Department of Musculoskeletal Radiology, Centre Hospitalier Régional Universitaire de Lille, Hôpital Roger Salengro, Lille, France.
Eur Radiol. 2012 Apr;22(4):765-71. doi: 10.1007/s00330-011-2308-y. Epub 2011 Oct 20.
To evaluate three-dimensional (3D) measurements of the lower extremity using a biplanar low-dose X-ray device in children and adolescents.
Firstly, 3D measurements of eight dried bones were analysed by a biplanar low-dose X-ray device (LDX) using stereoscopic software and compared with 3D computed tomography (CT). Secondly, 47 lower limbs of children and adolescents were studied using LDX two-dimensional (2D) and 3D measurements. Both parts were evaluated for femoral and tibial lengths and mechanical angles, frontal and lateral knee angulations, and the femoral neck-shaft angle.
The 3D specimen comparison between LDX and CT measurements showed no significant differences: femoral length (P = 0.069), tibial length (P = 0.059), femoral mechanical angle (P = 0.475), tibial mechanical angle (P = 0.067), frontal knee angulation (P = 0.198), lateral knee angulation (P = 0.646) and femoral neck-shaft angle (P = 0.068). The comparison between LDX 2D and 3D measurements showed significant differences in tibial length (P = 0.003), femoral mechanical angle (P < 0.001) and femoral neck-shaft angle (P = 0.001); other parameters were unremarkable.
The 3D LDX system presented reliable measurements compared with 3D CT. Differences between LDX 2D and 3D measurements were noted in the femoral mechanical angle, femoral neck-shaft angle and tibial length. Moderate to good interobserver agreement for the 3D LDX measurements were found.
Low radiation dose is essential when assessing potential lower extremity discrepancies. A new biplanar low-dose X-ray device can assess such discrepancies in children/adolescents. This LDX device provides equally reliable 3D measurements as prevalent practice LDX measurements carry good overall interobserver agreement.
评估使用双平面低剂量 X 射线设备对儿童和青少年下肢进行三维（3D）测量。
首先，使用立体软件分析双平面低剂量 X 射线设备（LDX）对 8 个干骨的 3D 测量值，并与 3D 计算机断层扫描（CT）进行比较。其次，使用 LDX 二维（2D）和 3D 测量值对 47 例儿童和青少年下肢进行研究。评估股骨和胫骨长度以及机械角度、前后膝角和股骨颈干角。
LDX 和 CT 测量的 3D 标本比较无显著差异：股骨长度（P = 0.069）、胫骨长度（P = 0.059）、股骨机械角度（P = 0.475）、胫骨机械角度（P = 0.067）、前膝角（P = 0.198）、侧膝角（P = 0.646）和股骨颈干角（P = 0.068）。LDX 2D 和 3D 测量值的比较在胫骨长度（P = 0.003）、股骨机械角度（P < 0.001）和股骨颈干角（P = 0.001）方面存在显著差异；其他参数无明显差异。
3D LDX 系统与 3D CT 相比，测量结果可靠。在股骨机械角度、股骨颈干角和胫骨长度方面，LDX 2D 和 3D 测量值存在差异。3D LDX 测量的观察者间一致性较好。
在评估潜在的下肢差异时，低辐射剂量至关重要。一种新的双平面低剂量 X 射线设备可以评估儿童/青少年的此类差异。该 LDX 设备提供与常用实践 LDX 测量同等可靠的 3D 测量值，具有良好的总体观察者间一致性。
