More Space, Less Noise—New-generation Low-Field Magnetic Resonance Imaging Systems Can Improve Patient Comfort: A Prospective 0.55T–1.5T-Scanner Comparison

Abstract

Objectives: The objectives of this study were to assess patient comfort when imaged on a newly introduced 0.55T low-field magnetic resonance (MR) scanner system with a wider bore opening compared to a conventional 1.5T MR scanner system. Materials and Methods: In this prospective study, fifty patients (mean age: 66.2 ± 17.0 years, 22 females, 28 males) underwent subsequent magnetic resonance imaging (MRI) examinations with matched imaging protocols at 0.55T (MAGNETOM FreeMax, Siemens Healthineers; Erlangen, Germany) and 1.5T (MAGNETOM Avanto Fit, Siemens Healthineers; Erlangen, Germany) on the same day. MRI performed between 05/2021 and 07/2021 was included for analysis. The 0.55T MRI system had a bore opening of 80 cm, while the bore diameter of the 1.5T scanner system was 60 cm. Four patient groups were defined by imaged body regions: (1) cranial or cervical spine MRI using a head/neck coil (n = 27), (2) lumbar or thoracic spine MRI using only the in-table spine coils (n = 10), (3) hip MRI using a large flex coil (n = 8) and (4) upper- or lower-extremity MRI using small flex coils (n = 5). Following the MRI examinations, patients evaluated (1) sense of space, (2) noise level, (3) comfort, (4) coil comfort and (5) overall examination impression on a 5-point Likert-scale (range: 1= “much worse” to 5 = “much better”) using a questionnaire. Maximum noise levels of all performed imaging studies were measured in decibels (dB) by a sound level meter placed in the bore center. Results: Sense of space was perceived to be “better” or “much better” by 84% of patients for imaging examinations performed on the 0.55T MRI scanner system (mean score: 4.34 ± 0.75). Additionally, 84% of patients rated noise levels as “better” or “much better” when imaged on the low-field scanner system (mean score: 3.90 ± 0.61). Overall sensation during the imaging examination at 0.55T was rated as “better” or “much better” by 78% of patients (mean score: 3.96 ± 0.70). Quantitative assessment showed significantly reduced maximum noise levels for all 0.55T MRI studies, regardless of body region compared to 1.5T, i.e., brain MRI (83.8 ± 3.6 dB vs. 89.3 ± 5.4 dB; p = 0.04), spine MRI (83.7 ± 3.7 dB vs. 89.4 ± 2.6 dB; p = 0.004) and hip MRI (86.3 ± 5.0 dB vs. 89.1 ± 1.4 dB; p = 0.04). Conclusions: Patients perceived 0.55T new-generation low-field MRI to be more comfortable than conventional 1.5T MRI, given its larger bore opening and reduced noise levels during image acquisition. Therefore, new concepts regarding bore design and noise level reduction of MR scanner systems may help to reduce patient anxiety and improve well-being when undergoing MR imaging.

Does bore size matter?—A comparison of the subjective perception of patient comfort during low field (0.55 Tesla) and standard (1.5 Tesla) MRI imaging

“…Nevertheless, many patients comparing both MRI scanners did perceive the larger bore diameter positively, while only one patients rated the MRI examination with the low field MRI scanner as “slightly worse” compared to the standard MRI scanner. These findings are in line with the results presented by Rusche et al [20] Their study also came to the conclusion that patients perceive the increased amount of space during examinations with the low field MRI scanner positively.…”

“…The noise level during the scanning procedure has been reported to be a major factor influencing the subjectively perceived patient comfort during MRI examinations. [4,16,20] The findings of the present study confirm the objectively measured noise levels reported by Rusche et al They found that the low field MRI scanner produces significantly less noise compared to a standard MRI scanner with 1.5 T; regardless of the body region. [20] Despite a good mean rating for the standard MRI scanner in the present study (mean 3.72 ± 1.46, median 4 = "rather not unpleasant"), the low field MRI scanner was rated even better with a mean rating of 4.26 ± 1.22 (median 5 = "not unpleasant at all," P = .008// corrected P = .032).…”

“…[4,16,20] The findings of the present study confirm the objectively measured noise levels reported by Rusche et al They found that the low field MRI scanner produces significantly less noise compared to a standard MRI scanner with 1.5 T; regardless of the body region. [20] Despite a good mean rating for the standard MRI scanner in the present study (mean 3.72 ± 1.46, median 4 = "rather not unpleasant"), the low field MRI scanner was rated even better with a mean rating of 4.26 ± 1.22 (median 5 = "not unpleasant at all," P = .008// corrected P = .032). Therefore, the low field MRI scanner may be advantageous for pediatric patients or adult patients who are afraid of loud noises.…”

“…In terms of scanner noise, a previous study revealed that the low field MRI scanner produces significantly lower noise levels compared to the standard MRI scanner (e.g., brain MRI 83.8 ± 3.6 decibel [dB] vs 89.3 ± 5.4 dB or spine MRI 83.7 ± 3.7 dB vs 89.4 ± 2.6 dB). [20]…”

“…In terms of scanner noise, a previous study revealed that the low field MRI scanner produces significantly lower noise levels compared to the standard MRI scanner (e.g., brain MRI 83.8 ± 3.6 decibel [dB] vs 89.3 ± 5.4 dB or spine MRI 83.7 ± 3.7 dB vs 89.4 ± 2.6 dB). [20] In terms of scanner table, the standard MRI scanner has a completely flat table, while the low field MRI scanner has a U-shaped table. Images of both MRI scanners can be found in Rusche et al [20]…”