Figure 2

Four lines, two distances, and two angles presented for application of the locator in a surgery. Graph (a) show Ml and PCl lines, SD, and angle α in a cross-sectional CT image; Graph (b) displays PUl and Hl lines, H/TD, and angle β in a lateral X-ray image. Graph (c) illustrates ML and HL lines on the body surface using an X-ray image. Graph (d) shows ML and HL lines, SD and H/TD, and point P on the body surface. Graph (e) depicts angles α and β on the two scale dials of the locator. Graph (f) shows the practical utilization of the locator. Ml and ML, linear median posterior; PCl, pedicle channel line; PUl, needle entry point on pedicle; Hl and HL, horizontal lines; SD, side opening distance; H/TD, head or tail tilt distance; angle α, extroversion angle; angle β, head or tail tilt angle; P, percutaneous puncture point; PH, a needle passing through the skin to the target point (pinhole surgery).