Figure 1

CT machine ascertainment of the intended cell puncture site, direction and depth. a, An axial (transverse) image. The red line indicates the upper intervertebral space of the intended puncture site and the direction. The green line shows that the intended puncture site is 3 cm away from the left edge of the marker. b, A sagittal image. The pink line represents the upper intervertebral space of the intended puncture site and the direction. The blue line shows the intended puncture depth of 7 cm, and the green line shows that the intended puncture site is located 1.9 cm below the upper marker.