TY - JOUR

T1 - Super Resolution Ultrasound Imaging using the Erythrocytes

T2 - I: Density Images

AU - Jensen, Jørgen Arendt

AU - Naji, Mostafa Amin

AU - Praesius, Sebastian Kazmarek

AU - Taghavi, Iman

AU - Schou, Mikkel

AU - Hansen, Lauge Naur

AU - Andersen, Sofie Bech

AU - Søgaard, Stinne Byrholdt

AU - Panduro, Nathalie Sarup

AU - Sørensen, Charlotte Mehlin

AU - Nielsen, Michael Bachmann

AU - Gundlach, Carsten

AU - Kjer, Hans Martin

AU - Dahl, Anders Bjorholm

AU - Tomov, Borislav Gueorguiev

AU - Ommen, Martin Lind

AU - Larsen, Niels Bent

AU - Thomsen, Erik Vilain

PY - 2024/6/10

Y1 - 2024/6/10

N2 - A new approach for vascular super resolution imaging using the erythrocytes as targets (SURE imaging) is described and investigated. SURE imaging does not require fragile contrast agent bubbles, making it possible to use the maximum allowable mechanical index for ultrasound scanning for an increased penetration depth. A synthetic aperture ultrasound sequence was employed with 12 virtual sources using a 10 MHz GE L8-18i-D linear array hockey stick probe. The axial resolution was 1.20λ,(185.0μm) and the lateral resolution was 1.50λ,(231.3μm). Field IIpro simulations were conducted on 12.5 μm radius vessel pairs with varying separations. A vessel pair with a separation of 70 μm could be resolved, indicating a SURE image resolution below half a wavelength. A Verasonics research scanner was used for the in vivo experiments to scan the kidneys of Sprague-Dawley rats for up to 46 s to visualize their microvasculature by processing from 0.1 up to 45 s of data for SURE imaging, and for 46.8 s for super resolution (SR) imaging with a SonoVue contrast agent. Afterward, the renal vasculature was filled with the ex vivo micro-CT contrast agent Microfil, excised, and scanned in a micro-CT scanner at both a 22.6 μm voxel size for 11 hours, and for 20 hours in a 5 μm voxel size for validating the SURE images. Comparing the SURE and micro-CT images revealed that vessels with a diameter of 28 μm, five times smaller than the ultrasound wavelength, could be detected, and the dense grid of microvessels in the full kidney was shown for scan times between 1 to 10 s. The vessel structure in the cortex was also similar for the SURE and SR images. Fourier ring correlation indicated a resolution capability of 29 μm. SURE images are acquired in seconds rather than minutes without any patient preparation or contrast injection, making the method translatable to clinical use.

AB - A new approach for vascular super resolution imaging using the erythrocytes as targets (SURE imaging) is described and investigated. SURE imaging does not require fragile contrast agent bubbles, making it possible to use the maximum allowable mechanical index for ultrasound scanning for an increased penetration depth. A synthetic aperture ultrasound sequence was employed with 12 virtual sources using a 10 MHz GE L8-18i-D linear array hockey stick probe. The axial resolution was 1.20λ,(185.0μm) and the lateral resolution was 1.50λ,(231.3μm). Field IIpro simulations were conducted on 12.5 μm radius vessel pairs with varying separations. A vessel pair with a separation of 70 μm could be resolved, indicating a SURE image resolution below half a wavelength. A Verasonics research scanner was used for the in vivo experiments to scan the kidneys of Sprague-Dawley rats for up to 46 s to visualize their microvasculature by processing from 0.1 up to 45 s of data for SURE imaging, and for 46.8 s for super resolution (SR) imaging with a SonoVue contrast agent. Afterward, the renal vasculature was filled with the ex vivo micro-CT contrast agent Microfil, excised, and scanned in a micro-CT scanner at both a 22.6 μm voxel size for 11 hours, and for 20 hours in a 5 μm voxel size for validating the SURE images. Comparing the SURE and micro-CT images revealed that vessels with a diameter of 28 μm, five times smaller than the ultrasound wavelength, could be detected, and the dense grid of microvessels in the full kidney was shown for scan times between 1 to 10 s. The vessel structure in the cortex was also similar for the SURE and SR images. Fourier ring correlation indicated a resolution capability of 29 μm. SURE images are acquired in seconds rather than minutes without any patient preparation or contrast injection, making the method translatable to clinical use.

U2 - 10.1109/TUFFC.2024.3411711

DO - 10.1109/TUFFC.2024.3411711

M3 - Journal article

C2 - 38857145

JO - I E E E Transactions on Ultrasonics, Ferroelectrics and Frequency Control

JF - I E E E Transactions on Ultrasonics, Ferroelectrics and Frequency Control

SN - 0885-3010

ER -