4.4. Acupuncture Intervention

4.4.1. Method of Intervention
We found that, during 1995 to 2014, 66.27% studies have used manual acupuncture as intervention method, and 18.93% studies have used the electroacupuncture as intervention method. Among those manual acupuncture studies, 78.57% studies have described the needle manipulation. During 2005–2014, the majority of acupuncture-neuroimaging studies (68.71%) still used manual acupuncture as intervention method, and 17.01% studies used the electroacupuncture as intervention method. Among the manual acupuncture studies, 79.21% studies have described the needle manipulation. The results indicated that (1) although the stimulation of manual acupuncture is hard to be quantified for the individual differences of manipulation induced by different practitioners, manual acupuncture, as the traditional acupuncture intervention, is easier to be accepted by investigators and (2) the majority of these studies with manual acupuncture treatment describe the acupuncture manipulation including sterilization, the angle and depth of needle insertion, and the duration of retaining needle to ensure consistency of acupuncture treatment. Considering the influence of different manipulation results, we should not allocate too many acupuncturists in one neuroimaging study. In order to ensure the accuracy of the results, it is better to perform acupuncture manipulation with one acupuncturist.
Meanwhile, transcutaneous electric acupoint stimulation, magnetic stimulation, heat stimulation, and laser acupuncture were used in some neuroimaging studies. The results indicated that not only manual acupuncture and electroacupuncture, but also other acupuncture-related interventions attract increasing interests of investigators. In the future, more attention should be paid to those acupuncture methods which have not or seldom been touched such as ear acupuncture, abdominal acupuncture, and wrist and ankle acupuncture.

4.4.2. Qualification of Acupuncturist and Operation Procedure
The qualification of acupuncturist and operation procedure is important in quality control of acupuncture trial. In our study, 59.5% of the studies have mentioned the qualification of acupuncturists and 79.88% of the studies have described the manipulation procedure of acupuncture. For the defined influence of the qualification of acupuncturist and manipulation procedure on clinical efficacy, the needling details including numbers of needle, depth of insertion, elicited response, and needle retention time and the background of practitioners including the duration of relevant training, length of clinical experience, and details of expertise in treating the specific condition being evaluated as well as any other experience that may be relevant to the trial should be reported according to the standards for reporting interventions in controlled trials of acupuncture (The STRICTA Recommendations) [199].

4.4.3. Deqi (Needle Sensation) and Evaluation of Sensation
Deqi (needle sensation) plays an important role in acupuncture efficacy. Clinical trials have demonstrated that acupuncture with needle sensation was superior to acupuncture without needle sensation for analgesia [200] and paralysis [201]. A neuroimaging study [54] also showed the significant differences of cerebral responses under the Deqi and non-Deqi condition. So it is important to record the Deqi sensation in acupuncture studies.
In this study, we found that the questionnaire-based forms such as 10-point VAS, MASS, SASS, Park questionnaire, Psychophysical Rating of Needling Sensation, and NSQ were used to assess the needle sensation in acupuncture-neuroimaging studies. Among them, 10-point VAS was the most commonly used (68.3%). However, the liabilities and validities of some specific or nonspecific questionnaires/scales for needle sensation need further investigation.