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Updated: May 8, 2026
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
7 Tesla MRI with a transmit/receive loopless antenna and B1-insensitive selective excitation
M Arcan Erturk1, AbdEl-Monem M El-Sharkawy, Jay Moore
1Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland, USA; Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, Maryland, USA.
This study demonstrates high-resolution magnetic resonance imaging (MRI) at 7 Tesla using a single interventional antenna, eliminating the need for external coils. This approach overcomes challenges like radiofrequency field inhomogeneity and heating for advanced imaging applications.
Area of Science:
- Medical Imaging
- Biophysics
- Magnetic Resonance Imaging
Background:
- High-field MRI at 7 Tesla (T) presents challenges with external coils due to radiofrequency (RF) field penetration, inhomogeneity, and heating.
- Internal loopless antennae have shown signal-to-noise ratio and field-of-view gains at 7T, suggesting potential for coil-free MRI.
Purpose of the Study:
- To evaluate if internal loopless antennae can perform interventional MRI at 7T without external coils.
- To assess the feasibility of achieving high-resolution MRI using a single transmit/receive antenna system.
Main Methods:
- External coils were replaced by semi-rigid or biocompatible loopless transmit/receive antennae.
- Spatially selective, B1-insensitive RF pulses compensated for the antenna's non-uniform B1-field.
- RF power was controlled to limit local temperature rise to ≤1°C.
Main Results:
- The transmit/receive antennae achieved a scout field-of-view up to 10 cm.
- High-resolution MRI (∼100 μm) was performed in 10-50 seconds in vitro.
- In vivo MRI of rabbit aorta demonstrated 100-300 μm resolution.
Conclusions:
- A simplified, low-power, single-device interventional MRI approach at 7T is feasible.
- This method offers potential for true high-resolution MRI, avoiding external coil complexities.
- The technique shows promise for advanced interventional and in vivo imaging applications.
