1 Department of Radiology and Imaging Sciences, National Institutes of Health, Clinical Center, 9000 Rockville Pike, Bldg 10, Rm 1C351, Bethesda, MD 20892.
2 Medical Robotics Laboratory, University of Georgia, College of Engineering, Athens, GA.
AJR Am J Roentgenol. 2018 Jan;210(1):207-213. doi: 10.2214/AJR.17.18498. Epub 2017 Sep 27.
In CT-guided intervention, translation from a planned needle insertion angle to the actual insertion angle is estimated only with the physician's visuospatial abilities. An iPhone app was developed to reduce reliance on operator ability to estimate and reproduce angles.
The iPhone app overlays the planned angle on the smartphone's camera display in real-time based on the smartphone's orientation. The needle's angle is selected by visually comparing the actual needle with the guideline in the display. If the smartphone's screen is perpendicular to the planned path, the smartphone shows the Bull's-Eye View mode, in which the angle is selected after the needle's hub overlaps the tip in the camera. In phantom studies, we evaluated the accuracies of the hardware, the Guideline mode, and the Bull's-Eye View mode and showed the app's clinical efficacy. A proof-of-concept clinical case was also performed.
The hardware accuracy was 0.37° ± 0.27° (mean ± SD). The mean error and navigation time were 1.0° ± 0.9° and 8.7 ± 2.3 seconds for a senior radiologist with 25 years' experience and 1.5° ± 1.3° and 8.0 ± 1.6 seconds for a junior radiologist with 4 years' experience. The accuracy of the Bull's-Eye View mode was 2.9° ± 1.1°. Combined CT and smart-phone guidance was significantly more accurate than CT-only guidance for the first needle pass (p = 0.046), which led to a smaller final targeting error (mean distance from needle tip to target, 2.5 vs 7.9 mm).
Mobile devices can be useful for guiding needle-based interventions. The hardware is low cost and widely available. The method is accurate, effective, and easy to implement.
在 CT 引导下的介入操作中，从计划的进针角度到实际进针角度的转换仅依赖于医生的空间想象能力。我们开发了一个 iPhone 应用程序，以减少对操作人员角度估计和重现能力的依赖。
该 iPhone 应用程序基于智能手机的方向，实时将计划的角度叠加到智能手机的摄像头显示上。通过在显示中视觉比较实际的针和指南，选择针的角度。如果智能手机的屏幕垂直于计划路径，则智能手机显示“牛眼视图”模式，在此模式下，当针的毂部与摄像头中的针尖重叠时选择角度。在体模研究中，我们评估了硬件、指南模式和牛眼视图模式的准确性，并展示了该应用程序的临床效果。还进行了一个概念验证的临床病例。
硬件精度为 0.37°±0.27°（平均值±标准差）。对于具有 25 年经验的高级放射科医师，平均误差和导航时间分别为 1.0°±0.9°和 8.7±2.3 秒，对于具有 4 年经验的初级放射科医师，平均误差和导航时间分别为 1.5°±1.3°和 8.0±1.6 秒。牛眼视图模式的准确性为 2.9°±1.1°。与仅 CT 引导相比，CT 和智能手机联合引导在第一次进针时明显更准确（p = 0.046），这导致了更小的最终目标误差（针尖到目标的平均距离，2.5 与 7.9mm）。
移动设备可用于引导基于针的介入操作。该硬件成本低，应用广泛。该方法准确、有效、易于实施。
