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Background: Ultrahigh-field (UHF) MRI advances towards clinical use. Patient compliance is generally high, but few large-scale studies have investigated the effects experienced in 7T MRI systems, especially considering peripheral nerve stimulation (PNS) and caregiving., Purpose: To evaluate the quantity, the intensity, and subjective experiences from short-term effects, focusing on the levels of comfort and compliance of subjects., Study Type: Prospective., Population: In all, 954 consecutive MRIs in 801 subjects for 3 years., Field Strength: 7T., Assessment: After the 7T examination, a questionnaire was used to collect data., Statistical Tests: Descriptive statistics, Spearman's rank correlation, Mann-Whitney U-test, and t-test., Results: The majority (63%) of subjects agreed that the MRI experience was comfortable and 93% would be willing to undergo future 7T MRI as a patient (5% undecided) and 82% for research purposes (12% undecided). The most common short-term effects experienced were dizziness (81%), inconsistent movement (68%), PNS (63%), headache (40%), nausea (32%), metallic taste (12%), and light flashes (8%). Of the subjects who reported having PNS (n = 603), 44% experienced PNS as "not uncomfortable at all," 45% as "little or very little uncomfortable," and 11% as "moderate to very much uncomfortable." Scanner room temperature was experienced more comfortable before (78%) than during (58%) examinations, and the noise level was acceptable by 90% of subjects. Anxiety before the examination was reported by 43%. Patients differed from healthy volunteers regarding an experience of headache, metallic taste, dizziness, or anxiety. Room for improvement was pointed out after 117 examinations concerning given information (n = 73), communication and sound system (n = 35), or nursing care (n = 15)., Data Conclusion: Subjectively reported effects occur in actively shielded 7T MRI and include physiological responses and individual psychological issues. Although leaving room for improvement, few subjects experienced these effects being so uncomfortable that they would lead to aversion to future UHF examinations., Level of Evidence: 1 TECHNICAL EFFICACY: Stage 5 J. Magn. Reson. Imaging 2020;52:1265-1276., (© 2020 The Authors. Journal of Magnetic Resonance Imaging published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.)

Objectives: The objectives were to survey MR safety incidents in Sweden during a 12-month period, to assess severity scores, and to evaluate the confidence of MR personnel in incident-reporting mechanisms., Method: Data were collected within a web-based questionnaire on safety in clinical MR environments with CT for comparison. Data reported MR and CT safety incidents (human injury, material damage, and close calls), incident severity, and confidence of participants in incident-reporting systems., Results: The study population consisted of 529 eligible participants. Participants reported 200 MR and 156 CT safety incidents. Among MR incidents, 16% were given the highest potential severity score. More MR workers (73%) than CT workers (50%) were confident in being aware of any incident occurring at their workplace. However, 69% MR workers (83% for CT) were not aware of reported incidents at their hospitals., Conclusion: Safety incidents resulting in human injury, material damage, and close calls in clinical MR environments do occur. According to national risk assessment recommendations, risk level is high. Results indicated that MR personnel tend to a false sense of security, as a high proportion of staff members were sure that they would have been aware of any incident occurring in their own department, while in reality, incidents did occur without their knowledge. We conclude that false sense of security exists for MR., Key Points: • Safety incidents in clinical MR environments still result in human injury and material damage. • Severity level of MR incidents-assessed using Swedish national risk assessment recommendations-is high. • Confidence of MR personnel in incident-reporting mechanisms is high, but reflects a false sense of security, as a high proportion of staff is unaware of reported incidents in the same workplace.

The objective of this study was to evaluate occurrence and strength of short-term effects experienced by study participants in an actively shielded (AS) 7 tesla (7 T) magnetic resonance (MR) scanner, to compare results with earlier reports on passively shielded (PS) 7 T MR scanners, and to outline possible healthcare strategies to improve patient compliance. Study participants (n = 124) completed a web-based questionnaire directly after being examined in an AS 7 T MR (n = 154 examinations). Most frequently experienced short-term effects were dizziness (84%) and inconsistent movement (70%), especially while moving into or out of the magnet. Peripheral nerve stimulation (PNS)-twitching-was experienced in 67% of research examinations and showed a dependence between strength of twitches and recorded predicted PNS values. Of the participants, 74% experienced noise levels as acceptable and the majority experienced body and room temperature as comfortable. Of the study participants, 95% felt well-informed and felt they had had good contact with the staff before the examination. Willingness to undergo a future 7 T examination was high (>90%). Our study concludes short-term effects are often experienced during examinations in an AS 7 T MR, leaving room for improvement in nursing care strategies to increase patient compliance. Bioelectromagnetics. 2019;9999:XX-XX. © 2019 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc., (© 2019 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.)

The magnetic resonance imaging (MRI) exposure environment is unique due to the mixture and intensity of magnetic fields involved. Current safety regulations are based on well-known acute effects of heating and neuroexcitation while the scientific grounds for possible long-term effects from MRI exposure are lacking. Epidemiological research requires careful exposure characterization, and as a first step toward improved exposure assessment we set out to characterize the MRI-patient exposure environment. Seven MRI sequences were run on a 3-Tesla scanner while the radiofrequency and gradient magnetic fields were measured inside the scanner bore. The sequences were compared in terms of 14 different exposure parameters. To study within-sequence variability, we varied sequence settings such as flip angle and slice thickness one at a time, to determine if they had any impact on exposure endpoints. There were significant differences between two or more sequences for all fourteen exposure parameters. Within-sequence differences were up to 60% of the corresponding between-sequence differences, and a 5-8 fold exposure increase was caused by variations in flip angle, slice spacing, and field of view. MRI exposure is therefore not only sequence-specific but also patient- and examination occurrence-specific, a complexity that requires careful consideration for an MRI exposure assessment in epidemiological studies to be meaningful. Bioelectromagnetics. 40:3-15, 2019. © 2018 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc., (© 2018 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.)