1. In vivo diffusion MRI of the human heart using a 300 mT/m gradient system.
- Author
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Afzali, Maryam, Mueller, Lars, Coveney, Sam, Fasano, Fabrizio, Evans, Christopher John, Engel, Maria, Szczepankiewicz, Filip, Teh, Irvin, Dall'Armellina, Erica, Jones, Derek K., and Schneider, Jürgen E.
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DIFFUSION magnetic resonance imaging ,CARDIAC magnetic resonance imaging ,CARDIAC imaging ,DIFFUSION gradients ,SCANNING systems - Abstract
Purpose: This work reports for the first time on the implementation and application of cardiac diffusion‐weighted MRI on a Connectom MR scanner with a maximum gradient strength of 300 mT/m. It evaluates the benefits of the increased gradient performance for the investigation of the myocardial microstructure. Methods: Cardiac diffusion‐weighted imaging (DWI) experiments were performed on 10 healthy volunteers using a spin‐echo sequence with up to second‐ and third‐order motion compensation (M2$$ {M}_2 $$ and M3$$ {M}_3 $$) and b=100, 450$$ b=100,450 $$, and 1000 s/mm2$$ \mathrm{s}/\mathrm{m}{\mathrm{m}}^2 $$ (twice the bmax$$ {b}_{\mathrm{max}} $$ commonly used on clinical scanners). Mean diffusivity (MD), fractional anisotropy (FA), helix angle (HA), and secondary eigenvector angle (E2A) were calculated for b = [100, 450] s/mm2$$ \mathrm{s}/\mathrm{m}{\mathrm{m}}^2 $$ and b = [100, 1000] s/mm2$$ \mathrm{s}/\mathrm{m}{\mathrm{m}}^2 $$ for both M2$$ {M}_2 $$ and M3$$ {M}_3 $$. Results: The MD values with M3$$ {M}_3 $$ are slightly higher than with M2$$ {M}_2 $$ with ΔMD=0.05±0.05[×10−3mm2/s](p=4e−5)$$ \Delta \mathrm{MD}=0.05\pm 0.05\kern0.3em \left[\times 1{0}^{-3}\kern0.3em {\mathrm{mm}}^2/\mathrm{s}\right]\kern0.3em \left(p=4e-5\right) $$ for bmax=450s/mm2$$ {b}_{\mathrm{max}}=450\kern0.3em \mathrm{s}/{\mathrm{mm}}^2 $$ and ΔMD=0.03±0.03[×10−3mm2/s](p=4e−4)$$ \Delta \mathrm{MD}=0.03\pm 0.03\kern0.3em \left[\times \kern0.3em 1{0}^{-3}\kern0.3em {\mathrm{mm}}^2/\mathrm{s}\right]\kern0.3em \left(p=4e-4\right) $$ for bmax=1000s/mm2$$ {b}_{\mathrm{max}}=1000\kern0.3em \mathrm{s}/{\mathrm{mm}}^2 $$. A reduction in MD is observed by increasing the bmax$$ {b}_{\mathrm{max}} $$ from 450 to 1000 s/mm2$$ \mathrm{s}/{\mathrm{mm}}^2 $$ (ΔMD=0.06±0.04[×10−3mm2/s](p=1.6e−9)$$ \Delta \mathrm{MD}=0.06\pm 0.04\kern0.3em \left[\times \kern0.3em 1{0}^{-3}\kern0.3em {\mathrm{mm}}^2/\mathrm{s}\right]\kern0.3em \left(p=1.6e-9\right) $$ for M2$$ {M}_2 $$ and ΔMD=0.08±0.05[×10−3mm2/s](p=1e−9)$$ \Delta \mathrm{MD}=0.08\pm 0.05\kern0.3em \left[\times \kern0.3em 1{0}^{-3}\kern0.3em {\mathrm{mm}}^2/\mathrm{s}\right]\kern0.3em \left(p=1e-9\right) $$ for M3$$ {M}_3 $$). The difference between FA, E2A, and HA was not significant in different schemes (p>0.05$$ p>0.05 $$). Conclusion: This work demonstrates cardiac DWI in vivo with higher b‐value and higher order of motion compensated diffusion gradient waveforms than is commonly used. Increasing the motion compensation order from M2$$ {M}_2 $$ to M3$$ {M}_3 $$ and the maximum b‐value from 450 to 1000 s/mm2$$ \mathrm{s}/{\mathrm{mm}}^2 $$ affected the MD values but FA and the angular metrics (HA and E2A) remained unchanged. Our work paves the way for cardiac DWI on the next‐generation MR scanners with high‐performance gradient systems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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