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J Abart

Publications and source records attributed to J Abart.

2 recordsLinked to original sources

[Safety aspects in MR imaging].

With the growing number of Magnetic Resonance Systems in operation in clinical practice, safety aspects gain increasing importance. Therefore, it is necessary to evaluate possible risks and effects on human health. After an introduction to the basic principles and techniques involved, the various effects on biological systems and especially the human organism caused by the static magnetic field, the alternating magnetic fields and the high frequency fields required are described on the basis of current literature and partially also on our own experience. Basic information for the safe operation of diagnostic Magnetic Resonance Systems is presented. Limits for exposure to magnetic fields and time-dependent changes of electromagnetic fields for patients and employees as suggested by health authorities are given.

Contraindications↗

Peripheral nerve stimulation by time-varying magnetic fields.

PURPOSE: A study was performed to assess the stimulation threshold for healthy adults using sinusoidally oscillating gradients. METHOD: One hundred thirteen healthy adults were examined in the study. ECG and physiological parameters were measured. All measurements were performed of both the head and the abdomen. The subjects were measured in the supine position with the region of interest positioned in the center of the gradient coils. The measurement was performed for three orthogonal, four oblique, and double oblique orientations. RESULTS: No volunteer reported painful, severe stimulation. The mean thresholds for peripheral stimulation in head and body measurement were similar: 85.5% of stimulation during examination of the head and 87.6% during measurements of the abdomen were reported when the y-gradient was used. CONCLUSION: The greatest frequency of reported stimulations occurs when the y-gradient is used. This was confirmed by the results and supports the hypothesis that orthogonal to the y-axis the body has its largest conductive loop, resulting in the strongest peripheral stimulation.

Adult↗