T1-Based Synthetic Magnetic Resonance Contrasts Improve Multiple Sclerosis and Focal Epilepsy Imaging at 7 T

Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved..

OBJECTIVES: Ultra-high field magnetic resonance imaging (MRI) (≥7 T) is a unique opportunity to improve the clinical diagnosis of brain pathologies, such as multiple sclerosis or focal epilepsy. However, several shortcomings of 7 T MRI, such as radiofrequency field inhomogeneities, could degrade image quality and hinder radiological interpretation. To address these challenges, an original synthetic MRI method based on T1 mapping achieved with the magnetization-prepared 2 rapid acquisition gradient echo (MP2RAGE) sequence was developed. The radiological quality of on-demand T1-based contrasts generated by this technique was evaluated in multiple sclerosis and focal epilepsy imaging at 7 T.

MATERIALS AND METHODS: This retrospective study was carried out from October 2017 to September 2019 and included 21 patients with different phenotypes of multiple sclerosis and 35 patients with focal epilepsy who underwent MRI brain examinations using a whole-body investigative 7 T magnetic resonance system. The quality of 2 proposed synthetic contrast images were assessed and compared with conventional images acquired at 7 T using the MP2RAGE sequence by 4 radiologists, evaluating 3 qualitative criteria: signal homogeneity, contrast intensity, and lesion visualization. Statistical analyses were performed on reported quality scores using Wilcoxon rank tests and further multiple comparisons tests. Intraobserver and interobserver reliabilities were calculated as well.

RESULTS: Radiological quality scores were reported higher for synthetic images when compared with original images, regardless of contrast, pathologies, or raters considered, with significant differences found for all 3 criteria (P < 0.0001, Wilcoxon rank test). None of the 4 radiologists ever rated a synthetic image "markedly worse" than an original image. Synthetic images were rated slightly less satisfying for only 3 epileptic patients, without precluding lesion identification.

CONCLUSION: T1-based synthetic MRI with the MP2RAGE sequence provided on-demand contrasts and high-quality images to the radiologist, facilitating lesion visualization in multiple sclerosis and focal epilepsy, while reducing the magnetic resonance examination total duration by removing an additional sequence.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:56

Enthalten in:

Investigative radiology - 56(2021), 2 vom: 01. Feb., Seite 127-133

Sprache:

Englisch

Beteiligte Personen:

Massire, Aurélien [VerfasserIn]
Seiler, Charlotte [VerfasserIn]
Troalen, Thomas [VerfasserIn]
Girard, Olivier M [VerfasserIn]
Lehmann, Pierre [VerfasserIn]
Brun, Gilles [VerfasserIn]
Bartoli, Axel [VerfasserIn]
Audoin, Bertrand [VerfasserIn]
Bartolomei, Fabrice [VerfasserIn]
Pelletier, Jean [VerfasserIn]
Callot, Virginie [VerfasserIn]
Kober, Tobias [VerfasserIn]
Ranjeva, Jean-Philippe [VerfasserIn]
Guye, Maxime [VerfasserIn]

Links:

Volltext

Themen:

Journal Article
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 15.10.2021

Date Revised 26.09.2023

published: Print

Citation Status MEDLINE

doi:

10.1097/RLI.0000000000000718

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM314257098