锥形束CT线性测量头颅骨的精确性

Linear measurement accuracy using cone-beam computed tomography for human skull

背景:锥形束CT在口腔医学中的应用日益广泛,优点不可取代,线性测量是其重要功能之一,线性测量在整个头颅范围内的精确性和可重复性有待进一步研究,不同的分辨率和扫描层厚对线性结果的影响也需要进一步研究。目的:评价锥形束CT在两种不同象素下对人头颅骨线性测量结果的精确性。方法:选取4个干头颅,选定其上22个解剖标志点进行11条线段长度的物理测量作为金标准,将头颅进行锥形束CT 0.3 mm和0.15 mm两种不同象素的扫描,在轴位图像和冠状位图像上进行线段测量,SPSS 17.0软件比较图像测量和物理测量值的差异。结果与结论:物理测量和图像测量结果的差值在-0.27-0.14之间,两种象素的差值均与物理测量结果之间差异无显著性意义(P>0.05),两种象素结果相比差异也没有显著性意义(P>0.05)。结果可见锥形束CT在轴向和冠状向上的线段测量具有很高的精确性,当进行线性测量时推荐使用较大的分辨率(0.3 mm),这样放射剂量更小,扫描时间更快。

BACKGROUND：Cone-beam computed tomography has been widely applied in the dentistry due to irreplaceable advantages. Among those advantages, linear measurement is one of the important ones. Further studies are suggest to explore the accuracy and repeatability of linear measurement for the whole skul , as wel as the effect of different resolution and scanning thickness on the linear measurement results. OBJECTIVE：To evaluate the accuracy of linear measurement using cone-beam computed tomography （Newtom VG） on the human skul , with two different voxel sizes. METHODS：In this study, 22 anatomic landmarks in four dry human skul s were marked and 11 linear measurements were obtained. These were considered to be the gold standard （real measurement）. The skul s were scanned by cone-beam computed tomography （Newtom VG） at two voxel sizes：0.3 mm and 0.15 mm. Linear measurement was performed in axial and coronal planes. SPSS software version 17 was used for data analysis between radiographic measurement and real measurement. RESULTS AND CONCLUSION：The mean differences of real and radiographic measurements were-0.27 to 0.14 in four different sections, and statistical analysis showed no significant difference between linear measurements and gold standard （P〉0.05）. There was no significant between two different voxel sizes＆nbsp;（P〉0.05）. Cone-beam computed tomography （Newtom VG） is highly accurate and reproducible in linear measurements in the axial and coronal planes. A cone-beam computed tomography scan with a larger voxel size （0.3 mm） is recommended, resulting in lower radiation dose and faster scan time.