Studies suggest that somewhere between 5 and 37 percent of patients experience significant anxiety in a conventional closed-bore MRI scanner. For a meaningful subset, the anxiety is severe enough to prevent completion of the exam — leading to failed scans, rescheduling, sedation, and ultimately delayed diagnoses. Open MRI was developed to address this problem, but the tradeoffs are real. Here is what both patients and facilities need to understand.
Closed MRI: Higher Field, Higher Performance
Conventional closed-bore MRI systems use a cylindrical superconducting magnet cooled with liquid helium to maintain field strengths of 1.5T or 3T. The physics of higher field strength is straightforward: stronger magnetic fields produce a stronger signal from hydrogen protons in tissue, which translates to higher signal-to-noise ratio (SNR). More SNR means faster scans, thinner slices, better resolution, and access to advanced applications like cardiac MRI, functional MRI (fMRI), and MR spectroscopy — applications that currently require 1.5T or higher.
The limitation is the bore: 60 to 70 cm in diameter and typically 160 to 200 cm deep. For claustrophobic patients, larger patients who fit poorly, anxious children, or patients requiring extended scan times, the closed bore is a meaningful barrier to completing the exam.
Open MRI: Designed for Patient Comfort
Open MRI systems use a different magnet architecture — typically a permanent magnet with two poles above and below the patient table, leaving the sides of the patient completely open. The Fujifilm APERTO Lucent is a representative example: a 0.4T permanent self-shielded magnet that requires no liquid helium, no chiller system, and no quench tube. The patient lies between the two magnet poles with an unobstructed view in all lateral directions.
The tradeoff is field strength. At 0.4T, the intrinsic SNR is lower than at 1.5T or 3T. This means scans take longer to achieve comparable SNR, resolution is generally lower, and some advanced applications available at higher field strengths are not feasible. However, the APERTO Lucent addresses this with technology designed to extract maximum image quality from the available field: IP-Recon iterative de-noising reconstruction improves SNR from any given acquisition, RADAR radial k-space acquisition reduces motion artifacts (important for anxious or pediatric patients), and multi-channel RF shimming enables fat suppression even at 0.4T — a capability that was historically difficult at lower field strengths.
When Open MRI Is the Right Choice
Open MRI systems like the APERTO Lucent excel in specific clinical and operational contexts. Claustrophobic patients represent the clearest case: the open design significantly reduces the rate of incomplete exams, eliminates the need for sedation in many cases, and improves the overall patient experience. For a facility with a significant claustrophobic patient population, the reduction in failed scans alone can justify the investment.
Bariatric patients benefit from both the open design and the table specifications: the APERTO Lucent table supports up to 500 pounds and features a wide lateral-shift floating design that lowers to 20 inches for easy patient transfers. Pediatric patients benefit from having a parent present, which dramatically reduces the need for sedation. Orthopedic imaging — MSK, spine, extremities — produces high-quality results at 0.4T that meet the diagnostic needs of most outpatient MSK practices. And the siting requirements are modest: a 13- by 17-foot room, single-phase 208V power, no chiller, no equipment room.
Bottom Line: Open MRI is not a compromise technology — it is the right tool for specific patient populations and clinical environments. For claustrophobic, bariatric, and pediatric patients, and for outpatient MSK and spine imaging, a modern 0.4T open MRI delivers clinical results that serve the patient well. Closed-bore systems remain essential for advanced neuroimaging, cardiac MRI, and applications requiring the highest resolution. The choice depends on your patient mix, not on which system has the bigger magnet.
Looking to replace you current MRI or add a new one? We would love to work with you. Check out full line of MRI systems by visiting our MRI Product Page
