Department of Radiology, University of Minnesota, Minneapolis, MN, 55455, USA.
Department of Radiology, University of Minnesota, Minneapolis, MN, 55455, USA.
Radiography (Lond). 2021 Aug;27(3):773-778. doi: 10.1016/j.radi.2020.12.003. Epub 2020 Dec 29.
In computed tomography (CT) imaging protocols, lack of practice standards and variability in head positioning may all yield substantial inter-study image variance in the clinical setting which may limit the diagnostic and comparative value of subsequent scans. We aimed to evaluate repeatability of multiplanar reformatting of head CT based on the tuberculum sella (TS) to internal occipital protuberance (IOP) reference line and reduce variance.
Reference lines that correspond to the TS-IOP plane on high-resolution CT scans were reviewed by technologists manually to calculate Yaw (z-rotation, rotation along the superoinferior direction), Pitch (x-rotation, rotation along the left-right direction), and Roll (y-rotation, rotation along the anteroposterior direction) angles in this pre-post design intervention study. The Yaw, Pitch, and Roll angles deviating from the reference TS-IOP in the head CT images before and after technologist training were measured with the technologists' actual graphical prescriptions, and their differences were calculated with t-tests. The intra-rater agreement was calculated using the intraclass correlation coefficient (ICC).
Mean pitch, yaw, and roll before technologist training was 6.7° ± 5.4°, 0.9° ± 1.5°, and 1.1° ± 1.2° and after training were 3.2° ± 2.6°, 0.6° ± 1.1°, and 0.6° ± 1.1°, respectively. Technologist training resulted in a significant decrease in pitch (p < 0.001) and roll (p = 0.001) inter-subject variability with respect to the TS-IOP line, however no significant difference for the yaw correction (p = 0.065) was noted. Intra-rater agreement regarding the reproducibility of TS-IOP reformation was excellent (ICC>0.950).
TS-IOP reference line corrected for direct roll, yaw, and pitch can be readily achieved by trained technologists.
Adoption of the TS-IOP reference line should facilitate intra- and intermodality comparisons, leading to more reproducible and readily interpretable CT images.
在计算机断层扫描（CT）成像方案中，缺乏实践标准和头部定位的可变性都可能导致临床研究中图像的大量差异，从而限制了后续扫描的诊断和比较价值。我们旨在评估基于鞍结节（TS）到枕内隆突（IOP）参考线的头部 CT 多平面重建的可重复性，并减少变异性。
在这项前后设计的干预研究中，技术人员手动审查了与高分辨率 CT 扫描中的 TS-IOP 平面相对应的参考线，以计算头 CT 图像中在技术人员培训前后偏离 TS-IOP 的 Yaw（z-旋转，沿上下方向旋转）、Pitch（x-旋转，沿左右方向旋转）和 Roll（y-旋转，沿前后方向旋转）角度。使用技术人员的实际图形处方测量培训前后技术人员头部 CT 图像中 TS-IOP 的 Yaw、Pitch 和 Roll 角度偏差，并使用 t 检验计算其差异。使用组内相关系数（ICC）计算内部评估者一致性。
在技术人员培训之前，平均Pitch、Yaw 和 Roll 分别为 6.7°±5.4°、0.9°±1.5°和 1.1°±1.2°，培训后分别为 3.2°±2.6°、0.6°±1.1°和 0.6°±1.1°。与 TS-IOP 线相比，技术人员培训导致 Pitch（p<0.001）和 Roll（p=0.001）的变异性显著降低，但 Yaw 校正无显著差异（p=0.065）。关于 TS-IOP 重建可重复性的内部评估者一致性非常好（ICC>0.950）。
经过训练的技术人员可以轻松实现通过 TS-IOP 参考线校正直接 Roll、Yaw 和 Pitch。
采用 TS-IOP 参考线应有助于模态内和模态间的比较，从而使 CT 图像更具可重复性和易于解释。
