Numerical computation of specific absorption rate and induced current for workers exposed to static magnetic fields of MRI scanners

Farrag, S. I.

doi:10.1109/iecbes.2014.7047576

Cited by 4 publications

(3 citation statements)

References 10 publications

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“…Powerful computing resources are necessary to implement these methods, and sophisticated numerical anatomical human models, with accurate characterization of dielectric properties of different tissues, must be available to obtain reliable results. However, a simplified approach to such evaluation has been proposed by recent papers, which is based on application tools that estimate the induced electric fields and current densities once the iso-gauss line map of the MRI scanner is known and by adopting a simplified formulation of Maxwell’s equation ( 14 , 43 , 44 ). These methods are usually implemented with a graphical user interface (GUI), in such a way to simulate the movements of a worker on the ground plane, with assigned walking path and speed.…”

Section: Discussionmentioning

confidence: 99%

Exposure Assessment and Biomonitoring of Workers in Magnetic Resonance Environment: An Exploratory Study

Sannino

Romeo

Scarfì

et al. 2017

Front. Public Health

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Magnetic resonance imaging (MRI) has evolved rapidly over the past few decades as one of the most flexible tools in medical research and diagnostic imaging. MRI facilities are important sources of multiple exposure to electromagnetic fields for both patients and health-care staff, due to the presence of electromagnetic fields of multiple frequency ranges, different temporal variations, and field strengths. Due to the increasing use and technological advancements of MRI systems, clearer insights into exposure assessment and a better understanding of possible harmful effects due to long-term exposures are highly needed. In the present exploratory study, exposure assessment and biomonitoring of MRI workers at the Radio-diagnostics Unit of the National Cancer Institute of Naples “Pascale Foundation” (Naples, Italy) have been carried out. In particular, exposure to the MRI static magnetic field (SMF) has been evaluated by means of personal monitoring, while an application tool has been developed to provide an estimate of motion-induced, time-varying electric fields. Measurement results have highlighted a high day-to-day and worker-to-worker variability of the exposure to the SMF, which strongly depends on the characteristics of the environment and on personal behaviors, and the developed application tool can be adopted as an easy-to-use tool for rapid and qualitative evaluation of motion-induced, time-varying electric field exposure. Regarding biomonitoring, the 24 workers of the Radio-diagnostics Unit were enrolled to evaluate both spontaneous and mitomycin C-induced chromosomal fragility in human peripheral blood lymphocytes, by means of the cytokinesis-block micronucleus assay. The study subjects were 12 MRI workers, representative of different professional categories, as the exposed group, and 12 workers with no MRI exposure history, as the reference group. The results show a high worker-to-worker variability for both field exposure assessment and biomonitoring, as well as several critical issues and practicalities to be faced with in this type of investigations. The procedures for risk assessment and biomonitoring proposed here can be used to inform future research in this field, which will require a refinement of exposure assessment methods and an enlargement of the number of subjects enrolled in the biomonitoring study to gain robust statistics and reliable results.

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Section: Discussionmentioning

confidence: 99%

Exposure Assessment and Biomonitoring of Workers in Magnetic Resonance Environment: An Exploratory Study

Sannino

Romeo

Scarfì

et al. 2017

Front. Public Health

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“…The iso-gauss line map ( fringe field ) of the MRI scanner brand Sigma GE 1.5 Tesla , Siemens 1T , Toshiba 0.5 T was actually measured using a Gaussmeter brand OXFORD Instruments using the HALL effect with resolution of 0.01mT (0.1 Gauss) [8].…”

Section: IIImentioning

confidence: 99%

Influence of motion speed in static magnetic fields of MRI scanners on the density of induced electric currents in bodies of MRI operators

Farrag

Kamel

2015

2015 E-Health and Bioengineering Conference (EHB)

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To compute values of electric currents induced in bodies of MRI operators as influenced by different motion speeds and by different scanner intensities, meanwhile verifying whether the guidelines recommended by the ICNIRP for occupational exposures is or not exceeded. Groups of MRI operators were approached. Three Motion speeds were recorded to perform the calculations. An equation was generated to describe the variability of induced electric currents with different motion speeds and magnetic flux densities of main magnets. Calculations based on the equation for induced electric currents clearly showed that, the magnet intensity was the most influential factor on the induced current values and surpassed the worker motion speed by sevenfold. Variations in magnet flux density and motion speed of operators influence intensity of induced currents in bodies of MRI workers. Use of actively shielded magnets is a must to reduce the intensities of induced currents in bodies of operators.

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“…Faulty RF shielding (FM radio interference), due to some copper lamina missing from the door, was detected with the use of a directional antenna ( Surveys concerning systems from 0.2 T up to 11.7 T have been reported (213 ic MF or to the induced time-varying field due to the movement in the , ii) the simulated exposure (217)(218)(219)(220) and even iii) the notion of mTh' (221). Measurements of all the fields have been also reported indicating the ELF overexposures (222,223) and even the WPM (weighted peak method) has .…”

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Αξιολόγηση Της Επαγγελματικής Έκθεσης Σε Ηλεκτρομαγνητικά Πεδία

Γουρζουλίδης¹

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Η έκθεση των εργαζομένων σε ηλεκτρομαγνητικά πεδία (ΗΜΠ), ζήτημα Υγείας και Ασφάλειας της Εργασίας (ΥΑΕ) με έντονο επιστημονικό, κοινωνικό και οικονομικό ενδιαφέρον, αποτέλεσε αντικείμενο έντονων εξελίξεων σε Ευρωπαϊκό επίπεδο τα τελευταία σχεδόν είκοσι χρόνια. Η νέα σχετική Οδηγία 2013/35/ΕΕ και το σχετικό εναρμονισμένο Ελληνικό π.δ. 120/2016, είναι η νομοθετική ολοκλήρωση του κρίσιμου αυτού θέματος.Ο υπογράφων, στα πλαίσια της ενασχόλησης του με τις μη-ιοντίζουσες ακτινοβολίες ως ερευνητής του Πανεπιστημίου Θεσσαλίας, σε συνεργασία με το Υπουργείο Εργασίας (αρμόδιο για την έγκαιρη και ουσιαστική εφαρμογή της Οδηγίας), εκπόνησε πιλοτικό ερευνητικό πρόγραμμα διερεύνησης της επαγγελματικής έκθεσης σε ΗΜΠ σε συνεργασία με το Γραφείο Μη-Ιοντιζουσών Ακτινοβολιών της Ελληνικής Επιτροπής Ατομικής Ενέργειας. Πραγματοποιήθηκαν μετρήσεις και αξιολόγηση της έκθεσης σε κατάλληλα επιλεγμένες θέσεις σε εγκαταστάσεις της ΔΕΗ, του ΟΣΕ, της ΕΡΤ, σε νοσοκομεία με συστήματα Απεικόνισης Μαγνητικού Συντονισμού, στον ΟΛΠ, σε βιομηχανικές και ερευνητικές εγκαταστάσεις, αλλά και σε χώρους γραφείων.Η συντριπτική πλειοψηφία των μετρήσεων δεν παρουσίασε υπερβάσεις των οριακών τιμών έκθεσης της Οδηγίας, ενώ στις περισσότερες περιπτώσεις δεν υπερβαίνονται ούτε τα εθνικά όρια για τον γενικό πληθυσμό. Οι λίγες περιπτώσεις υπερβάσεων είναι εξαιρετικά τοπικά εντοπισμένες και διαχειρίσιμες με τεχνικά και οργανωτικά μέτρα στην βάση των αρχών της ΥΑΕ. Ανοικτό θέμα παραμένει η συντήρηση του εξοπλισμού που εκπέμπει ΗΜΠ, διότι σε περίπτωση που είναι ενεργός ενδέχεται να υπάρχουν σημαντικές υπερβάσεις.Ο διάχυτος, περισσότερο κοινωνικός, προβληματισμός γύρω από τα ΗΜΠ υπάρχει συνήθως για πολύ χαμηλές ή/και απροσδιόριστες εκθέσεις. Με την παρούσα εργασία δημιουργήθηκε επιπλέον γνώση για την συνολική κατάσταση στην Ελλάδα, η οποία αποτελεί πυλώνα για την διαχείριση των ΗΜΠ σε χώρους εργασίας στην χώρα μας αλλά και διεθνώς.

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Numerical computation of specific absorption rate and induced current for workers exposed to static magnetic fields of MRI scanners

Cited by 4 publications

References 10 publications

Exposure Assessment and Biomonitoring of Workers in Magnetic Resonance Environment: An Exploratory Study

Exposure Assessment and Biomonitoring of Workers in Magnetic Resonance Environment: An Exploratory Study

Influence of motion speed in static magnetic fields of MRI scanners on the density of induced electric currents in bodies of MRI operators

Αξιολόγηση Της Επαγγελματικής Έκθεσης Σε Ηλεκτρομαγνητικά Πεδία

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