High Time-Resolved Cardiac Functional Imaging Using Temporal Regularization for Small Animal on a Clinical 3T Scanner

Abstract

Abstract-Accurate assessment of mice cardiac function with magnetic resonance imaging is essential for longitudinal studies and for drug development related to cardiovascular diseases. Whereas dedicated small animal MR scanners are not readily available, it would be a great advantage to be able to perform cardiac assessment on clinical systems, in particular, in the context of translational research. However, mouse imaging remains challenging since it requires both high spatial and temporal resolutions, while gradient performances of clinical scanners often limit the reachable parameters. In this study, we propose a new cine sequence, named "interleaved cine," which combines two repetitions of a standard cine sequence shifted in time in order to reach resolution parameters compatible with mice imaging. More precisely, this sequence allows temporal resolution to be reduced to 6.8 ms instead of 13.5 ms initially imposed by the system's hardware. We also propose a two-step denoising algorithm to suppress some artifacts inherent to the new interleaved cine thus allowing an efficient enhancement of the image quality. In particular, we model and suppress the periodic intensity pattern and further denoise the sequence by soft thresholding of the temporal Fourier coefficients. This sequence was successfully validated with mass and function measurements on relevant mice models of cardiovascular diseases.

Treatment with the CC chemokine-binding protein Evasin-4 improves post-infarction myocardial injury and survival in mice

“…Imaging was performed on a 3T MR scanner (Magnetom TIM Trio, Siemens Medical Solutions, Erlangen, Germany) with a dedicated two-channel mouse receiver coil (Rapid biomedical GmbH, Rimpar, Germany). A turboflash cine sequence assessed myocardial function: FOV 66 mm, in plane resolution 257 µm, slice thickness 1 mm, 5-7 consecutive slices to cover the whole left ventricle (no slice overlap), TE/TR effective 6.5/6.8 ms, flip angle 30, GRAPPA with acceleration factor 2, 3 averages, typical acquisi- (18). The sequences were ECG and respiratory gated.…”

Magnetic resonance imaging and ultrasound elastography in the context of preclinical pharmacological research: significance for the 3R principles

“…In the past few years, efforts were pursued to reduce the acquisition times by employing image denoising strategies based on filtering or convoluted neural networks. For instance, denoising has been demonstrated to improve small rodent MRI of the heart ( Delattre et al, 2012 ; Tricot et al, 2017 ), the kidney ( de Senneville et al, 2020 ; Starke et al, 2021 ) and the central nervous system ( Wells et al, 2010 ; Kim et al, 2016 ; Wang et al, 2019 ) as well as spectroscopic analyses ( Simões et al, 2022 ). Even functional connectivity assessments may profit from denoising, as shown in a rat model of sporadic Alzheimer’s disease ( Diao et al, 2021 ).…”