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Purpose: To shorten the acquisition time of magnetization-prepared absolute transmit field (B ) mapping known as presaturation TurboFLASH, or satTFL, to enable single breath-hold whole-heart 3D B mapping.
Methods: SatTFL is modified to remove the delay between the reference and prepared images (typically 5 T ), with matching transmit configurations for excitation and preparation RF pulses. The new method, called Sandwich, is evaluated as a 3D sequence, measuring whole-brain and gated whole-heart B maps in a single breath-hold. We evaluate the sensitivity to B and T using numerical Bloch, extended phase graph, and Monte Carlo simulations. Phantom and in vivo images were acquired in both the brain and heart using an 8-channel transmit 7 Tesla MRI system to support the simulations. A segmented satTFL with a short readout train was used as a reference.
Results: The method significantly reduces acquisition times of 3D measurements from 360 s to 20 s, in the brain, while simultaneously reducing bias in the measured B due to T and magnetization history. The mean coefficient of variation was reduced by 81% for T s of 0.5-3 s compared to conventional satTFL. In vivo, the reproducibility coefficient for flip angles in the range 0-130° was 4.5° for satTFL and 4.7° for our scheme, significantly smaller than for a short TR satTFL sequence, which was 12°. The 3D sequence measured B maps of the whole thorax in 26 heartbeats.
Conclusion: Our adaptations enable faster B mapping, with minimal T sensitivity and lower sensitivity to magnetization history, enabling single breath-hold whole-heart absolute B mapping.
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http://dx.doi.org/10.1002/mrm.29497 | DOI Listing |
Cureus
August 2025
Respiratory Medicine, Birmingham Heartlands Hospital (Part of University Hospitals Birmingham NHS Trust), Birmingham, GBR.
We report the management of a 64-year-old male with newly diagnosed bulbar-onset myasthenia gravis (MG) who was hospitalized with acute neuromuscular respiratory insufficiency. This case highlights the challenges in monitoring respiratory function in MG patients, especially in the presence of bulbar and nuchal weakness, and emphasizes the potential utility of single breath-hold time (SBHT) over forced vital capacity (FVC) as a reliable bedside monitoring tool. Despite initial stabilization with intravenous immunoglobulin (IVIG), the patient deteriorated, requiring escalation to the intensive care unit (ICU), and the clinical worsening corresponded with the SBHT rather than with FVC.
View Article and Find Full Text PDFMagn Reson Imaging
September 2025
Julius-Maximilians-Universität Würzburg, Department of Experimental Physics 5, Germany.
Purpose: Presenting a technique to quantify the transverse relaxation time T, which is associated with the diffusion of water molecules through the internal magnetic field gradients of the lung in-vivo.
Methods: A Half-Fourier-Acquired Single-shot Turbo spin-Echo (HASTE) pulse sequence with Hahn-echo preparation was implemented and used for image acquisition. Quantification of T was performed by acquiring multiple images with identical TE, but with a different number of refocusing pulses between excitation and signal acquisition.
Magn Reson Med
September 2025
Radiology, Weill Cornell Medicine, New York, New York, USA.
Purpose: To develop a multiparametric free-breathing three-dimensional, whole-liver quantitative maps of water T, water T, fat fraction (FF) and R*.
Methods: A multi-echo 3D stack-of-spiral gradient-echo sequence with inversion recovery and T-prep magnetization preparations was implemented for multiparametric MRI. Fingerprinting and a neural network based on implicit neural representation (FINR) were developed to simultaneously reconstruct the motion deformation fields, the static images, perform water-fat separation, and generate T, T, R*, and FF maps.
Eur J Radiol
August 2025
Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Objectives: To investigate whether warming gadoxetic acid affects the frequency and degree of artifacts in the arterial phase of MRI.
Methods: This prospective study included patients who underwent gadoxetic acid-enhanced MRI (April 2016-November 2017 and June-November 2018) at a single center. Either warmed (37 °C, n = 134) or non-warmed (24 °C, n = 137) gadoxetic acid was intravenously injected at a dose of 0.
AJNR Am J Neuroradiol
August 2025
From Tu Lab for Diagnostic Research (SR, OZ, CKH, LHT) and Department of Radiology and Biomedical Imaging (SR, CH, IDDS, JKN, OZ, CKH, CFEK, LHT), Yale School of Medicine, New Haven, CT, USA.
Magnetic resonance imaging (MRI) of the lumbosacral plexus (LSP) is a critical tool for evaluating pelvic and lower extremity peripheral nerve disorders. The rarity of this exam type and the complexity of underlying anatomy can produce challenges for interpretation. This pictorial review outlines a structured approach for evaluating lumbosacral plexus MRI (LSP MRI), emphasizing key imaging anatomy, MRI protocols, and a spectrum of commonly encountered pathologies to aid radiologists in interpretating LSP MRI.
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