Mitigating slice cross-talk in multi-slice multi-echo spin echo T 2 mapping.

Autor: Brui EA; School of Physics and Engineering, ITMO University, Saint-Petersburg, Russia., Badrieva Z; School of Physics and Engineering, ITMO University, Saint-Petersburg, Russia., de Mayenne CA; Paris Science et Lettres, E'cole Supe'rieure de Physique et de Chimie Industrielle de la ville de Paris, Paris, France., Rapacchi S; Centre de Résonance Magnétique Biologique et Médicale, Aix-Marseille Universite, CNRS, Marseille, France., Troalen T; Siemens Healthcare SAS, Courbevoie, France., Bendahan D; Centre de Résonance Magnétique Biologique et Médicale, Aix-Marseille Universite, CNRS, Marseille, France.
Jazyk: angličtina
Zdroj: Magnetic resonance in medicine [Magn Reson Med] 2024 May; Vol. 91 (5), pp. 2089-2103. Date of Electronic Publication: 2023 Dec 29.
DOI: 10.1002/mrm.29987
Abstrakt: Purpose: To investigate whether a T 2 inter-slice variation could occur when a multi-slice multi-echo spin echo (MESE) sequence is used for image acquisition and to propose an enhanced method for reconstructing T 2 maps that can effectively address and correct these variations.
Methods: Bloch simulations were performed accounting for the direct saturation effect to evaluate magnetization changes in multi-slice 2D MESE sequence. Experimental phantom scans were performed to validate these simulations. An improved version of the dictionary-based reconstruction approach was proposed, enabling the creation of a multi-slice dictionary of echo modulation curves (EMC). The corresponding method has been assayed considering inter-slice T 2 variation with phantoms and in lower leg.
Results: Experimental and numerical study illustrate that direct saturation leads to a bias of EMCs. This bias during the T 2 maps reconstructions using original single-slice EMC-dictionary method led to inter-slice T 2 variation of 2.03% in average coefficient of variation (CV) in agarose phantoms, and up to 2.8% in vivo (for TR = 2 s, slice gap = 0%). A reduction of CV was observed when increasing the gap up to 100% (0.36% in phantoms, and up to 1.5% in vivo) or increasing TR up to 4 s (0.76% in phantoms, and up to 1.9% in vivo). Matching the multi-slice experimental data with multi-slice dictionaries provided a reduced CV of 0.54% in phantoms and up to 2.3% in vivo.
Conclusion: T 2 values quantified from multi-slice MESE images using single-slice dictionaries are biased. A dedicated multi-slice EMC method providing the appropriate dictionaries can reduce the inter-slice T 2 variation.
(© 2023 International Society for Magnetic Resonance in Medicine.)
Databáze: MEDLINE
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