Objective To observe the time-effect of stimulation of the embedded poly glycolide-co-lactide(PGLA)suture in Sanyinjiao(SP6)area in normal human body

so as to provide an experimental evidence for clinical application of micro-invasion suture-embedding at an appropriate interval.Methods A total of 8 healthy volunteer students(3 boys and 5 girls

ranging in age from 24 to 27 years)were recruited in the present study.A piece of sterilized PGLA suture was implanted into the left SP6 using minimally invasive surgery after strict local skin disinfection.The fat-suppression T2 weighted magnetic resonance images(MRI

displaying local lesion after eliminating interference of fat tissue signals)

and T2 mapping 8-echo train images were acquired before and 8 h

3

7

10 and 14 days after PGLA suture embedment by using a MR imaging system.After transformation of the T2-mapping 8-echo train images into T2-mapping images by using a relevant software

the T2 values(meaning the relaxation time of the local muscle)of the left SP6 were measured

followed by analysis of the signal intensity of T2 weighted fat-suppression images and T2 values at different time-points.Results Before the suture embedding

no abnormal signals were found in the signal intensity of T2 weighted fat-suppression images.After PGLA suture embedment

the local signal intensity of T2 WI fatsuppression images was relatively increased at the 8 th h

and on day 3

7

10 and 14 relevant to pre-embedment

but gradually atte-nuated on day 10 and 14.The T2 values were significantly increased at the 5 time-points of post-embedment(all P<0.01)

but without significant differences among the 8 thh

the 3 rd and 7 thd(P>0.05)

and being markedly lowered on day 14 relevant to day 7(P<0.01)in spite of being still markedly higher than that of pre-embedding(P<0.01).Conclusion The signal intensity of T2 weighted fat-suppression images and T2 values acquired from PGLA-suture-embedded SP6 acupoint area in healthy subjects may keep at least for 2 weeks

suggesting that the stimulating reaction of suture-embedment persists more than 14 days.Hence

when a micro-invasion embedding with PGLA suture performed

the interval of two weeks would be appropriate.