Magnetic Resonance in Medicine最新文献

{"title":"High-resolution and high-fidelity diffusion tensor imaging of cervical spinal cord using 3D reduced-FOV multiplexed sensitivity encoding (3D-rFOV-MUSE)","authors":"","doi":"10.1002/mrm.30558","DOIUrl":"https://doi.org/10.1002/mrm.30558","url":null,"abstract":"","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"94 1","pages":"C1"},"PeriodicalIF":3.0,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30558","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871710","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":"MR-Cavitation Dynamics Encoded (MR-CaDE) imaging.","authors":"Dinank Gupta, Tarana P Kaovasia, Steven P Allen, Jon-Fredrik Nielsen, Timothy L Hall, Zhen Xu, Douglas C Noll","doi":"10.1002/mrm.30517","DOIUrl":"https://doi.org/10.1002/mrm.30517","url":null,"abstract":"<p><strong>Purpose: </strong>To develop methods for dynamic cavitation monitoring of a non-invasive ultrasound mechanical ablation technology (histotripsy) in the brain and test its feasibility for treatment monitoring in ex-vivo brain in a human MRI scanner.</p><p><strong>Methods: </strong>A Gradient Echo (GRE) pulse sequence was modified with a bipolar gradient to perform MR-Cavitation Dynamics Encoded (MR-CaDE) imaging. Cavitation generated by histotripsy sonication was monitored using MR-CaDE imaging in ex-vivo bovine brain tissues on a <math> <semantics><mrow><mn>3</mn> <mi>T</mi></mrow> <annotation>$$ 3mathrm{T} $$</annotation></semantics> </math> human MRI scanner. Bipolar gradients with a b-value of <math> <semantics><mrow><mtext>b</mtext> <mo>=</mo> <mn>50</mn> <mi>s</mi> <mo>/</mo> <msup><mrow><mtext>mm</mtext></mrow> <mrow><mn>2</mn></mrow> </msup> </mrow> <annotation>$$ mathrm{b}=50mathrm{s}/{mathrm{mm}}^2 $$</annotation></semantics> </math> and smaller were used while a trigger was sent from the MR scanner to the histotripsy driving electronics. MR acquisition was performed with TE/TR: <math> <semantics><mrow><mn>19</mn> <mspace></mspace> <mtext>ms</mtext> <mo>/</mo> <mn>100</mn> <mspace></mspace> <mtext>ms</mtext></mrow> <annotation>$$ 19kern.2em mathrm{ms}/100kern.2em mathrm{ms} $$</annotation></semantics> </math> with 1.5-cycle histotripsy sonications at 1 pulse/TR. Feasibility of treatment monitoring was also evaluated for histotripsy through an excised human skull.</p><p><strong>Results: </strong>The MR-CaDE imaging pulse sequence was used to perform treatment monitoring of cavitation generated by histotripsy with a temporal resolution of <math> <semantics><mrow><mn>0.5</mn> <mspace></mspace> <mtext>s</mtext></mrow> <annotation>$$ 0.5kern.2em mathrm{s} $$</annotation></semantics> </math> with a spiral readout. A decrease in the image magnitude and an increase in the phase was observed with an increasing number of histotripsy sonications. The magnitude image exhibited a peak loss of 50%, and the phase image exhibited a maximum increase of 0.64rad compared to the baseline signal level in the brain. The peak signal magnitude change aligned well with the array's geometrical focus, and the post-histotripsy lesion visualized on a DWI ( <math> <semantics><mrow><mtext>b</mtext> <mo>=</mo> <mn>1000</mn> <mspace></mspace> <mtext>s/mm</mtext> <msup><mrow><mo> </mo></mrow> <mrow><mn>2</mn></mrow> </msup> </mrow> <annotation>$$ mathrm{b}=1000kern.2em mathrm{s}/{mathrm{mm}}^2 $$</annotation></semantics> </math> ) scan with an alignment error of <math> <semantics><mrow><mn>0.71</mn> <mspace></mspace> <mtext>mm</mtext></mrow> <annotation>$$ 0.71kern.2em mathrm{mm} $$</annotation></semantics> </math> and <math> <semantics><mrow><mn>1.25</mn> <mspace></mspace> <mtext>mm</mtext></mrow> <annotation>$$ 1.25kern.2em mathrm{mm} $$</annotation></semantics> </math> in the transverse and longitudinal axes, respectively. The area of the histotripsy respon","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803425","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":"Cerebrovascular reactivity differences in healthy cerebral gray and white matter.","authors":"Harrison T Levine, Julien Poublanc, Ece Su Sayin, James Duffin, Olivia Sobczyk, Joseph A Fisher, David J Mikulis","doi":"10.1002/mrm.30481","DOIUrl":"https://doi.org/10.1002/mrm.30481","url":null,"abstract":"<p><strong>Purpose: </strong>To quantify the speed and magnitude of cerebrovascular reactivity (CVR) metrics in hemispheric gray and white matter.</p><p><strong>Methods: </strong>A standardized isoxic hypercapnic cerebrovascular stimulus was administered using an automated arterial gas targeting system while monitoring blood oxygen-level dependent MRI. The correlation between the blood oxygen-level dependent signal and end-tidal partial pressure of carbon dioxide were measured over time, enabling calculation of CVR metrics including the magnitude and speed (TAU) of the vascular response. The average CVR magnitude and TAU metrics were obtained from 50 healthy participants in the following regions: anterior, middle, and posterior cerebral artery (ACA, MCA, PCA) territory gray matter, the striatum, the thalamus, and hemispheric white matter.</p><p><strong>Results: </strong>The average MCA CVR is 17.39% greater than ACA CVR (95% confidence interval [CI]: 3.50, 31.28), and the average PCA CVR is 43.03% (95% CI: 29.13, 56.91) and 21.84% (95% CI: 10.00, 33.68) greater than ACA CVR and MCA CVR, respectively. The average TAU in the six regions were ACA = 29.5 ± 9.7 s, MCA = 29.4 ± 8.7 s, PCA = 28.6 ± 10.2 s, striatum = 30.5 ± 8.9 s, thalamus = 25.7 ± 10.0 s, and white matter = 46.3 ± 6.9 s. TAU was similar among all regions investigated except for the white matter, which was approximately 60% slower than the other regions (p < 0.0001).</p><p><strong>Conclusion: </strong>In healthy individuals, there are significant differences in CVR metrics among the ACA, MCA, PCA gray-matter vascular territories, thalamus, striatum, and hemispheric white matter. Future investigations of CVR should consider the presence of regional variability in CVR metrics when comparing healthy and diseased populations.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143795811","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":"Accelerated multi-shell diffusion MRI with Gaussian process estimated reconstruction of multi-band imaging.","authors":"Xinyu Ye, Karla L Miller, Wenchuan Wu","doi":"10.1002/mrm.30518","DOIUrl":"https://doi.org/10.1002/mrm.30518","url":null,"abstract":"<p><strong>Purpose: </strong>This work aims to propose a robust reconstruction method exploiting shared information across shells to increase the acquisition speed of multi-shell diffusion-weighted MRI (dMRI), enabling rapid tissue microstructure mapping.</p><p><strong>Theory and methods: </strong>Local q-space points share similar information. Gaussian Process can exploit the q-space smoothness in a data-driven way and provide q-space signal estimation based on the signals from a q-space neighborhood. The Diffusion Acceleration with Gaussian process Estimated Reconstruction (DAGER) method uses the signal estimation from Gaussian process as a prior in a joint k-q reconstruction and improves image quality under high acceleration factors compared to conventional (k-only) reconstruction. In this work, we extend the DAGER method by introducing a multi-shell covariance function and correcting for Rician noise distribution in magnitude data when fitting the Gaussian process model. The method was evaluated with both simulation and in vivo data.</p><p><strong>Results: </strong>Simulated and in-vivo results demonstrate that the proposed method can significantly improve the image quality of reconstructed dMRI data with high acceleration both in-plane and slice-wise, achieving a total acceleration factor of 12. The improvement of image quality allows more robust diffusion model fitting compared to conventional reconstruction methods, enabling advanced multi-shell diffusion analysis within much shorter scan time.</p><p><strong>Conclusion: </strong>The proposed method enables highly accelerated dMRI which can shorten the scan time of multi-shell dMRI without sacrificing quality compared to conventional practice. This may facilitate a wider application of advanced dMRI models in basic and clinical neuroscience.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143795809","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":"Time-course manganese chloride biodistribution and manganese-induced MRI contrast in mouse organs.","authors":"Keyu Zhuang, Kyle D W Vollett, Minbo Hou, Yan Chang, Hai-Ling Margaret Cheng","doi":"10.1002/mrm.30522","DOIUrl":"https://doi.org/10.1002/mrm.30522","url":null,"abstract":"<p><strong>Purpose: </strong>To optimize manganese-enhanced MRI (MEMRI) in mice by profiling the time-course biodistribution and associated T₁ contrast enhancement of MnCl₂ injected subcutaneously to avoid abrupt spikes in blood manganese levels.</p><p><strong>Methods: </strong>Manganese (Mn) biodistribution and Mn-induced T₁ contrast in healthy female adult CD-1 mice were investigated at two doses (0.2 and 0.4 mmol/kg) and 2, 6, and 24 h following injection. T₁-weighted MRI and T₁ mapping were performed at 3 T. The heart, liver, kidneys, leg skeletal muscle, lungs, spleen, and blood were collected and quantified for Mn content using inductively coupled plasma atomic emission spectroscopy. Toxicity was assessed on hematoxylin and eosin histological sections of the heart, liver, kidneys, lungs, and spleen.</p><p><strong>Results: </strong>An injection dose of 0.2 mmol/kg produced significant T₁ enhancement in the heart, liver, and kidneys, reaching peak enhancement at 2 h following injection. Doubling the dose did not produce further T₁ enhancement in the heart, liver, nor kidneys. Skeletal muscle reached peak enhancement at 24 h and required an injection dose of 0.4 mmol/kg. Inductively coupled plasma atomic emission spectroscopy-measured tissue-level Mn content corroborated MRI results and revealed peak Mn concentration also at 2 h following injection in the spleen, lungs, and blood. No organ toxicity was observed at either dose on histology.</p><p><strong>Conclusion: </strong>The subcutaneous injection route provided substantial T₁ contrast enhancement in all tissues investigated, without toxicity at the maximum dose of 0.4 mmol/kg tested. However, the injection dose and optimal postinjection imaging interval must be tailored to the organ of interest.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143795813","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":"3D joint T1/T1ρ/T2 mapping and water-fat imaging for contrast-agent free myocardial tissue characterization at 1.5T","authors":"","doi":"10.1002/mrm.30526","DOIUrl":"https://doi.org/10.1002/mrm.30526","url":null,"abstract":"","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 6","pages":"C1"},"PeriodicalIF":3.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30526","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143778260","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":"The effect of concomitant gradient fields on MRI with long readout radial-based trajectories.","authors":"Michael A Malmberg, Henrik Odéen, Seong-Eun Kim, Dennis L Parker","doi":"10.1002/mrm.30521","DOIUrl":"https://doi.org/10.1002/mrm.30521","url":null,"abstract":"<p><strong>Purpose: </strong>To demonstrate in theory and practice that concomitant gradient fields (CCGF) can produce substantial imaging artifacts in scans utilizing radial-based trajectories and to provide strategies to mitigate these effects.</p><p><strong>Theory and methods: </strong>A framework was developed to relate concomitant gradient phase to local point-spread-function distortion, which was used to evaluate the effects of trajectory choice and imaging parameters on imaging artifacts. Gradient waveforms for realistic imaging scenarios were simulated and used to determine the effect of CCGF. Phantom and in vivo experiments were performed at 3 T to validate theoretical predictions.</p><p><strong>Results: </strong>CCGF-induced artifacts are shown to be produced in part by increased variation in concomitant gradient phase across view angles. This is shown to increase with increasing gradient strength and contrast index in radial-based trajectories. Phase variation across view angles and the associated artifacts are shown to be effectively diminished via azimuthal rotation down the echo train in the helical EPI and helical stack-of-stars trajectories introduced in this work.</p><p><strong>Conclusions: </strong>Concomitant gradient fields are found to produce non-negligible imaging artifacts in long readout radial-based trajectories due to variations in the associated phase accrual across view angles. Azimuthal rotation of the readout direction down the echo train, as implemented in the helical EPI and helical stack-of-stars trajectories, is shown in simulations, phantoms, and in vivo to mitigate these effects. Substantial improvement is seen in cases of nonaxial imaging with multiple contrasts, quickly varying B₀ inhomogeneity, and/or high gradient amplitudes.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143780413","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":"Short-term gradient imperfections in high-resolution EPI lead to Fuzzy Ripple artifacts.","authors":"Laurentius Renzo Huber, Rüdiger Stirnberg, A Tyler Morgan, David A Feinberg, Philipp Ehses, Lasse Knudsen, Omer Faruk Gulban, Kenshu Koiso, Isabel Gephart, Stephanie Swegle, Susan G Wardle, Andrew S Persichetti, Alexander J S Beckett, Tony Stöcker, Nicolas Boulant, Benedikt A Poser, Peter A Bandettini","doi":"10.1002/mrm.30489","DOIUrl":"https://doi.org/10.1002/mrm.30489","url":null,"abstract":"<p><strong>Purpose: </strong>High-resolution fMRI is a rapidly growing research field focused on capturing functional signal changes across cortical layers. However, the data acquisition is limited by low spatial frequency EPI artifacts; termed here as Fuzzy Ripples. These artifacts limit the practical applicability of acquisition protocols with higher spatial resolution, faster acquisition speed, and they challenge imaging in inferior regions of the brain.</p><p><strong>Methods: </strong>We characterize Fuzzy Ripple artifacts across commonly used sequences and distinguish them from conventional EPI Nyquist ghosts and off-resonance effects. To investigate their origin, we employ dual-polarity readouts.</p><p><strong>Results: </strong>Our findings indicate that Fuzzy Ripples are primarily caused by readout-specific imperfections in k-space trajectories, which can be exacerbated by short-term eddy current, and by inductive coupling between third-order shims and readout gradients. We also find that these artifacts can be mitigated through complex-valued averaging of dual-polarity EPI or by disconnecting the third-order shim coils.</p><p><strong>Conclusion: </strong>The proposed mitigation strategies allow overcoming current limitations in layer-fMRI protocols: Achieving resolutions beyond 0.8 mm is feasible, and even at 3T, we achieved 0.53 mm voxel functional connectivity mapping. Sub-millimeter sampling acceleration can be increased to allow sub-second TRs and laminar whole brain protocols with up to GRAPPA 8. Sub-millimeter fMRI is achievable in lower brain areas, including the cerebellum.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772737","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":"<ArticleTitle xmlns:ns0=\"http://www.w3.org/1998/Math/MathML\">Electrical properties based <ns0:math> <ns0:mrow><ns0:msubsup><ns0:mi>B</ns0:mi> <ns0:mn>1</ns0:mn> <ns0:mo>+</ns0:mo></ns0:msubsup> </ns0:mrow> </ns0:math> prediction for electrical properties tomography reconstruction evaluation.","authors":"Thierry G Meerbothe, Kyu-Jin Jung, Chuanjiang Cui, Dong-Hyun Kim, Cornelis A T van den Berg, Stefano Mandija","doi":"10.1002/mrm.30520","DOIUrl":"https://doi.org/10.1002/mrm.30520","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Purpose: &lt;/strong&gt;In MR electrical properties tomography (EPT), conductivity and permittivity are reconstructed from MR measurements. However, depending on the reconstruction method, reconstructed electrical properties (EPs) show large variability in vivo, reducing confidence in the reconstructed values for clinical application in practice. To overcome this problem we present a method to evaluate the reconstructed EPs using a physics-based &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;B&lt;/mi&gt; &lt;mn&gt;1&lt;/mn&gt; &lt;mo&gt;+&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; estimation model.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;A physics-based method using a finite difference based recurrent relation is used to estimate the &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;B&lt;/mi&gt; &lt;mn&gt;1&lt;/mn&gt; &lt;mo&gt;+&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; field from a set of given EPs and the boundary of the measured &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;B&lt;/mi&gt; &lt;mn&gt;1&lt;/mn&gt; &lt;mo&gt;+&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; field. Reconstructed EPs can be evaluated by comparing the estimated &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;B&lt;/mi&gt; &lt;mn&gt;1&lt;/mn&gt; &lt;mo&gt;+&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; field with the measured &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;B&lt;/mi&gt; &lt;mn&gt;1&lt;/mn&gt; &lt;mo&gt;+&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; field. The method was first validated in simulations and afterward tested using MRI data from phantoms and in vivo.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;The simulation experiments show that the &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;B&lt;/mi&gt; &lt;mn&gt;1&lt;/mn&gt; &lt;mo&gt;+&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; field can be accurately estimated, within 90 s for a typical brain at 1 mm&lt;sup&gt;3&lt;/sup&gt; isotropic resolution, when correct EPs are used as input. When incorrect EPs are used as input the estimated &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;B&lt;/mi&gt; &lt;mn&gt;1&lt;/mn&gt; &lt;mo&gt;+&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; fields shows differences with the measured &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;B&lt;/mi&gt; &lt;mn&gt;1&lt;/mn&gt; &lt;mo&gt;+&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; fields. These differences directly correspond to the errors in the underlying EPs, enabling detection of errors in the reconstructions. The results obtained in MRI experiments using phantoms and in vivo show the applicability of the method in practice.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;With the proposed method, &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;B&lt;/mi&gt; &lt;mn&gt;1&lt;/mn&gt; &lt;mo&gt;+&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; fields can be accurately estimated from EPs. This approach can be used to evaluate EPT reconstructions and conseq","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772731","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":"Open-source implementation of X-nuclear sequences using the Pulseq framework.","authors":"Xiaoxi Liu, Di Cui, Peder E Z Larson, Dirk Mayer, Andreas Korzowski, Jon-Fredrik Nielsen, Rolf F Schulte, Changhua Mu, Lucas Carvajal, Duan Xu, Jeremy W Gordon, Daniel B Vigneron, Robert R Flavell, Zhen J Wang","doi":"10.1002/mrm.30509","DOIUrl":"https://doi.org/10.1002/mrm.30509","url":null,"abstract":"<p><strong>Purpose: </strong>Create vendor-neutral modular sequences for X-nuclear acquisitions and build an X-nuclear-enabled Pulseq interpreter for GE (GE HealthCare, Waukesha, WI) scanners.</p><p><strong>Methods: </strong>We designed a modular 2D gradient echo spiral sequence to support several sequence formats and a modular metabolite-specific 3D balanced steady-state free precession sequence for hyperpolarized (HP) carbon-13 (¹³C) MRI. In addition, we developed a new Pulseq interpreter for GE scanners, named TOPPE MNS (TOPPE Multi-Nuclear Spectroscopy), to implement X-nuclear acquisitions capabilities. We evaluated TOPPE MNS and the modular sequences through phantom studies using phosphorus-31 (³¹P), hydrogen-2 (²H), and ¹³C coils, and in vivo studies including a human brain deuterium metabolic imaging study at natural abundance, HP ¹³C animal studies, and human renal studies.</p><p><strong>Results: </strong>Data from the ¹³C phantom showed the accuracy of designed modular sequences and consistent performance with the product sequences. ³¹P, ²H, and ¹³C phantom studies and a multi-vendor/multi-version ¹³C phantom study showed accurate excitation and spatial encoding functionalities. A ²H-MRS brain volunteer study, HP [1-¹³C]pyruvate animal study, and human renal study showed good image quality with SNR comparable to those reported in the published literature. These results demonstrated the reproducibility of the TOPPE MNS GE interpreter and modular spiral sequences.</p><p><strong>Conclusion: </strong>We have designed a modular 2D gradient echo spiral sequence supporting several sequence formats and a modular metabolic-specific 3D balanced steady-state free precession sequence for ¹³C acquisition, as well as developed a GE interpreter with X-nucleus capabilities. Our work paves the way for future multi-site studies with acquisitions for X-nuclei across MRI vendors and software versions.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772733","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}