Fluid suppression in amide proton transfer-weighted (APTw) CEST imaging: New theoretical insights and clinical benefits

Schüre JR, Casagranda S, Sedykh M, Liebig P, Papageorgakis C, Mancini L, Bisdas S, Nichelli L, Pinter N, Mechtler L, Jafari R, Boddaert N, Dangouloff-Ros V, Poujol J, Schmidt M, Dörfler A, Zaiß M (2023)

Publication Type: Journal article

Publication year: 2023

Journal

DOI: 10.1002/mrm.29915

Abstract

Purpose: Amide proton transfer-weighted (APTw) MRI at 3T provides a unique contrast for brain tumor imaging. However, APTw imaging suffers from hyperintensities in liquid compartments such as cystic or necrotic structures and provides a distorted APTw signal intensity. Recently, it has been shown that heuristically motivated fluid suppression can remove such artifacts and significantly improve the readability of APTw imaging. Theory and Methods: In this work, we show that the fluid suppression can actually be understood by the known concept of spillover dilution, which itself can be derived from the Bloch-McConnell equations in comparison to the heuristic approach. Therefore, we derive a novel post-processing formula that efficiently removes fluid artifact, and explains previous approaches. We demonstrate the utility of this APTw assessment in silico, in vitro, and in vivo in brain tumor patients acquired at MR scanners from different vendors. Results: Our results show a reduction of the CEST signals from fluid environments while keeping the APTw-CEST signal intensity almost unchanged for semi-solid tissue structures such as the contralateral normal appearing white matter. This further allows us to use the same color bar settings as for conventional APTw imaging. Conclusion: Fluid suppression has considerable value in improving the readability of APTw maps in the neuro-oncological field. In this work, we derive a novel post-processing formula from the underlying Bloch-McConnell equations that efficiently removes fluid artifact, and explains previous approaches which justify the derivation of this metric from a theoretical point of view, to reassure the scientific and medical field about its use.

Authors with CRIS profile

Involved external institutions

Université Sorbonne Paris Cité France (FR) Olea Medical - Improved Diagnosis for Life France (FR) University College London Hospitals (UCLH) United Kingdom (GB) Pitié-Salpêtrière University Hospital / Hôpital universitaire Pitié-Salpêtrière France (FR) Dent Neurologic Institute United States (USA) (US) Philips Professional Healthcare Netherlands (NL) GE Healthcare France France (FR)

How to cite

APA:

Schüre, J.-R., Casagranda, S., Sedykh, M., Liebig, P., Papageorgakis, C., Mancini, L.,... Zaiß, M. (2023). Fluid suppression in amide proton transfer-weighted (APTw) CEST imaging: New theoretical insights and clinical benefits. Magnetic Resonance in Medicine. https://doi.org/10.1002/mrm.29915

MLA:

Schüre, Jan-Rüdiger, et al. "Fluid suppression in amide proton transfer-weighted (APTw) CEST imaging: New theoretical insights and clinical benefits." Magnetic Resonance in Medicine (2023).

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