Analysis of brainstem activitywith fMRI during low-level of pain- a feasibility study with innocuous cold stimuli

Background: In functional magnetic resonance imaging (fMRI)studies, there are limitedpublished data on the functional map of the human brainstem. Objective: The primary goals of this pilot study were to assess the feasibility and  to map  the  neural activity in the human brainstem with fMRIby equal intensity by low-level of thermal stimuli on the peripheral sensors of the skin. Patients and Methods: FMRI studies of the brainstem were carried out on 6healthyindividuals in a 3T MRI machine. Noxious thermal stimuli was applied on the peripheral sensitisation nerves on the arm. FMRI data spanned from the brainstem location by a 32-head channel and analysed using a fixed-effects General Linear Model to discriminate signal intensity changes from physiological motion. The results were normalised and combined to show the activity at each location on a voxel-by-voxel basis. Areas of physiological activity were recognisedwith comparison to the  number of atlases. Results: Noxious and innocuous related activation clusters were approved in thisapplied method. There were considerable activity in the midbrain, pons, medulla and reticular formation. The results  of this pilot study are similar and in some anatomical regions even better with head coils than obtained with previous fMRI spinal coil studies.We obtained evidence of localization of the following nuclei by using this method, asfollows: major activities in the inferior anterior parts of pons and the junction with medulla includes the (olive and pyramids),superior cerebella pundicle, rostral portion of medulla (RMV), Broadmann areas  [5,2] touch and temperature sensation  areas with the innocuous stimuli; activation in the left side of the medulla the (olive and pyramids), the left side of pons, the left side of midbrain, Broadmann area [5,7] pain and temperature sensation areas with noxious stimuli. Conclusion:This pilotstudy provides useful evidenceoflow-painful and innocuous information transmitted  between the peripheral nervous system and the central nervous system in healthy participants.It also demonstrates how peripheral sensitisation induces physiological changes in the brainstem  correlates with noxious and innocuous thermal transmission

Bioeffects of 1.5T Static Magnetic Field on the DNA Strand of Human Leukocytes in Vitroduring MRI Scan

Background: The non ionization of magnetic resonance fields effect sreported   with radical pair recombination. Which   is one of the familiar methods by which static magnetic felid interact with biological systems. Exposure to static magnetic fields can effect on the paramagnetic free radicals by increasing  the concentration, the activity and life time of paramagnetic free radicals, which might lead to genetic mutation, oxidative stress, and in some times with apoptosis. Objective: To estimate the genotoxicity on DNA molecule during expose to static magnetic field 1.5T of magnetic resonance imaging. Patients and Methods: The five blood   samples were irradiated  to 1.5T static magnetic field at different periods (10,20,30,40,and 50 minutes correspondingly). All exposures were performed at room temperature. Cellular  DNA damage had been  analyzed by the alkaline comet assay.                                                                     Results: The results approved a significant increasing  in the rate of recurrence of single-strand DNA breaks next to the  exposure of  a 1.5T of magnetic resonance imaging at 50 min. According to these  results the exposure with 3T magnetic resonance imaging encourage genotoxic effects in human lymphocytes could be suggested. Conclusion: To conclude, in the present study, employing alkaline comet assay, it has been demonstrated thatmagnetic resonance imaging- induced  DNA damages is significant in  leukocytes at 50 minute after exprosure to 1.5T magnetic resonance imaging