Subjectively Reported Effects Experienced in an Actively Shielded 7T MRI: A Large‐Scale Study

• Published in: Journal of magnetic resonance imaging Vol. 52; no. 4; pp. 1265 - 1276
• Main Authors: Hansson, Boel, Markenroth Bloch, Karin, Owman, Titti, Nilsson, Markus, Lätt, Jimmy, Olsrud, Johan, Björkman‐Burtscher, Isabella M.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.10.2020; Wiley Subscription Services, Inc
• Subjects: Acceptable noise levels; Anxiety; Aversion; Clinical Medicine; Communications systems; Data collection; dizziness; Field strength; Headache; Health Sciences; Healthy Volunteers; Humans; Hälsovetenskap; Klinisk medicin; Magnetic Resonance Imaging; Medical and Health Sciences; Medical Engineering; Medicin och hälsovetenskap; Medicinteknik; Movement; Nausea; Noise levels; Nursing; Patient compliance; peripheral nerve stimulation; Peripheral nerves; Physiological effects; Physiological responses; Population studies; Prospective Studies; Radiologi och bildbehandling; Radiology and Medical Imaging; Room temperature; safety; Sensory stimulation; Statistical analysis; Statistical tests; Taste; ultrahigh field; Vertigo; anxiety; patient compliance; dizziness; ultrahigh field; safety; peripheral nerve stimulation
• ISSN: 1053-1807; 1522-2586; 1522-2586
• DOI: 10.1002/jmri.27139

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.