Fig. 1

Different sagittal views under ultrasound. a Parasagittal oblique view. b Spinous process view. c In the near spinous process view, the spinal canal is clearly shown without bony structures. d Schematic diagram of the vertebral body shows the position of the different views in the transverse section, as well as the location of the puncture point (red dot). e During the puncture process, the left hand held the probe for real-time guidance, and the right hand inserted the needle along the fixed angle on the guide frame