Allegri F, Carugno C, Ravasini R, Bordin M, Turra S, Gigante C
Istituto di Radiologia, Università, Padova.
Radiol Med. 1989 Mar;77(3):182-6.
The torsional angle was calculated goniometrically of 9 femurs and 2 tibio-peroneal groups, and then compared to the values obtained from CT scans of the corresponding bones. The results show how the methods adopted up to now have been inaccurate and have yielded only gross definitions of the axis of the femoral neck. As far as this feature is concerned, an error of +/- 6.5 degrees can be estimated, with limits of confidence of 95%, after applying a more accurate system of measurement to the images and considering statistical interferences. After pointing out the advantages of this method, we suggest that the test performed in vivo be systematically proposed to all those patients in whom a more accurate diagnosis would lead to a different medical/surgical therapy considering that: 1) the inevitable error such a measurement bears can be contained between acceptable limits; 2) the radiation dose sufficient to distinguish the bone from the other surrounding tissues is much reduced with respect to the dosage necessary to perform a common CT of the inferior limbs. It comprises one topogram and four tomograms, with a total dose to the patient of approximately 10-20 mGy.
通过测角法计算了9个股骨和2个胫腓骨组的扭转角，然后将其与相应骨骼CT扫描获得的值进行比较。结果表明，到目前为止所采用的方法是不准确的，只能得出股骨颈轴线的大致定义。就这一特征而言，在对图像应用更精确的测量系统并考虑统计干扰后，可以估计出±6.5度的误差，置信度为95%。在指出该方法的优点后，我们建议对所有那些更准确的诊断会导致不同医疗/手术治疗的患者系统地进行这种体内测试，原因如下：1）这种测量所产生的不可避免的误差可以控制在可接受的范围内；2）与进行下肢普通CT所需的剂量相比，足以将骨骼与周围其他组织区分开的辐射剂量大大降低。它包括一张定位图和四张断层图，患者所接受的总剂量约为10 - 20毫戈瑞。
