Hi, I'm Kathleen Hay from the Mateo Center in the Department of Radiology at Massachusetts General Hospital and Harvard Medical School. Today we will show you a procedure for functional magnetic resonance imaging during acupuncture stimulation. When we first started to apply FMRI to image the effects of acupuncture on the brain, we had no idea what the data would look like.
Over the years, we have built a database of acupuncture with FMRI monitoring as several major acupuncture points in approximately 200 subjects in health and in disease, providing a strong foundation for future studies. Dr.Kenneth Qua, MRI, physicist from the Martin Center, directed the FMRI imaging. In these studies, he will be delivering the concluding remarks, mainly practicing acupuncturist and research.
Acupuncturist at the center will perform the acupuncture procedures. Dr.Vitali Napal, expert in acupuncture FMRI at the center, will demonstrate the data acquisition process with physiological monitoring. So let's get started.
During the scanning session, physiological parameters such as the electrocardiogram or ECG GX skin response or SCR and respiration are recorded from the subject. The signals are recorded with a power lab attached to a computer equipped with chart software from 80 instruments, which amplifies digitizes and records the signals coming from the subject. To set up the respiratory belt system that is used to record respiration, plug the transducer into a power outlet in the scanner control room and feed the belt through the inlet into the scanner room.
To synchronize the physiological data with the FMRI data, connect A BNC cable from the FMRI scanner trigger box to the power lab in the control room. The chart software can then be set up to start recording when a signal is received from the scanner. Now gathered the ECG monitoring devices, you'll need four ECG electrodes and an ECG cable connected to an MRI compatible rolling portable cart to measure skin conductance, plug two SER connectors into the breakout box in the scanning room and have skin conductance gel.
Ready Now let's begin prepping the subject for the scan. Before you begin, make sure that the subject is not anxious or fatigued and has eaten a light meal prior to the scan. As this can affect the brain response to acupuncture stimulation, bring the subject into the scanner room and have them insert earplugs to protect their ears from the noise of the scanner.
Now, place the subject onto the scanner bed and use cushioned supports to immobilize their head. Acupuncture scans are especially susceptible to head motion artifacts because of their low signal to noise ratio. To reduce body motion, place a support under the subject's knees to keep the heels from touching the surface of the stretcher, fasten the head coil and to make final adjustments to the support cushions to ensure that the subject is comfortable.
Because an average session lasts two hours, comfort is vital for uninterrupted scanning. MRI compatible. Physiological monitoring can be performed during scanning if desired.
ECG signal quality should be verified before recording. In this demonstration, we are using a 1.5 Tesla Siemens Avanto MRI system equipped for echo planar imaging with a standard quadratic head coil. For studies with acupuncture stimulation, thinner brain slices should be acquired.
To reduce susceptibility artifacts, use slices three millimeters thick with a 0.6 millimeter or 0.75 millimeter gap in the sagittal or axial orientation to cover the entire brain, including the brainstem and cerebellum. Acquire functional scans with a T two weighted gradient echo sequence with repetition time or TR of four seconds, and an echo time or TE of 30 milliseconds, field of view, or FOV 200 millimeters, matrix 64 by 64 and flip angle 90. The shorter TE helps reduce susceptibility artifacts while the relatively long TR permits whole brain coverage with high spatial resolution.
The amygdala hippocampus, ventral medial prefrontal cortex and subgenual areas located at the base of the brain are particularly susceptible to signal loss. Check the echo planar images to ensure good coverage in these regions. Using a 1.5 Tesla instead of higher field strength magnets for data collection will help to minimize such artifacts for specialized studies.
Be sure to proceed image collection by at least four dummy scans to allow for equilibration of the FMRI signal. Now let's see how to perform acupuncture during an FMRI experiment, begin by instructing the subject to relax, keep their eyes closed, and refrain from moving during the scanning. To avoid noxious stimulation, instruct the subject to raise one finger.
If any of the acupuncture sensations approaches a pain rating score of eight out of 10 and to raise two fingers in case of any degree of sharp pain before the scanning begins. Insert a sterile disposable high quality all silver acupuncture needle into the acupoint vertically. The needle can be manipulated by gentle rotation or by lift and thrusting.
The rotation technique is used more often. Test the subject sensitivity to needle manipulation to estimate the depth of insertion and the manipulation force required to elicit, to achieve without causing undue discomfort or noxious pain. During the 10 minute scan, rotate the needle at one hurts during two two minute blocks separated by rest period in which the needle is left in place.
Make sure not to approach or leave the subject directly before or after the stimulation period as that motion could affect the results. Repeat the procedure on the other acupoints. For sensory control or sham acupuncture, we deliver superficial tactile stimulation to the acupoint with a size 5.88 von frame monofilament and a matched paradigm.
This is done before real acupuncture stimulation to the acupoint. It can be done by free tapping of the filament or by inserting filament through a guiding tube used for acupuncture needles. Upon completion of acupuncture stimulation, record the force with which the needle resists manipulation.
At the end of each scan, have an investigator other than the acupuncturist ask the subject to grade the sensations experienced. On a scale of zero to 10. The list of acupuncture sensations is derived from the acupuncture community rather than from typical pain questionnaires in the literature.
The FMRI data is then categorized according to the psychological response to chi, to chi, mixed with sharp pain, no acupuncture sensations, and sharp pain only. It is extremely rare to encounter sharp pain only. Here's a look at some representative FMRI data, which we processed with A FNI.
Other software such as FS LO free surfer can also be used. Functional scans are overlaid over the high resolution anatomical maps of the cohort. All group maps shown here are threshold at P less than 0.0001 uncorrected.
First, let's see how acupuncture deci differs from tactile stimulation. This is data from a group of 37 subjects in acupuncture. Deci clusters of deactivated structures appeared at the medial prefrontal cortex, medial parietal cortex, and medial temporal lobe on both hemispheres.
Such changes were sparse in tactile stimulation. The right lateral temporal lobe also exhibited more marked deactivation during acupuncture. In contrast to deactivation, tactile stimulation showed more activation of the sensory motor BA 43 and association cortex BA 22.
The right anterior insula was paradoxically activated during acupuncture but not tactile stimulation. Here we see the correlation between the psychophysical and hemodynamic response. This graph represents acupuncture deci compared to DEI plus sharp pain.
The prominent deactivation of the medial prefrontal cortex, medial parietal cortex and medial temporal seen with dechy absent pain was attenuated in the presence of pain with pain. Activation of the sensory motor and association. Cortices became more prominent and a subset of the limbic regions such as the middle cingulate supplemental motor area, posterior cingulate, BA 23 amygdala and cerebellar verus became activated.
Activation of the insula in deci was localized to the right anterior division while activation in pain did not show specific localizations. Here we see overlap of limbic paralympic neocortical networks or LP NN from 48 subjects during acupuncture stimulation with the default mode network or DMN, the clusters of deactivated regions during acupuncture stimulation in the medial prefrontal cortex, medial parietal cortex and temporal lobe of the lp NN by general linear model analysis and by model free fuzzy cluster analysis showed market similarity with the core regions of the DMN. We have just shown you how to monitor the dynamic effect of acupuncture on the human brain.
Using FMRI when doing this procedure, it's important to remember to pay attention to the subject's comfort and psychophysical response aiming to generate their CHI and avoid noxious stimulation. So that's it. Thanks for watching and good luck with the experiment.
