Magnetic Resonance in Medicine最新文献

{"title":"Free-breathing phase-sensitive inversion recovery T₁-weighted imaging for improved visualization of focal liver lesions.","authors":"Yavuz Muslu, Julius F Heidenreich, Jan-Peter Grunz, Ty A Cashen, Sagar Mandava, Ali Pirasteh, Diego Hernando, Scott B Reeder","doi":"10.1002/mrm.70042","DOIUrl":"https://doi.org/10.1002/mrm.70042","url":null,"abstract":"<p><strong>Purpose: </strong>Gadoxetic acid-enhanced hepatobiliary phase T₁-weighted (T₁w) MRI is effective for the detection of focal liver lesions but lacks sufficient T₁ contrast to distinguish benign from malignant lesions. Although the addition of T₂, diffusion, and dynamic contrast-enhanced T₁w imaging improves lesion characterization, these methods often do not provide adequate spatial resolution to identify subcentimeter lesions. This work proposes a high-resolution, volumetric, free-breathing liver MRI method that produces colocalized fat-suppressed, variable T₁w images from a single acquisition, thereby improving both lesion detection and characterization.</p><p><strong>Theory and methods: </strong>This method combines stack-of-stars radial sampling, magnetization preparation, and chemical shift encoding to enable free-breathing, T₁w imaging with water/fat separation. A model-based image reconstruction algorithm reconstructs images from highly undersampled k-space data. Pseudo-T₁ relaxation maps are calculated from the variable T₁w images. The feasibility of this method was investigated in patients undergoing clinical contrast-enhanced MRI examinations for detection and characterization of focal liver lesions at both 1.5 and 3.0 T. An expert reader study was conducted to evaluate the method's performance, compared with the hepatobiliary phase-navigated T₁w MRI based on image quality and lesion conspicuity.</p><p><strong>Results: </strong>Expert readers found that at shorter inversion times (TIs) (˜500 ms), the proposed method had superior liver-lesion contrast for characterizing simple cysts and metastases, compared with navigated T₁w images.</p><p><strong>Conclusion: </strong>The proposed method produces colocalized fat-suppressed, variable T₁w images from a single acquisition that may improve focal liver lesion detection and characterization.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145023593","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":"Simultaneous in vivo detection of spectrally resolved glutamate, glutamine, and glutathione at 3 T with NAA-aspartyl editing and echo-time optimization.","authors":"Li An, Sungtak Hong, Tara Turon, Adriana J Pavletic, Christopher S Johnson, Jun Shen","doi":"10.1002/mrm.70076","DOIUrl":"https://doi.org/10.1002/mrm.70076","url":null,"abstract":"<p><strong>Purpose: </strong>To achieve spectrally resolved in vivo detection of glutamate, glutamine, and glutathione at 3 T.</p><p><strong>Methods: </strong>Difference editing of N-acetylaspartate CH₂ protons (NAA-CH₂) combined with a new echo-time (TE) optimization approach is introduced. Difference editing was used to detect NAA-CH₂ independently of NAA-CH₃, thereby eliminating systematic errors arising from constrained fitting of the entire NAA molecule. Numerical optimization of TE and TE₁ minimized interference from highly dominant glutamate in glutamine detection in the ON/OFF sum spectrum. In vivo data were acquired from 6 healthy participants, including 2 who underwent oral administration of [U-¹³C]glucose.</p><p><strong>Results: </strong>The NAA-aspartyl-edited, cleaned-up in vivo spectrum showed distinct separation of glutamate, glutamine, and glutathione peaks at 3 T, facilitating spectral quantification and clinical applications. The post-¹³C proton MR-spectroscopy spectra clearly demonstrated the dynamic ¹³C-labeling of glutamate C4 following oral [U-¹³C]glucose intake.</p><p><strong>Conclusion: </strong>This technique enables simultaneous spectral resolution of glutamate, glutamine, and glutathione peaks at 3 T using difference editing of NAA-CH₂ and an optimized TE of 85 ms. Additionally, it demonstrates, for the first time, the feasibility of measuring ¹³C turnovers of spectrally resolved glutamate at 3 T with the high sensitivity and spatial resolution of proton MR spectroscopy.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145023552","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":"Outlook on zero/ultrashort echo time techniques in functional MRI.","authors":"Silvia Mangia, Shalom Michaeli, Olli Gröhn","doi":"10.1002/mrm.70065","DOIUrl":"https://doi.org/10.1002/mrm.70065","url":null,"abstract":"<p><p>Since its introduction more than 30 years ago, the blood oxygenation level-dependent (BOLD) contrast remains the most widely used method for functional MRI (fMRI) in humans and animal models. The BOLD contrast is typically acquired with echo planar imaging (EPI) to obtain sensitization of the signal during the echo time (TE) to dynamic changes in deoxyhemoglobin content, while achieving high spatiotemporal resolution and full brain coverage. However, EPI-based fMRI also faces multiple shortcomings, including sensitivity to body motion, susceptibility-related signal dropouts, interference with multimodal sensors, and loud acoustic noise. Here we provide a succinct overview and outlook of alternative strategies for fMRI relying on free induction decay-based techniques, which, by using zero/ultrashort TE, inherently solve most of these challenges. Such approaches are receiving increasing attention in the field of fMRI, motivated by initial findings in humans and animal models in which robust functional contrast was obtained despite the absence of an echo, primarily via sensitization to inflowing blood. We therefore discuss the benefits and current shortcomings of zero/ultrashortTE fMRI versus conventional EPI-based fMRI, the opportunities for enabling fMRI designs that are challenging with EPI-based approaches, and the state of progress toward use in clinical settings. Overall, zero/ultrashortTE fMRI is predicted to become a powerful new tool for basic, clinical, and preclinical research, especially for applications at ultrahigh magnetic fields, studies in awake animals, multimodal imaging, investigations requiring minimization of scanning noise, and fMRI beyond the brain.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145006332","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":"Sampling of non-Gaussian Ensemble Average Propagators for the simulation of diffusion magnetic resonance images.","authors":"Justino R Rodríguez-Galván, Pablo Villacorta-Aylagas, Susana Merino-Caviedes, Federico Simmross-Wattenberg, Carlos Castillo-Passi, Pablo Irarrazaval, Antonio Tristán-Vega, Carlos Alberola-López","doi":"10.1002/mrm.70080","DOIUrl":"https://doi.org/10.1002/mrm.70080","url":null,"abstract":"<p><strong>Purpose: </strong>(a) To design a methodology for drawing random samples of any Ensemble Average Propagator (EAP) (b) to modify the KomaMRI simulator to accommodate them as realistic spin movements to simulate diffusion MRI (dMRI) and (c) to compare these simulations with those based on the Diffusion Tensor (DT) model.</p><p><strong>Theory and methods: </strong>The rejection method is used for random sampling of EAPs: starting from a probability law that is easily sampled, and whose density function wraps the target EAP, samples are accepted when they lie inside the targeted region. This is used to sample the EAP as described by Mean Apparent Propagator MRI (MAP-MRI) and in Spherical Convolution (SC) based on Spherical Harmonics (SH). With this methodology, MAP-MRI and SC representations are calculated over in-vitro pig hearts images, and a simulation of a pulsed-gradient spin echo (PGSE) dMRI sequence inside the myocardial wall is undertaken with the KomaMRI simulator.</p><p><strong>Results: </strong>MAP-MRI shows better agreement with the actual acquisition than conventional DT-based simulations, in terms of Mean Squared Errors and correlation with improvements up to 1.7 % for the former and 2.2 % for the latter.</p><p><strong>Conclusion: </strong>dMRI sequences can be simulated accurately (yet, efficiently) if phantoms with a proper per-spin description of the diffusion process are made available. Moreover, our findings suggest that the study of non-Gaussian diffusion of the heart might be feasible, at least in vitro.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145006365","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":"Abdominal simultaneous 3D water T₁ and T₂ mapping using a free-breathing Cartesian acquisition with spiral profile ordering.","authors":"Jonathan Stelter, Kilian Weiss, Lisa Steinhelfer, Jakob Meineke, Weitong Zhang, Bernhard Kainz, Rickmer F Braren, Dimitrios C Karampinos","doi":"10.1002/mrm.70040","DOIUrl":"https://doi.org/10.1002/mrm.70040","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Purpose: &lt;/strong&gt;To develop a method for abdominal simultaneous 3D water &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; ( &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mi&gt;w&lt;/mi&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ mathrm{w}{T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; ) and &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_2 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; ( &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mi&gt;w&lt;/mi&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ mathrm{w}{T}_2 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; ) mapping with isotropic resolution using a free-breathing Cartesian acquisition with spiral profile ordering (CASPR) at 3 T.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;The proposed data acquisition combines a Look-Locker scheme with the modified BIR-4 adiabatic preparation pulse for simultaneous &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mi&gt;w&lt;/mi&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ mathrm{w}{T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; and &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mi&gt;w&lt;/mi&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ mathrm{w}{T}_2 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; mapping. CASPR is employed for efficient and flexible k-space sampling at isotropic resolution during free breathing. The imaging pipeline includes subspace reconstruction, water-fat separation, and &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {B}_0 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; -specific dictionary matching. The proposed method was validated in a water-fat relaxometry phantom using spin echo-based reference techniques and was compared with MOLLI &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; and GRASE &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_2 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; mapping in 10 volunteers. The method's flexibility was assessed at isotropic resolutions of 2.5, 3, and 3.5 mm, with corresponding scan times of 7:19, 5:23, and 3:52 min. Additionally, the method was applied to 9 oncological patients with abdominal pathologies.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Phantom experiments demonstrated good agreement between the proposed method and spin echo-based reference techniques across a wide range of &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mi&gt;w&lt;/mi&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ mathrm{w}{T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; and &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mi&gt;w&lt;/mi&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ mathrm{w}{T}_2 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; value","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145006376","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":"Characterizing the imaging environment for supine breast MRI.","authors":"Judith Zimmermann, Jana Vincent, Fraser Robb, Bruce L Daniel, Brian A Hargreaves, Catherine J Moran","doi":"10.1002/mrm.70029","DOIUrl":"https://doi.org/10.1002/mrm.70029","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Purpose: &lt;/strong&gt;Supine breast MRI has the potential to improve over standard prone breast magnetic resonance imaging (MRI) in terms of efficiency and image quality, image alignment with diagnostic and treatment procedures, and overall accessibility. This study aims to characterize potential technical challenges of imaging in the supine position: (i) &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_0 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt;  field inhomogeneities, (ii) &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt; &lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt;  variations, (iii) respiratory-induced breast motion, and (iv) supine breast geometry.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Ten healthy subjects were scanned at 3T in both prone and supine positions to quantify and compare (i) and (ii) between both positions, and to assess (iii) in the supine position. Breast image volumes from a wider population (N = 40, healthy volunteers and patients) were analyzed to obtain breast shape metrics to characterize (iv).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;&lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_0 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt;  field inhomogeneity increased from prone positioning (2SD: &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mn&gt;122&lt;/mn&gt; &lt;mspace&gt;&lt;/mspace&gt; &lt;mtext&gt;Hz&lt;/mtext&gt; &lt;mo&gt;±&lt;/mo&gt; &lt;mn&gt;25&lt;/mn&gt; &lt;mspace&gt;&lt;/mspace&gt; &lt;mtext&gt;Hz&lt;/mtext&gt;&lt;/mrow&gt; &lt;annotation&gt;$$ 122kern0.2em mathrm{Hz}pm 25kern0.2em mathrm{Hz} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; ) to supine positioning (2SD: &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mn&gt;152&lt;/mn&gt; &lt;mspace&gt;&lt;/mspace&gt; &lt;mtext&gt;Hz&lt;/mtext&gt; &lt;mo&gt;±&lt;/mo&gt; &lt;mn&gt;15&lt;/mn&gt; &lt;mspace&gt;&lt;/mspace&gt; &lt;mtext&gt;Hz&lt;/mtext&gt;&lt;/mrow&gt; &lt;annotation&gt;$$ 152kern0.2em mathrm{Hz}pm 15kern0.2em mathrm{Hz} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; ), and &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt; &lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {mathrm{B}}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt;  flip angle variations (from prescribed &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;30&lt;/mn&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mo&gt;∘&lt;/mo&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {30}^{circ } $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; ) were greater in the supine position (2SD ranging &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;7&lt;/mn&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mo&gt;∘&lt;/mo&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {7}^{circ } $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; to &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;13&lt;/mn&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mo&gt;∘&lt;/mo&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {13}^{circ } $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; ) than in the prone position (2SD ranging &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mo&gt;∘&lt;/mo&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {6}^{circ } $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; to &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mrow&gt;","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145006330","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":"Summary from the 2025 International Society for Magnetic Resonance in Medicine workshop on body MRI: Unsolved problems and unmet needs.","authors":"Elizabeth M Hecht, Houchun Harry Hu, Suraj D Serai, Holden H Wu, Ryan L Brunsing, Alexander R Guimaraes, Sila Kurugol, Kristina I Ringe, Ali B Syed","doi":"10.1002/mrm.70055","DOIUrl":"https://doi.org/10.1002/mrm.70055","url":null,"abstract":"<p><p>In March of 2025, 145 attendees convened at the Hub for Clinical Collaboration of the Children's Hospital of Philadelphia for the inaugural International Society for Magnetic Resonance in Medicine (ISMRM) Body MRI Study Group workshop entitled \"Body MRI: Unsolved Problems and Unmet Needs.\" Approximately 24% of the attendees were MD or MD/PhD's, 45% were PhD's, and 30% were early-career trainees and postdoctoral associates. Among the invited speakers and moderators, 28% were from outside the United States, with a 40:60% female-to-male ratio. The 2.5-day program brought together a multidisciplinary group of scientists, radiologists, technologists, and trainees. Session topics included quantitative imaging biomarkers, low- and high-field strengths, artifact and motion correction, rapid imaging and focused protocols, and artificial intelligence. Another key session focused on the importance of team science and allowed speakers from academia and industry to share their personal experiences and offer advice on how to successfully translate new MRI technology into clinical practice. This article summarizes key points from the event and perceived unmet clinical needs within the field of body MRI.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145000906","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 theoretical interpretation of diffusion weighted and intravoxel incoherent motion imaging for cerebrospinal fluid flow.","authors":"Tomohiro Otani, Yoshitaka Bito, Shigeki Yamada, Yoshiyuki Watanabe, Shigeo Wada","doi":"10.1002/mrm.70062","DOIUrl":"https://doi.org/10.1002/mrm.70062","url":null,"abstract":"<p><strong>Purpose: </strong>Diffusion-weighted imaging (DWI) and intravoxel incoherent motion (IVIM) imaging are well-established approaches for evaluating cerebrospinal fluid (CSF) flow in subarachnoid and perivascular spaces, and have recently been applied to study ventricular CSF flow. However, DWI does not directly measure flow velocity, and the physical implications of DWI measurements are unclear. This study aimed to provide a theoretical interpretation of the DWI and IVIM imaging of CSF flow velocity fields.</p><p><strong>Theory: </strong>The general semi-analytical form of the signal attenuations caused by fluid flow and the resultant apparent diffusion coefficient were derived from the Bloch-Torrey equation for arbitrary <math> <semantics><mrow><mi>b</mi></mrow> <annotation>$$ b $$</annotation></semantics> </math> values.</p><p><strong>Methods: </strong>The fundamental properties of the signal attenuation in laminar flow velocity fields were investigated. A Monte Carlo simulation of the IVIM parameter estimation was performed based on these signal attenuations, taking background noise into consideration.</p><p><strong>Results: </strong>The developed theoretical framework indicates that signal attenuations in DWI detect intravoxel flow velocity standard deviations ranging from approximately 0.1 to 10 mm/s within the range of practical scan parameter settings. The lower bounds of the DWI flow profiles appeared where the flow effect was an order of magnitude lower than the molecular diffusion effects, even when <math> <semantics><mrow><mi>b</mi></mrow> <annotation>$$ b $$</annotation></semantics> </math> increased. The IVIM fitting parameters reflected the flow effects of the signal attenuations despite an inconsistency with the original IVIM model assumptions.</p><p><strong>Conclusion: </strong>The physical implications of signal attenuation in DWI have been theoretically clarified. This framework provides a useful basis for understanding CSF flow dynamics and considering appropriate imaging settings.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145000950","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":"Rapid free-breathing myocardial T₁ mapping with free-running interleaved multi-slice acquisition and respiratory motion correction using self-navigated auto calibration.","authors":"Hongzhang Huang, Zijian Zhou, Zhenfeng Lyu, Qinfang Miao, Genqiang Chen, Peng Hu, Haikun Qi","doi":"10.1002/mrm.70071","DOIUrl":"https://doi.org/10.1002/mrm.70071","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Purpose: &lt;/strong&gt;To develop a rapid 2D free-running myocardial &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; mapping technique that is robust to through-plane respiratory motion.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;A free-running golden angle radial sequence consisting of &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; encoding and self-navigated auto motion calibration (SNAC) was developed. The &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; encoding adopted inversion recovery (IR) prepared interleaved multi-slice acquisition with optimized inter-slice gap to ensure a uniform excitation of the middle slice regardless of through-plane respiratory motion. The flip angles were alternated between the odd and even IR readouts to correct flip-angle errors. SNAC was designed to calibrate the through-plane motion with the respiratory self-navigation signal extracted from the free-running sequence, and integrate the multi-slice data into a through-plane motion-corrected 2D slice for &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; mapping reconstruction. Numerical simulations were performed to optimize the key sequence parameters, followed by phantom and in-vivo imaging to validate the accuracy and repeatability.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Numerical simulations yielded the dual flip angles minimizing &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; estimation errors and the adjacent slice offset achieving uniformity in the superimposed slice profile. Phantom experiments demonstrated a strong correlation between the proposed and reference method, and no dependence of the free-running &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; estimation on heart rates. Adding through-plane respiratory motion correction significantly improved the in-vivo &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; mapping sharpness and visual quality. Validated against the conventional breath-hold mapping technique, the motion corrected free-running method achieved comparable &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt; &lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; mapping quality and repeatability.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;Respiratory motion is effectively suppressed in the p","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145000904","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":"Navigator motion-resolved MR fingerprinting using implicit neural representation: Feasibility for free-breathing three-dimensional whole-liver multiparametric mapping.","authors":"Chao Li, Jiahao Li, Jinwei Zhang, Eddy Solomon, Alexey V Dimov, Pascal Spincemaille, Thanh D Nguyen, Martin R Prince, Yi Wang","doi":"10.1002/mrm.70063","DOIUrl":"https://doi.org/10.1002/mrm.70063","url":null,"abstract":"<p><strong>Purpose: </strong>To develop a multiparametric free-breathing three-dimensional, whole-liver quantitative maps of water T₁, water T₂, fat fraction (FF) and R₂*.</p><p><strong>Methods: </strong>A multi-echo 3D stack-of-spiral gradient-echo sequence with inversion recovery and T₂-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 T₁, T₂, R₂*, and FF maps. FINR performance was evaluated in 10 healthy subjects by comparison with quantitative maps generated using conventional breath-holding imaging.</p><p><strong>Results: </strong>FINR consistently generated sharp images in all subjects free of motion artifacts. FINR showed minimal bias and narrow 95% limits of agreement for T₁, T₂, R₂*, and FF values in the liver compared with conventional imaging. FINR training took about 3 h per subject, and FINR inference took less than 1 min to produce static images and motion deformation fields.</p><p><strong>Conclusions: </strong>FINR is a promising approach for 3D whole-liver T₁, T₂, R₂*, and FF mapping in a single free-breathing continuous scan.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144959399","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}