Magnetic Resonance in Medicine最新文献

{"title":"Improving ungated steady-state cardiac perfusion using transition bands","authors":"Jason K. Mendes,&nbsp;Johnathan V. Le,&nbsp;Andrew E. Arai,&nbsp;Ravi Ranjan,&nbsp;Edward V. R. DiBella,&nbsp;Ganesh Adluru","doi":"10.1002/mrm.30467","DOIUrl":"10.1002/mrm.30467","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Although gated first-pass contrast-enhanced sequences are the clinical standard for cardiovascular MR perfusion, some patient conditions necessitate using ungated steady-state sequences. However, through-plane cardiac motion and blood flow into the left ventricle can disrupt the magnetization steady state of the tissue, and perfusion quantification based on a steady-state assumption will contain errors. The tissue magnetization steady-state disruption can be eliminated with a proposed sequence modification that simultaneously excites transition bands with no change in the sequence resolution or timing parameters.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Theory and Methods</h3>\u0000 \u0000 <p>The proposed sequence modification simultaneously excites two transition bands adjacent to the imaged region. The transition bands experience the same consistent excitation history as the imaged slices. Thus, any tissue that moves into an imaged slice location from a transition band location will not disrupt the magnetization steady state. Gradient dephasing and radiofrequency spoiling are used to null the transition band signal so that it does not contribute to the reconstructed images. Transition bands were added to a two-dimensional ungated steady-state radial FLASH (fast low-angle shot) sequence with simultaneous multiband imaging on a PRISMA 3T MRI scanner. Phantom, normal canine, and human subject data are presented.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Transition bands reduce the amount of tissue magnetization disruption to the steady state without adding artifacts to the imaged slices. Myocardial blood flow maps from a selected normal canine study and a normal human subject show good uniformity and consistency to literature values for all slices. Perfusion estimates with the proposed method also demonstrate good consistency with saturation-recovery methods commonly used for myocardial perfusion imaging.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>We have demonstrated that the proposed transition bands can reduce quantification errors resulting from blood flow into the left ventricle and through-plane cardiac and respiratory motion. There is no loss of image-acquisition efficiency, and temporal resolution is unchanged with this technique.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"94 1","pages":"199-214"},"PeriodicalIF":3.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30467","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143441389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using deep feature distances for evaluating the perceptual quality of MR image reconstructions","authors":"Philip M. Adamson,&nbsp;Arjun D. Desai,&nbsp;Jeffrey Dominic,&nbsp;Maya Varma,&nbsp;Christian Bluethgen,&nbsp;Jeff P. Wood,&nbsp;Ali B. Syed,&nbsp;Robert D. Boutin,&nbsp;Kathryn J. Stevens,&nbsp;Shreyas Vasanawala,&nbsp;John M. Pauly,&nbsp;Beliz Gunel,&nbsp;Akshay S. Chaudhari","doi":"10.1002/mrm.30437","DOIUrl":"10.1002/mrm.30437","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Commonly used MR image quality (IQ) metrics have poor concordance with radiologist-perceived diagnostic IQ. Here, we develop and explore deep feature distances (DFDs)—distances computed in a lower-dimensional feature space encoded by a convolutional neural network (CNN)—as improved perceptual IQ metrics for MR image reconstruction. We further explore the impact of distribution shifts between images in the DFD CNN encoder training data and the IQ metric evaluation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We compare commonly used IQ metrics (PSNR and SSIM) to two “out-of-domain” DFDs with encoders trained on natural images, an “in-domain” DFD trained on MR images alone, and two domain-adjacent DFDs trained on large medical imaging datasets. We additionally compare these with several state-of-the-art but less commonly reported IQ metrics, visual information fidelity (VIF), noise quality metric (NQM), and the high-frequency error norm (HFEN). IQ metric performance is assessed via correlations with five expert radiologist reader scores of perceived diagnostic IQ of various accelerated MR image reconstructions. We characterize the behavior of these IQ metrics under common distortions expected during image acquisition, including their sensitivity to acquisition noise.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>All DFDs and HFEN correlate more strongly with radiologist-perceived diagnostic IQ than SSIM, PSNR, and other state-of-the-art metrics, with correlations being comparable to radiologist inter-reader variability. Surprisingly, out-of-domain DFDs perform comparably to in-domain and domain-adjacent DFDs.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>A suite of IQ metrics, including DFDs and HFEN, should be used alongside commonly-reported IQ metrics for a more holistic evaluation of MR image reconstruction perceptual quality. We also observe that general vision encoders are capable of assessing visual IQ even for MR images.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"94 1","pages":"317-330"},"PeriodicalIF":3.0,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143374359","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":"Chemical shift and relaxation regularization improve the accuracy of 1H MR spectroscopy analysis","authors":"Martin Wilson","doi":"10.1002/mrm.30462","DOIUrl":"10.1002/mrm.30462","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Accurate analysis of metabolite levels from ¹H MRS data is a significant challenge, typically requiring the estimation of approximately 100 parameters from a single spectrum. Signal overlap, spectral noise, and common artifacts further complicate the analysis, leading to instability and reports of poor agreement between different analysis approaches. One inconsistently used method to improve analysis stability is known as regularization, where poorly determined parameters are partially constrained to take a predefined value. In this study, we examine how regularization of frequency and linewidth parameters influences analysis accuracy.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The accuracy of three MRS analysis methods was compared: (1) ABfit, (2) ABfit-reg, and (3) LCModel, where ABfit-reg is a modified version of ABfit incorporating regularization. Accuracy was assessed on synthetic MRS data generated with random variability in the frequency shift and linewidth parameters applied to each basis signal. Spectra (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>N</mi>\u0000 <mo>=</mo>\u0000 <mn>1000</mn>\u0000 </mrow>\u0000 <annotation>$$ N=1000 $$</annotation>\u0000 </semantics></math>) were generated across a range of SNR values (10, 30, 60, 100) to evaluate the impact of variable data quality.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Comparison between ABfit and ABfit-reg demonstrates a statistically significant (<i>p</i> &lt;  0.0005) improvement in accuracy associated with regularization for each SNR regime. An approximately 10% reduction in the mean squared metabolite errors was found for ABfit-reg compared to LCModel for SNR &gt;10 (<i>p</i> &lt;  0.0005). Furthermore, Bland-Altman analysis shows that incorporating regularization into ABfit enhances its agreement with LCModel.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Regularization is beneficial for MRS fitting and accurate characterization of the frequency and linewidth variability in vivo may yield further improvements.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 6","pages":"2287-2296"},"PeriodicalIF":3.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30462","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143123194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accurate and precise in vivo liver 3D T1 mapping at 3T","authors":"Gabriela Belsley,&nbsp;Ferenc E. Mózes,&nbsp;Damian J. Tyler,&nbsp;Matthew D. Robson,&nbsp;Elizabeth M. Tunnicliffe","doi":"10.1002/mrm.30448","DOIUrl":"10.1002/mrm.30448","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Purpose&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;To develop an accurate and precise liver 3D &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;T&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; mapping method using only scanner-agnostic sequences.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;While the spoiled gradient-recalled echo sequence is widely available on clinical scanners, variable flip angle &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;T&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; mapping methods based on this sequence provide biased &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;T&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; estimates, with the largest systematic error arising from &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;B&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {B}_1^{+} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; inhomogeneities. To correct for this, the flip angle was mapped using a 2D gradient-echo double-angle method approach. To correct for the confounding effect of fat on liver &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;T&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;B&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;/mrow&gt;\u0000 ","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 6","pages":"2331-2345"},"PeriodicalIF":3.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30448","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143123192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tissue-to-fluid water-exchange imaging using T2-selective saturation labeling","authors":"Manuel Taso,&nbsp;David C. Alsop","doi":"10.1002/mrm.30452","DOIUrl":"10.1002/mrm.30452","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To propose and implement a new method to study water exchange between brain tissue and fluids.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>An MLEV T₂-preparation combined with a cerebrospinal fluid (CSF) nulling inversion recovery was implemented in combination with an ultralong–echo time (TE) three-dimensional fast spin-echo readout. To handle systematic imperfections and isolate the exchange signal, T₂-prepared images were subtracted from one of two control images. The first control turned off the T₂ preparation and adjusted inversion timing to correct for relaxation. The second control used the same T₂ preparation but shifted in time. Preparations were implemented on a 3T scanner and tested in 14 healthy volunteers. We evaluated the exchange signal magnitude and distribution, as well as robustness against B₁ imperfection and intrasession reproducibility. We also compared the signal to that measured with ultralong-TE arterial spin labeling, another suggested marker of water exchange.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Initial experiments using the T₂-preparation off control demonstrated a detectable exchange signal especially in the choroid plexus, but with substantial residual signal in CSF spaces, suggesting imperfect subtraction of non-exchanging spins. When using the time shifted control, we greatly reduced subtraction errors. Signal was consistently measured in the choroid plexus and at the boundaries between cortex and CSF with much higher signal-to-noise ratio and spatial resolution than ultralong-TE arterial spin labeling.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The measured water exchange distribution appears consistent with the localization of aquaporin channels at the CSF boundary. Because aquaporin activity may reflect CSF production and glymphatic clearance, our method may provide a noninvasive marker of these functions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"94 1","pages":"150-165"},"PeriodicalIF":3.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143123196","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 60-channel high-density flexible receive array for pediatric abdominal MRI","authors":"Wonje Lee,&nbsp;Yunjeong Stickle,&nbsp;Clyve Follante,&nbsp;Thomas Grafendorfer,&nbsp;Taeyoung Yang,&nbsp;Fraser Robb,&nbsp;Fan Zhang,&nbsp;John Pauly,&nbsp;Greig Scott,&nbsp;Shreyas Vasanawala,&nbsp;Ali Syed","doi":"10.1002/mrm.30456","DOIUrl":"10.1002/mrm.30456","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Conventional MRI coils offer suboptimal parallel imaging performance for young children. Our goal was to enhance imaging acceleration by dedicated, flexible high-density coil design for pediatric patients at 3T.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We design, construct, and evaluate a highly flexible small loop array. Key design notes include full-wave simulation and analysis of the dual-turn loop, miniature feedboard allocation at the loop center, and cable management. Phantom experiments and adult and pediatric volunteer case studies were conducted to evaluate the small loop array imaging performance compared to commercial reference coils.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Dual-turn loop configuration forms higher preamp decoupling impedance than the same size single-turn, supporting a flexible form factor that requires a wide range of critical overlap. Both phantom and in-vivo studies demonstrate superior parallel imaging performance or high spatial resolution imaging using the small loop, compared to commercial reference coils.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>A dedicated high-density coil array with a minimum inter-component interference layout design allows a flexible form factor and higher imaging accelerations. Phantom and in-vivo volunteer case studies demonstrate promising results in improving efficiency for pediatric patients in routine clinical imaging procedures.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 6","pages":"2655-2666"},"PeriodicalIF":3.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143123190","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":"MPRAGElike: A novel approach to generate T1w images from multi-contrast gradient echo images for brain segmentation","authors":"Marc-Antoine Fortin,&nbsp;Rüdiger Stirnberg,&nbsp;Yannik Völzke,&nbsp;Laurent Lamalle,&nbsp;Eberhard Pracht,&nbsp;Daniel Löwen,&nbsp;Tony Stöcker,&nbsp;Pål Erik Goa","doi":"10.1002/mrm.30453","DOIUrl":"10.1002/mrm.30453","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Brain segmentation and multi-parameter mapping (MPM) are important steps in neurodegenerative disease characterization. However, acquiring both a high-resolution T1w sequence like MPRAGE (standard input to brain segmentation) and an MPM in the same neuroimaging protocol increases scan time and patient discomfort, making it difficult to combine both in clinical examinations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A novel approach to synthesize T1w images from MPM images, named MPRAGE_<i>like</i>, is proposed and compared to the standard technique used to produce synthetic MPRAGE images (<i>syn</i>MPRAGE). Twenty-three healthy subjects were scanned with the same imaging protocol at three different 7T sites using universal parallel transmit RF pulses. SNR, CNR, and automatic brain segmentation results from both MPRAGE_<i>like</i> and <i>syn</i>MPRAGE were compared against an acquired MPRAGE.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The proposed MPRAGE_<i>like</i> technique produced higher SNR values than <i>syn</i>MPRAGE for all regions evaluated while also having higher CNR values for subcortical structures. MPRAGE was still the image with the highest SNR values overall. For automatic brain segmentation, MPRAGE_<i>like</i> outperformed <i>syn</i>MPRAGE when compared to MPRAGE (median Dice Similarity Coefficient of 0.90 versus 0.29 and Average Asymmetric Surface Distance of 0.33 versus 2.93 mm, respectively), in addition to being simple, flexible, and considerably more robust to low image quality than <i>syn</i>MPRAGE.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The MPRAGE_<i>like</i> technique can provide a better and more reliable alternative to <i>syn</i>MPRAGE as a substitute for MPRAGE, especially when automatic brain segmentation is of interest and scan time is limited.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"94 1","pages":"134-149"},"PeriodicalIF":3.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30453","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143123195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptable, wearable, and stretchable coils: A review","authors":"Thejas Vishnu Ramesh,&nbsp;Folk W. Narongrit,&nbsp;Joseph V. Rispoli","doi":"10.1002/mrm.30428","DOIUrl":"10.1002/mrm.30428","url":null,"abstract":"<p>Over the last four decades, there have been various evolutions in the design and development of coils, from volume coils to the recent introduction of wireless receive arrays. A recent aim has been to develop coils that can closely conform to the anatomy of interest to increase the acquired signal. This goal has given rise to designs ranging from adaptable transmit coils to on-body stretchable receive arrays made using fabric or elastomer substrates. This review covers the design, fabrication details, experimental setup, and MRI results of adaptable, wearable, and stretchable MRI coils. The active and passive automatic tuning and matching strategies are examined with respect to mitigating signal-to-noise ratio reduction when the coil form is altered. A brief discussion of wireless MRI coils, which provide a solution to overcome the cabling issues associated with MRI coil development, is also included. The adaptable, wearable, and stretchable coils and various coil tuning techniques represent innovative radiofrequency coil solutions that pave the way for next-generation MRI hardware development.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 5","pages":"2186-2208"},"PeriodicalIF":3.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30428","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143123193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel multifrequency-tuned transceiver array for human-brain 31P-MRSI at 7 T","authors":"Xin Li,&nbsp;Xiao-Hong Zhu,&nbsp;Xiao-Liang Zhang,&nbsp;Matt Waks,&nbsp;Wei Chen","doi":"10.1002/mrm.30449","DOIUrl":"10.1002/mrm.30449","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Phosphorus-31 (³¹P) MR spectroscopy imaging (MRSI) at 7 T is a powerful tool for investigating high-energy phosphate metabolism in human brains with significantly improved signal-to-noise ratio (SNR) and spectral resolution. However, this imaging technique requires dual-frequency radiofrequency coil for performing brain anatomical imaging and B₀ shimming at proton (¹H) operation frequency, and ³¹P MRSI at lower operation frequency. Herein, we introduce a novel ³¹P-¹H dual-frequency radiofrequency coil design using a double-tuned and double-matched (DODO) coil that does not require complex circuitry or two coil layers and exhibits similar imaging performance as to single-frequency control coils for both ³¹P and ¹H imaging operations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We constructed an eight-element ³¹P-¹H dual-frequency DODO transceiver array and compared its performance with a quadrature-driven dual-tuned eight-element ³¹P and eight-element ¹H transverse electromagnetic volume coil for both phantom and in vivo human-brain ³¹P-MRSI studies at 7 T.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The DODO transceiver array achieved high spatiotemporal resolution ³¹P MRSI with 2.5-cc nominal voxel size and 22-min scan time covering the entire human brain, showing excellent SNR for mapping cerebral phosphorous metabolites such as phosphocreatine, adenosine triphosphate, and other low-concentration metabolites. Compared with the transverse electromagnetic volume coil, the DODO array demonstrated large improvements in ³¹P-MRSI SNR in both phantom and human brain studies, with over 5-fold SNR gain in peripheral regions and over 2-fold SNR gain in central brain regions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>This simple and cost-effective array design and excellent performance can greatly benefit human-brain ³¹P-MRSI applications at 7 T.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 6","pages":"2640-2654"},"PeriodicalIF":3.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30449","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143123191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Romer-EPTI: Rotating-view motion-robust super-resolution EPTI for SNR-efficient distortion-free in-vivo mesoscale diffusion MRI and microstructure imaging","authors":"","doi":"10.1002/mrm.30457","DOIUrl":"https://doi.org/10.1002/mrm.30457","url":null,"abstract":"","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 4","pages":"C1"},"PeriodicalIF":3.0,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30457","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}