Improving the sensitivity of spin‐echo fMRI at 3T by highly accelerated acquisitions

Abstract: Purpose
Spin‐echo (SE) functional MRI (fMRI) can be highly advantageous compared to gradient‐echo (GE) fMRI with respect to magnetic field‐inhomogeneity artifacts. However, at 3T, the majority of blood oxygenation level‐dependent (BOLD) fMRI experiments are performed using urn:x-wiley:07403194:media:mrm28715:mrm28715-math-0001‐weighted GE sequences because of their superior sensitivity compared to SE‐fMRI. The presented SE implementation of a highly accelerated GE pulse sequence therefore aims to improve the sensitivity of SE‐fMRI while profiting from a reduction of susceptibility‐induced signal dropout.

Methods
Spin‐echo MR encephalography (SE‐MREG) is compared with the more conventionally used spin‐echo echo‐planar imaging (SE‐EPI) and spin‐echo simultaneous multislice (SE‐SMS) at 3T in terms of capability to detect neuronal activations and resting‐state functional connectivity. For activation analysis, healthy subjects underwent consecutive SE‐MREG (pulse repetition time [TR] = 0.25 seconds), SE‐SMS (TR = 1.3 seconds), and SE‐EPI (TR = 4.4 seconds) scans in pseudorandomized order applied to a visual block design paradigm for generation of t‐statistics maps. For the investigation of functional connectivity, additional resting‐state data were acquired for 5 minutes and a seed‐based correlation analysis using Stanford’s FIND (Functional Imaging in Neuropsychiatric Disorders) atlas was performed.

Results
The increased sampling rate of SE‐MREG relative to SE‐SMS and SE‐EPI improves the sensitivity to detect BOLD activation by 33% and 54%, respectively, and increases the capability to extract resting‐state networks. Compared with a brain region that is not affected by magnetic field inhomogeneities, SE‐MREG shows 2.5 times higher relative signal strength than GE‐MREG in mesial temporal structures.

Conclusion
SE‐MREG offers a viable possibility for whole‐brain fMRI with consideration of brain regions that are affected by strong susceptibility‐induced magnetic field gradients

Angaben zum Objekt

• Standort: Deutsche Nationalbibliothek Frankfurt am Main
• Umfang: Online-Ressource
• Ausgabe: Online first
• Sprache: Englisch
• Anmerkungen: Magnetic resonance in medicine. - (2021) , ISSN: 1522-2594

Beteiligte, Orts- und Zeitangaben

• Ereignis: Veröffentlichung
• (wo): Freiburg
• (wer): Universität
• (wann): 2021
• Urheber: Barghoorn, Antonia ; Riemenschneider, Bruno ; Hennig, Jürgen ; LeVan, Pierre

Weitere Informationen

• DOI: 10.1002/mrm.28715
• URN: urn:nbn:de:bsz:25-freidok-1940251
• Rechteinformation: Kein Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Letzte Aktualisierung: 25.03.2025, 13:50 MEZ