Giulio Zanotti

Subjective symptoms and their evolution in a small group of magnetic resonance imaging (MRI) operators recently engaged.

Abstract Using a specific questionnaire, we examined subjective symptoms in a group of 17 physicians (9 males and 8 females, mean age 32.9 ± 3.71), attending a Postgraduate Medical School in Radiology and engaged in MRI for less than 1 year. Sixteen subjects (94%) reported the presence of at least one of the investigated symptoms during the period of MRI activity. The main symptoms were: unusual drowsiness/tiredness (88%), concentration problems (82%), headaches (76%), sleep disorders (47%), nausea (47%), illusion of movement (47%) and dizziness/vertigo (35%); the former two were subjectively related to MRI by the majority of the operators. These symptoms appeared (or worsened) in more than 15 min and, in the vast majority disappeared 30 min, or more, after the end of exposure. In 13 subjects (81%), the symptom (or some symptoms) appeared at least weekly. In this small group of health care workers recently exposed to MRI, the prevalence of subjective symptoms was higher than reported in other similar studies but, notably, the majority of subjects (77%) reported a regression within 4–8 weeks, suggesting some form of adaptation.

1650a Subjective symptoms in magnetic resonance imaging operators: preliminary results of an italian study

Introduction Magnetic Resonance Imaging (MRI) operators are exposed to significant levels of electromagnetic fields (EMF). In these workers an elevated prevalence of variuos subjective symptoms has been reported. Even if most symptoms are non-specific, in some recent studies a group of 5 more specific symptoms, defined ‘core symptoms’, was proposed: vertigo, nausea, head ringing, magnetophosphenes and metallic taste. Our aim was to investigate the prevalence of subiective symptoms, including ‘core symptoms’, in Italian MRI operators, in order to evaluate the association with exposure. Methods A sample of 152 MRI operators working in 6 different hospitals in Italy was collected. No measurments were available, so for each participant exposure was estimated based on scanner type (<1T, 1.5T –<3T and ≥3T respectively) and on the total number of MRI procedures followed. In all operators an ad hoc questionnaire including relevant sociodemographic and occupational data, and the occurrence of subjective symptoms based our previous experience, was collected. The influence of stress was also evaluated. The relation between occupational exposure and symptoms was studied using multivariate analysis. Result The multivariate analysis shows a significant correlation between exposure level and the total number of investigated symptoms. The results were confirmed considering the specific subset of ‘core symptoms’ based on previous literature data. In the multivariate model, the weight of the other covariate factors was not significant. The overall results were substantially confirmed considering the effect of work stress. Discussion and conclusions In the observed group of MRI operators the total number of subjective symptoms was associated with EMF exposure; the subset of ‘core symptoms’ also proved significantly dose-related with exposure. The symptoms prevalence was not significantly influenced by work stress. The results support the association between subjective symptoms and EMF exposure in MRI operators. Another conclusion is that the appearance of the specific group of ‘core symptoms’ may be usefully investigated in health surveillance of MRI operators.