Subjective symptoms in Magnetic Resonance Imaging operators: prevalence, short-term evolution and possible related factors.

BACKGROUND: The number of Magnetic Resonance Imaging (MRI) operators is rapidly increasing. In these workers, a high prevalence of certain subjective symptoms has been described but until now scant research is available on this topic. OBJECTIVES: To assess the prevalence and the evolution of symptoms over time in a group of operators recently engaged in MRI, also considering the possible role played by factors such as age, gender and occupational stress. METHODS: In 17 physicians exclusively engaged in MRI - 6 working with 1.5 T scanners only and 11 with both 1.5 and 3T - subjective symptoms were evaluated at the beginning of MRI activity and after 2 months by using an ad hoc questionnaire. The questionnaire also included items on occupational stress. RESULTS: At the start of MRI activity, 81% of the subjects reported at least one of the investigated symptoms; after 2 months, 85% of the symptomatic operators reported the regression of one or more symptoms. In operators with high exposure (1.5 and 3 T scanners), the mean number of symptoms tended to be higher compared with those with lower exposure (1.5 T only), and the reduction after 2 months was significantly greater. In the whole group, occupational stress was significantly correlated with the total number of symptoms and to some of the symptoms more specifically. As stress did not differ between highly- and lowly- exposed, there is no reason to assume an influence on the observed differences in the prevalence and reduction of symptoms. CONCLUSIONS: Our data suggest that MRI operators may experience various symptoms at the beginning of activity, rapidly reversible in a few weeks. The trend over longer periods deserves further study. Occupational stress may play a role in symptoms. The duration of previous MRI work (particularly short-term) as well as work-related stress should be adequately addressed in future studies on subjective symptoms in operators.

Subjective Symptoms in Magnetic Resonance Imaging Personnel: A Multi-Center Study in Italy.

Introduction: Magnetic Resonance Imaging (MRI) personnel have significant exposure to static and low-frequency time-varying magnetic fields. In these workers an increased prevalence of different subjective symptoms has been observed. The aim of our study was to investigate the prevalence of non-specific subjective symptoms and of "core symptoms" in a group of MRI personnel working in different centers in Italy, and of possible relationships with personal and occupational characteristics. Methods: The occurrence of 11 subjective symptoms was evaluated using a specific questionnaire with 240 subjects working in 6 different Italian hospitals and research centers, 177 MRI health care and research personnel and 63 unexposed subjects employed in the same departments. Exposure was subjectively investigated according to the type of MRI scanner (≤1.5 vs. ≥3 T) and to the number of MRI procedures attended and/or performed by the personnel, even if no information on how frequently the personnel entered the scanner room was collected. The possible associations among symptoms and estimated EMF exposure, the main characteristics of the population, and job stress perception were analyzed. Results: Eighty-six percent of the personnel reported at least one symptom; drowsiness, headache, and sleep disorders were the most frequent. The total number of symptoms did not differ between exposed persons and controls. Considering the total number of annual MRI procedures reported by the personnel, no significant associations were found nor with the total number of symptoms, nor with "core symptoms." Only subjects complaining of drowsiness also reported a significantly higher mean annual number of MRI procedures with ≤ 1.5 T scanners when compared with exposed subjects without drowsiness. In a multivariate model, subjects with a high level of perceived stress complained of more symptoms (p = 0.0002). Conclusions: Our study did not show any association between the occurrence of reversible subjective symptoms, including the more specific "core symptoms," and the occupational exposure of MRI personnel to static and low-frequency time-varying magnetic fields. On the other hand, the role played by occupational stress appears to be not negligible. In further research in this field, measurements of EMF exposure should be considered.