title: 3 Tesla magnetic resonance imaging noise in standard head and neck sequence does not cause temporary threshold shift in high frequency.
abstract: High acoustic noise level is one of the unavoidable side effects of 3 T magnetic resonance imaging (MRI). A case of hearing loss after 3 T MRI has been reported in this institution and hence this study. The objective of this study was to determine whether temporary threshold shift (TTS) in high frequency hearing occurs in patients undergoing 3 T MRI scans of the head and neck. A total of 35 patients undergoing head and neck 3 T MRI for various clinical indications were tested with pure tone audiometry in different frequencies including high frequencies, before and after the MRI scan. Any threshold change from the recorded baseline of 10 dB was considered significant. All patients were fitted with foamed 3 M earplugs before the procedure following the safety guidelines for 3 T MRI. The mean time for MRI procedure was 1,672 s (range 1,040-2,810). The noise dose received by each patient amounted to an average of 3,906.29% (1,415-9,170%). The noise dose was derived from a normograph used by Occupational Noise Surveys. This was calculated using the nomograph of L eq, L EX, noise dose and time. There was no statistically significant difference between the hearing threshold before and after the MRI procedures for all the frequencies (paired t test, P > 0.05). For patients using 3 M foamed earplugs, noise level generated by 3 T MRI during routine clinical sequence did not cause any TTS in high frequency hearing.
authors.affiliation: ORL Department, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia. yennlynn@yahoo.com.|, A5-1 Laman Impian Garden Villas, Jalan PJU 3/24, Sunway Damansara, 47810, Petaling Jaya, Selangor, Malaysia. yennlynn@yahoo.com.
authors.forename: Elizabeth Yenn Lynn
authors.initials: EY
authors.lastname: Lim
authors.affiliation: ORL Department, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia.
authors.forename: Ing Ping
authors.initials: IP
authors.lastname: Tang
authors.affiliation: Opthalmology Department, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Peyman
authors.affiliation: Department of Diagnostic and Bioimaging, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia.
authors.forename: Norlisah
authors.initials: N
authors.lastname: Ramli
authors.affiliation: ORL Department, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia.
authors.forename: Prepageran
authors.initials: P
authors.lastname: Narayanan
authors.affiliation: ORL Department, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia.
authors.forename: Raman
authors.initials: R
authors.lastname: Rajagopalan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006317:Hearing Loss, Noise-Induced / Q000209:etiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009622:Noise; D055815:Young Adult
keywords: 3 T magnetic resonant imaging; High frequency hearing loss; Temporary threshold shift