2. Methods

2.1. Searching Strategy
We searched the original articles published during 1995 to 2014 on PubMed (http://www.ncbi.nlm.nih.gov/pubmed/) using the following MeSH terms and search strategies: ((“Acupuncture” [Mesh] OR “Acupuncture Therapy” [Mesh] OR “Acupuncture, Ear” [Mesh] OR “Acupuncture Points” [Mesh] OR “Acupuncture Analgesia” [Mesh])) AND ((“Neuroimaging” [Mesh] OR “Functional Neuroimaging” [Mesh] OR “Functional MRI” [Mesh] OR “PET” [Mesh] OR “EEG” [Mesh])).
We screened the bibliographies of identified trials and reviewed articles for further potentially relevant publication. Subsequently, we screened the full texts and assessed whether these articles met the inclusion criteria.

2.2. Inclusion and Exclusion Criteria
The articles would be included if they were (1) original articles; (2) acupuncture-neuroimaging studies on human beings; (3) published in English; and (4) published during 1995 to 2014.
The articles would be excluded if they were (1) reviews or editorials or trial protocols; (2) acupuncture-neuroimaging studies on animals; or (3) duplicate articles.

2.3. Data Extraction and Analysis
We extracted the data including the author (nationality, affiliation, and component), sample size, characteristics of the participant (patients or the health, age, gender, race, handedness, emotional state, acupuncture experience, and accompanying symptoms), neuroimaging technology, acupuncture intervention (method of intervention, manipulation procedure, Deqi/needle sensation, and acupuncturist), and ethical review. The data analysis was conducted after data extraction.