NMR in Biomedicine最新文献

{"title":"Neurometabolic Stability and Heritability in the Adolescent Brain: A Preliminary Longitudinal Twin MRS Study.","authors":"Christoph Hamann, Andjela Markovic, Julien Caccia, Andrzej Badek, Salome Wild, Kristina Adorjan, Michael Kaess, Ruth Tuura, Leila Tarokh","doi":"10.1002/nbm.70292","DOIUrl":"10.1002/nbm.70292","url":null,"abstract":"<p><p>Early adolescence is a critical period of brain development. This study examined regional neurometabolite ratios, their longitudinal stability, and their heritability during early adolescence. Forty-four adolescent twins (mean age: 13.25 years; SD = 1.01 years; 18 females; 25 monozygotic twins) underwent magnetic resonance spectroscopy (MRS) of the prefrontal cortex (GABA-edited MEGA-PRESS) and thalamus (short-echo-time PRESS) at baseline and 6 months later (n = 32; mean age: 13.72 years; SD = 0.97; 14 females; 19 monozygotic twins). We observed stable neurometabolite ratios in both regions across time. Moderate genetic contributions were estimated for Glx (glutamate and glutamine)/(Cr + PCr) in the prefrontal cortex as well as for glutamate/(Cr + PCr) and total choline-containing compounds (PCho + GPC)/(Cr + PCr) in the thalamus. These preliminary findings highlight region-specific and genetically influenced neurometabolic markers in early adolescence.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 6","pages":"e70292"},"PeriodicalIF":2.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13092461/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of Inflammation in In Vivo Mouse Myocardium Using Longitudinal Rotating Frame Relaxation Time (T_1ρ) and T₂ Relaxation Time Maps.","authors":"Elias Ylä-Herttuala, Haja Sherief Nazimutheen Mustafa, Muhammad Arsalan Khan, Mari Merentie, Galina Wirth, Svetlana Laidinen, Lari Holappa, Seppo Ylä-Herttuala, Timo Liimatainen","doi":"10.1002/nbm.70304","DOIUrl":"10.1002/nbm.70304","url":null,"abstract":"<p><p>Cardiac magnetic resonance imaging (MRI) is a gold standard to assess functional and anatomical properties of the living heart. Inflammation changes the myocardial tissue and, furthermore, MR relaxation properties. Continuous-wave (CW) longitudinal rotating frame relaxation time (T_1ρ) mapping has been used to assess myocardial fibrosis and inflammation. Conventional T₂ relaxation time is a known marker of edema in the myocardium. In this study, we assessed myocardial inflammation after viral infection in a mouse heart using CW-T_1ρ and T₂ relaxation times. Adenoviral human vascular endothelial growth factor-A₁₆₅ (AdVEGF-A₁₆₅) and empty control adenoviral vector with cytomegalovirus promoter (AdCMV) gene transfers were used to induce inflammation in the mouse myocardium. In vivo CW-T_1ρ and T₂ relaxation time measurements were performed in both groups (AdVEGF-A₁₆₅ and AdCMV) after -1-, 1-, 3-, 7-, 14-, 21-, and 28-day post-injection. The inflammation associated with gene transfer was verified by hematoxylin and eosin staining after 14-day post-injection. One day after AdVEGF-A₁₆₅ and AdCMV injections and inflammatory reactions, CW-T_1ρ showed a significant increase, which stayed increased as a function of time. T₂ also increased significantly after both injections and inflammatory reactions as compared to before injections. Contrast difference between inflammation and remote areas was visually observed in both groups in CW-T_1ρ and T₂ maps. Hematoxylin and eosin staining revealed the area of inflammation after Ad injection in both groups after 14-day post-injection. This study showed that both acute and chronic phases of the inflammatory reaction in mouse myocardium caused by myocardial adenoviral injections were associated with increased CW-T_1ρ and T₂ relaxation time constants. Furthermore, the inflammatory reaction can be followed up with rotating frame and conventional relaxation time mappings.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 6","pages":"e70304"},"PeriodicalIF":2.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13129243/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147777419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response to Letter to the Editor: 'Muscle Membrane Permeability Determined by ³¹P-MRS and DT-MRI as a Biomarker for the Progression of Becker Muscular Dystrophy'.","authors":"Esther J Schrama, Melissa T Hooijmans, Nienke M van de Velde, Erik H Niks, Hermien E Kan, Donnie Cameron","doi":"10.1002/nbm.70241","DOIUrl":"https://doi.org/10.1002/nbm.70241","url":null,"abstract":"","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 3","pages":"e70241"},"PeriodicalIF":2.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146156133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metabolomic Relationships Between Lung Cancer and Alzheimer's Disease Using Serum Nuclear Magnetic Resonance Spectroscopy.","authors":"Zuzanna Kobus, Marta Kobus, Ella J Zhang, Rajshree Ghosh Biswas, Jiashang Chen, Jonathan X Zhou, Angela Rao, Katharina S Hollmann, Piet Habbel, Johannes Nowak, Li Su, David P Kaul, Steven E Arnold, David C Christiani, Leo L Cheng","doi":"10.1002/nbm.70186","DOIUrl":"10.1002/nbm.70186","url":null,"abstract":"<p><p>Lung cancer (LC) and Alzheimer's disease (AD) are both age-associated diseases with high rates of mortality. Studies have reported a possible inverse relationship between LC and AD incidences; however, possible shared molecular mechanisms have not been well investigated. Better characterizations of both diseases and their potential molecular relationships may advance the development of successful therapies for both LC and AD. Metabolomics, as a holistic study of the entire measurable metabolome, has the potential to probe into their metabolic connections. Herein, we used high-resolution magic angle spinning (HRMAS) nuclear magnetic resonance (NMR) spectroscopy to study 36 human serum samples collected from primary lung adenocarcinoma patients with or without AD, or AD and related dementia (ADRD). We identified 88 metabolites with 66 metabolites differentiating LC patients from controls, and 80 metabolites discerning LC patients without ADRD from those with ADRD. Our results demonstrate the capability of metabolomics to reveal inversely dysregulated glycolysis, oxidative phosphorylation, and proline metabolism in LC and ADRD.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 1","pages":"e70186"},"PeriodicalIF":2.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12805822/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145649100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diffusion Tensor Imaging of Short T₂ Tissues Using Quantitative Ultrashort Echo Time Double-Echo Steady-State: A Feasibility Study.","authors":"Jinil Park, Sam Sedaghat, Eddie Fu, Youngkyoo Jung, Lorenzo Nardo, Abhijit J Chaudhari, Heejung Bang, Hyungseok Jang","doi":"10.1002/nbm.70184","DOIUrl":"10.1002/nbm.70184","url":null,"abstract":"<p><p>To evaluate the feasibility of diffusion tensor imaging (DTI) using quantitative ultrashort echo time double-echo steady-state (qUTE-DESS) MRI in short T₂ musculoskeletal tissues, we validated it in phantoms, an ex vivo porcine hoof, and an in vivo human knee. The qUTE-DESS sequence was implemented on a clinical 3 T MRI system, enabling simultaneous estimation of T₁, T₂, and diffusivity in tissues with rapid signal decay. Data were acquired with six diffusion-weighting orientations (x, y, z, xy, yz, xz) to obtain mean diffusivity (MD) and fractional anisotropy (FA). Sucrose and agarose phantoms demonstrated linear relationships between T₁, T₂, or diffusivity and their concentrations (R² > 0.88). A celery phantom demonstrated anisotropic diffusion by revealing elevated FA in fibrous structures. In experiments with the porcine hoof and healthy volunteers' knees, qUTE-DESS generated high-resolution parameter maps of MD and FA across various tissues, including cartilage, meniscus, tendon, ligament, and muscle, effectively capturing short T₂ components that conventional DTI could not visualize. By preserving ultrashort echo signals, qUTE-DESS appeared to overcome the limitations of spin-echo-based DTI, which suffers from longer echo times and subsequent signal loss in short T₂ tissues. Therefore, this approach may serve as a valuable quantitative imaging tool for assessing microstructural features in the musculoskeletal system, facilitating detection and evaluation of joint abnormalities or degenerative changes. The results suggest qUTE-DESS can provide insight into both long and short T₂ tissues, offering potential benefits in clinical diagnosis and research. Further studies should assess its diagnostic utility in larger cohorts with musculoskeletal pathologies.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 1","pages":"e70184"},"PeriodicalIF":2.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145649105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Motion and Flow Robust Free-Breathing Diffusion Kurtosis Imaging of the Kidney.","authors":"Nima Gilani, Malika Kumbella, Mary Bruno, Jelle Veraart, Xiaochun Li, Judith D Goldberg, Dibash Basukala, Hersh Chandarana, Eric E Sigmund","doi":"10.1002/nbm.70168","DOIUrl":"10.1002/nbm.70168","url":null,"abstract":"<p><p>The development of noninvasive MRI biomarkers as surrogates of histopathological features in kidney tissue requires detailed explorations of contrast. Therefore, we studied kidney diffusion kurtosis imaging (DKI) with a wide array of encodings, including flow compensation, variable directional sampling, and cardiac gating regimes. Twelve healthy volunteers underwent DKI at 5-10 diffusion weightings (b-values) ranging from 0 to 1200 smm^-2 with 12 or 30 directional samplings, bipolar or flow-compensated diffusion gradient waveforms, and at systolic or diastolic cardiac phases. DKI biomarkers, mean diffusivity (MD) and kurtosis (MK), were interrogated using a directionally robust fitting algorithm compared to conventional fits. The combination of flow compensation and cardiac triggering at the diastolic phase in the kidneys reduced flow effects on DKI. In systole, flow-compensated waveforms significantly reduced MD and MK for both cortex and medulla: cortex MD: 3.00 versus 2.55 μm² ms^-1, medulla MD: 2.80 versus 2.39 μm² ms^-1, cortex MK: 0.58 versus 0.45, and medulla MK: 0.60 versus 0.47 (all p < 0.05). Flow suppression alleviated requirements for processing the DKI at higher minimum b-values, as neither MD nor MK significantly differed at the diastolic phase for minimum b-values of 0 versus 200 smm^-2: cortex MD: 2.30 versus 2.28 μm² ms^-1, p = 0.278; medulla MD: 2.29 versus 2.28 μm² ms^-1, p = 0.437; cortex MK: 0.37 versus 0.36, p = 0.308; and medulla MK: 0.40 versus 0.40, p = 0.904. Flow-compensated waveforms mitigate cardiac and respiratory motion-related artifacts at higher diffusion encodings in addition to microcirculation effects. The robust fitting initially developed for brain DKI is highly applicable to the kidneys because it disentangles tissue-specific directional diffusion information from artifacts.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 12","pages":"e70168"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12707544/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145459424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decontrasted Image Registration Improves Quantification of Extracellular Volume and Fractional Myocardial Blood Volume.","authors":"Meng Lu, Mostafa Mahmoudi, Kim-Lien Nguyen, Yibin Xie","doi":"10.1002/nbm.70179","DOIUrl":"10.1002/nbm.70179","url":null,"abstract":"<p><p>Accurate quantification of extracellular volume (ECV) and fractional myocardial blood volume (fMBV) in cardiac magnetic resonance (CMR) relies on precise alignment between precontrast and postcontrast images. Variable image contrast often undermines conventional motion correction, causing misalignment due to respiration or cardiac motion. Herein, we present a registration approach that accounts for varying image contrast levels and cardiac motion to achieve more precise and high-quality quantitative cardiac mapping. Patients with suspected myocardial diseases underwent cardiac MRI with Gadavist (0.1 mmol/kg, n = 11) and ferumoxytol (4.0 mg/kg cumulative, n = 9) enhancement for ECV and fMBV measurements, respectively. T1 maps were generated using the MOLLI sequence. To remove contrast variations across different inversion times and contrast doses, precontrast and postcontrast MOLLI images were grouped and processed using correlation-weighted representations based on the myocardium and blood pool signals. Groupwise registration is performed based on the maximization of mutual information. The image registration accuracy and mapping precision of the proposed method were assessed relative to those of conventional methods. ResultsCompared with the conventional groupwise registration approach, the proposed decontrasted approach showed superior alignment between images of different contrasts, as evidenced by the higher Dice scores (mean 0.77 vs. 0.69, p < 0.001). It also eliminated artifacts commonly observed owing to image misalignment (all 11 cases showed improvement). Improved myocardial mapping precision was observed for both ECV (median coefficient of variation, 0.14 vs. 0.27; p < 0.001) and fMBV (median coefficient of variation, 0.59 vs. 0.71; p < 0.001). It also reduced individual myocardial segmental variations in the ECV (5.8 to 3.58, p < 0.001) and fMBV maps (9.86 to 7.93, p < 0.001). Overall, decontrasted image registration improves the precision of contrast-enhanced myocardial parametric mapping by reducing the misalignment between multicontrast images. This framework may be extended to other postprocessing tasks in cardiac MRI that involve variable image contrasts.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 12","pages":"e70179"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13037656/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145513365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative MRI of Muscle Denervation in Subacute Parsonage-Turner Syndrome: A Prospective, Longitudinal Study.","authors":"Ek T Tan, Tim Y Li, Yenpo Lin, Gracyn J Campbell, Michelle Akerman, Shayna E Turbin, Joseph H Feinberg, Carlo J Milani, Kiril Kiprovski, Darryl B Sneag","doi":"10.1002/nbm.70172","DOIUrl":"10.1002/nbm.70172","url":null,"abstract":"<p><p>Parsonage-Turner syndrome (PTS) is a spontaneous neuropathy characterized by severe upper extremity pain and muscle denervation and is considered to be a rare disease that is under-recognized. Quantitative MRI (qMRI) characterizes muscle denervation but has not been previously assessed in a longitudinal PTS cohort. The aims of this study are to prospectively and longitudinally characterize qMRI changes in PTS patients at baseline (< 6 months' symptom onset) and at follow-up timepoints (3, 6, and 12 months), to measure associations against electromyography (EMG) and muscle strength, and to predict muscle strength at follow-up. A total of 49 subjects (age = 47.2 ± 14.0 years, 31 M/18 F) underwent 3-Tesla qMRI with T2-mapping, diffusion-based muscle fiber diameter, volumetry, and fat fraction (FF) mapping. Image segmentation of involved muscles was performed by two raters. Linear regression between qMRI metrics and days from symptom onset (DSO) was performed. Pearson's correlation quantified correlations between qMRI metrics, and Kendall's tau assessed correlations between qMRI and EMG and muscle strength. For predictive modeling of muscle strength, a generalized linear model was used, and the coefficient of determination (r²) was compared for combinations of baseline inputs. Regression detected a mean T2 increase of 0.66 ms/week and a mean muscle fiber diameter decrease of 0.96 μm/week within DSO of 100. Muscle fiber diameter correlated with muscle volume (r = 0.850). T2 correlated with EMG (|τ| = 0.34-0.78) and muscle strength (|τ| = 0.40-0.83) in most muscles that could be analyzed. Muscle fiber diameter was correlated to EMG (|τ| = 0.43-0.72) and muscle strength in some muscles (|τ| = 0.39-0.56). The addition of baseline T2 values improved the prediction of muscle strength at 3-month (from r² = 0.57 to 0.67, with -0.057 to -0.068 muscle grade per ms T2), at 6-month (r² = 0.40-0.59, -0.057 to -0.071 grade per ms), and at 12-month follow-up (r² = 0.40-0.62, -0.053 to -0.080 grade per ms). Muscle qMRI measurements in PTS depict muscle denervation and provide complementary characterization of muscle quality for diagnosis and follow-up assessment.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 12","pages":"e70172"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13081261/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145431529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlation-Weighted ²³Na Magnetic Resonance Fingerprinting in the Brain.","authors":"Lauren F O'Donnell, Gonzalo G Rodriguez, Gregory Lemberskiy, Zidan Yu, Olga Dergachyova, Martijn Cloos, Guillaume Madelin","doi":"10.1002/nbm.70150","DOIUrl":"10.1002/nbm.70150","url":null,"abstract":"&lt;p&gt;&lt;p&gt;We developed a new sodium magnetic resonance fingerprinting ( &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mn&gt;23&lt;/mn&gt;&lt;/msup&gt; &lt;mi&gt;Na&lt;/mi&gt;&lt;/mrow&gt; &lt;annotation&gt;$$ {}^{23}mathrm{Na} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; MRF) method for the simultaneous mapping of &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mn&gt;1&lt;/mn&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;msubsup&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt; &lt;mo&gt;,&lt;/mo&gt; &lt;mtext&gt;long&lt;/mtext&gt;&lt;/mrow&gt; &lt;mo&gt;*&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_{2,mathrm{long}}^{ast } $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; , &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt; &lt;mo&gt;,&lt;/mo&gt; &lt;mtext&gt;short&lt;/mtext&gt;&lt;/mrow&gt; &lt;mo&gt;*&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_{2,mathrm{short}}^{ast } $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; , and sodium density with built-in &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mi&gt;Δ&lt;/mi&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;$$ varDelta {B}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; (radiofrequency transmission inhomogeneities) and &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mi&gt;Δ&lt;/mi&gt; &lt;msub&gt;&lt;mi&gt;f&lt;/mi&gt; &lt;mn&gt;0&lt;/mn&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ varDelta {f}_0 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; (frequency offsets) parameters. We based our &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mn&gt;23&lt;/mn&gt;&lt;/msup&gt; &lt;mi&gt;Na&lt;/mi&gt;&lt;/mrow&gt; &lt;annotation&gt;$$ {}^{23}mathrm{Na} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; MRF implementation on a 3D FLORET sequence with 23 radiofrequency pulses. To capture the complex spin &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;mfrac&gt;&lt;mn&gt;3&lt;/mn&gt; &lt;mn&gt;2&lt;/mn&gt;&lt;/mfrac&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ frac{3}{2} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; dynamics of the &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mn&gt;23&lt;/mn&gt;&lt;/msup&gt; &lt;mi&gt;Na&lt;/mi&gt;&lt;/mrow&gt; &lt;annotation&gt;$$ {}^{23}mathrm{Na} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; nucleus, the fingerprint dictionary was simulated using the irreducible spherical tensor operators formalism. The dictionary contained 831,512 entries covering a wide range of &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mn&gt;1&lt;/mn&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;msubsup&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt; &lt;mo&gt;,&lt;/mo&gt; &lt;mtext&gt;long&lt;/mtext&gt;&lt;/mrow&gt; &lt;mo&gt;*&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_{2,mathrm{long}}^{ast } $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; , &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt; &lt;mo&gt;,&lt;/mo&gt; &lt;mtext&gt;short&lt;/mtext&gt;&lt;/mrow&gt; &lt;mo&gt;*&lt;/mo&gt;&lt;/msubsup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_{2,mathrm{short}}^{ast } $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; , &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mi&gt;Δ&lt;/mi&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;$$ Delta {B}_1^{+} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; factor, and &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mi&gt;Δ&lt;/mi&gt; &lt;msub&gt;&lt;mi&gt;f&lt;/mi&gt; &lt;mn&gt;0&lt;/mn&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ Delta {f}_0 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; parameters. Fingerprint matching was performed using the Pearson correlation and the resulting relaxation maps were weighted with a subset of the highest co","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 11","pages":"e70150"},"PeriodicalIF":2.7,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145302368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feasibility of a UTE Stack-of-Spirals Sequence for T_1ρ Mapping of Achilles Tendinopathy.","authors":"Anmol Monga, Hector L de Moura, Vaibhavi Rathod, Marcelo V W Zibetti, Smita Rao, Ravinder Regatte","doi":"10.1002/nbm.70149","DOIUrl":"10.1002/nbm.70149","url":null,"abstract":"<p><p>We analyzed the feasibility of using a UTE stack-of-spirals turbo FLASH (STFL) sequence to measure T_1ρ relaxation in the Achilles tendon. Six HS (25-31 years) and five AT patients (32-47 years) participated. The study evaluates the clinical utility of the STFL sequence to generate T_1ρ maps using mono-exponential (ME) and bi-exponential (BE) fitting models. In a phantom experiment, ME-T_1ρ values and SNR estimated from the STFL sequence are compared with those of the Cartesian turbo FLASH (CTFL) sequence. In human subjects, we evaluate differences in estimated ME (ME-T_1ρ) and BE parameters (short T_1ρ, long T_1ρ, and short fraction) between AT and HS groups along with repeatability of STFL. The agarose phantom demonstrates biases of 2.89% (3% agarose), -1.88% (5%), and -0.92% (7%) between ME-T_1ρ values from STFL and CTFL. In the bovine Achilles tendon, STFL shows a large bias of -58.6%, with a lower median ME-T_1ρ (2.9 ms) than CTFL (4.6 ms). SNR is higher in STFL (77.05-80.72 for 3%-7% agarose; 24.43 for bovine tendon) than CTFL (66.73-58.97 for agarose; 3.21 for bovine tendon). ME and BE parameters were averaged over the entire Achilles tendon, and none showed significant group differences (p > 0.05; effect size = 0.05-0.22). Subregional analysis showed that in the mid-Achilles tendon, short and long BE-T_1ρ components were 26% and 37% lower in AT than HS, though not statistically significant. The LDA-combined BE parameter showed significant group separation in the midtendon region (p = 0.016; effect size = 1.53). In HS, the long BE-T_1ρ component showed subregional variation (p = 0.006), increasing 58% from calcaneal to midtendon, and then decreasing 23% toward the intramuscular region. ME and BE fitting showed high repeatability with scan-rescan variations of 2.64% (T_1ρ), 3.38% (short T_1ρ), 3.0% (long T_1ρ), and 0.21% (short fraction). We demonstrated the feasibility of using STFL for T_1ρ quantification in the Achilles tendon.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 11","pages":"e70149"},"PeriodicalIF":2.7,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12966955/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145252154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}