Ghostine Bachir, Sauret Christophe, Assi Ayman, Bakouny Ziad, Khalil Nour, Skalli Wafa, Ghanem Ismat
Institut de Biomécanique Humaine Georges Charpak, Arts et Métiers ParisTech, Paris, France.
Laboratory of Biomechanics and Medical Imaging, Faculty of Medicine, University of Saint-Joseph, Beirut, Lebanon.
Eur Radiol. 2017 Mar;27(3):1295-1302. doi: 10.1007/s00330-016-4452-x. Epub 2016 Jun 10.
Radiographs are often performed to assess pelvic and hip parameters, but results depend upon correct pelvis positioning. Three-dimensional (3D) reconstruction from biplanar-radiographs should provide parameters that are less sensitive to pelvic orientation, but this remained to be evaluated.
Computerized-tomographic scans of six patients were used both as a reference and for generating simulated frontal and lateral radiographs. These simulated radiographs were generated while introducing axial rotations of the pelvis ranging from 0° to 20°. Simulated biplanar-radiographs were utilized by four operators, three times each, to perform pelvic 3D-reconstructions. These reconstructions were used to assess the trueness, precision and global uncertainty of radiological pelvic and hip parameters for each position.
In the neutral position, global uncertainty ranged between ± 2° for pelvic tilt and ± 9° for acetabular posterior sector angle and was mainly related to precision errors (ranging from 1.5° to 7°). With increasing axial rotation, global uncertainty increased and ranged between ± 5° for pelvic tilt and ± 11° for pelvic incidence, sacral slope and acetabular anterior sector angle, mainly due to precision errors.
Radiological parameters obtained from 3D-reconstructions, based on biplanar-radiographs, are less sensitive to axial rotation compared to plain radiographs. However, the axial rotation should nonetheless not exceed 10°.
• Pelvic radiological parameters could be affected by patient malpositioning. • Biplanar radiograph-based 3D reconstructions were performed at increments of axial rotation. • Trueness, precision and global uncertainty were evaluated for pelvic and hip radiological parameters. • Hip parameters were less affected by rotation compared to pelvic parameters. • Maintaining the pelvis close to the neutral position is recommended to ensure the highest possible accuracy.
通常通过X线片来评估骨盆和髋关节参数，但结果取决于骨盆的正确定位。双平面X线片的三维（3D）重建应能提供对骨盆方向不太敏感的参数，但这仍有待评估。
对6例患者的计算机断层扫描既用作参考，也用于生成模拟正位和侧位X线片。在引入骨盆从0°到20°的轴向旋转时生成这些模拟X线片。4名操作人员分别对模拟双平面X线片进行3次操作，以进行骨盆三维重建，并用于评估每个位置的骨盆和髋关节放射学参数的准确性、精密度和总体不确定性。
在中立位时，骨盆倾斜度的总体不确定性在±2°之间，髋臼后扇区角的总体不确定性在±9°之间，主要与精密度误差有关（范围为1.5°至7°）。随着轴向旋转增加，总体不确定性增加，骨盆倾斜度的总体不确定性在±5°之间，骨盆入射角、骶骨坡度和髋臼前扇区角的总体不确定性在±11°之间，主要是由于精密度误差。
与普通X线片相比，基于双平面X线片的三维重建获得的放射学参数对轴向旋转不太敏感。然而，轴向旋转仍不应超过10°。
• 患者位置不当可能会影响骨盆放射学参数。• 基于双平面X线片的三维重建以轴向旋转增量进行。• 评估了骨盆和髋关节放射学参数的准确性、精密度和总体不确定性。• 与骨盆参数相比，髋关节参数受旋转的影响较小。• 建议将骨盆保持在接近中立位，以确保尽可能高的准确性。
