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OBJECTIVES: Magnetic resonance imaging (MRI) is a critical noninvasive technique for evaluating liver steatosis, with efficient and precise fat quantification being essential for diagnosing liver diseases. This study leverages 5 T ultra-high-field MRI to demonstrate the clinical significance of liver fat quantification, and explores the consistency and accuracy of the Proton Density Fat Fraction (PDFF) in the liver across different magnetic field strengths and measurement methodologies. METHODS: The study involved phantoms with lipid contents ranging from 0 % to 30 % and 35 participants (21 females, 14 males; average age 30.17 ± 13.98 years, body mass index 25.84 ± 4.76, waist-hip ratio 0.84 ± 0.09). PDFF measurements were conducted using chemical shift encoded (CSE) MRI at 5 T, 3 T, and 1.5 T, alongside magnetic resonance spectroscopy (MRS) at 5 T and 1.5 T for both liver and phantoms, analyzed using jMRUI software. The MRS-derived PDFF values served as the reference standard. Repeatability of 5 T MRI measurements was assessed through correlation analysis, while accuracy was evaluated using linear regression analysis against the reference standards. RESULTS: The CSE-PDFF measurements at 5 T demonstrated strong consistency with those at 3 T and 1.5 T, showing high intraclass correlation coefficients (ICC) of 0.988 and 0.980, respectively (all p < 0.001). There was also significant consistency across ROIs within liver lobes, with ICC values ranging from 0.975 to 0.986 (all p < 0.001). MRS-PDFF measurements for both phantoms and liver at 5 T and 1.5 T exhibited substantial agreement, with ICC values of 0.996 and 0.980, respectively (all p < 0.001). Particularly, ICC values for ROIs in the liver ranged from 0.963 to 0.990 (all p < 0.001). Despite overall agreement, statistically significant differences were noted in specific ROIs within the liver lobes (p = 0.004 and 0.012). The CSE and MRS PDFF measurements at 5 T displayed strong consistency, with an ICC of 0.988 (p < 0.001), and significant agreement was also found between 5 T CSE and 1.5 T MRS PDFF measurements, with an ICC of 0.978 (p < 0.001). Agreement was significant within the ROIs of the liver lobes on the same platform at 5 T, with ICC values ranging from 0.986 to 0.991 (all p < 0.001). CONCLUSION: PDFF measurements at 5 T MR imaging exhibited both accuracy and repeatability, indicating that 5 T imaging provides reliable quantification of liver fat content and shows substantial potential for clinical diagnostic applications.

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Gallbladder carcinoma (GBC) presents a significant clinical challenge due to its aggressive nature and often asymptomatic progression, resulting in late-stage diagnoses and a poor prognosis. Early detection and accurate staging are pivotal for improving patient outcomes, highlighting the critical role of advanced imaging techniques in oncological practice. Magnetic resonance spectroscopy (MRS) has emerged as a valuable non-invasive tool capable of assessing biochemical changes within tissues, including alterations in choline metabolism-a biomarker indicative of cell membrane turnover and proliferation. This review explores the application of MRS in evaluating choline levels in gallbladder carcinoma, synthesizing current literature to elucidate its potential in clinical settings. By analyzing studies investigating the correlation between choline levels detected via MRS and tumor characteristics, this review underscores MRS's role in enhancing diagnostic precision and guiding therapeutic decision-making. Moreover, it discusses the challenges and limitations associated with MRS in clinical practice alongside future research and technological advancement directions. Ultimately, integrating MRS into the diagnostic armamentarium for gallbladder carcinoma promises to improve early detection and treatment outcomes. This review provides insights into the evolving landscape of MRS in oncology, emphasizing its contribution to personalized medicine approaches aimed at optimizing patient care and management strategies for GBC.

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BACKGROUND: Despite different intracranial tumour subtypes varying largely in their prognoses and recommended treatment regimens, they can have markedly similar appearances on standard radiology, especially in paediatric patients where they tend to occur in the midline. There is a need for a non-invasive, accurate method of determining tumour diagnosis to help expedite treatment planning. Existing studies have found magnetic resonance spectroscopy (MRS) to have value in diagnosing intracranial tumours in adults. The aim of this study was to investigate whether MRS could be accurate in diagnosing and grading paediatric intracranial tumours. METHODS: The hospital database was retrospectively searched for paediatric intracranial tumour patients ≤18 years that had 1.5 T MRS data available. Medical and demographic data were collected from existing records including MRS metabolites N-acetylaspartate (NAA), creatine (Cr), and choline (Cho), and final histopathologic diagnosis. MRS metabolites were then statistically compared against final histopathologic diagnosis. RESULTS: In total, 166 patients were included. In the overall cohort, the tumour to control tissue Cr ratio was significantly higher in grade 1 than grade 4 tumours (P=0.03), and tumour Cho/Cr was significantly higher in grade 4 than grade 1 tumours (P=0.004). When analyzing tumour subtypes, control tissue Cr was significantly higher in embryonal/germ cell tumours than glial tumours (P=0.044). Binary logistic regression models including MRS metabolite ratios and age, sex, and tumour location covariates could diagnose grade 4 tumours [area under the curve (AUC) =0.857], and grade 1 tumours (AUC =0.766) with reasonable accuracy. CONCLUSIONS: This study suggests that MRS has benefits in the non-invasive diagnosis of paediatric intracranial tumours, in particular, identifying low- and high-grade tumours. Future advances in MRS technology, and larger cross-sectional studies will be necessary to improve the clinical integration of MRS for accurate non-invasive paediatric intracranial tumour diagnosis.

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Background: Hereditary Spastic Paraplegias (HSP) are genetic neurodegenerative disorders affecting the corticospinal tract. No established neuroimaging biomarker is associated with this condition. Methods: A total of 46 patients affected by HSP, genetically and clinically evaluated and tested with SPRS scores, and 46 healthy controls (HC) matched by age and gender underwent a single-voxel Magnetic Resonance Spectroscopy sampling (MRS) of bilateral pre-central and pre-frontal regions. MRS data were analyzed cross-sectionally (at T0 and T1) and longitudinally (T0 vs. T1). Results: Statistically significant data showed that T0 mI/Cr in the pre-central areas of HSP patients was higher than in HC. In the left (L) pre-central area, NAA/Cr was significantly lower in HSP than in HC. In the right (R) pre-frontal area, NAA/Cr was significantly lower in HSP patients than in HC. HSP SPG4 subjects had significantly lower Cho/Cr concentrations in the L pre-central area compared to HC. Among the HSP subjects, non-SPG4 patients had significantly higher mI/Cr in the L pre-central area compared to SPG4 patients. In the R pre-frontal area, NAA/Cr was reduced, and ml/Cr was higher in non-SPG4 patients compared to SPG4 patients. Comparing "pure" and "complex" forms, NAA/Cr was higher in pHSP than in cHSP in the R pre-central and R pre-frontal areas. The longitudinal analysis, which involved fewer patients (n = 30), showed an increase in mI/Cr concentration in the L pre-frontal area among HSP subjects with respect to baseline. The patients had significantly higher SPRS scores at follow-up, with a significant positive correlation between SPRS scores and mI/Cr in the L pre-central area, while in bilateral pre-frontal areas, lower SPRS scores corresponded to higher NAA/Cr concentrations. To explore the discriminating power of MRS in correctly identifying HSP and controls, an inference tree methodology classified HSP subjects and controls with an overall accuracy of 73.9%, a sensitivity of 87.0%, and a specificity of 60.9%. Conclusion: This pilot study indicates that brain MRS is a valuable approach that could potentially serve as an objective biomarker in HSP.

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Background: Advanced MRI-based neuroimaging techniques, such as perfusion and spectroscopy, have been increasingly incorporated into routine follow-up protocols in patients treated for high-grade glioma (HGG), to help differentiate tumor progression from treatment effect. However, these techniques' influence on clinical management remains poorly understood. Objective: To evaluate the impact of MRI-based advanced neuroimaging on clinical decision-making in patients with HGG in the posttreatment setting. Methods: This prospective study, performed at a comprehensive cancer center from March 1, 2017, to October 31, 2020, included adult patients treated by chemoradiation for WHO grade 4 diffuse glioma who underwent MRIbased advanced neuroimaging (comprising multiple perfusion imaging sequences and spectroscopy) to further evaluate findings on conventional MRI equivocal for tumor progression versus treatment effect. The ordering neuro-oncologists completed surveys before and after each advanced neuroimaging session. The percent of care episodes with a change between the intended and actual management plan on the surveys conducted before and after advanced neuroimaging, respectively, was computed and compared with a previously published percent using the Wald test for independent samples proportions. Results: The study included 63 patients (mean age, 55±13 years; 36 women, 27 men) who underwent 70 advanced neuroimaging sessions. Ordering neuro-oncologists' intended and actual management plans on the surveys completed before and after advanced neuroimaging, respectively, differed in 44% (31/70, [95% CI: 33-56%]) of episodes, which differed from the previously published frequency of 8.5% (5/59) (p<.001). These management plan changes included selection of a different plan for 6/8 episodes with an intended plan to enroll patients in a clinical trial, 12/19 episodes with an intended plan to change chemotherapeutic agents, 4/8 episodes with an intended plan of surgical intervention, and 1/2 episodes with an intended plan of re-irradiation. The ordering neuro-oncologists found advanced neuroimaging to be helpful in 93% (95% CI: 87%-99%) (65/70) of episodes. Conclusion: Neuro-oncologists' management plans changed in a substantial fraction of adult patients with HGG who underwent advanced neuroimaging to further evaluate conventional MRI findings equivocal for tumor progression versus treatment effect. Clinical Impact: The findings support incorporation of advanced neuroimaging into HGG posttreatment monitoring protocols.

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BACKGROUND: Inhibition of kinases is the ever-expanding therapeutic approach to various types of cancer. Typically, assessment of the treatment response is accomplished by standard, volumetric imaging procedures, performed weeks to months after the onset of treatment, given the predominantly cytostatic nature of the kinase inhibitors, at least when used as single agents. Therefore, there is a great clinical need to develop new monitoring approaches to detect the response to kinase inhibition much more promptly. Noninvasive 1H magnetic resonance spectroscopy (MRS) can measure in vitro and in vivo concentration of key metabolites which may potentially serve as biomarkers of response to kinase inhibition. METHODS: We employed mantle cell lymphoma (MCL) cell lines demonstrating markedly diverse sensitivity of inhibition of Bruton's tyrosine kinase (BTK) regarding their growth and studied in-depth effects of the inhibition on various aspects of cell metabolism including metabolite synthesis using metabolomics, glucose and oxidative metabolism by Seahorse XF technology, and concentration of index metabolites lactate, alanine, total choline and taurine by 1H MRS. RESULTS: Effective BTK inhibition profoundly suppressed key cell metabolic pathways, foremost pyrimidine and purine synthesis, the citrate (TCA) cycle, glycolysis, and pyruvate and glutamine/alanine metabolism. It also inhibited glycolysis and amino acid-related oxidative metabolism. Finally, it profoundly and quickly decreased concentration of lactate (a product of mainly glycolysis) and alanine (an indicator of amino acid metabolism) and, less universally total choline both in vitro and in vivo, in the MCL xenotransplant model. The decrease correlated directly with the degree of inhibition of lymphoma cell expansion and tumor growth. CONCLUSIONS: Our results indicate that BTK inhibition exerts a broad and profound suppressive effect on cell metabolism and that the affected index metabolites such as lactate, alanine may serve as early, sensitive, and reliable biomarkers of inhibition in lymphoma patients detectable by noninvasive MRS-based imaging method. This kind of imaging-based detection may also be applicable to other kinase inhibitors, as well as diverse lymphoid and non-lymphoid malignancies.

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Purpose: Relaxation correction is crucial for accurately estimating metabolite concentrations measured using in vivo magnetic resonance spectroscopy (MRS). However, the majority of MRS quantification routines assume that relaxation values remain constant across the lifespan, despite prior evidence of T2 changes with aging for multiple of the major metabolites. Here, we comprehensively investigate correlations between T2 and age in a large, multi-site cohort. Methods: We recruited approximately 10 male and 10 female participants from each decade of life: 18-29, 30-39, 40-49, 50-59, and 60+ years old (n=101 total). We collected PRESS data at 8 TEs (30, 50, 74, 101, 135, 179, 241, and 350 ms) from voxels placed in white-matter-rich centrum semiovale (CSO) and gray-matter-rich posterior cingulate cortex (PCC). We quantified metabolite amplitudes using Osprey and fit exponential decay curves to estimate T2. Results: Older age was correlated with shorter T2 for tNAA, tCr3.0, tCr3.9, tCho, Glx, and tissue water in CSO and PCC; rs = -0.21 to -0.65, all p<0.05, FDR-corrected for multiple comparisons. These associations remained statistically significant when controlling for cortical atrophy. T2 values did not differ across the adult lifespan for mI. By region, T2 values were longer in the CSO for tNAA, tCr3.0, tCr3.9, Glx, and tissue water and longer in the PCC for tCho and mI. Conclusion: These findings underscore the importance of considering metabolite T2 changes with aging in MRS quantification. We suggest that future 3T work utilize the equations presented here to estimate age-specific T2 values instead of relying on uniform default values.

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Background: Muscle fat infiltration (MFI) is increasingly recognized as a critical factor influencing muscle function and metabolic health. Accurate quantification of MFI is essential for diagnosing and monitoring various muscular and metabolic disorders. Quantitative Dixon (Q-Dixon) magnetic resonance imaging (MRI) and high-speed T2-corrected multi-echo (HISTO) magnetic resonance spectroscopy (MRS) are both advanced imaging techniques that offer potential for detailed assessment of MFI. However, the validity and reliability of these methods in measuring volumetric changes in muscle composition, particularly in both thigh and paravertebral muscles, have not been thoroughly compared. This study aims to validate volumetric measurements using Q-Dixon MRI against HISTO MRS in thigh and paravertebral muscles, taking into account the heterogeneity of MFI. Methods: A retrospective study was conducted with 54 subjects [mean age, 60 years; 38 male (M)/16 female (F)] for thigh muscle and 56 subjects (mean age, 50 years; 22 M/34 F) for paravertebral muscle assessment using a 3-Tesla MRI. The proton density fat fraction (PDFF) was measured with Q-Dixon MRI and HISTO MRS within the upper-middle part of quadriceps femoris and paravertebral muscles at L4/5 level in volumes-of-interest (VOIs). The corresponding volumetric Q-Dixon freehand VOI PDFF was measured. Scatterplots, Bland-Altman plots, Spearman correlation coefficients, and Wilcoxon signed rank test with Bonferroni correction were employed. The Kruskal-Wallis H tests followed by Bonferroni-corrected post hoc tests were analyzed to compare parameter differences with visual MFI grades. Results: Q-Dixon cubic VOI PDFF correlated positively with HISTO MRS PDFF in thigh (r=0.96, P<0.001) and paravertebral groups (r=0.98, P<0.001), with insignificant differences (P=0.29, 0.82, respectively). Both PDFF values from cubic VOIs in Q-Dixon and HISTO MRS differed from the freehand Q-Dixon PDFF (all P<0.001). Only for <5% HISTO MRS PDFF, there was a difference between HISTO MRS PDFF and Q-Dixon cubic VOI PDFF (P=0.002). Conclusions: Volumetric Q-Dixon cubic VOI PDFF exhibited good correlation and consistency with HISTO MRS PDFF for quantitative fat assessment in thigh and paravertebral muscles except for muscles with fat fraction <5%, and the Q-Dixon freehand VOI PDFF offers a more comprehensive assessment of the actual MFI compared to cubic VOI.

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This review comprehensively explores the evolving role of neuroimaging, specifically magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS), in epilepsy research and clinical practice. Beginning with a concise overview of epilepsy, the discussion emphasizes the crucial importance of neuroimaging in diagnosing and managing this complex neurological disorder. The review delves into the applications of advanced MRI techniques, including high-field MRI, resting-state fMRI, and connectomics, highlighting their impact on refining our understanding of epilepsy's structural and functional dimensions. Additionally, it examines the integration of machine learning in the analysis of intricate neuroimaging data. Moving to the clinical domain, the review outlines the utility of neuroimaging in pre-surgical evaluations and the monitoring of treatment responses and disease progression. Despite significant strides, challenges and limitations are discussed in the routine clinical incorporation of neuroimaging. The review explores promising developments in MRI and MRS technology, potential advancements in imaging biomarkers, and the implications for personalized medicine in epilepsy management. The conclusion underscores the transformative potential of neuroimaging and advocates for continued exploration, collaboration, and technological innovation to propel the field toward a future where tailored, effective interventions improve outcomes for individuals with epilepsy.

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Background and objective Magnetic resonance spectroscopy (MRS) is a magnetic resonance imaging technique used to identify in vivo metabolites non-invasively within the tissue of interest. It plays an important role in diagnosing brain lesions, particularly tumors and infections. There are certain metabolites whose levels are increased or decreased in brain tumors, the ratios of which can also be used to grade the tumors as high- or low-grade. This study aimed to assess the spectrum of different metabolites in intraaxial gliomas using magnetic resonance spectroscopy and to assess the usefulness of their ratios for grading gliomas into high-grade and low-grade. Methods This descriptive cross-sectional study was performed in the radiology department of Nobel Medical College and Teaching Hospital, Biratnagar, Nepal over one year (September 2019 to September 2020). Thirty-five patients diagnosed as having intra-axial tumors were enrolled. After taking informed consent the examination findings were recorded in structured proforma. Siemens' 3 Tesla open magnet MAGNETOM Skyra (Siemens Healthineers AG, Munich, Germany) MR scanner was used to evaluate each patient. Data was analyzed using the software Statistical Package for Social Sciences (SPSS), version 26.0 (IBM Corp., Armonk, NY). Results Out of 35 patients scanned, 18 had high-grade glioma and 17 had low-grade glioma. High-grade glioma had a choline/creatine (Cho/Cr) ratio of 2.44 ± 0.78 and a choline/N-acetyl-aspartate (Cho/NAA) ratio of 2.05 ± 0.84. Low-grade glioma had a Cho/Cr ratio of 1.48 ± 0.50 and a Cho/NAA ratio of 1.41 ± 0.19. Fourteen out of eighteen high-grade gliomas had raised lipid/lactate peaks. The sensitivity, specificity, positive and negative predictive values (PPV and NPV), and accuracy for diagnosing high-grade glioma with a Cho/Cr ratio cut-off of 1.5 was 83.3 %, 82.4%, 83.3%,82.4 %, and 82.85% respectively. Conclusion MRS metabolite ratios can be used to diagnose and grade gliomas. Cho/Cr, Cho/NAA, and the presence or absence of lipid/lactate peak can significantly improve the sensitivity, specificity, predictive values, and accuracy of preoperative glioma grading when used in conjunction with conventional MRI.

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MRS is a noninvasive technique to measure different metabolites in the brain. Changes in the levels of certain metabolites can be used as surrogate markers for Alzheimer's disease. They can potentially be used for diagnosis, prediction of prognosis, or even assessing response to treatment.There are different techniques for MRS acquisitions including STimulated Echo Acquisition Mode (STEAM) and Point Resolved Spectroscopy (PRESS). In terms of localization, single or multi-voxel methods can be used. Based on current data: 1. NAA, marker of neuronal integrity and viability, reduces in AD with longitudinal changes over the time as the disease progresses. There are data claiming that reduction of NAA is associated with tau accumulation, early neurodegenerative processes, and cognitive decline. Therefore, it can be used as a stage biomarker for AD to assess the severity of the disease. With advancement of disease modifying therapies, there is a potential role for NAA in the future to be used as a marker of response to treatment. 2. mI, marker of glial cell proliferation and activation, is associated with AB pathology and has early changes in the course of the disease. The NAA/mI ratio can be predictive of AD development with high specificity and can be utilized in the clinical setting to stratify cases for further evaluation with PET for potential treatments. 3. The changes in the level of other metabolites such as Chol, Glu, Gln, and GABA are controversial because of the lack of standardization of MRS techniques, current technical limitations, and possible region specific changes. 4. Ultrahigh field MRS and more advanced techniques can overcome many of these limitations and enable us to measure more metabolites with higher accuracy. 5. Standardization of MRS techniques, validation of metabolites' changes against PET using PET-guided technique, and longitudinal follow-ups to investigate the temporal changes of the metabolites in relation to other biomarkers and cognition will be crucial to confirm the utility of MRS as a potential noninvasive biomarker for AD.

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Energy metabolism is fundamental for life. It encompasses the utilization of carbohydrates, lipids, and proteins for internal processes, while aberrant energy metabolism is implicated in many diseases. In the present study, using three-dimensional (3D) printing from polycarbonate via fused deposition modeling, we propose a multi-nuclear radiofrequency (RF) coil design with integrated 1H birdcage and interchangeable X-nuclei (2H, 13C, 23Na, and 31P) single-loop coils for magnetic resonance imaging (MRI)/magnetic resonance spectroscopy (MRS). The single-loop coil for each nucleus attaches to an arc bracket that slides unrestrictedly along the birdcage coil inner surface, enabling convenient switching among various nuclei and animal handling. Compared to a commercial 1H birdcage coil, the proposed 1H birdcage coil exhibited superior signal-excitation homogeneity and imaging signal-to-noise ratio (SNR). For X-nuclei study, prominent peaks in spectroscopy for phantom solutions showed excellent SNR, and the static and dynamic peaks of in vivo spectroscopy validated the efficacy of the coil design in structural imaging and energy metabolism detection simultaneously.

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Background and Objective: Osteomyelitis, a severe bone infection caused mainly by pyogenic organisms, poses diagnostic challenges due to its non-specific magnetic resonance imaging (MRI) manifestations. Conventional MRI, though the imaging modality of choice, often exhibits signal abnormalities with overlapping differential diagnoses, potentially leading to overestimation of infection extent and duration. To address these limitations, advanced MRI sequences, including dynamic contrast-enhanced (DCE) MRI, 1H magnetic resonance spectroscopy (MRS), diffusion-weighted imaging (DWI), and Dixon techniques have emerged as promising alternatives. This narrative review explores the potential role of these sequences in aiding the differential diagnosis of osteomyelitis. Methods: We used the PubMed database to search for relevant articles using the MeSH keywords: (osteomyelitis) AND (advanced MRI sequences) and we manually selected the most suitable studies to include in our review. Articles outside of original studies were also included. Only records in English or French were considered. Key Content and Findings: In particular, DWI is useful for characterizing fluid collections, distinguishing bone infarcts, and bacterial skull base osteomyelitis from neoplastic lesions. Moreover, DWI assists in differentiating diabetic foot osteomyelitis (DFO) from Charcot neuro-osteoarthropathy, facilitates the diagnosis of pediatric acute osteoarticular infections, and aids in distinguishing osteomyelitis from Modic I degenerative changes. Additionally, DWI proves valuable in monitoring spinal infections and distinguishing pedal osteomyelitis from other conditions, even in patients with renal impairment. DCE-MRI enhances MRI specificity by assessing contrast uptake over time, providing valuable insights into inflammatory microenvironments. It aids in detecting DFO, differentiating it from acute Charcot arthropathy, and distinguishing osteomyelitis from neuropathic arthropathy. Moreover, DCE-MRI shows potential in assessing response to antibiotic therapy in spinal infections. Dixon acquisition improves image quality and facilitates the detection of bone marrow abnormalities, aiding in the differentiation of diabetic foot from osteomyelitis. It also assists in distinguishing osteomyelitis from neuropathic arthropathy and provides valuable information in evaluating the diabetic foot. Proton MR spectroscopy, a well-established modality, offers metabolic information that can differentiate malignant from benign lesions. Conclusions: The role of advanced MRI techniques in evaluating osteomyelitis remains to be fully defined, and further research is required to explore its potential utility in this context. In conclusion, the incorporation of advanced MRI sequences has shown promise in improving the differential diagnosis of osteomyelitis. Future investigations exploring combinations of these techniques and their clinical applications hold significant potential to enhance diagnostic accuracy and patient outcomes.

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BACKGROUND: Major depressive disorder (MDD) is characterized by depressed mood or loss of interest or pleasure. Generally, women are twice as likely as men to have depression. Taurine, a type of amino acid, plays critical roles in neuronal generation, differentiation, arborization, and formation of synaptic connections. Importantly, it enhances proliferation and synaptogenesis in the hippocampus. When injected into animals, taurine has an antidepressant effect. However, there is no in vivo evidence to show an association between taurine concentration in the human brain and the development of MDD. METHODS: Forty-one unmedicated young women with MDD (ages 18-29) and 43 healthy control participants matched for gender and age were recruited in South Korea. Taurine concentration was measured in the hippocampus, anterior cingulate cortex, and occipital cortex of the MDD and healthy control groups using proton magnetic resonance spectroscopy at 7T. Analysis of covariance was used to examine differences in taurine concentration, adjusting for age as a covariate. RESULTS: Taurine concentration in the hippocampus was lower (F1,75 = 5.729, p = .019, Δη2 = 0.073) for the MDD group (mean [SEM] = 0.91 [0.06] mM) than for the healthy control group (1.13 [0.06] mM). There was no significant difference in taurine concentration in the anterior cingulate cortex or occipital cortex between the two groups. CONCLUSIONS: This study demonstrates that a lower level of taurine concentration in the hippocampus may be a novel characteristic of MDD.

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BACKGROUND AND OBJECTIVES: Blood-based biomarkers and advanced neuroimaging modalities such as magnetic resonance spectroscopy (MRS) or diffusion tensor imaging (DTI) have enhanced our understanding of the pathophysiology of mild traumatic brain injury (mTBI). However, there is limited published data on how blood biomarkers relate to neuroimaging biomarkers post-mTBI. METHODS: To investigate this, 30 patients with mTBI and 21 healthy controls were enrolled. Data was collected at two timepoints postinjury: acute, < 24 h, (blood) and subacute, four-to-six weeks, (blood and imaging). Interleukin (IL) 6 and 10 (inflammation), free thiols (systemic oxidative stress) and neurofilament light (NF-L) (axonal injury) were quantified in plasma. The neurometabolites total N-acetyl aspartate (tNAA) (neuronal energetics), Myo-Inositol (Ins) and total Choline (tCh) (inflammation) and, Glutathione (GSH, oxidative stress) were quantified using MRS. RESULTS: Concentrations of IL-6 and IL-10 were significantly elevated in the acute phase post-mTBI, while NF-L was elevated only in the subacute phase. Total NAA was lowered in patients with mTBI, although this difference was only nominally significant (uncorrected P < 0.05). Within the patient group, acute IL-6 and subacute tNAA levels were negatively associated (r = - 0.46, uncorrected-P = 0.01), albeit not at a threshold corrected for multiple testing (corrected-P = 0.17). When age was added as a covariate a significant increase in correlation magnitude was observed (ρ = - 0.54, corrected-P = 0.03). CONCLUSION: This study demonstrates potential associations between the intensity of the inflammatory response in the acute phase post-mTBI and neurometabolic perturbations in the subacute phase. Future studies should assess the longitudinal dynamics of blood-based and imaging biomarkers after injury.

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This case report highlights the diagnostic challenges encountered in a 30-year-old female presenting with fever followed by Wernicke's aphasia without right-sided weakness, ultimately diagnosed as tumefactive demyelination (TD). TD is a rare neurological condition often misidentified as brain tumors or inflammatory disorders. The case emphasizes the importance of precise differentiation through advanced magnetic resonance imaging, showing restricted diffusion at lesion edges and the absence of gadolinium enhancement. Accurate diagnosis is crucial for tailored treatment and prognostic assessment. This case contributes to our understanding of TD and underscores the need for continued research and collaboration in the field of rare neurological disorders.

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Background: Caffeine is the most widely consumed psychostimulant. Despite this, the effects of acute caffeine intake on brain metabolite levels remain largely unknown. We aimed to investigate the effect of acute caffeine intake on brain metabolite concentrations in different caffeine consumption habit groups and to explore the association between metabolite changes and sleepiness. Methods: Forty-five healthy adults were divided into groups based on their daily caffeine consumption: ≥1 cup/day, <1 cup/day, and no consumption. The exclusion criteria were the presence of neurological disorder, habitual consumption of mind-altering substances, and individuals who were unable to undergo magnetic resonance imaging. Mescher-Garwood point resolved spectroscopy and conventional spectroscopy data were acquired at 3 Tesla from voxels in the thalamus and posterior cingulate cortex (PCC). Subjective sleepiness was measured with the Karolinska Sleepiness Scale. Results: The results of two-way repeated measures analysis of variance indicated a significant interaction effect between time and group for glutamate, glycerylphosphocholine and phosphocholine (GPC + PCH), myo-inositol, glutamate + glutamine (Glx), and creatine and phosphocreatine (Cr + PCr) of the thalamus (all P<0.01), and glutamate (P<0.0001), GPC + PCH (P=0.016), and Glx (P<0.0001) of the PCC. The change between pre- and post-caffeine intake results with significant reductions in γ-aminobutyric acid-positive macromolecule (GABA+) (thalamus, P=0.011), Glx (thalamus, P=0.002), glutamate (PCC, P<0.0001), and significant increments in GPC + PCH (thalamus, P=0.012 and PCC, P<0.0001), myo-inositol (thalamus, P=0.009), and Glx (PCC, P<0.0001). The change among the groups, with the ≥1 cup/day was significantly higher than the <1 cup/day or no consumption for glutamate (PCC, P=0.028), GPC (thalamus, P=0.001; PCC, P=0.026), and Cr + PCr (PCC, P=0.035); ≥1 cup/day was significantly lower than <1 cup/day and no consumption for glutamate (thalamus, P<0.0001), Cr + PCr (thalamus, P=0.003), Glx (thalamus, P=0.014), and myo-inositol (PCC, P=0.009). Bivariate correlation analysis revealed that GABA+ in the thalamus voxel (r=-0.7676; P<0.0001) was negatively correlated with subjective sleepiness. Conclusions: Higher caffeine consumption had a significant impact on brain metabolites. Magnetic resonance spectroscopy was sensitive in measuring brain metabolite fluctuations after caffeine intake, particularly the levels of GABA+ in the thalamus, which was significantly correlated with sleepiness.

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Background: Proton magnetic resonance spectroscopy (1H MRS) is an imaging method for quantification of bone marrow fat. It has been used for evaluation of bone marrow changes in patients with chronic disorders, such as chronic kidney disease (CKD). In these patients, there is a high turnover state, with an excessive amount of non-mineralized component of bone, leading to skeletal fragility and subsequent increased fracture risk. Methods: Thirty CKD patients underwent magnetic resonance spectroscopy (MRS) and quantitative computed tomography (QCT), and eight healthy controls underwent MRS at lumbar spine. Proton density fat fraction (PDFF) and volumetric bone mineral density (vBMD) of L1-L3 were determined from MRS and QCT respectively. CKD patients were divided into three groups according to glomerular filtration rate (GFR); for each patient, blood levels of parathyroid hormone (PTH) were also reported. Paired t-tests, Pearson's correlation coefficients and analysis of variance were applied. Results: The mean age of patients was 59.6±11.5 years, mean GFR value was 21.5±8.8 mL/min and mean PTH value was 149.2±53.1 pg/mL. PDFF at L1-L3 levels was significantly higher in CKD patients compared to controls (71.4±8.7 vs. 55.5±7.6; P<0.001) and showed an inverse correlation with vBMD (r=-0.71; P<0.001). PDFF significantly increased from CKD group 1 to CKD group 3 (P=0.002) and was inversely correlated with GFR (r=-0.53; P=0.003). There was no significant association between PDFF and PTH values (P>0.05). Conclusions: In CKD patients, PDFF assessed by MRS at lumbar spine is higher than in healthy population, correlates with bone loss assessed by QCT and significantly increases with the worsening of renal function. MRS is a reliable and highly repeatable tool for PDFF quantification in CKD patients.

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BACKGROUND: While magnetic resonance imaging (MRI) provides high resolution anatomical images with sharp soft tissue contrast, magnetic resonance spectroscopy (MRS) enables non-invasive detection and measurement of biochemicals and metabolites. However, MRS has low signal-to-noise ratio (SNR) when concentrations of metabolites are in the range of millimolar. Standard approach of using a high number of signal averaging (NSA) to achieve sufficient SNR comes at the cost of a long acquisition time. PURPOSE: We propose to use deep-learning approaches to denoise MRS data without increasing NSA. This method has potential to reduce the acquisition time as well as improve SNR and quality of spectra, which could enhance the diagnostic value and broaden the clinical applications of MRS. METHODS: The study was conducted using data collected from the brain spectroscopy phantom and human subjects. We utilized a stack auto-encoder (SAE) network to train deep learning models for denoising low NSA data (NSA = 1, 2, 4, 8, and 16) randomly truncated from high SNR data collected with high NSA (NSA = 192), which were also used to obtain the ground truth. We applied both self-supervised and fully-supervised training approaches and compared their performance of denoising low NSA data based on improvement in SNR. To prevent overfitting, the SAE network was trained in a patch-based manner. We then tested the denoising methods on noise-containing data collected from the phantom and human subjects, including data from brain tumor patients. We evaluated their performance by comparing the SNR levels and mean squared errors (MSEs) calculated for the whole spectra against high SNR "ground truth", as well as the value of chemical shift of N-acetyl-aspartate (NAA) before and after denoising. RESULTS: With the SAE model, the SNR of low NSA data (NSA = 1) obtained from the phantom increased by 28.5% and the MSE decreased by 42.9%. For low NSA data of the human parietal and temporal lobes, the SNR increased by 32.9% and the MSE decreased by 63.1%. In all cases, the chemical shift of NAA in the denoised spectra closely matched with the high SNR spectra without significant distortion to the spectra after denoising. Furthermore, the denoising performance of the SAE model was more effective in denoising spectra with higher noise levels. CONCLUSIONS: The reported SAE denoising method is a model-free approach to enhance the SNR of MRS data collected with low NSA. With the denoising capability, it is possible to acquire MRS data with a few NSA, shortening the scan time while maintaining adequate spectroscopic information for detecting and quantifying the metabolites of interest. This approach has the potential to improve the efficiency and effectiveness of clinical MRS data acquisition by reducing the scan time and increasing the quality of spectroscopic data.

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