NMR in Biomedicine最新文献

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Identifying biochemical changes in the kidney using proton nuclear magnetic resonance in an adenine diet chronic kidney disease mouse model. 利用质子核磁共振识别腺嘌呤饮食慢性肾病小鼠模型中肾脏的生化变化。
IF 2.7 4区 医学
NMR in Biomedicine Pub Date : 2024-12-01 Epub Date: 2024-09-04 DOI: 10.1002/nbm.5257
Tyrone L R Humphries, Glenda C Gobe, Aaron J Urquhart, Robert J Ellis, Graham J Galloway, David A Vesey, Ross S Francis
{"title":"Identifying biochemical changes in the kidney using proton nuclear magnetic resonance in an adenine diet chronic kidney disease mouse model.","authors":"Tyrone L R Humphries, Glenda C Gobe, Aaron J Urquhart, Robert J Ellis, Graham J Galloway, David A Vesey, Ross S Francis","doi":"10.1002/nbm.5257","DOIUrl":"10.1002/nbm.5257","url":null,"abstract":"<p><p>This study aimed to investigate the metabolic changes in the kidneys in a murine adenine-diet model of chronic kidney disease (CKD). Kidney fibrosis is the common pathological manifestation across CKD aetiologies. Sustained inflammation and fibrosis cause changes in preferred energy metabolic pathways in the cells of the kidney. Kidney cortical tissue from mice receiving a control or adenine-supplemented diet for 8 weeks (late inflammation and fibrosis) and 12 weeks (8 weeks of treatment followed by 4 weeks recovery) were analysed by 2D-correlated nuclear magnetic resonance spectroscopy and compared with histopathology and biomarkers of kidney damage. Tissue metabolite and lipid levels were assessed using the MestreNova software. Expression of genes related to inflammation, fibrosis, and metabolism were measured using quantitative polymerase chain reaction. Animals showed indicators of severely impaired kidney function at 8 and 12 weeks. Significantly increased fibrosis was present at 8 weeks but not in the recovery group suggesting some reversal of fibrosis and amelioration of inflammation. At 8 weeks, metabolites associated with glycolysis were increased, while lipid signatures were decreased. Genes involved in fatty acid oxidation were decreased at 8 weeks but not 12 weeks while genes associated with glycolysis were significantly increased at 8 weeks but not at 12 weeks. In this murine model of CKD, kidney fibrosis was associated with the accumulation of triglyceride and free lactate. There was an up-regulation of glycolytic enzymes and down-regulation of lipolytic enzymes. These metabolic changes reflect the energy demands associated with progressive kidney disease where there is a switch from fatty acid oxidation to that of glycolysis.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":" ","pages":"e5257"},"PeriodicalIF":2.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142126284","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}
引用次数: 0
Accelerated 2D radial Look-Locker T1 mapping using a deep learning-based rapid inversion recovery sampling technique. 利用基于深度学习的快速反演恢复采样技术加速二维径向 Look-Locker T1 绘图。
IF 2.7 4区 医学
NMR in Biomedicine Pub Date : 2024-12-01 Epub Date: 2024-10-02 DOI: 10.1002/nbm.5266
Eze Ahanonu, Ute Goerke, Kevin Johnson, Brian Toner, Diego R Martin, Vibhas Deshpande, Ali Bilgin, Maria Altbach
{"title":"Accelerated 2D radial Look-Locker T1 mapping using a deep learning-based rapid inversion recovery sampling technique.","authors":"Eze Ahanonu, Ute Goerke, Kevin Johnson, Brian Toner, Diego R Martin, Vibhas Deshpande, Ali Bilgin, Maria Altbach","doi":"10.1002/nbm.5266","DOIUrl":"10.1002/nbm.5266","url":null,"abstract":"<p><p>Efficient abdominal coverage with T1-mapping methods currently available in the clinic is limited by the breath hold period (BHP) and the time needed for T1 recovery. This work develops a T1-mapping framework for efficient abdominal coverage based on rapid T1 recovery curve (T1RC) sampling, slice-selective inversion, optimized slice interleaving, and a convolutional neural network (CNN)-based T1 estimation. The effect of reducing the T1RC sampling was evaluated by comparing T1 estimates from T1RC ranging from 0.63 to 2.0 s with reference T1 values obtained from T1RC = 2.5-5 s. Slice interleaving methodologies were evaluated by comparing the T1 variation in abdominal organs across slices. The repeatability of the proposed framework was demonstrated by performing acquisition on test subjects across imaging sessions. Analysis of in vivo data based on retrospectively shortening the T1RC showed that with the CNN framework, a T1RC = 0.84 s yielded T1 estimates without significant changes in mean T1 (p > 0.05) or significant increase in T1 variability (p > 0.48) compared to the reference. Prospectively acquired data using T1RC = 0.84 s, an optimized slice interleaving scheme, and the CNN framework enabled 21 slices in a 20 s BHP. Analyses across abdominal organs produced T1 values within 2% of the reference. Repeatability experiments yielded Pearson's correlation, repeatability coefficient, and coefficient of variation of 0.99, 2.5%, and 0.12%, respectively. The proposed T1 mapping framework provides full abdominal coverage within a single BHP.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":" ","pages":"e5266"},"PeriodicalIF":2.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142365944","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}
引用次数: 0
Reducing thermal noise in high-resolution quantitative magnetic resonance imaging rotating frame relaxation mapping of the human brain at 3 T. 降低 3 T 人脑高分辨率定量磁共振成像旋转帧弛豫映射中的热噪声。
IF 2.7 4区 医学
NMR in Biomedicine Pub Date : 2024-12-01 Epub Date: 2024-08-21 DOI: 10.1002/nbm.5228
Sara Ponticorvo, Antonietta Canna, Steen Moeller, Mehmet Akcakaya, Gregory J Metzger, Pavel Filip, Lynn E Eberly, Shalom Michaeli, Silvia Mangia
{"title":"Reducing thermal noise in high-resolution quantitative magnetic resonance imaging rotating frame relaxation mapping of the human brain at 3 T.","authors":"Sara Ponticorvo, Antonietta Canna, Steen Moeller, Mehmet Akcakaya, Gregory J Metzger, Pavel Filip, Lynn E Eberly, Shalom Michaeli, Silvia Mangia","doi":"10.1002/nbm.5228","DOIUrl":"10.1002/nbm.5228","url":null,"abstract":"<p><p>Quantitative maps of rotating frame relaxation (RFR) time constants are sensitive and useful magnetic resonance imaging tools with which to evaluate tissue integrity in vivo. However, to date, only moderate image resolutions of 1.6 x 1.6 x 3.6 mm<sup>3</sup> have been used for whole-brain coverage RFR mapping in humans at 3 T. For more precise morphometrical examinations, higher spatial resolutions are desirable. Towards achieving the long-term goal of increasing the spatial resolution of RFR mapping without increasing scan times, we explore the use of the recently introduced Transform domain NOise Reduction with DIstribution Corrected principal component analysis (T-NORDIC) algorithm for thermal noise reduction. RFR acquisitions at 3 T were obtained from eight healthy participants (seven males and one female) aged 52 ± 20 years, including adiabatic T1ρ, T2ρ, and nonadiabatic Relaxation Along a Fictitious Field (RAFF) in the rotating frame of rank n = 4 (RAFF4) with both 1.6 x 1.6 x 3.6 mm<sup>3</sup> and 1.25 x 1.25 x 2 mm<sup>3</sup> image resolutions. We compared RFR values and their confidence intervals (CIs) obtained from fitting the denoised versus nondenoised images, at both voxel and regional levels separately for each resolution and RFR metric. The comparison of metrics obtained from denoised versus nondenoised images was performed with a two-sample paired t-test and statistical significance was set at p less than 0.05 after Bonferroni correction for multiple comparisons. The use of T-NORDIC on the RFR images prior to the fitting procedure decreases the uncertainty of parameter estimation (lower CIs) at both spatial resolutions. The effect was particularly prominent at high-spatial resolution for RAFF4. Moreover, T-NORDIC did not degrade map quality, and it had minimal impact on the RFR values. Denoising RFR images with T-NORDIC improves parameter estimation while preserving the image quality and accuracy of all RFR maps, ultimately enabling high-resolution RFR mapping in scan times that are suitable for clinical settings.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":" ","pages":"e5228"},"PeriodicalIF":2.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11650668/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142018171","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}
引用次数: 0
Significant age-related differences between lower leg muscles of older and younger female subjects detected by ultrashort echo time magnetization transfer modeling. 通过超短回波时间磁化转移建模检测老年女性和年轻女性小腿肌肉之间与年龄有关的显著差异。
IF 2.7 4区 医学
NMR in Biomedicine Pub Date : 2024-12-01 Epub Date: 2024-08-18 DOI: 10.1002/nbm.5237
Saeed Jerban, Hamidreza Shaterian Mohammadi, Jiyo S Athertya, Amir Masoud Afsahi, Niloofar Shojaeiadib, Dina Moazamian, Samuel R Ward, Gina Woods, Christine B Chung, Jiang Du, Eric Y Chang
{"title":"Significant age-related differences between lower leg muscles of older and younger female subjects detected by ultrashort echo time magnetization transfer modeling.","authors":"Saeed Jerban, Hamidreza Shaterian Mohammadi, Jiyo S Athertya, Amir Masoud Afsahi, Niloofar Shojaeiadib, Dina Moazamian, Samuel R Ward, Gina Woods, Christine B Chung, Jiang Du, Eric Y Chang","doi":"10.1002/nbm.5237","DOIUrl":"10.1002/nbm.5237","url":null,"abstract":"<p><p>Magnetization transfer (MT) magnetic resonance imaging (MRI) can be used to estimate the fraction of water and macromolecular proton pools in tissues. MT modeling paired with ultrashort echo time acquisition (UTE-MT modeling) has been proposed to improve the evaluation of the myotendinous junction and fibrosis in muscle tissues, which the latter increases with aging. This study aimed to determine if the UTE-MT modeling technique is sensitive to age-related changes in the skeletal muscles of the lower leg. Institutional review board approval was obtained, and all recruited subjects provided written informed consent. The legs of 31 healthy younger (28.1 ± 6.1 years old, BMI = 22.3 ± 3.5) and 20 older (74.7 ± 5.5 years old, BMI = 26.7 ± 5.9) female subjects were imaged using UTE sequences on a 3 T MRI scanner. MT ratio (MTR), macromolecular fraction (MMF), macromolecular T2 (T2-MM), and water T2 (T2-W) were calculated using UTE-MT modeling for the anterior tibialis (ATM), posterior tibialis (PTM), soleus (SM), and combined lateral muscles. Results were compared between groups using the Wilcoxon rank sum test. Three independent observers selected regions of interest (ROIs) and processed UTE-MRI images separately, and the intraclass correlation coefficient (ICC) was calculated for a reproducibility study. Significantly lower mean MTR and MMF values were present in the older compared with the younger group in all studied lower leg muscles. T2-MM showed significantly lower values in the older group only for PTM and SM muscles. In contrast, T2-W showed significantly higher values in the older group. The age-related differences were more pronounced for MMF (-17 to -19%) and T2-W (+20 to 47%) measurements in all muscle groups compared with other investigated MR measures. ICCs were higher than 0.93, indicating excellent consistency between the ROI selection and MRI measurements of independent readers. As demonstrated by significant differences between younger and older groups, this research emphasizes the potential of UTE-MT MRI techniques in evaluating age-related skeletal muscle changes.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":" ","pages":"e5237"},"PeriodicalIF":2.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142000466","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}
引用次数: 0
Single-shot multi-b-value (SSMb) diffusion-weighted MRI using spin echo and stimulated echoes with variable flip angles. 使用自旋回波和可变翻转角刺激回波的单次多 b 值(SSMb)扩散加权磁共振成像。
IF 2.7 4区 医学
NMR in Biomedicine Pub Date : 2024-12-01 Epub Date: 2024-09-22 DOI: 10.1002/nbm.5261
Guangyu Dan, Kaibao Sun, Qingfei Luo, Xiaohong Joe Zhou
{"title":"Single-shot multi-b-value (SSMb) diffusion-weighted MRI using spin echo and stimulated echoes with variable flip angles.","authors":"Guangyu Dan, Kaibao Sun, Qingfei Luo, Xiaohong Joe Zhou","doi":"10.1002/nbm.5261","DOIUrl":"10.1002/nbm.5261","url":null,"abstract":"<p><p>Conventional diffusion-weighted imaging (DWI) sequences employing a spin echo or stimulated echo sensitize diffusion with a specific b-value at a fixed diffusion direction and diffusion time (Δ). To compute apparent diffusion coefficient (ADC) and other diffusion parameters, the sequence needs to be repeated multiple times by varying the b-value and/or gradient direction. In this study, we developed a single-shot multi-b-value (SSMb) diffusion MRI technique, which combines a spin echo and a train of stimulated echoes produced with variable flip angles. The method involves a pair of 90° radio frequency (RF) pulses that straddle a diffusion gradient lobe (G<sub>D</sub>), to rephase the magnetization in the transverse plane, producing a diffusion-weighted spin echo acquired by the first echo-planar imaging (EPI) readout train. The magnetization stored along the longitudinal axis is successively re-excited by a series of n variable-flip-angle pulses, each followed by a diffusion gradient lobe G<sub>D</sub> and a subsequent EPI readout train to sample n stimulated-echo signals. As such, (n + 1) diffusion-weighted images, each with a distinct b-value, are acquired in a single shot. The SSMb sequence was demonstrated on a diffusion phantom and healthy human brain to produce diffusion-weighted images, which were quantitative analyzed using a mono-exponential model. In the phantom experiment, SSMb provided similar ADC values to those from a commercial spin-echo EPI (SE-EPI) sequence (r = 0.999). In the human brain experiment, SSMb enabled a fourfold scan time reduction and yielded slightly lower ADC values (0.83 ± 0.26 μm<sup>2</sup>/ms) than SE-EPI (0.88 ± 0.29 μm<sup>2</sup>/ms) in all voxels excluding cerebrospinal fluid, likely due to the influence of varying diffusion times. The feasibility of using SSMb to acquire multiple images in a single shot for intravoxel incoherent motion (IVIM) analysis was also demonstrated. In conclusion, despite a relatively low signal-to-noise ratio, the proposed SSMb technique can substantially increase the data acquisition efficiency in DWI studies.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":" ","pages":"e5261"},"PeriodicalIF":2.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142292261","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}
引用次数: 0
Elliptical Halbach magnet and gradient modules for low-field portable magnetic resonance imaging. 用于低场便携式磁共振成像的椭圆形哈尔巴赫磁体和梯度模块。
IF 2.7 4区 医学
NMR in Biomedicine Pub Date : 2024-12-01 Epub Date: 2024-09-30 DOI: 10.1002/nbm.5258
Fernando Galve, Eduardo Pallás, Teresa Guallart-Naval, Pablo García-Cristóbal, Pablo Martínez, José M Algarín, Jose Borreguero, Rubén Bosch, Francisco Juan-Lloris, José M Benlloch, Joseba Alonso
{"title":"Elliptical Halbach magnet and gradient modules for low-field portable magnetic resonance imaging.","authors":"Fernando Galve, Eduardo Pallás, Teresa Guallart-Naval, Pablo García-Cristóbal, Pablo Martínez, José M Algarín, Jose Borreguero, Rubén Bosch, Francisco Juan-Lloris, José M Benlloch, Joseba Alonso","doi":"10.1002/nbm.5258","DOIUrl":"10.1002/nbm.5258","url":null,"abstract":"<p><p>This study aims to develop methods to design the complete magnetic system for a truly portable MRI scanner for neurological and musculoskeletal (MSK) applications, optimized for field homogeneity, field of view (FoV), and gradient performance compared to existing low-weight configurations. We explore optimal elliptic-bore Halbach configurations based on discrete arrays of permanent magnets. In this way, we seek to improve the field homogeneity and remove constraints to the extent of the gradient coils typical of Halbach magnets. Specifically, we have optimized a tightly packed distribution of magnetic Nd<sub>2</sub>Fe<sub>14</sub>B cubes with differential evolution algorithms and a second array of shimming magnets with interior point and differential evolution methods. We have also designed and constructed an elliptical set of gradient coils that extend over the whole magnet length, maximizing the distance between the lobe centers. These are optimized with a target field method minimizing a cost function that considers also heat dissipation. We have employed the new toolbox to build the main magnet and gradient modules for a portable MRI scanner designed for point-of-care and residential use. The elliptical Halbach bore has semi-axes of 10 and 14& cm, and the magnet generates a field of 87& mT homogeneous down to 5700& ppm (parts per million) in a 20-cm diameter FoV; it weighs 216& kg and has a width of 65& cm and a height of 72& cm. Gradient efficiencies go up to around 0.8& mT/m/A, for a maximum of 12& mT/m within 0.5& ms with 15& A and 15& V amplifier. The distance between lobes is 28& cm, significantly increased with respect to other Halbach-based scanners. Heat dissipation is around 25& W at maximum power, and gradient deviations from linearity are below 20% in a 20-cm sphere. Elliptic-bore Halbach magnets enhance the ergonomicity and field distribution of low-cost portable MRI scanners, while allowing for full-length gradient support to increase the FoV. This geometry can be potentially adapted for a prospective low-cost whole-body technology.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":" ","pages":"e5258"},"PeriodicalIF":2.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142350984","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}
引用次数: 0
Validation of an ultrahigh contrast divided subtracted inversion recovery technique using a standard T1 phantom. 使用标准 T1 模体验证超高对比度分减反转复原技术。
IF 2.7 4区 医学
NMR in Biomedicine Pub Date : 2024-12-01 Epub Date: 2024-10-02 DOI: 10.1002/nbm.5269
Mark Bydder, Fadil Ali, Paul Condron, Daniel M Cornfeld, Gil Newburn, Eryn E Kwon, Maryam Tayebi, Miriam Scadeng, Tracy R Melzer, Samantha J Holdsworth, Graeme M Bydder
{"title":"Validation of an ultrahigh contrast divided subtracted inversion recovery technique using a standard T<sub>1</sub> phantom.","authors":"Mark Bydder, Fadil Ali, Paul Condron, Daniel M Cornfeld, Gil Newburn, Eryn E Kwon, Maryam Tayebi, Miriam Scadeng, Tracy R Melzer, Samantha J Holdsworth, Graeme M Bydder","doi":"10.1002/nbm.5269","DOIUrl":"10.1002/nbm.5269","url":null,"abstract":"<p><p>The divided subtracted inversion recovery (dSIR) is a high T<sub>1</sub> contrast technique that shows changes in white matter in patients with traumatic brain injury and hypoxic injury. The changes can be explained by small differences in T<sub>1</sub>; however, to date, there has been no independent validation of the technique using a standard reference. The present study develops the theory of the dSIR signal and performs validation using the NIST/ISMRM T<sub>1</sub> phantom. Non-idealities are explored, including the influence of noise bias and finite repetition time (TR), which leads to the introduction of an optimally efficient TR for inversion recovery acquisitions. Results show excellent agreement with theoretical calculations.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":" ","pages":"e5269"},"PeriodicalIF":2.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142361857","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}
引用次数: 0
Diffusion MRI in prostate cancer with ultra-strong whole-body gradients. 利用超强全身梯度对前列腺癌进行弥散磁共振成像。
IF 2.7 4区 医学
NMR in Biomedicine Pub Date : 2024-12-01 Epub Date: 2024-08-27 DOI: 10.1002/nbm.5229
Malwina Molendowska, Marco Palombo, Kieran G Foley, Krishna Narahari, Fabrizio Fasano, Derek K Jones, Daniel C Alexander, Eleftheria Panagiotaki, Chantal M W Tax
{"title":"Diffusion MRI in prostate cancer with ultra-strong whole-body gradients.","authors":"Malwina Molendowska, Marco Palombo, Kieran G Foley, Krishna Narahari, Fabrizio Fasano, Derek K Jones, Daniel C Alexander, Eleftheria Panagiotaki, Chantal M W Tax","doi":"10.1002/nbm.5229","DOIUrl":"10.1002/nbm.5229","url":null,"abstract":"<p><p>Diffusion-weighted MRI (dMRI) is universally recommended for the detection and classification of prostate cancer (PCa), with PI-RADS recommendations to acquire b-values of ≥1.4 ms/μm<sup>2</sup>. However, clinical dMRI suffers from a low signal-to-noise ratio (SNR) as the consequence of prolonged echo times (TEs) attributable to the limited gradient power in the range of 40-80 mT/m. To overcome this, MRI systems with strong gradients have been designed but so far have mainly been applied in the brain. The aim of this work was to assess the feasibility, data quality, SNR and contrast-to-noise ratio (CNR) of measurements in PCa with a 300 mT/m whole-body system. A cohort of men without and with diagnosed PCa were imaged on a research-only 3T Connectom Siemens MRI system equipped with a gradient amplitude of 300 mT/m. dMRI at high b-values were acquired using high gradient amplitudes and compared with gradient capabilities mimicking clinical systems. Data artefacts typically amplified with stronger gradients were assessed and their correction evaluated. The SNR gains and lesion-to-healthy tissue CNR were statistically tested investigating the effect of protocol and b-value. The diagnostic quality of the images for different dMRI protocols was assessed by an experienced radiologist using a 5-point Likert scale and an adapted PI-QUAL scoring system. The strong gradients for prostate dMRI allowed a significant gain in SNR per unit time compared with clinical gradients. Furthermore, a 1.6-2.1-fold increase in CNR was observed. Despite the more pronounced artefacts typically associated with strong gradients, a satisfactory correction could be achieved. Smoother and less biased parameter maps were obtained with protocols at shorter TEs. The results of this study show that dMRI in PCa with a whole-body 300-mT/m scanner is feasible without a report of physiological effects, SNR and CNR can be improved compared with lower gradient strengths, and artefacts do not negate the benefits of strong gradients and can be ameliorated. This assessment provides the first essential step towards unveiling the full potential of cutting-edge scanners, now increasingly becoming available, to advance early detection and diagnostic precision.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":" ","pages":"e5229"},"PeriodicalIF":2.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142081057","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}
引用次数: 0
Comparison of compartmental analytical Blood-Oxygen-Level-Dependent functional Magnetic Resonance Imaging models against Monte Carlo simulations performed over cortical micro-angiograms. 将分区分析型血氧饱和度依赖性功能磁共振成像模型与通过皮层微血管图进行的蒙特卡罗模拟进行比较。
IF 2.7 4区 医学
NMR in Biomedicine Pub Date : 2024-12-01 Epub Date: 2024-09-08 DOI: 10.1002/nbm.5252
Jordan Charest, Mathieu Walsh, Élie Genois, Emmanuelle Sévigny, Pierre-Olivier Schwarz, Louis Gagnon, Michèle Desjardins
{"title":"Comparison of compartmental analytical Blood-Oxygen-Level-Dependent functional Magnetic Resonance Imaging models against Monte Carlo simulations performed over cortical micro-angiograms.","authors":"Jordan Charest, Mathieu Walsh, Élie Genois, Emmanuelle Sévigny, Pierre-Olivier Schwarz, Louis Gagnon, Michèle Desjardins","doi":"10.1002/nbm.5252","DOIUrl":"10.1002/nbm.5252","url":null,"abstract":"<p><p>Blood oxygen level-dependent functional magnetic resonance imaging (BOLD fMRI) arises from a physiological and physical cascade of events taking place at the level of the cortical microvasculature which constitutes a medium with complex geometry. Several analytical models of the BOLD contrast have been developed, but these have not been compared directly against detailed bottom-up modeling methods. Using a 3D modeling method based on experimentally measured images of mice microvasculature and Monte Carlo simulations, we quantified the accuracy of two analytical models to predict the amplitude of the BOLD response from 1.5 to 7 T, for different echo time (TE) and for both gradient echo and spin echo acquisition protocols. We also showed that accounting for the tridimensional structure of the microvasculature results in more accurate prediction of the BOLD amplitude, even if the values for SO<sub>2</sub> were averaged across individual vascular compartments. A secondary finding is that modeling the venous compartment as two individual compartments results in more accurate prediction of the BOLD amplitude compared with standard homogenous venous modeling, arising from the bimodal distribution of venous SO<sub>2</sub> across the microvasculature in our data.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":" ","pages":"e5252"},"PeriodicalIF":2.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142154711","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}
引用次数: 0
Arterial input function estimation compensating for inflow and partial voluming in dynamic contrast-enhanced MRI. 动态对比增强磁共振成像中补偿流入和部分容积的动脉输入功能估算。
IF 2.7 4区 医学
NMR in Biomedicine Pub Date : 2024-12-01 Epub Date: 2024-08-06 DOI: 10.1002/nbm.5225
Chih-Hsien Tseng, Martijn A Nagtegaal, Matthias J P van Osch, Jaap Jaspers, Alejandra Mendez Romero, Piotr Wielopolski, Marion Smits, Frans M Vos
{"title":"Arterial input function estimation compensating for inflow and partial voluming in dynamic contrast-enhanced MRI.","authors":"Chih-Hsien Tseng, Martijn A Nagtegaal, Matthias J P van Osch, Jaap Jaspers, Alejandra Mendez Romero, Piotr Wielopolski, Marion Smits, Frans M Vos","doi":"10.1002/nbm.5225","DOIUrl":"10.1002/nbm.5225","url":null,"abstract":"<p><p>Both inflow and the partial volume effect (PVE) are sources of error when measuring the arterial input function (AIF) in dynamic contrast-enhanced (DCE) MRI. This is relevant, as errors in the AIF can propagate into pharmacokinetic parameter estimations from the DCE data. A method was introduced for flow correction by estimating and compensating the number of the perceived pulse of spins during inflow. We hypothesized that the PVE has an impact on concentration-time curves similar to inflow. Therefore, we aimed to study the efficiency of this method to compensate for both effects simultaneously. We first simulated an AIF with different levels of inflow and PVE contamination. The peak, full width at half-maximum (FWHM), and area under curve (AUC) of the reconstructed AIFs were compared with the true (simulated) AIF. In clinical data, the PVE was included in AIFs artificially by averaging the signal in voxels surrounding a manually selected point in an artery. Subsequently, the artificial partial volume AIFs were corrected and compared with the AIF from the selected point. Additionally, corrected AIFs from the internal carotid artery (ICA), the middle cerebral artery (MCA), and the venous output function (VOF) estimated from the superior sagittal sinus (SSS) were compared. As such, we aimed to investigate the effectiveness of the correction method with different levels of inflow and PVE in clinical data. The simulation data demonstrated that the corrected AIFs had only marginal bias in peak value, FWHM, and AUC. Also, the algorithm yielded highly correlated reconstructed curves over increasingly larger neighbourhoods surrounding selected arterial points in clinical data. Furthermore, AIFs measured from the ICA and MCA produced similar peak height and FWHM, whereas a significantly larger peak and lower FWHM was found compared with the VOF. Our findings indicate that the proposed method has high potential to compensate for PVE and inflow simultaneously. The corrected AIFs could thereby provide a stable input source for DCE analysis.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":" ","pages":"e5225"},"PeriodicalIF":2.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141897906","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}
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