Direct imaging of white matter ultrashort T2∗ components at 7 Tesla

Müller M, Egger N, Sommer S, Wilferth T, Meixner C, Laun FB, Mennecke A, Schmidt M, Huhn K, Rothhammer V, Uder M, Dörfler A, Nagel AM (2022)

Publication Language: English

Publication Type: Journal article

Publication year: 2022

Journal

Magnetic Resonance Imaging Elsevier

Book Volume: 86

Pages Range: 107-117

DOI: 10.1016/j.mri.2021.11.016

Abstract

Purpose: To demonstrate direct imaging of the white matter ultrashort T2∗ components at 7 Tesla using inversion recovery (IR)-enhanced ultrashort echo time (UTE) MRI. To investigate its characteristics, potentials and limitations, and to establish a clinical protocol. Material and methods: The IR UTE technique suppresses long T2∗ signals within white matter by using adiabatic inversion in combination with dual-echo difference imaging. Artifacts arising at 7 T from long T2∗ scalp fat components were reduced by frequency shifting the IR pulse such that those frequencies were inverted likewise. For 8 healthy volunteers, the T2∗ relaxation times of white matter were then quantified. In 20 healthy volunteers, the UTE difference and fraction contrast were evaluated. Finally, in 6 patients with multiple sclerosis (MS), the performance of the technique was assessed. Results: A frequency shift of −1.2 ppm of the IR pulse (i.e. towards the fat frequency) provided a good suppression of artifacts. With this, an ultrashort compartment of (68 ± 6) % with a T2∗ time of (147 ± 58) μs was quantified with a chemical shift of (−3.6 ± 0.5) ppm from water. Within healthy volunteers' white matter, a stable ultrashort T2∗ fraction contrast was calculated. For the MS patients, a significant fraction reduction in the identified lesions as well as in the normal-appearing white matter was observed. Conclusions: The quantification results indicate that the observed ultrashort components arise primarily from myelin tissue. Direct IR UTE imaging of the white matter ultrashort T2∗ components is thus feasible at 7 T with high quantitative inter-subject repeatability and good detection of signal loss in MS.

Authors with CRIS profile

Max Müller Institute of Radiology Nico Egger Professur für metabolische und funktionelle MR-Bildgebung Tobias Wilferth Institute of Radiology Christian Meixner Institute of Radiology Frederik Bernd Laun Professur für quantitative MR-Bildgebung (Heisenberg-Professur) Angelika Mennecke Department of Neuroradiology Manuel Schmidt Department of Neuroradiology Konstantin Huhn Department of Neurology Veit Rothhammer Heisenbergprofessur für Neuroimmunologie Michael Uder Lehrstuhl für Diagnostische Radiologie Arnd Dörfler Department of Neuroradiology Armin Michael Nagel Professur für metabolische und funktionelle MR-Bildgebung

Involved external institutions

Siemens AG, Healthcare Sector DE Germany (DE)

How to cite

APA:

Müller, M., Egger, N., Sommer, S., Wilferth, T., Meixner, C., Laun, F.B.,... Nagel, A.M. (2022). Direct imaging of white matter ultrashort T2∗ components at 7 Tesla. Magnetic Resonance Imaging, 86, 107-117. https://doi.org/10.1016/j.mri.2021.11.016

MLA:

Müller, Max, et al. "Direct imaging of white matter ultrashort T2∗ components at 7 Tesla." Magnetic Resonance Imaging 86 (2022): 107-117.

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