[Study on safe depth of needling at acupoints of kidney regions based on MRI imaging]

To measure the dangerous depth and the effective safe depth of needling at acupoints of kidney regions based on MRI imaging, and to provide the imaging support for clinical practice.

The abdominal enhanced T1 MRI imaging of horizontal plane of 61 healthy subjects was included, the anatomical structure of bilateral Weishu (BL 21), Sanjiaoshu (BL 22), Shenshu (BL 23), Weicang (BL 50), Huangmen (BL 51) and Zhishi (BL 52) was analyzed, and the dangerous depth and effective safe depth of perpendicular and oblique needling were measured between the left and right sides and subjects with different body sizes.

There were no significant differences between dangerous depth and effective safe depth of perpendicular and oblique needling at bilateral acupoints of kidney region (P>0.05). The dangerous depth and effective safe depth of perpendicular and oblique needling at bilateral acupoints of kidney region in the moderate group were larger than the underweight group (P<0.05), while those in the overweight group were larger than the moderate group and the underweight group (P<0.05).

The safe depth of needling at acupoints of kidney region is related to body size, for moderate weight and overweight patients, the needling depth could be increased for better efficacy, while for underweight patients, the recommend direction and depth of needling should be restricted to avoid acupuncture accident.