Preliminary Study On Functional Magnetic Resonance Imaging Of Acupuncture Using Arterial Spin Labeling Technique

Objective:Acupuncture research is a kind of brain functional research that many scholars have been keen on in recent years. Many scholars used blood oxygenation level dependent functional MRI imaging studies and demonstrated some results,but the results were not the same.The main cause of the difference is the influence factors of the experimental technology itself. In this study, we selected healthy volunteers as subjects. All subjects received acupuncture by the same acupuncturist at the left ST36. Based on BOLD-f MRI and ASL, in order to investigate the feasibility of ASL technology on acupuncture mechanism study, we observed the distribution and size of activated brain areas and compared the cerebral blood flow(r CBF) of activated brain areas.Methods:(1) 20 cases were selected as BOLD-f MRI group and each case accepted three BOLD-f MRI scans(before acupuncture, during acupuncture and after acupuncture).A modified block design was used in the acupuncture state. The experimental data were processed by AFNI software, the results were analyzed by single sample t-test, corrected by Monte Carlo simulation method, P = 0.001 calculated alpha < 0.05 minimum cluster size voxels(176 individual element), extracted Parameters Figure cof value and changed into z-value. Through the threshold correction, the position, signal type and position coordinate system Z of the active region were recorded.(2) 20 healthy volunteers were selected as ASL-f MRI group and received ASL-f MRI examination in the resting state.The scan mode was the same as BOLD-f MRI, the modified block design and the acupuncturist were all the same.After the experimental processing by AFNI software, two-sample t-test was used to calculate the differences of cerebral activation area between the data in the state of acupuncture and before the acupuncture state. The results were corrected by Monte Carlo simulation method, P = 0.001 calculated alpha < 0.05 minimum cluster size voxels(176 individual element), extracted Parameters Figure cof value and changed into z-value, calculated the change of activated brain areas and the rate of change.(3) Statistical analyze recults were compared between BOLD-f MRI group and ASL-f MRI group, including similarities and differences between the two groups. The rate of r CBF changes in activated brain areas had also been calculated for ASL-f MRI group.Results:(1) Compared with the BOLD group, the ASL group not only showed the somatosensory related brain areas(bilateral SII, insula, thalamus and cingulate cortex) and motor related brain areas(SMA)activation, but also the SI, frontal lobe, parietal lobe, anterior cingulate cortex and other brain regions showed activation, but the activation of the white matter area was significantly decreased.(2) The amplitude of signal change was higher in the ASL group, the rate of r CBF was(9.21 + 2.82) %?Conclusions:(1) Acupunctured at left ST36, in the ASL-f MRI group and the BOLD-f MRI group, there were some common activated brain areas in the somatosensory related brain regions, which contains bilateral thalamus, bilateral supplementary motor area(SII), bilateral insular lobe, and bilateral middle cingulate cortex,and in the motor related brain regions,such as right medial frontal region(SMA).The activated brain areas are consistent with most scholars accepted activated regions by acupuncturing at ST36. This shows the feasibility of acupuncture for functional brain study by using arterial spin labeling perfusion imaging.(2) Compared with the BOLD-f MRI group, the ASL-f MRI group not only showed the somatosensory related brain areas(bilateral SII, insula, thalamus and middle cingulate cortex) and motor related brain areas(SMA)activation, but also the SI, anterior cingulate cortex, inferior parietal lobe, frontal lobe, red nucleus, pontine reticular formation and surrounding brain regions showed more activated brain areas.This shows that using arterial spin labeling perfusion imaging technique for functional magnetic resonance imaging even under such a high P value which P take in 0.001,it can still get more activated brain areas compared with the BOLD –f MRI method by acupuncturing at ST36,and has higher sensitivity.(3) Compared with the BOLD-f MRI group, in the ASL-f MRI group, the possible artifacts were significantly reduced and the amplitude of signal change was higher. The average of the signal change amplitude(r CBF amplitude) was 5.566 + 1.219, the signal change rate(r CBF rate) in the activated brain areas was(9.212 +2.818)%,which was significantly higher than the change rate of less than 1% that based on BOLD-f MRI.Therefore, the ASL-f MRI has high stability and repeatability.