MRI of the human brain at 130 microtesla

Area of Science:

• Medical Imaging
• Biophysics
• Neuroscience

Background:

• Conventional MRI systems operate at high magnetic fields, limiting accessibility and increasing costs.
• Ultralow field MRI (ULFMRI) offers potential for portable, cost-effective neuroimaging.
• Developing ULFMRI techniques is crucial for expanding MRI applications.

Purpose of the Study:

• To present in vivo human brain imaging using a novel ultralow field MRI (ULFMRI) system.
• To demonstrate advanced contrast manipulation techniques for ULFMRI.
• To explore potential applications of ULFMRI in neuroscience and clinical settings.

Main Methods:

• Acquisition of in vivo human brain images using a 130 μT ULFMRI system with prepolarization (80 mT).
• Detection of NMR signals using a superconducting gradiometer and SQUID.
• Measurement of longitudinal relaxation times (T1) for various brain tissues and fluids.
• Construction of inversion recovery sequences combined with Carr-Purcell-Meiboom-Gill echo trains for enhanced contrast.

Main Results:

• Successful generation of in vivo human brain images at ultralow magnetic fields.
• Demonstration of selective tissue visualization, including an image showing only blood.
• Enhanced intrinsic T1 contrast achieved through advanced pulse sequences.
• Acquisition of 2D images revealing T1 and T2 relaxation times, showing similar contrast at ULF.

Conclusions:

• ULFMRI is a viable technique for in vivo human brain imaging with enhanced contrast capabilities.
• The presented methods allow for selective highlighting of specific biological tissues, such as blood.
• Potential applications include integration with magnetoencephalography and non-contrast imaging of tumors.