Fig. 4
Ultrasound guided puncture procedure. a Needle was showed in the puncture procedure. b When blood was injected, the signal of flow blood was monitored by ultrasound, and boundary between cisterna magna and brain stem was disturbed by the high signal. c Blood in subarachnoid space at 1Â day after modeling. CM cisterna magna, BS brain stem, Blue line dura mater, Red arrowhead puncture needle, Blue block blood signal, Red arrow blood in subarachnoid space