Complex B<sub>1</sub><sup>+</sup> mapping with Carr‐Purcell spin echoes and its application to electrical properties tomography

Iyyakkunnel, Santhosh; Weigel, Matthias; Ganter, Carl; Bieri, Oliver

doi:10.1002/mrm.29020

Cited by 3 publications

(1 citation statement)

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“…Another important consideration is that in practice simultaneous B 1 magnitude and phase acquisition is necessary to avoid registration errors. One approach to simultaneous acquisition is based on the Carr-Purcell Spin Echos (Iyyakkunnel et al 2022). However their method has to be further developed for high fidelity results.…”

Section: Discussionmentioning

confidence: 99%

Bias correction for phase-based cr-MREPT using low resolution B1+ magnitude

Çan,

Ider

2024

Phys. Med. Biol.

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Objective Full-form Magnetic Resonance Electrical Properties Tomography (MREPT) requires both B1+ magnitude and phase information. Since B1+ phase can be obtained faster and with higher SNR compared to B1+ magnitude, several phase-based methods have been developed for conductivity imaging. However, phase-based methods suffer from a concave bias due to the assumption that ∇|B1+| is negligible in the ROI. Approach In this paper, we re-derive the central equation of phase-based cr-MREPT without assuming that ∇|B1+| is negligible and thus propose a correction method directly integrated into the equation system. Main Results Proposed method successfully corrects the concave bias on both simulated and experimental data and significantly increases image quality. Significance The proposed correction method depends on a very low-resolution |B1+| map, and therefore the imaging time does not increase significantly for obtaining B1+ magnitude. Moreover, correction can be achieved using simulated B1+ magnitude, hence completely removing the additional imaging requirement.

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Section: Discussionmentioning

confidence: 99%

Bias correction for phase-based cr-MREPT using low resolution B1+ magnitude

Çan,

Ider

2024

Phys. Med. Biol.

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Complex B₁⁺ mapping with Carr‐Purcell spin echoes and its application to electrical properties tomography

Iyyakkunnel

Weigel

Ganter

et al. 2021

Magnetic Resonance in Med

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Fast bias-corrected conductivity mapping using stimulated echoes

Iyyakkunnel,

Weigel,

Bieri

2024

Magn Reson Mater Phy

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Objective To demonstrate the potential of a double angle stimulated echo (DA-STE) method for fast and accurate “full” homogeneous Helmholtz-based electrical properties tomography using a simultaneous $${B}_{1}^{+}$$ B 1 + magnitude and transceive phase measurement. Methods The combination of a spin and stimulated echo can be used to yield an estimate of both $${B}_{1}^{+}$$ B 1 + magnitude and transceive phase and thus provides the means for “full" EPT reconstruction. An interleaved 2D acquisition scheme is used for rapid acquisition. The method was validated in a saline phantom and compared to a double angle method based on two single gradient echo acquisitions (GRE-DAM). The method was evaluated in the brain of a healthy volunteer. Results The $${B}_{1}^{+}$$ B 1 + magnitude obtained with DA-STE showed excellent agreement with the GRE-DAM method. Conductivity values based on the “full” EPT reconstruction also agreed well with the expectations in the saline phantom. In the brain, the method delivered conductivity values close to literature values. Discussion The method allows the use of the “full” Helmholtz-based EPT reconstruction without the need for additional measurements. As a result, quantitative conductivity values are improved compared to phase-based EPT reconstructions. DA-STE is a fast complex-$${B}_{1}^{+}$$ B 1 + mapping technique that could render EPT clinically relevant at 3 T.

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Complex B₁⁺ mapping with Carr‐Purcell spin echoes and its application to electrical properties tomography

Abstract: This is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Cited by 3 publications

References 45 publications

Bias correction for phase-based cr-MREPT using low resolution B1+ magnitude

Bias correction for phase-based cr-MREPT using low resolution B1+ magnitude

Complex B₁⁺ mapping with Carr‐Purcell spin echoes and its application to electrical properties tomography

Fast bias-corrected conductivity mapping using stimulated echoes

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Complex B1+ mapping with Carr‐Purcell spin echoes and its application to electrical properties tomography

Abstract: This is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Cited by 3 publications

References 45 publications

Bias correction for phase-based cr-MREPT using low resolution B1+ magnitude

Bias correction for phase-based cr-MREPT using low resolution B1+ magnitude

Complex B1+ mapping with Carr‐Purcell spin echoes and its application to electrical properties tomography

Fast bias-corrected conductivity mapping using stimulated echoes

Contact Info

Product

Resources

About

Complex B₁⁺ mapping with Carr‐Purcell spin echoes and its application to electrical properties tomography

Complex B₁⁺ mapping with Carr‐Purcell spin echoes and its application to electrical properties tomography