Interleaved flow-sensitive dephasing (iFSD): Toward enhanced blood flow suppression and preserved T1 weighting and overall signals in 3D TSE-based neuroimaging

Qingle Kong; Jiayu Xiao; Mark S Shiroishi; Nasim Sheikh-Bahaei; Steven Y Cen; Kasra Khatibi; William J Mack; Jason C Ye; Paul E Kim; Xiaoming Bi; David Saloner; Qi Yang; Eric Chang; Zhaoyang Fan

doi:10.1002/mrm.30391

Interleaved flow-sensitive dephasing (iFSD): Toward enhanced blood flow suppression and preserved T₁ weighting and overall signals in 3D TSE-based neuroimaging

Magn Reson Med. 2024 Dec 8. doi: 10.1002/mrm.30391. Online ahead of print.

Authors

Qingle Kong¹, Jiayu Xiao¹, Mark S Shiroishi¹, Nasim Sheikh-Bahaei¹, Steven Y Cen¹, Kasra Khatibi², William J Mack², Jason C Ye³, Paul E Kim¹, Xiaoming Bi⁴, David Saloner⁵, Qi Yang⁶, Eric Chang³, Zhaoyang Fan^{1

3

7}

Affiliations

¹ Department of Radiology, University of Southern California, Los Angeles, California, USA.
² Department of Neurological Surgery, University of Southern California, Los Angeles, California, USA.
³ Department of Radiation Oncology, University of Southern California, Los Angeles, California, USA.
⁴ Siemens Medical Solutions USA Inc., Los Angeles, California, USA.
⁵ Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
⁶ Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, People's Republic of China.
⁷ Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA.

PMID: 39648519
DOI: 10.1002/mrm.30391

Abstract

Purpose: To develop and validate a 3D turbo spin-echo (TSE)-compatible approach to enhancing black-blood (BB) effects while preserving T₁ weighting and overall SNR.

Methods: Following the excitation RF pulse, a 180° RF pulse sandwiched by a pair of flow-sensitive dephasing (FSD) gradient pulses in the phase- (y) and partition-encoding (z) directions, respectively, is added. The polarity of FSD gradients in z direction is toggled every TR, achieving an interleaved FSD (iFSD) configuration in y-z plane. The technique was optimized and evaluated in 18 healthy volunteers and 32 patients with neurovascular disease or brain metastases. Comparisons were made among TSE with and without one of BB preparations: iFSD, delay alternating with nutation for tailored excitation, and motion-sensitized driven equilibrium.

Results: iFSD-TSE achieved the best blood flow suppression indicated by venous sinus SNR and parenchyma-to-sinus contrast-to-noise ratio (CNR). iFSD-TSE yielded slightly lower white matter SNR (106.6 ± 32.9) and white-to-gray matter CNR (27.3 ± 8.1) compared to TSE (111.4 ± 31.5 and 28.6 ± 8.8), which were significantly higher than those of delay alternating with nutation for tailored excitation-prepared TSE (84.3 ± 25.0 and 16.8 ± 4.8) and motion-sensitized driven equilibrium-prepared TSE (77.3 ± 26.6 and 15.9 ± 5.3). At the neurovascular wall lesions, iFSD-TSE yielded the highest wall-to-lumen CNR among the three sequences with a BB preparation, all of which significantly outperformed TSE. iFSD-TSE effectively suppressed slow-flow artifacts that otherwise mimicked an atherosclerotic lesion or strongly contrast-enhancing vessel wall. In diagnosing brain metastases, iFSD allowed for highest inter-reader agreement (κ 0.75) and shortest reading time.

Conclusion: iFSD is a promising approach compatible with 3D TSE for robust blood flow suppression and preserved T₁ weighting and overall SNR.

Keywords: 3D TSE; T1‐weighted; black‐blood MRI; blood suppression; brain metastasis detection; interleaved flow‐sensitive dephasing; vessel wall imaging.