MRI scanners provide excellent soft tissue contrast at resolutions of the order of 1 cubic mm, making them powerful tools for clinical diagnosis. Over the past half-century, the trend has been to use increasingly higher magnetic field strengths to obtain better signal-to-noise ratios (SNR) and contrast between tissues. However, using higher main magnetic field strengths has its own limitations, such as increased risk of tissue heating and implant safety, as well as high initial setup and operating costs.
Ultra-low field MRIs (ULF, main magnetic fields of less than 0.1T) with their lower costs, smaller footprint, and portable design could offer easier access to imaging for patients in need. Since the mechanical force experienced by metallic objects scale up with magnetic field strength, it becomes feasible to use ULF MRI in the vicinity of other medical equipment in environments such as the intensive care unit. Additionally, RF heating and the number of imaging artifacts caused by metal implants are far lower in ULF MRI compared to conventional scanners thereby increasing the pool of patients who could get an MRI. ULF scanners could be designed to have built-in RF shielding systems and have small fringe fields that allow them to be sited in small spaces and are even light enough to be made fully portable. Given these unique features, ULF MRI has the potential to revolutionize patient care.
Low SNR and bias-field distortions are inherent to ULF MRI. Innovative solutions need to be developed to overcome these drawbacks before clinically relevant images can be obtained. Some of the approaches that have been taken towards this include novel RF-encoding strategies for image formation, innovative noise cancellation techniques, optimal gradient coil designs, and reconstruction algorithms. We aim to cover these and other relevant innovations in this Research Topic.
We are proposing to compile manuscripts detailing technical advances and case reports that would make ULF a reality in the clinical setting.
MRI scanners provide excellent soft tissue contrast at resolutions of the order of 1 cubic mm, making them powerful tools for clinical diagnosis. Over the past half-century, the trend has been to use increasingly higher magnetic field strengths to obtain better signal-to-noise ratios (SNR) and contrast between tissues. However, using higher main magnetic field strengths has its own limitations, such as increased risk of tissue heating and implant safety, as well as high initial setup and operating costs.
Ultra-low field MRIs (ULF, main magnetic fields of less than 0.1T) with their lower costs, smaller footprint, and portable design could offer easier access to imaging for patients in need. Since the mechanical force experienced by metallic objects scale up with magnetic field strength, it becomes feasible to use ULF MRI in the vicinity of other medical equipment in environments such as the intensive care unit. Additionally, RF heating and the number of imaging artifacts caused by metal implants are far lower in ULF MRI compared to conventional scanners thereby increasing the pool of patients who could get an MRI. ULF scanners could be designed to have built-in RF shielding systems and have small fringe fields that allow them to be sited in small spaces and are even light enough to be made fully portable. Given these unique features, ULF MRI has the potential to revolutionize patient care.
Low SNR and bias-field distortions are inherent to ULF MRI. Innovative solutions need to be developed to overcome these drawbacks before clinically relevant images can be obtained. Some of the approaches that have been taken towards this include novel RF-encoding strategies for image formation, innovative noise cancellation techniques, optimal gradient coil designs, and reconstruction algorithms. We aim to cover these and other relevant innovations in this Research Topic.
We are proposing to compile manuscripts detailing technical advances and case reports that would make ULF a reality in the clinical setting.
