NMR in Biomedicine最新文献

{"title":"Estimating the Sodium Content: A Case Series of Benign and Malignant Renal Tumours Using ²³Na-MRI at 3 T.","authors":"Ines Horvat-Menih, Jonathan R Birchall, Maria J Zamora-Morales, Alice Bebb, Joshua D Kaggie, Frank Riemer, Andrew B Gill, Andrew N Priest, Marta Wylot, Iosif A Mendichovszky, Anne Y Warren, James Jones, James N Armitage, Thomas J Mitchell, Grant D Stewart, Mary A McLean, Ferdia A Gallagher","doi":"10.1002/nbm.70338","DOIUrl":"10.1002/nbm.70338","url":null,"abstract":"<p><p>Accurate and non-invasive subtyping of localised renal tumours is an important unmet clinical challenge in uro-oncology and has significant implications for patient mortality and quality of life. Developing novel imaging methods to characterise and stratify indeterminate kidney tumours at an early stage has the potential to address this clinical challenge. Here we applied sodium MRI (²³Na-MRI) to estimate kidney tumour sodium content in a prospectively recruited case series of 10 patients (mean age ± SD 64 ± 8 years; 7:3 male:female ratio). The patients had localised renal tumours which included six renal oncocytomas (ROs), two chromophobe renal cell carcinomas (chRCCs), three clear cell RCCs (ccRCC) and one papillary RCC (pRCC). The patients underwent ²³Na-MRI at 3 T (3D sodium cones and double-angle B₁ mapping) and ¹H-MRI which included R₂* mapping and intravoxel incoherent motion (IVIM) diffusion weighted imaging (DWI). The following imaging parameters were quantified within the renal tumours and in the normal-appearing kidney parenchyma: apparent total sodium concentration (TSC); apparent ²³Na and ¹H relaxation rates (R₂*); perfusion fraction (f_p); and diffusion coefficient (D_t). ²³Na-MRI findings were correlated with conventional ¹H-MRI measures of perfusion, hypoxia and cellularity. The mean apparent TSC in ccRCC and in pRCC were 135 ± 59 mM and 81 mM, respectively. The apparent TSC was significantly higher in ROs compared to chRCCs: 162 ± 58 mM vs. 71 ± 2 mM (p < 0.05). The apparent TSC inversely correlated with ¹H-R₂* (Spearman r = -0.39, p < 0.05). In conclusion, this study showed the feasibility and potential of using ²³Na-MRI in renal tumours to probe sodium concentrations. These preliminary findings suggest a differential sodium content between benign ROs and malignant chRCCs. The inverse correlation between sodium concentration and ¹H-R₂* as a surrogate of hypoxia may indicate a biophysical relationship between the two which requires further validation in larger patient cohorts.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 8","pages":"e70338"},"PeriodicalIF":2.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13291926/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148308878","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":"Susceptibility Source Separation Unveils Paramagnetic and Diamagnetic Trajectories in Healthy Brains From 5 to 90 Years.","authors":"Tereza Beatriz Oliveira Assunção, Nashwan Naji, Peter Seres, Christian Beaulieu, Alan H Wilman","doi":"10.1002/nbm.70349","DOIUrl":"10.1002/nbm.70349","url":null,"abstract":"<p><p>Susceptibility source separation (SSS) enables independent evaluation of both paramagnetic iron and diamagnetic myelin in the human brain. The aim of this work was to analyze healthy brain lifespan trajectories of paramagnetic and diamagnetic susceptibilities in deep gray matter (DGM) and white matter (WM) from a large database (339 subjects, 5 to 90 years), all acquired at 3 T on the same scanner, using χ-separation and comparing it to two other common SSS methods (χ-sepnet and APART-QSM). A 3D multiple echo gradient echo sequence was used to measure phase, R2* and QSM, as well as dual echo fast spin echo to measure R2. The mean value of WM and DGM regions was calculated for SSS output maps and plotted against age to evaluate trajectories across the lifespan. With χ-separation, most DGM regions showed an increasing trend with age in the paramagnetic map, except for thalamus, which showed an inverted-U quadratic trajectory, and all DGM regions showed an increase in diamagnetic content with age. In WM, for the paramagnetic maps, body of corpus callosum, splenium and corticospinal tract showed an inverted quadratic trajectory, cingulum an increasing exponential, while no significant changes were seen in genu. For the diamagnetic WM maps, all regions followed a similar trajectory, increase in early life, peak around 40 to 60 years, and decrease with age. The different SSS approaches yielded different curve shapes and mean values in many instances. For example, APART-QSM had consistently lower ppb values, χ-sepnet had biologically unexpected results for early ages, and χ-separation data had higher standard deviation of best-fit residuals when compared to the other evaluated methods for all analyzed regions and maps. All SSS methods enabled depiction of independent iron and myelin trends; however, different results between methods suggest caution in choosing SSS methods and the need for further methodological advances.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 8","pages":"e70349"},"PeriodicalIF":2.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13334517/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148391606","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":"Serum ¹H-NMR Metabolomic Profiling of Full-Thickness Rotator Cuff Tears: A Hypothesis-Generating Case-Control Pilot Study.","authors":"Tahir Burak Sarıtaş, Cemil Ertürk, Volkan Arıcı, Burak Yıldırım, Halil Büyükdoğan, Metin Demirel, Sahabettin Selek","doi":"10.1002/nbm.70318","DOIUrl":"10.1002/nbm.70318","url":null,"abstract":"<p><p>Rotator cuff (RC) tears are a prevalent source of shoulder pain that restrict everyday activities and diminish quality of life. While MRI reveals structural damage in the tendon, it is uncertain if RC illness is also indicated in the body's circulating metabolites. The establishment of systemic signals may guide the future creation of blood-based biomarker panels; however, existing evidence is currently insufficient. This exploratory, hypothesis-generating case-control study investigated serum metabolites via proton nuclear magnetic resonance (¹H-NMR) in persons with full-thickness RC injuries and age- and sex-matched healthy controls (50 cases, 50 controls). Spectra underwent meticulous quality assessments, and predetermined statistical analyses were conducted with management of false discoveries. We also examined how well different metabolites discriminated RC tears from controls and explored which metabolic pathways were most represented. Numerous metabolites exhibited variations between the groups. Concentrations of N-carbamoyl-β-alanine, taurine, erythritol, and N-acetylaspartate were elevated in RC tears, but levels of 3-methylhistidine and proline were diminished. Pathway enrichment revealed pyrimidine metabolism, bile-acid biosynthesis, taurine/hypotaurine metabolism, β-alanine metabolism, and histidine metabolism, indicating coordinated perturbations at the pathway level rather than isolated alterations. These data must be regarded as preliminary and hypothesis-generating, lacking the establishment of causation or immediate clinical applicability. Although preliminary, these findings are scientifically significant because they suggest that full-thickness RC tears may be associated with a coordinated systemic metabolic signature rather than only a focal tendon abnormality. This systems-level perspective adds to the current understanding of RC pathology by generating biologically plausible hypotheses related to tissue remodeling, oxidative stress adaptation, and energy metabolism. Prospective longitudinal investigations with targeted quantification, external validation, and integration with imaging and clinical outcomes are required before clinical translation.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 7","pages":"e70318"},"PeriodicalIF":2.8,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148042989","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":"Dipolar Order Mapping Based on Spin-Lock Magnetic Resonance Imaging.","authors":"Zijian Gao, Qianxue Shan, Ziqin Zhou, Ziqiang Yu, Weitian Chen","doi":"10.1002/nbm.70331","DOIUrl":"10.1002/nbm.70331","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Inhomogeneous magnetization transfer (ihMT) is sensitive to dipolar order associated with motion-restricted macromolecules and can be characterized by the dipolar relaxation time &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt; &lt;mi&gt;D&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_{1D} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; . In this study, we propose a spin-lock MRI framework for &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt; &lt;mi&gt;D&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_{1D} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; quantification. Specifically, we introduce a &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt; &lt;mi&gt;D&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_{1D} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; -sensitive metric, &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mtext&gt;RATI&lt;/mtext&gt; &lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt; &lt;mtext&gt;dosl&lt;/mtext&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ RATI{O}_{dosl} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; , derived from the distinct relaxation rate &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;R&lt;/mi&gt; &lt;mtext&gt;dosl&lt;/mtext&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {R}_{dosl} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; , defined as the difference between dual-frequency and single-frequency &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;R&lt;/mi&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt; &lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {R}_{1rho } $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; measurements. To enable dual-frequency spin-lock acquisition, we developed a dedicated rotary-echo spin-lock sequence. Based on this framework, we further estimated &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt; &lt;mi&gt;D&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_{1D} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; and the macromolecular proton fraction (MPF) within a unified acquisition. The proposed method was evaluated using numerical simulations, phantom experiments, and in vivo imaging in the healthy human brain. Simulations demonstrated high sensitivity of &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mtext&gt;RATI&lt;/mtext&gt; &lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt; &lt;mtext&gt;dosl&lt;/mtext&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ RATI{O}_{dosl} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; to &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt; &lt;mi&gt;D&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_{1D} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; and supported the robustness of the proposed approach under the investigated conditions. Phantom experiments showed measurable ihMT contrast and supported the feasibility of &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt; &lt;mi&gt;D&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_{1D} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; estimation using &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mtext&gt;RATI&lt;/mtext&gt; &lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt; &lt;mtext&gt;dosl&lt;/mtext&gt;&lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ RATI{O}_{dosl} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; . In vivo experiments demonstrated simultaneous &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;T&lt;/mi&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt; &lt;mi&gt;D&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {T}_{1D} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; and MPF mapping using only three spin-lock-prepared images. Across","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 7","pages":"e70331"},"PeriodicalIF":2.8,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13275185/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148271611","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":"<ArticleTitle xmlns:ns0=\"http://www.w3.org/1998/Math/MathML\">Repeatability of Simultaneous <ns0:math> <ns0:semantics> <ns0:mrow><ns0:msup><ns0:mrow /> <ns0:mrow><ns0:mn>1</ns0:mn></ns0:mrow> </ns0:msup> </ns0:mrow> <ns0:annotation>$$ {}^1 $$</ns0:annotation></ns0:semantics> </ns0:math> H/ <ns0:math> <ns0:semantics> <ns0:mrow><ns0:msup><ns0:mrow /> <ns0:mrow><ns0:mn>23</ns0:mn></ns0:mrow> </ns0:msup> </ns0:mrow> <ns0:annotation>$$ {}^{23} $$</ns0:annotation></ns0:semantics> </ns0:math> Na MR Fingerprinting in Knee Cartilage at 7 T.","authors":"Anne Adlung, Dimitri Martel, Baptiste Busi, Zidan Yu, Gonzalo Gabriel Rodriguez, Lauren F O'Donnell, Thorsten Kirsch, Martijn Cloos, Amparo Ruiz, Guillaume Madelin","doi":"10.1002/nbm.70321","DOIUrl":"10.1002/nbm.70321","url":null,"abstract":"&lt;p&gt;&lt;p&gt;This study evaluates the repeatability of a 3D simultaneous &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {}^1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; H/ &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {}^{23} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; Na MR fingerprinting (MRF) sequence in knee cartilage of healthy volunteers. Eight healthy volunteers underwent four knee scans each with 3D simultaneous &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {}^1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; H/ &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {}^{23} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; Na MRF at 7 T. Proton density (PD), tissue sodium concentration (TSC), and &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {}^1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; H and &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {}^{23} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; Na relaxation time maps were acquired over two visits with two consecutive acquisitions at both visits. Mean values and standard deviations of all MRF metrics were measured in three knee cartilage regions: patellar, femorotibial medial, and femorotibial lateral. Image processing included &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {}^1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; H and &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {}^{23} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; Na MRF dictionary matching, B &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msubsup&gt;&lt;mrow&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;$$ {}_1^{-} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; correction, TSC and PD quantification, and image registration between the scans. Repeatability was assessed using the coefficient of variation (CV) and intraclass correlation coefficient (ICC) for all measurements and Bland-Altman plots to compare intraday and interday measurement differences. Mean TSC values over all subjects and cartilage regions were 162  &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;/mrow&gt; &lt;annotation&gt;$$ pm $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt;  29 mM, with a CV of 12%  &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;/mrow&gt; &lt;annotation&gt;$$ pm $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt;  1%. Mean &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;/mrow&gt; &lt;/msup&gt; &lt;/mrow&gt; &lt;annotation&gt;$$ {}^{23} $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; Na T &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mrow&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;$$ {}_1 $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt; (30  &lt;math&gt; &lt;semantics&gt;&lt;mrow&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;/mrow&gt; &lt;annotation&gt;$$ pm $$&lt;/annotation&gt;&lt;/semantics&gt; &lt;/math&gt;  2 ms) and T &lt;math&gt; &lt;semantics&gt; &lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;mn&gt;","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 7","pages":"e70321"},"PeriodicalIF":2.8,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13383806/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148265269","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":"Sustainable Low-Field Cardiovascular Magnetic Resonance in Changing Healthcare Systems-An Update.","authors":"Muhammad Umair, Ahmed Marey, Sanjana Murali, Udunna C Anazodo, Adrienne E Campbell-Washburn, Ntobeko A B Ntusi, Orlando P Simonetti, Thoralf Niendorf, Regina Mammen, Sola Adeleke","doi":"10.1002/nbm.70311","DOIUrl":"10.1002/nbm.70311","url":null,"abstract":"<p><p>Cardiovascular magnetic resonance (CMR) is the gold standard imaging modality for evaluating cardiac structure, function, and myocardial tissue characteristics, yet its widespread adoption remains limited by cost, technological complexity, and infrastructure barriers-especially in low- and middle-income countries (LMICs). Recent advances in low-field (LF) CMR, particularly around 0.55 Tesla, demonstrate that strong diagnostic performance can be achieved despite reduced signal-to-noise ratios. Optimized hardware, including advanced gradient coils and radiofrequency systems, as well as AI-driven image reconstruction techniques, has greatly enhanced image quality. LF magnets offer notable advantages that reduce infrastructure demands and simplify protocols-both critical for lower resource settings. Clinical applications in cardiac function, tissue characterization, flow quantification, and even interventional procedures have expanded through sequences adapted to LFs, including novel approaches to myocardial mapping and real-time imaging. Concurrently, cryogen-free magnet designs and smaller system footprints have simplified installation and lowered operational costs. These developments bolster the feasibility of scaling CMR in environments where high-field scanners are prohibitively expensive or challenging to maintain. Moreover, greater accessibility to LF CMR could help bridge global disparities in cardiovascular diagnostics, enabling earlier detection of cardiomyopathies and ischemic heart disease in underserved regions. Although challenges remain-such as reduced signal-to-noise ratio, slower acquisition times, and limited availability of cardiac-specific hardware-ongoing innovations and collaborative global initiatives position LF CMR as a transformative, sustainable solution for modern cardiovascular care worldwide.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 7","pages":"e70311"},"PeriodicalIF":2.8,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148055989","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":"In Situ pH Determination Using ¹H-MRS Acetate Chemical Shift for Noninvasive Postmortem Examinations.","authors":"Sabina Frese, Dominic Gascho, Michael J Thali, Sebastian Kozerke, Niklaus Zoelch","doi":"10.1002/nbm.70323","DOIUrl":"10.1002/nbm.70323","url":null,"abstract":"<p><p>Magnetic resonance spectroscopy provides novel noninvasive tools for postmortem forensic investigations. While postmortem temperature assessment using ¹H-MRS has recently been established, noninvasive determination of brain tissue pH remains largely unexplored despite evidence linking pH to the cause of death. In this study, we investigated the feasibility of in situ brain pH determination using postmortem ¹H-MRS based on the chemical shift difference between myo-inositol (mI, reference metabolite) and acetate (Ace, indicator metabolite) in 58 decedents. LCModel-based fitting strategies were evaluated using simulations that mimic postmortem brain ¹H-MRS spectra in order to identify the most accurate and precise approach and to assess factors affecting chemical shift determination. The in situ MRS data were subsequently analyzed using the optimal strategy. Brain pH values derived from the mI-Ace chemical shift difference were validated against pH measurements obtained from homogenized brain tissue samples. Our results demonstrate that the optimal fitting is achieved by allowing increased flexibility in the chemical shift determination of Ace. Using this approach, robust detection of low pH values in postmortem brain tissue is achieved. These findings demonstrate the feasibility of Ace-based ¹H-MRS for noninvasive in situ assessment of postmortem brain pH and indicate its potential for forensic applications.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 7","pages":"e70323"},"PeriodicalIF":2.8,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148138672","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":"Residual Water Suppression in MRS Using HLSVD With Automatic Component Selection Strategy.","authors":"Yi-Ru Lin, Zheng-De Hong, Shang-Yueh Tsai","doi":"10.1002/nbm.70325","DOIUrl":"10.1002/nbm.70325","url":null,"abstract":"<p><p>Residual water signals in magnetic resonance spectroscopy (MRS) can distort baselines and complicate metabolite quantification, particularly in regions with poor field homogeneity and in MRSI. The Hankel Lanczos singular value decomposition (HLSVD) method is widely used for Residual water removal, but its performance depends on the number of components selected. This study proposes an automatic approach that combines HLSVD with the residual water to metabolite variance ratio (RWVR) for component selection. The RWVR, defined as the variance of spectral fluctuations in the water region (4.2-5.2 ppm) normalized to the metabolite region (0.5-4.0 ppm). HLSVD was applied using component numbers between 10 and 32, and the configuration yielding the minimal RWVR was chosen as optimal. The method was evaluated on single voxel spectroscopy (SVS) data from four brain regions and on MRSI datasets acquired at 3 T. The Residual Water Index, defined as the variance ratio before and after RW removal, was used to assess suppression performance. Optimal component numbers were more frequently found in the range of 22-32, consistent with prior reports. With the identified component numbers, acceptable spectra across both SVS and MRSI can be produced. While multiple component numbers often yielded similar outcomes, some choices led to unacceptable spectra with baseline distortions. RWVR provided an effective indicator for avoiding such outcomes. Residual water index values were generally low, confirming effective suppression, though a small subset of cases exhibited irregular residual water lineshapes and higher RWVR. By evaluating multiple component numbers and choosing the configuration that minimizes RWVR, the proposed method avoids manual tuning and ensures acceptable suppression across both SVS and MRSI data. This approach offers a practical solution for large-scale studies where consistent and reliable residual water removal is essential.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 7","pages":"e70325"},"PeriodicalIF":2.8,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148138653","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":"Magnetic Resonance Imaging at 14 Tesla of Prostate Biopsies Obtained after Prostatectomy.","authors":"Fredrik Langkilde, Stefan Kuczera, Vasiliki Spyratou, Johan Stranne, Stephan E Maier","doi":"10.1002/nbm.70316","DOIUrl":"10.1002/nbm.70316","url":null,"abstract":"<p><p>This study aimed to investigate the feasibility of MR diffusion imaging of fresh prostate needle biopsy cores in a 14 Tesla vertical bore NMR system. Biopsies sampled from the index tumor and a presumed tumor-free area of eight prostatectomy specimens underwent diffusion-weighted imaging using conventional pulsed gradient spin echoes (PGSE) and stimulated echo acquisition mode (STEAM) with different gradient separation times between 10 and 400 ms at nominal b values ranging from 0 up to 5000 s/mm². The apparent diffusion coefficient (ADC) was determined over the b-value range 0-1000 s/mm². Kurtosis and biexponential models were fitted to measured signals at effective b values within the range 0-2000 and 0-5000 s/mm², respectively. Moreover, monoexponential models were fitted over the same b-value ranges. After imaging, all biopsies underwent histopathological evaluation. For all diffusion gradient separation times evaluated, the ADC of histopathologically confirmed tumor and normal tissue was not significantly different (p = 0.140 at 10 ms gradient separation time). Irrespective of the investigated tissue type, for an increasing gradient separation time up to 150 ms ADC decreased. For longer times up to 400 ms no further change was evident. For short diffusion gradient separation times, the Akaike information criterion (AIC) favored the biexponential model in almost all voxels, but for longer diffusion gradient separation times, in a majority of voxels the AIC favored the monoexponential model over either the kurtosis or biexponential model. Imaging of fresh prostate biopsies is feasible. At short diffusion times, in agreement with the presence of at least two distinct compartments, the signal decay is well described by a biexponential model. At long diffusion times, the ADC is lower, and a monoexponential model tends to be more appropriate, indicating the presence of exchange between compartments.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 7","pages":"e70316"},"PeriodicalIF":2.8,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147988465","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":"A Mixed Single-Echo and Multiecho MyoFoldstar for Simultaneous Quantification of Myocardial T₁, T₂, T₂*, and Wall Motion.","authors":"Rui Guo, Guozhao Dong, Bowei Liu, Yu Lian, Yifei Jiang, Xiaomeng Yang, Peng Wu, Yingwei Fan, Ancong Wang, Jingjing Xiao, Haiyan Ding, Xiaoying Tang","doi":"10.1002/nbm.70320","DOIUrl":"10.1002/nbm.70320","url":null,"abstract":"<p><p>This study aimed to propose a mixed single-echo and multiecho MyoFoldstar sequence enabling simultaneous myocardial multiparametric mapping and wall-motion quantification. MyoFoldstar is designed as a 2D, single breath-holding sequence that sequentially performs joint T₁/T₂ mapping, T₂* mapping, and cine imaging within 17 heartbeats, using a golden-angle radial gradient-echo (GRE) readout and ECG synchronization. The joint T₁/T₂ mapping collects seven single-shot, single-echo images on the first seven heartbeats with inversion and T₂ preparation (T₂prep). The subsequent T₂* mapping acquires multishot, multiecho data over six heartbeats, followed by segmented cine with a single-echo readout over four heartbeats. In vivo feasibility was demonstrated in 12 healthy volunteers at 3 T and compared with conventional single-task sequences (MOLLI and SASHA for T₁, T₂prep bSSFP for T₂, and BB-meGRE for T₂*). Accuracy was validated in phantom studies. Both in vivo and phantom studies demonstrated the feasibility of MyoFoldstar for simultaneously acquiring cardiac T₁, T₂, T₂*, and cine imaging. MyoFoldstar-derived myocardial T₁ (1521 ± 102 ms), T₂ (43.2 ± 3.0 ms), and T₂* (19.2 ± 2.4 ms) showed good agreement with values from conventional single-task sequences (T₁: 1248 ± 35 ms by MOLLI and 1580 ± 38 ms by SASHA; T₂: 43.5 ± 2.2 ms by T₂prep bSSFP; T₂*: 23.4 ± 2.6 ms by BB-meGRE). Compared with conventional cine, MyoFoldstar images exhibited reduced myocardium-blood contrast, yet left ventricular function quantifications were mainly preserved (r > 0.9). Phantom results indicated that MyoFoldstar achieves good accuracy relative to reference standards. MyoFoldstar enables rapid myocardial T₁, T₂, T₂*, and cine imaging within a single breath-hold scan, delivering a time-saving and comprehensive assessment of cardiovascular magnetization resonance.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 7","pages":"e70320"},"PeriodicalIF":2.8,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148055957","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}