Non-invasive magnetic detection of human injury currents.
OBJECTIVE
Injury currents are a hallmark of acute lesions in polarized cells. Our objective was to develop a non-invasive technique for monitoring human near-DC injury currents in vivo.


METHODS
Using diagnostic muscle biopsy as controlled paradigm, injury-related magnetic DC-fields were mapped for 60 min postsurgery over leg muscle lesions of 9 subjects. A 49-channel magnetometer was used in combination with a mechanical horizontal modulation of the subject beneath the sensor array.


RESULTS
Magnetic DC-field maps showed salient differences between biopsy and contralateral legs in 8/9 patients with a characteristic slowly decaying field in all biopsy legs. A variety of anomalous DC-field patterns was recorded over the biopsy sites, corresponding to theoretically predicted geometric variations of equivalent DC-current dipoles, i.e. wound surfaces, pointing into opposing muscle fibre ends. By contrast, all control measurements showed an elongated dipolar DC-field pattern. Additionally, mean global DC-field strengths were significantly higher over biopsy legs compared to the contralateral site.


CONCLUSIONS
Our pilot data illustrate that human injury currents can be detected using non-invasive magnetometry. Thus, DC-magnetometry may provide an essential new tool for clinical monitoring of injury currents, possibly also in brain tissue, e.g. in case of anoxic or peri-infarct depolarizations.
Carbon
Maren
M
Neurophysics Group, Department of Neurology, Charité-University Medicine Berlin, Campus Benjamin Franklin, 12200 Berlin, Germany. mcarbon@nshs.edu
Wübbeler
Gerd
G
Mackert
Bruno-Marcel
BM
Mackert
Jan
J
Ramsbacher
Josef
J
Trahms
Lutz
L
Curio
Gabriel
G
D000328:Adult; D000368:Aged; D004553:Electric Conductivity; D005260:Female; D006801:Humans; D007866:Leg; D008280:Magnetics; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009135:Muscular Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D010865:Pilot Projects