DiSpect

Our research focuses on developing a non-contrast MRI method, Displacement Spectrum Imaging (DiSpect) [1,2], to trace blood flow sources using blood water as an endogenous MRI tracer. DiSpect is a generalization of the Displacement Encoding via Stimulated Echoes (DENSE) [3,4], which encodes information on the source position of blood during spin-tagging. After some time (10 ms to ~3 seconds), the blood enters an imaging slice. Through repeated encoding that is cardiac gated, DiSpect can trace back blood sources for each image voxel. DiSpect has the unique ability to untangle complex flow patterns, even under very slow flow conditions, since even very slow flow would be displaced by a considerable amount during these long evolution times. We have demonstrated that DiSpect can probe both arterial sources [3] and venous territories [4] in-vivo.

References

[1] Zhang Z, Karasan E, Gopalan K, Liu C, Lustig M. DiSpect: Displacement spectrum imaging of flow and tissue perfusion using spin-labeling and stimulated echoes. Magn Reson Med. 2021 Nov;86(5):2468-2481.
[2] Karasan E, Zhang Z, Lustig M. Reverse Perfusion of Venous Flow using DiSpect. Annual meeting of the ISMRM 2022, London UK
[3] Aletras AH, Ding S, Balaban RS, Wen H. DENSE: Displacement Encoding with Stimulated Echoes in Cardiac Functional MRI. Journal of Magnetic Resonance 1999;137(1):247-252.
[4] Gilson WD, Yang Z, French BA, Epstein FH. Complementary displacement-encoded MRI for contrast-enhanced infarct detection and quantification of myocardial function in mice. Magnetic Resonance in Medicine 2004;51(4):744-752.