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Here we describe a simple and inexpensive protocol for preparing ex vivo rodent phantoms for use in MR imaging studies. The experimental animals are perfused and fixed with formaldehyde, and then wrapped with gauze and sealed with liquid latex. This yields a phantom that preserves all organs in situ, and which avoids the need to keep fixed animals and organs in containers that have dimensions very different from living animals. This is especially important for loading in MR detectors, and specifically the RF coils, they are usually used with. The phantom can be safely stored and conveniently reused, and can provide MR scientists with a realistic phantom with which to establish protocols in preparation for preclinical in vivo studies-for renal, brain, and body imaging. The phantom also serves as an ideal teaching tool, for trainees learning how to perform preclinical MRI investigations of the kidney and other target organs, while avoiding the need for handling living animals, and reducing the total number of animals required.This protocol chapter is part of the PARENCHIMA initiative "MRI Biomarkers for CKD " (CA16103), a community-driven Action of the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers.

PURPOSE: To examine the performance of compressed sensing (CS) in reconstructing low signal-to-noise ratio (SNR) (19)F MR signals that are close to the detection threshold and originate from small signal sources with no a priori known location. METHODS: Regularization strength was adjusted automatically based on noise level. As performance metrics, root-mean-square deviations, true positive rates (TPRs), and false discovery rates were computed. CS and conventional reconstructions were compared at equal measurement time and evaluated in relation to high-SNR reference data. (19)F MR data were generated from a purpose-built phantom and benchmarked against simulations, as well as from the experimental autoimmune encephalomyelitis mouse model. We quantified the signal intensity bias and introduced an intensity calibration for in vivo data using high-SNR ex vivo data. RESULTS: Low-SNR (19)F MR data could be reliably reconstructed. Detection sensitivity was consistently improved and data fidelity was preserved for undersampling and averaging factors of α = 2 or = 3. Higher α led to signal blurring in the mouse model. The improved TPRs at α = 3 were comparable to a 2.5-fold increase in measurement time. Whereas CS resulted in a downward bias of the (19)F MR signal, Fourier reconstructions resulted in an unexpected upward bias of similar magnitude. The calibration corrected signal-intensity deviations for all reconstructions. CONCLUSION: CS is advantageous whenever image features are close to the detection threshold. It is a powerful tool, even for low-SNR data with sparsely distributed (19)F signals, to improve spatial and temporal resolution in (19)F MR applications.

The objective of this study was the design, implementation, evaluation and applica-tion of a compact wideband self-grounded bow-tie (SGBT) radiofrequency(RF) antenna building block that supports anatomical proton (1H) MRI, fluorine (19F)MRI, MR thermometry and broadband thermal intervention integrated in a whole-body 7.0 T system.Design considerations and optimizations were conducted with numerical electromag-netic field (EMF) simulations to facilitate a broadband thermal intervention frequencyof the RF antenna building block. RF transmission (B1+) field efficiency and specificabsorption rate (SAR) were obtained in a phantom, and the thigh of human voxelmodels (Ella, Duke) for1H and19F MRI at 7.0 T. B1+efficiency simulations were vali-dated with actual flip-angle imaging measurements. The feasibility of thermal inter-vention was examined by temperature simulations (f = 300, 400 and 500 MHz) in aphantom. The RF heating intervention (Pin= 100 W, t = 120 seconds) was validatedexperimentally using the proton resonance shift method and fiberoptic probes fortemperature monitoring. The applicability of the SGBT RF antenna building block forin vivo1H and19F MRI was demonstrated for the thigh and forearm of a healthyvolunteer.The SGBT RF antenna building block facilitated19F and1H MRI at 7.0 T as well asbroadband thermal intervention (234-561 MHz). For the thigh of the human voxelmodels, a B1+efficiency≥11.8μT/√kW was achieved at a depth of 50 mm. Tempera-ture simulations and heating experiments in a phantom demonstrated a temperatureincreaseΔT >7 K at a depth of 10 mm.The compact SGBT antenna building block provides technology for the design ofintegrated high-density RF applicators and for the study of the role of temperature in (patho-) physiological processes by adding a thermal intervention dimension to an MRI device (Thermal MR).

5G and AI (Artificial Intelligence) are changing industrial production and offer great potential for manufacturing enterprises. One of the effects resulting from the increasing quantity of production data is the increasing demands of transmission of large amounts of data, fast transmission speed, and rapid data analysis. However, merely relying on traditional communication technology and manual data processing does not lead to high transmission performance and low analysis time. It is essential to integrate 5G and AI technology to flexibly transmit large amounts of data and real-time data. To demonstrate the feasibility and potential of these two technologies, a concept was developed at the Advanced Manufacturing Technology Center (AMTC) at the Tongji University (Shanghai, China) and further implemented in the AMTC learning factory in cooperation with wbk of Karlsruhe Institute of Technology (Karlsruhe, Germany) and Ruhr-University Bochum (Bochum, Germany). This paper presents the learning factory design in detail, describing the concept design, training environment and training phases in the AMTC learning factory. It is followed by a case study consisting of specific examples of 5G and AI, implemented in the AMTC learning factory. The importance of integrated 5G and AI applications is pointed out and discussed.

OBJECTIVE: Fluorine MR would benefit greatly from enhancements in signal-to-noise ratio (SNR). This study examines the sensitivity gain of (19)F MR that can be practically achieved when moving from 9.4 to 21.1 T. MATERIALS AND METHODS: We studied perfluoro-15-crown-5-ether (PFCE) at both field strengths (B(0)), as a pure compound, in the form of nanoparticles (NP) as employed to study inflammation in vivo, as well as in inflamed tissue. Brains, lymph nodes (LNs) and spleens were obtained from mice with experimental autoimmune encephalomyelitis (EAE) that had been administered PFCE NPs. All samples were measured at both B(0) with 2D-RARE and 2D-FLASH using (19)F volume radiofrequency resonators together. T(1) and T(2) of PFCE were measured at both B(0) strengths. RESULTS: Compared to 9.4 T, an SNR gain of > 3 was observed for pure PFCE and > 2 for PFCE NPs at 21.1 T using 2D-FLASH. A dependency of (19)F T(1) and T(2) relaxation on B(0) was demonstrated. High spatially resolved (19)F MRI of EAE brains and LNs at 21.1 T revealed signals not seen at 9.4 T. DISCUSSION: Enhanced SNR and T(1) shortening indicate the potential benefit of in vivo (19)F MR at higher B(0) to study inflammatory processes with greater detail.