[Imaging study on safety of deep needling at Dachangshu (BL 25)].

Objective: Based on magnetic resonance imaging technology, the dangerous depth of straight needling and the safety of deep needling at Dachangshu (BL 25) are discussed, and data support is provided for standardizing deep needling at Dachangshu (BL 25).
Methods: The horizontal cross-sectional images of 148 healthy adult subjects under the spinous process of the 4th lumbar vertebra were collected by magnetic resonance instrument, the anatomical structure was analyzed, and the dangerous depth of straight needling at Dachangshu (BL 25) was measured.
Results: The dangerous depth of straight needling at Dachangshu (BL 25) was (11.2±1.3) cm and (11.0±1.2) cm on the left and right sides of males, and (9.8±1.3) cm and (9.7±1.3) cm on the left and right sides of females. There was a positive correlation between the dangerous depth of straight needling at Dachangshu (BL 25) and body mass index (BMI). In the case of similar body size, the dangerous depth of straight needling at Dachangshu(BL 25) in males was greater than that in females ( P <0.01).
Conclusion: At present, the deep needling at Dachangshu (BL 25) used in clinic is safe. In clinical application of the deep needling at Dachangshu (BL 25), the depth of needle insertion can be determined according to body size and gender.