Ultrafast Ultrasound Imaging for Super-Resolution Preclinical Cardiac PET

• Published in: Molecular imaging and biology Vol. 22; no. 5; pp. 1342 - 1352
• Main Authors: Perez-Liva, Mailyn, Yoganathan, Thulaciga, Herraiz, Joaquin, Porée, Jonathan, Tanter, Mickael, Balvay, Daniel, Viel, Thomas, Garofalakis, Anikitos, Provost, Jean, Tavitian, Bertrand
• Format: Journal Article
• Language: English
• Published: Springer Verlag 01.10.2020
• Subjects: Bioengineering; Imaging; Life Sciences; Image quality; Super-resolution; Cardiac Positron Emission Tomography; Ultrafast Ultrasound Imaging
• ISSN: 1536-1632
• DOI: 10.1007/s11307-020-01512-w

Abstract Purpose Physiological motion and partial volume effect (PVE) significantly degrade the quality of cardiac positron emission tomography (PET) images in the fast-beating hearts of rodents. Several Super-resolution (SR) techniques using a priori anatomical information have been proposed to correct motion and PVE in PET images. Ultrasound is ideally suited to capture real-time high-resolution cine images of rodent hearts. Here, we evaluated an ultrasound-based SR method using simultaneously acquired and co-registered PET-CT-Ultrafast Ultrasound Imaging (UUI) of the beating heart in closed-chest rodents. Procedures The method was tested with numerical and animal data ( n = 2) acquired with the non-invasive hybrid imaging system PETRUS that acquires simultaneously PET, CT, and UUI. Results We showed that ultrasound-based SR drastically enhances the quality of PET images of the beating rodent heart. For the simulations, the deviations between expected and mean reconstructed values were 2 % after applying SR. For the experimental data, when using Ultrasound-based SR correction, contrast was improved by a factor of two, signal-to-noise ratio by 11 %, and spatial resolution by 56 % (~ 0.88 mm) with respect to static PET. As a consequence, the metabolic defect following an acute cardiac ischemia was delineated with much higher anatomical precision. Conclusions Our results provided a proof-of-concept that image quality of cardiac PET in fast-beating rodent hearts can be significantly improved by ultrasound-based SR, a portable low-cost technique. Improved PET imaging of the rodent heart may allow new explorations of physiological and pathological situations related with cardiac metabolism.