Fuji Masahiro, Oba Hiroki, Ikegami Shota, Uehara Masashi, Fujinaga Yasunari, Takahashi Jun
Shinshu University Hospital, Matsumoto, Japan.
Eur Spine J. 2025 May 23. doi: 10.1007/s00586-025-08947-1.
Comparative study of radiation doses in intraoperative cone-beam computed tomography (CBCT) using an anthropomorphic phantom.
Compare the portrait and conventional landscape CBCT imaging methods under intraoperative conditions focusing on dose reduction rate, image quality, and imaging range. Intraoperative CBCT improves the accuracy of pedicle screw (PS) insertion in posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). We recently introduced portrait imaging for intraoperative CBCT in PS insertion using surgery navigation for AIS. However, evidence is scarce on the comparative radiation dose and image quality of this orientation versus landscape imaging.
A human body phantom was equipped with radiophotoluminescent glass dosimeters both inside and on the surface for measuring radiation doses under portrait and landscape CBCT imaging methods. Radiation doses were evaluated by average dose index (ADI), surface dose (D), central dose (D), and displayed dose (D). Image quality was assessed using the contrast-to-noise ratio (CNR) on phantom images. Imaging range was measured using sagittal image craniocaudal length and axial image diameter.
The respective mean ± standard deviation radiation doses for portrait and landscape imaging were 42.9 ± 0.7 and 50.6 ± 1.1 mGy for ADI (i.e., approximately 15% less radiation dose for portrait), 53.9 ± 1.6 and 65.2 ± 1.2 mGy for D, 21.1 ± 1.4 and 21.4 ± 1.0 mGy for D, and 146.6 and 145.0 mGy for D. The CNR results revealed comparable image qualities for portrait and landscape imaging of 2.23 ± 0.22 and 2.18 ± 0.19, respectively. The respective craniocaudal imaging range was 24.6 cm and 18.4 cm, while the axial imaging range was 17.6 cm and 23.7 cm.
Portrait-mode CBCT allows for a wider craniocaudal imaging range and enables intraoperative CBCT imaging at lower radiation doses without compromising image quality.
使用拟人化体模对术中锥形束计算机断层扫描（CBCT）的辐射剂量进行比较研究。
比较术中条件下纵向和传统横向CBCT成像方法在剂量降低率、图像质量和成像范围方面的差异。术中CBCT可提高青少年特发性脊柱侧凸（AIS）后路脊柱融合术（PSF）中椎弓根螺钉（PS）置入的准确性。我们最近在使用手术导航的AIS的PS置入术中引入了纵向成像用于术中CBCT。然而，关于这种成像方向与横向成像相比的辐射剂量和图像质量的证据很少。
在人体体模内部和表面均配备放射性光致发光玻璃剂量计，以测量纵向和横向CBCT成像方法下的辐射剂量。通过平均剂量指数（ADI）、表面剂量（D）、中心剂量（D）和显示剂量（D）评估辐射剂量。使用体模图像上的对比噪声比（CNR）评估图像质量。使用矢状位图像的头尾长度和轴位图像的直径测量成像范围。
纵向和横向成像的各自平均±标准差辐射剂量，ADI分别为42.9±0.7和50.6±1.1 mGy（即纵向辐射剂量约低15%），D分别为53.9±1.6和65.2±1.2 mGy，D分别为21.1±1.4和21.4±1.0 mGy，D分别为146.6和145.0 mGy。CNR结果显示纵向和横向成像的图像质量相当，分别为2.23±0.22和2.18±0.19。各自的头尾成像范围分别为24.6 cm和18.4 cm，而轴位成像范围分别为17.6 cm和23.7 cm。
纵向模式CBCT可实现更宽的头尾成像范围，并能在不影响图像质量的情况下以较低辐射剂量进行术中CBCT成像。
