Objective
To analyze the diagnostic value of digital infrared thermographic imaging(DITI) and to compare the therapeutic effects of lidocaine injection(LI) and dry needling(DN) in the treatment of myofacial pain syndrome(MPS) by using the DITI and visual analogue scale(VAS).

Method
After 20 minutes adaptation time, 41 patients with MPS and 15 controls undertook DITI. LI and DN were randomly given in the trigger points of the patient group and to either side of the upper trapezius muscle in the controls. The effects of treatment were immediately assessed by measuring the temperature difference(ΔT) of the involved area and the corresponding area on the opposite side of the body using the DITI and VAS. Follow up assessments of VAS, change of VAS, ΔT and change of ΔT were performed 1, 3, 5 and 7 days after the treatment, respectively.

Result: 1) The sensitivity and specificity of hot spots for TrP were 78.1% and 73.3 %, respectively. 2) ΔT and VAS continuously declined for 7 days after the treatment as compared to before the treatment in groups Ia (n= 16, ΔT＞0.6℃, LI) and Ib (n=16, ΔT＞0.6℃, DN). 3) ΔT and VAS ware not statistically different for groups Ia and Ib. 4) There was no statistically significant correlation between ΔT and VAS in both groups I and Ib.

Conclusion
These data suggest that DITI can be used as one of the valuable tools for the evaluation of trigger points. No significant difference noted in the therapeutic effects of LI and DN for MPS.