为研究骨关节炎变化对骨测量（骨矿物质含量，单位为g）和骨矿物质面积密度（BMD，单位为g/cm²）的影响，在有和没有腰椎骨赘钙化（OC）的患者中测量了这两个参数。使用QDR2000在体外1个月和6个月期间BMD的精度误差，SB模式分别为0.4%和0.6%，三种FB模式分别为0.5%和0.7%。对于QDR1000仅提供SB模式。使用该扫描模式，QDR1000和QDR2000在体外的BMD差异（δ =
0.1%）不显著。体内BMD的短期（同一天）重复性，SB模式为0.85%，FB扫描模式为1.1%（n = 33）。中期（1个月）精度误差，SB模式为0.9%，FB模式为1.5%（n = 11）。我们门诊和风湿病科751例患者的脊柱BMD，FB模式比SB模式低1.7%（分别为0.878±0.137与0.888±0.146 g/cm²）。与SB模式相比，FB模式下髋部的BMD值也较低（1.8%）（分别为0.805±0.111与0.821±0.111 g/cm²）。使用QDR2000时，脊柱（r = 0.99）和髋部（r = 0.98）的SB和FB之间存在高度显著相关性（P < 0.00001）。QDR1000和QDR2000在脊柱（r = 0.97）和髋部（r = 0.93）的相关性较低。（摘要截短于250字）
