Magnetic Resonance in Medicine最新文献

{"title":"B₀ navigator enables respiratory motion navigation in radial stack-of-stars liver Look-Locker T₁ mapping.","authors":"Jonathan Stelter, Kilian Weiss, Veronika Spieker, Julia A Schnabel, Rickmer F Braren, Dimitrios C Karampinos","doi":"10.1002/mrm.30567","DOIUrl":"https://doi.org/10.1002/mrm.30567","url":null,"abstract":"<p><strong>Purpose: </strong>To develop a <math> <semantics> <mrow> <msub><mrow><mi>B</mi></mrow> <mrow><mn>0</mn></mrow> </msub> </mrow> <annotation>$$ {B}_0 $$</annotation></semantics> </math> self-navigation approach to estimate respiratory motion for motion-corrected liver <math> <semantics> <mrow> <msub><mrow><mi>T</mi></mrow> <mrow><mn>1</mn></mrow> </msub> </mrow> <annotation>$$ {T}_1 $$</annotation></semantics> </math> mapping using a Look-Locker acquisition with radial stack-of-stars trajectory.</p><p><strong>Methods: </strong>The proposed method derives 1D field-map profiles from the oversampled k-space center to estimate a normalized breathing curve and the <math> <semantics> <mrow> <msub><mrow><mi>B</mi></mrow> <mrow><mn>0</mn></mrow> </msub> </mrow> <annotation>$$ {B}_0 $$</annotation></semantics> </math> variation amplitude for each slice and coil. <math> <semantics> <mrow> <msub><mrow><mi>B</mi></mrow> <mrow><mn>0</mn></mrow> </msub> </mrow> <annotation>$$ {B}_0 $$</annotation></semantics> </math> drift and contrast variations, inherent to the Look-Locker acquisition, were modeled and corrected by fitting and demodulating drift and offset terms. The breathing curve was employed to bin data into motion states for motion-resolved reconstruction, followed by water-specific <math> <semantics> <mrow> <msub><mrow><mi>T</mi></mrow> <mrow><mn>1</mn></mrow> </msub> </mrow> <annotation>$$ {T}_1 $$</annotation></semantics> </math> mapping. Simulations with an anatomical body model and in vivo experiments with a Look-Locker multi-echo gradient echo sequence were performed to validate the technique. The estimated normalized breathing curve was compared with magnitude- and phase-based self-navigation approaches using principal component analysis.</p><p><strong>Results: </strong>The proposed <math> <semantics> <mrow> <msub><mrow><mi>B</mi></mrow> <mrow><mn>0</mn></mrow> </msub> </mrow> <annotation>$$ {B}_0 $$</annotation></semantics> </math> self-navigation reliably estimated the normalized breathing curve and the <math> <semantics> <mrow> <msub><mrow><mi>B</mi></mrow> <mrow><mn>0</mn></mrow> </msub> </mrow> <annotation>$$ {B}_0 $$</annotation></semantics> </math> variation amplitude in simulations and in vivo. <math> <semantics> <mrow> <msub><mrow><mi>B</mi></mrow> <mrow><mn>0</mn></mrow> </msub> </mrow> <annotation>$$ {B}_0 $$</annotation></semantics> </math> variation amplitudes increased with greater tissue displacement, with median values across slices and coils ranging from 4 to 15 Hz at 3 T in volunteers. Motion-resolved reconstruction using the estimated breathing curve reduced motion artifacts and improved image and <math> <semantics> <mrow> <msub><mrow><mi>T</mi></mrow> <mrow><mn>1</mn></mrow> </msub> </mrow> <annotation>$$ {T}_1 $$</annotation></semantics> </math> mapping quality compared to motion-averaged reconstruction.</p><p><strong>Conclusion: </strong><math> <semantics> <mrow> <msub><mrow><mi>B</mi></mrow> <mrow><mn>0</mn></mrow>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144111127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TE optimization for J-difference editing of 2-hydroxyglutarate at 3T.","authors":"Kimberly L Chan, Rutul Hapani, Elizabeth A Maher, Toral R Patel, Anke Henning","doi":"10.1002/mrm.30561","DOIUrl":"https://doi.org/10.1002/mrm.30561","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate the TE dependence of the edited 2-hydroxyglutarate (2HG) signal, its separation from co-edited glutamate plus glutamine (Glx), and fit accuracy in the presence of nuisance signals using a MEGA-PRESS sequence.</p><p><strong>Methods: </strong>Simulations were performed at TEs 70-160 ms to assess the signal intensity and 2HG-Glx overlap as a function of TE. The effect of the 2HG-Glx spectral overlap on the fit accuracy of 2HG was evaluated on simulated 2HG-edited spectra with in vivo parameter variations. Data were acquired at TEs of 70 and 90 ms in 13 glioma patients to estimate the TE-dependence of the 2HG and Glx signal intensity and at a TE of 120 ms in eight glioma patients to estimate the in vivo 2HG, Glx, and water T2 relaxation times.</p><p><strong>Results: </strong>A TE of 90 ms was found to produce a maximal 2HG integral, which was 23% larger than that at a TE of 70 ms in vivo without a significant increase in 2HG-Glx overlap. Lipid and residual water were 26% and 16% lower, respectively, at a TE of 90 ms versus 70 ms. Fit-quality numbers were 49% lower at a TE of 90 ms versus 70 ms, indicating enhanced fits at a TE of 90 ms. The in vivo T2 relaxation times of 2HG, Glx, and water were 264, 177, and 110 ms, respectively.</p><p><strong>Conclusion: </strong>A TE of 90 ms was best with a maximal 2HG signal, minimal 2HG-Glx overlap, and minimal residual water and lipid contamination.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144111141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-center benchmarking of cervical spinal cord RF coils for 7 T MRI: A traveling spines study.","authors":"Eva Alonso-Ortiz, Daniel Papp, Robert L Barry, Kyota Poëti, Alan C Seifert, Kyle M Gilbert, Nibardo Lopez-Rios, Jan Paska, Falk Eippert, Nikolaus Weiskopf, Laura Beghini, Nadine N Graedel, Robert Trampel, Martina F Callaghan, Christoph S Aigner, Patrick Freund, Maryam Seif, Aurélien Destruel, Virginie Callot, Johanna Vannesjo, Julien Cohen-Adad","doi":"10.1002/mrm.30551","DOIUrl":"10.1002/mrm.30551","url":null,"abstract":"<p><strong>Purpose: </strong>The depth within the body, small diameter, long length, and varying tissue surrounding the spinal cord impose specific considerations when designing RF coils. The optimal coil configuration for 7 T cervical spinal cord MRI is unknown and currently there are very few coil options. The purpose of this work was (1) to establish a quality control protocol for evaluating 7 T cervical spinal cord coils, and (2) to use that protocol to evaluate the performance of four different coil designs.</p><p><strong>Methods: </strong>Three healthy volunteers and a custom anthropomorphic phantom (the traveling spines cohort) were scanned at seven 7 T imaging centers using a common protocol and each center's specific cervical spinal cord coil. Four different coil designs were tested (two in-house, one Rapid Biomedical, and one MRI.TOOLS design).</p><p><strong>Results: </strong>The Rapid Biomedical coil was found to have the highest <math> <semantics> <mrow><msubsup><mi>B</mi> <mn>1</mn> <mo>+</mo></msubsup> </mrow> <annotation>$$ {mathrm{B}}_1^{+} $$</annotation></semantics> </math> efficiency, whereas one of the in-house designs (NeuroPoly Lab) had the highest SNR and the largest spinal cord coverage. The MRI.TOOLS coil had the most uniform <math> <semantics> <mrow><msubsup><mi>B</mi> <mn>1</mn> <mo>+</mo></msubsup> </mrow> <annotation>$$ {mathrm{B}}_1^{+} $$</annotation></semantics> </math> profile along the cervical spinal cord; however, it was limited in its ability to provide the requested flip angles (especially for larger individuals). The latter was also the case for the second in-house coil (MSSM).</p><p><strong>Conclusion: </strong>The results of this study serve as a guide for the spinal cord MRI community in selecting the most suitable coil based on specific requirements and offer a standardized protocol for assessing future coils.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144111137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving quantitative BOLD-based measures of oxygen extraction fraction using hyperoxia BOLD-derived measures of blood volume.","authors":"Alan J Stone, Nicholas P Blockley","doi":"10.1002/mrm.30559","DOIUrl":"https://doi.org/10.1002/mrm.30559","url":null,"abstract":"<p><strong>Purpose: </strong>Streamlined quantitative BOLD (sqBOLD) is a refinement of the quantitative BOLD (qBOLD) technique capable of producing noninvasive and quantitative maps of oxygen extraction fraction (OEF) in a clinically feasible scan time. However, sqBOLD measurements of OEF have been reported as being systematically lower than expected in healthy brain. Because the qBOLD framework infers OEF from the ratio of the reversible transverse relaxation rate ( <math> <semantics> <mrow><msubsup><mi>R</mi> <mn>2</mn> <mo>'</mo></msubsup> </mrow> <annotation>$$ {mathrm{R}}_2^{prime } $$</annotation></semantics> </math> ) and deoxygenated blood volume (DBV), this underestimation has been attributed the overestimation of DBV. Therefore, this study proposes the use of an independent measure of DBV using hyperoxia BOLD and investigates whether this results in improved estimates of OEF.</p><p><strong>Methods: </strong>Monte Carlo simulations were used to simulate the qBOLD and hyperoxia-BOLD signals and to compare the systematic and noise-related errors of sqBOLD and the new hyperoxia-qBOLD (hqBOLD) technique. Experimentally, sqBOLD and hqBOLD measurements were performed and compared with TRUST (T₂ relaxation under spin tagging)-based oximetry in the sagittal sinus.</p><p><strong>Results: </strong>Simulations showed a large improvement in the uncertainty of DBV measurements, leading to a much improved dynamic range for OEF measurements with hqBOLD. In a group of 10 healthy volunteers, hqBOLD produced measurements of OEF in cortical gray matter (OEF_hqBOLD = 38.1 ± 10.1%) that were not significantly different from TRUST oximetry measures (OEF_TRUST = 40.4 ± 7.7%), whereas sqBOLD-derived measures (OEF_sqBOLD = 16.1 ± 3.1%) were found to be significantly different.</p><p><strong>Conclusion: </strong>The simulations and experiments in this study demonstrate that an independent measure of DBV provides improved estimates of OEF.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144111133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RF shimming strategy for an open 60-channel RF transmit 7T MRI head coil for routine use on the single transmit mode.","authors":"Andrea N Sajewski, Tales Santini, Anthony DeFranco, Jacob Berardinelli, Hecheng Jin, Jinghang Li, Cong Chu, Jeremy J Berardo, Tamer S Ibrahim","doi":"10.1002/mrm.30563","DOIUrl":"https://doi.org/10.1002/mrm.30563","url":null,"abstract":"<p><strong>Purpose: </strong>To develop an radiofrequency (RF) shimming approach for operating the 2nd Generation Tic Tac Toe RF coil system (60 transmit channels integrated with 32-channel receive insert) for routine use in 7T neuro MRI on the single transmit mode.</p><p><strong>Methods: </strong>RF simulations were performed and used to develop non-subject-specific RF shim cases over three anatomically detailed head models: adult male, adult female, and child female. Multi-ROI shimming strategies were developed and implemented. <math> <semantics> <mrow><msubsup><mi>B</mi> <mn>1</mn> <mo>+</mo></msubsup> </mrow> <annotation>$$ {mathrm{B}}_1^{+} $$</annotation></semantics> </math> maps and in vivo images were acquired on the single transmit mode of a 7T scanner using the RF shim cases derived from the computer simulations.</p><p><strong>Results: </strong>The availability of 60 transmit channels enables more control over <math> <semantics> <mrow><msubsup><mi>B</mi> <mn>1</mn> <mo>+</mo></msubsup> </mrow> <annotation>$$ {mathrm{B}}_1^{+} $$</annotation></semantics> </math> efficiency, specific absorption rate (SAR) efficiency, and <math> <semantics> <mrow><msubsup><mi>B</mi> <mn>1</mn> <mo>+</mo></msubsup> </mrow> <annotation>$$ {mathrm{B}}_1^{+} $$</annotation></semantics> </math> homogeneity using RF shimming. On the single transmit mode, the 2nd generation Tic Tac Toe RF coil system consistently provides homogeneous <math> <semantics> <mrow><msubsup><mi>B</mi> <mn>1</mn> <mo>+</mo></msubsup> </mrow> <annotation>$$ {mathrm{B}}_1^{+} $$</annotation></semantics> </math> field distribution with extended coverage into the temporal lobes, cerebellum, reaching all the way to C5-C6. Safe levels of SAR are also achieved.</p><p><strong>Conclusion: </strong>By using a non-subject specific RF shimming approach derived from computer simulations, the 2nd generation Tic Tac Toe RF coil system allows for robust, routine neuroimaging (>1750 in vivo scanning sessions over the past 28 months) at 7T in single transmit mode.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144111139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MULti-TImepoint VElocity-selective Reconciled with Spatially-sElective (MULTIVERSE) ASL: Improving robustness to both shortened and prolonged arterial transit time.","authors":"Feng Xu, Dan Zhu, Dapeng Liu, Anja Soldan, Marilyn Albert, Martin A Lindquist, Doris D M Lin, Qin Qin","doi":"10.1002/mrm.30540","DOIUrl":"https://doi.org/10.1002/mrm.30540","url":null,"abstract":"<p><strong>Purpose: </strong>To improve the quantification of existing multi-timepoint arterial spin labeling (ASL) methods in estimating cerebral blood flow (CBF) and arterial transit time (ATT) for a wider range of ATTs.</p><p><strong>Methods: </strong>MULti-TImepoint VElocity-selective Reconciled with Spatially-sElective (MULTIVERSE) ASL utilizes multi-delay pseudo-continuous (PC) ASL and velocity-selective (VS) ASL with spatially defined bolus, and joint fitting to estimate CBF and ATT. Numerical simulations were performed to evaluate the accuracy and precision of single-delay and multi-delay PCASL and VSASL, as well as the proposed MULTIVERSE ASL, in quantifying CBF and ATT across an extended range of ATTs. The CBF and ATT estimates between multi-delay PCASL, VSASL, and MULTIVERSE ASL were compared across healthy volunteers.</p><p><strong>Results: </strong>Numerical simulations showed that the utility of MULTIVERSE ASL improved the accuracy and precision over an extended ATT range of up to 4000 ms. In vivo scans from healthy subjects demonstrated that MULTIVERSE ASL led to reduced uncertainty in CBF and ATT quantification compared to multi-post-labeling delay PCASL while maintaining comparable repeatability.</p><p><strong>Conclusion: </strong>This novel and straightforward approach improves the accuracy and precision of the fitted CBF and ATT over an extended range of ATT, which is not possible with existing ASL methods. Brain scans from healthy subjects demonstrated the feasibility and reliability of the technique, highlighting the clinical potential of ASL-based perfusion mapping in various altered physiological and pathological conditions.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144094289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Groupwise image registration with edge-based loss for low-SNR cardiac MRI.","authors":"Xuan Lei, Philip Schniter, Chong Chen, Rizwan Ahmad","doi":"10.1002/mrm.30486","DOIUrl":"https://doi.org/10.1002/mrm.30486","url":null,"abstract":"<p><strong>Purpose: </strong>The purpose of this study is to perform image registration and averaging of multiple free-breathing single-shot cardiac images, where the individual images may have a low signal-to-noise ratio (SNR).</p><p><strong>Methods: </strong>To address low SNR encountered in single-shot imaging, especially at low field strengths, we propose a fast deep learning (DL)-based image registration method, called Averaging Morph with Edge Detection (AiM-ED). AiM-ED jointly registers multiple noisy source images to a noisy target image and utilizes a noise-robust pre-trained edge detector to define the training loss. We validate AiM-ED using synthetic late gadolinium enhanced (LGE) images from the MR extended cardiac-torso (MRXCAT) phantom and free-breathing single-shot LGE images from healthy subjects (24 slices) and patients (5 slices) under various levels of added noise. Additionally, we demonstrate the clinical feasibility of AiM-ED by applying it to data from patients (6 slices) scanned on a 0.55T scanner.</p><p><strong>Results: </strong>Compared with a traditional energy-minimization-based image registration method and DL-based VoxelMorph, images registered using AiM-ED exhibit higher values of recovery SNR and three perceptual image quality metrics. An ablation study shows the benefit of both jointly processing multiple source images and using an edge map in AiM-ED.</p><p><strong>Conclusion: </strong>For single-shot LGE imaging, AiM-ED outperforms existing image registration methods in terms of image quality. With fast inference, minimal training data requirements, and robust performance at various noise levels, AiM-ED has the potential to benefit single-shot CMR applications.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144016891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative T₂ mapping of lung parenchyma at 9.4 T: A feasibility study in three murine models of interstitial lung disease.","authors":"Grzegorz Kwiatkowski, Aleksandra Kaszlikowska, Laura Seldeslachts, Lauren Michiels, Tadeusz Pałasz, Uwe Himmelreich, Greetje Vande Velde, Stefan Chłopicki","doi":"10.1002/mrm.30534","DOIUrl":"https://doi.org/10.1002/mrm.30534","url":null,"abstract":"<p><strong>Purpose: </strong>To validate the feasibility of quantitative T₂ mapping as a novel, gadolinium-free, preclinical biomarker of interstitial lung disease (ILD).</p><p><strong>Methods: </strong>Quantitative T₂ mapping of lung parenchyma was obtained with multiple-slice multiple-echo readout. A mono-exponential model of magnetization decay was fit to the data to obtain parametric maps of T₂ relaxation time in four slices across whole lungs. The measurements were performed in three clinically relevant murine models ILD: acute lung injury due to endotoxemia, chronic recovery phase post-influenza infection, and bleomycin-induced interstitial lung fibrosis.</p><p><strong>Results: </strong>Quantitative maps of T₂ relaxation in healthy mice showed a mean value of 10.51 ± 0.56 ms. During ILD development, the mean T₂ increased up to threefold, showing high sensitivity to altered tissue water content due to augmented fraction of macromolecules in fibrosis or inflammation associated with disease progression.</p><p><strong>Conclusion: </strong>T₂ mapping of mouse lungs can be successfully applied at 9.4 T, offering quantitative insights through parametric T₂ mapping across various ILD models without requiring contrast agents. The proposed method for evaluating lung tissue damage is adaptable to other interstitial lung diseases.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144024787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A pathway toward clinical translation of hyperpolarized [1,4-¹³C₂,2,3-d₂]fumarate as an imaging biomarker for early cellular necrosis in vivo.","authors":"Jonathan R Birchall, Pascal Wodtke, Ashley Grimmer, Esben S S Hansen, Lotte B Bertelsen, Nikolaj Bøgh, Marta Wylot, Maria J Zamora-Morales, Otso Arponen, Ines Horvat-Menih, Elizabeth C Latimer, Fung Tan, Evita Pappa, Johann Graggaber, Joseph Cheriyan, Kelly Holmes, Matthew J Locke, Helen Sladen, Joan Boren, Mikko I Kettunen, Anita Chhabra, Ian B Wilkinson, Christoffer Laustsen, Kevin Brindle, Mary A McLean, Ferdia A Gallagher","doi":"10.1002/mrm.30519","DOIUrl":"https://doi.org/10.1002/mrm.30519","url":null,"abstract":"<p><strong>Purpose: </strong>The detection of hyperpolarized carbon-13 (HP ¹³C)-fumarate conversion to ¹³C-malate using ¹³C-MRSI is a biomarker for early detection of cellular necrosis. Here, we describe the translation of HP ¹³C-fumarate as a novel human imaging agent, including the evaluation of biocompatibility and scaling up of the hyperpolarization methods for clinical use.</p><p><strong>Methods: </strong>Preclinical biological validation was undertaken in fumarate hydratase-deficient murine tumor models and controls. Safety and biocompatibility of ¹³C-fumarate was assessed in healthy rats (N = 18) and in healthy human volunteers (N = 9). The dissolution dynamic nuclear polarization process for human doses of HP ¹³C-fumarate was optimized in phantoms. Finally, 2D ¹³C-MRSI following injection of HP ¹³C-fumarate was performed in an ischemia-reperfusion porcine kidney model (N = 6).</p><p><strong>Results: </strong>Fumarate-to-malate conversion was reduced by 42%-71% in the knockdown murine tumor model compared to wildtype tumors. Twice-daily injection of ¹³C-fumarate in healthy rats at the maximum evaluated dose (120 mg/kg/day) showed no significant persistent blood or tissue effects. Healthy human volunteers injected at the maximum dose (3.84 mg/kg) and injection rate (5 mL/s) showed no statistically significant changes in vital signs or blood measurements 1 h post-injection. Spectroscopic evidence of fumarate-to-malate conversion was observed in the ischemic porcine kidney (0.96 mg/kg).</p><p><strong>Conclusion: </strong>HP ¹³C-fumarate has shown promise as a novel and safe hyperpolarized agent for monitoring cellular necrosis. This work provides the basis for future imaging of HP ¹³C-fumarate metabolism in humans.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144064104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering clinical translation of OGSE diffusion MRI.","authors":"Ante Zhu, Eric S Michael, Hua Li, Tim Sprenger, Yihe Hua, Seung-Kyun Lee, Desmond Teck Beng Yeo, Jennifer A McNab, Franciszek Hennel, Els Fieremans, Dan Wu, Thomas K F Foo, Dmitry S Novikov","doi":"10.1002/mrm.30510","DOIUrl":"https://doi.org/10.1002/mrm.30510","url":null,"abstract":"<p><p>Oscillating gradient spin echo (OGSE) diffusion MRI (dMRI) can probe the diffusive dynamics on short time scales ≲10 ms, which translates into the sensitivity to tissue microstructure at the short length scales <math> <semantics><mrow><mo>≲</mo> <mn>10</mn> <mspace></mspace> <mi>μ</mi></mrow> <annotation>$$ lesssim 10kern0.3em upmu $$</annotation></semantics> </math> m. OGSE-based tissue microstructure imaging techniques able to characterize the cell diameter and cellular density have been established in pre-clinical studies. The unique image contrast of OGSE dMRI has been shown to differentiate tumor types and malignancies, enable early diagnosis of treatment effectiveness, and reveal different pathophysiology of lesions in stroke and neurological diseases. Recent innovations in high-performance gradient human MRI systems provide an opportunity to translate OGSE research findings in pre-clinical studies to human research and the clinic. The implementation of OGSE dMRI in human studies has the promise to advance our understanding of human brain microstructure and improve patient care. Compared to the clinical standard (pulsed gradient spin echo), engineering OGSE diffusion encoding for human imaging is more challenging. This review summarizes the impact of hardware and human biophysical safety considerations on the waveform design, imaging parameter space, and image quality of OGSE dMRI. Here we discuss the effects of the gradient amplitude, slew rate, peripheral nerve stimulation, cardiac stimulation, gradient driver, acoustic noise and mechanical vibration, eddy currents, gradient nonlinearity, concomitant gradient, motion and flow, and signal-to-noise ratio. We believe that targeted engineering for safe, high-quality, and reproducible imaging will enable the translation of OGSE dMRI techniques into the clinic.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144000921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}