Joao Tourais, Guruprasad Krishnamoorthy, Jouke Smink, Marcel Breeuwer, Marc Kouwenhoven
{"title":"Variable density and anisotropic field-of-view for 3D Stack-of-Stars radial imaging.","authors":"Joao Tourais, Guruprasad Krishnamoorthy, Jouke Smink, Marcel Breeuwer, Marc Kouwenhoven","doi":"10.1007/s10334-025-01283-x","DOIUrl":"https://doi.org/10.1007/s10334-025-01283-x","url":null,"abstract":"<p><strong>Objective: </strong>To develop a non-iterative method for applying elliptical field-of-view (FOV) to radial imaging and evaluate it for Stack-Of-Stars (SOS) with variable radial density in the <math><msub><mi>k</mi> <mi>z</mi></msub> </math> direction.</p><p><strong>Materials and methods: </strong>New analytic expressions were derived to compute the radial profile angles for an elliptical FOV with and without golden angle sampling. With a major-to-minor-axis FOV ratio of 1:0.5, anisotropic FOV and variable density SOS were evaluated, using point spread function analysis, phantom imaging, and in vivo pelvic imaging.</p><p><strong>Results: </strong>Compared with conventional SOS, elliptical density in <math><msub><mi>k</mi> <mi>z</mi></msub> </math> reduced scan time by 20%, while maintaining similar levels of radial aliasing artifacts. Anisotropic FOV reduced scan time by 31%, resulting in similar levels of radial aliasing artifacts at low undersampling for objects with matching in-plane anisotropy. Combining both techniques resulted in a 45% scan time reduction. Alternatively, when compared to conventional SOS using identical scan time, variable density and anisotropic FOV both displayed a lower level of radial aliasing artifacts, although for anisotropic FOV this effect was less pronounced at higher undersampling.</p><p><strong>Discussion: </strong>Variable density and anisotropic FOV can reduce scan time and/or reduce aliasing artifacts for SOS. The new analytical expressions for elliptical FOV will facilitate future studies on anisotropic FOV radial imaging.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145292635","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}
Narjes Ahmadian, Mark Gosselink, Sigrid Otto, Dimitri Welting, Kiki Tesselaar, Tom Snijders, Pieter van Eijsden, Jeanine Prompers, Dennis Klomp, Evita Wiegers
{"title":"Dynamic deuterium metabolic imaging in glioblastoma at 7T.","authors":"Narjes Ahmadian, Mark Gosselink, Sigrid Otto, Dimitri Welting, Kiki Tesselaar, Tom Snijders, Pieter van Eijsden, Jeanine Prompers, Dennis Klomp, Evita Wiegers","doi":"10.1007/s10334-025-01299-3","DOIUrl":"https://doi.org/10.1007/s10334-025-01299-3","url":null,"abstract":"<p><strong>Objective: </strong>This study investigates the dynamic metabolic characteristics of glioblastoma (GBM) using Deuterium Metabolic Imaging (DMI) at 7 T, aiming to dynamically characterize the Warburg effect in vivo.</p><p><strong>Material and methods: </strong>Five newly diagnosed GBM patients underwent dynamic DMI prior to any treatment. 3D <sup>2</sup>H free-induction-decay (FID)-Magnetic resonance spectroscopy imaging (MRSI) measurements (11:44 min per scan) were performed at 7 T during ~ 100 min following [6,6'-<sup>2</sup>H<sub>2</sub>]glucose consumption. Venous plasma glucose and plasma <sup>2</sup>H-Glc atom percent enrichment (APE) levels were measured during the scan. Brain <sup>2</sup>H-glucose (<sup>2</sup>H-Glc),<sup>2</sup>H-Glutamate/Glutamine (<sup>2</sup>H-Glx), <sup>2</sup>H-Lactate (<sup>2</sup>H-Lac), <sup>2</sup>H-Lac/<sup>2</sup>H-Glx were analyzed with a two-level (time and tissue type) Linear Mixed Model.</p><p><strong>Results: </strong>Brain <sup>2</sup>H-Glc levels were similar across tissue types. <sup>2</sup>H-Glx was significantly lower in tumors compared to normal appearing brain tissue (NABT) (p < 0.01). <sup>2</sup>H-Lac was significantly higher in tumors compared to NABT (P < 0.01). The <sup>2</sup>H-Lac/<sup>2</sup>H-Glx ratio provided tumor-specific contrast, starting 40-50 min post [6,6'-<sup>2</sup>H<sub>2</sub>]glucose consumption. Venous plasma glucose and <sup>2</sup>H-Glc APE increased within 50 min and venous <sup>2</sup>H-Glc APE stabilized at ~ 60%.</p><p><strong>Discussion: </strong>Dynamic DMI at 7 T reveals metabolic alterations in GBM, particularly through the <sup>2</sup>H-Lac/<sup>2</sup>H-Glx ratio. This contrast was primarily driven by decreased <sup>2</sup>H-Glx rather than profoundly increased <sup>2</sup>H-Lac. These findings support the utility of DMI in assessing metabolic reprogramming in brain tumors.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145251709","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":"Using intra-voxel incoherent motion MRI to dynamically evaluate the attenuating effects of donafenib combined with carvedilol in a thioacetamide-induced hepatic fibrosis rat model.","authors":"Jiacheng Liu, Yaowei Bai, Wei Yao, Peng Sun, Binqian Zhou, Xiaoming Liu, Bin Liang, Chuansheng Zheng","doi":"10.1007/s10334-025-01241-7","DOIUrl":"10.1007/s10334-025-01241-7","url":null,"abstract":"<p><strong>Objective: </strong>This study aimed to dynamically evaluate the attenuating effects of donafenib combined with carvedilol using intra-voxel incoherent motion (IVIM) MRI at different time points of disease course in a thioacetamide (TAA)-induced hepatic fibrosis rat model.</p><p><strong>Methods: </strong>In this study, 40 male Sprague-Dawley rats received TAA for 6 weeks to induce liver fibrosis and were divided into four groups randomly (N = 10). From week 3 to week 6 of modeling, each group of rats received daily gavage of vehicle, carvedilol (CARV), donafenib (DON), and donafenib plus carvedilol (DON + CARV), respectively. IVIM MRI was used to assess the degree of liver fibrosis in the above groups at 0, 2, 4, and 6 weeks after modeling. Liver fibrosis was classified according to the METAVIR scoring system (F0-F4). IVIM parameters were calculated using a biexponential fitting model, and a least-squares fitting approach was applied for parameter estimation.</p><p><strong>Results: </strong>The mean pathological collagen areas and the expression of α-SMA and collagen I in the CARV, DON, and DON + CARV groups were significantly less than that in the vehicle group (P < 0.001). IVIM-derived parameters (D, D<sup>*</sup>, and f) and ADC values were negatively correlated with the fibrosis levels (D: r<sup>2</sup> = 0.594, P < 0.001; D<sup>*</sup>: r<sup>2</sup> = 0.556, P < 0.001; f: r<sup>2</sup> = 0.737, P < 0.001; ADC: r<sup>2</sup> = 0.694, P < 0.001). At 4 and 6 weeks after modeling, the mean IVIM parameters and ADC values of the DON + CARV group were significantly higher than those of the vehicle group.</p><p><strong>Conclusion: </strong>IVIM MRI is a noninvasive and valuable dynamic monitoring tool for liver fibrosis, and it was useful to monitor the dynamic inhibition process of donafenib and carvedilol on liver fibrosis in a TAA-induced rat model.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":"781-790"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143649582","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 method to measure renal inner medullary perfusion using MR renography.","authors":"A de Boer, K Sharma, B Alhummiany, S P Sourbron","doi":"10.1007/s10334-025-01225-7","DOIUrl":"10.1007/s10334-025-01225-7","url":null,"abstract":"<p><strong>Objective: </strong>In the kidney, the medulla is most susceptible to damage in case of hampered perfusion or oxygenation. Due to separate regulation of cortical and medullary perfusion, measurement of both is crucial to improve the understanding of renal pathophysiology. We aim to develop and evaluate a physiologically accurate model to measure renal inner medullary (F<sub>med</sub>) and cortical perfusion (F<sub>cor</sub>) separately.</p><p><strong>Materials and methods: </strong>We developed a 7-compartment model of renal perfusion and used an iterated approach to fit 10 free parameters. Model stability and accuracy were tested on both patient data and simulations. Cortical perfusion and F<sub>T</sub> (tubular flow or glomerular filtration rate per unit of tissue volume) were compared to a conventional 2-compartment filtration model.</p><p><strong>Results: </strong>Average (standard deviation) F<sub>med</sub> was 37(23)mL/100 mL/min. Fitting stability as expressed by the median (interquartile range) coefficient of variation between fits was 0.0(0.0-5.8)%, with outliers up to 81%. In simulations, F<sub>med</sub> was underestimated by around 8%. Intra-class correlation coefficients for F<sub>cor</sub> and F<sub>T</sub> as measured with the 2- and 7- compartment model were 0.87 and 0.63, respectively.</p><p><strong>Discussion: </strong>We developed a pharmacokinetic model closely following renal physiology. Although the results were vulnerable for overfitting, relatively stable results could be obtained even for F<sub>med</sub>.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":"791-802"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12497669/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143425658","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}
Mar Fernandez Salamanca, Rita Simões, Malgorzata Deręgowska-Cylke, Pim J van Leeuwen, Henk G van der Poel, Elise Bekers, Marcos A S Guimaraes, Uulke A van der Heide, Ivo G Schoots
{"title":"Beyond Gleason grading: MRI radiomics to differentiate cribriform growth from non-cribriform growth in prostate cancer men.","authors":"Mar Fernandez Salamanca, Rita Simões, Malgorzata Deręgowska-Cylke, Pim J van Leeuwen, Henk G van der Poel, Elise Bekers, Marcos A S Guimaraes, Uulke A van der Heide, Ivo G Schoots","doi":"10.1007/s10334-025-01251-5","DOIUrl":"10.1007/s10334-025-01251-5","url":null,"abstract":"<p><strong>Objective: </strong>To differentiate cribriform (GP4Crib+) from non-cribriform growth and Gleason 3 patterns (GP4Crib-/GP3) using MRI.</p><p><strong>Methods: </strong>Two hundred and ninety-one operated prostate cancer men with pre-treatment MRI and whole-mount prostate histology were retrospectively included. T2-weighted, apparent diffusion coefficient (ADC) and fractional blood volume maps from 1.5/3T MRI systems were used. 592 histological GP3, GP4Crib- and GP4Crib+ regions were segmented on whole-mount specimens and manually co-registered to MRI sequences/maps. Radiomics features were extracted, and an erosion process was applied to minimize the impact of delineation uncertainties. A logistic regression model was developed to differentiate GP4Crib+ from GP3/GP4Crib- in the 465 remaining regions. The differences in balanced accuracy between the model and baseline (where all regions are labeled as GP3/GP4Crib-) and 95% confidence intervals (CI) for all metrics were assessed using bootstrapping.</p><p><strong>Results: </strong>The logistic regression model, using the 90th percentile ADC feature with a negative coefficient, showed a balanced accuracy of 0.65 (95% CI: 0.48-0.79), receiver operating characteristic area under the curve (AUC) of 0.75 (95% CI: 0.54-0.92), a precision-recall AUC of 0.35 (95% CI: 0.14-0.68).</p><p><strong>Conclusion: </strong>The radiomics MRI-based model, trained on Gleason sub-patterns segmented on whole-mount specimen, was able to differentiate GP4Crib+ from GP3/GP4Crib- patterns with moderate accuracy. The most dominant feature was the 90th percentile ADC. This exploratory study highlights 90th percentile ADC as a potential biomarker for cribriform growth differentiation, providing insights into future MRI-based risk assessment strategies.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":"817-827"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12497665/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144015507","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}
Yu Ueda, Tsutomu Tamada, Atsushi Higaki, Ayumu Kido, Hiroyasu Sanai, Kazunori Moriya, Taro Takahara, Makoto Obara, Marc Van Cauteren
{"title":"Synthetic DWI: contrast improvement for diffusion-weighted imaging in prostate using T1 shine-through by synthesizing images with adjusted TR and TE.","authors":"Yu Ueda, Tsutomu Tamada, Atsushi Higaki, Ayumu Kido, Hiroyasu Sanai, Kazunori Moriya, Taro Takahara, Makoto Obara, Marc Van Cauteren","doi":"10.1007/s10334-025-01243-5","DOIUrl":"10.1007/s10334-025-01243-5","url":null,"abstract":"<p><strong>Objective: </strong>To investigate whether synthetic DWI (SyDWI) calculated with short TR and zero TE can improve diffusion contrast in prostate compared to conventional DWI acquired with standard TR and TE.</p><p><strong>Materials and methods: </strong>Thirty-two patients who underwent multiparametric MRI (mp-MRI) on a 3.0 T scanner were enrolled. For SyDWI, DWIs at b0 were acquired with two different TRs and TEs in addition to b1000 and b2000 images acquired with single conventional TR and TE. Contrast ratio (CR) was compared between SyDWI calculated with TR of 1000 ms and TE of 0 ms and conventional DWI acquired with TR of 6000 ms and TE of 70 ms.</p><p><strong>Results: </strong>The mean CR between prostate cancer (PCa) and normal prostate, and between PCa and benign prostatic hyperplasia (BPH), is significantly higher in SyDWI compared to conventional DWI for both b-values of 1000 and 2000 s/mm<sup>2</sup>. In addition, contrast within some lesions is now visualized, suggesting that tumour heterogeneity can be observed that is not seen with conventional DWI.</p><p><strong>Conclusion: </strong>SyDWI calculated with TR of 1000 ms and TE of 0 ms significantly improves diffusion contrast between PCa and normal prostate or BPH, and within the lesion, compared to conventional DWI as a result of T1 shine-through.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":"771-780"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700817","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}
Eu Jin Lim, Pohchoo Seow, Aditya Tri Hernowo, Nicole Keong Chwee Har
{"title":"Systematic comparison of semi-automated VBM pipelines for assessing chemoradiotherapy effects on the tumoural and non-tumoural brain in glioblastoma multiforme.","authors":"Eu Jin Lim, Pohchoo Seow, Aditya Tri Hernowo, Nicole Keong Chwee Har","doi":"10.1007/s10334-025-01263-1","DOIUrl":"10.1007/s10334-025-01263-1","url":null,"abstract":"<p><strong>Objective: </strong>Current voxel-based morphometry (VBM) studies of chemoradiotherapy effects on healthy tissues of the glioblastoma multiforme (GBM) brain faces challenges with neuroanatomical distortions (tumour, tumour oedema and resection cavities). Our aim is to compare current semi-automated segmentation methods and evaluate their reliability in investigating the effects of chemoradiotherapy on the tumoural and non-tumoural brain.</p><p><strong>Materials and methods: </strong>VBM pipelines of CAT12 and FSL were performed and compared on an open-sourced imaging brain tumour dataset (Burdenko's Glioblastoma Progression dataset). The pre- and post-chemoradiotherapy grey (GM) and white matter (WM), and cerebrospinal fluid (CSF) volumes of whole brain, tumour-containing and nontumour containing hemispheres were derived and compared between both pipelines. Brain volumetric agreement and consistency between FSL and CAT12 were assessed using Bland-Altman plots and Intraclass correlation coefficient (ICC).</p><p><strong>Results: </strong>Post-chemoradiotherapy GM volumes were significantly reduced in whole brain, tumour-containing and nontumour-containing hemispheres with a compensatory significant increase in CSF volumes, while WM volumes had no significant changes. Visual inspection revealed misclassification of tissue classes in the presence of neuroanatomical distortion for both pipelines, but FSL demonstrated superiority in tissue classification in the presence of a haematoma. Consequentially, Bland-Altman plots and ICC showed better agreement and consistency between FSL and CAT12 in GM<sub>ICC</sub> (0.70 (0.53-0.82); p < 0.001), WM<sub>ICC</sub> (0.75 (0.60-0.85); p < 0.001) and CSF<sub>ICC</sub> (0.55 (0.32-0.71); p < 0.001) volumes of nontumour-containing hemispheres than whole brain and tumour-containing hemispheres.</p><p><strong>Conclusions: </strong>VBM studies of chemoradiotherapy effects on the brain post-tumour resection remain challenging due to neuroanatomical distortions. A reliable alternative is to use nontumour-containing hemispheres with no anatomical distortion.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":"829-843"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144143158","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}
Muhammad Ahmad Sultan, Chong Chen, Yingmin Liu, Katarzyna Gil, Karolina Zareba, Rizwan Ahmad
{"title":"An unsupervised method for MRI recovery: deep image prior with structured sparsity.","authors":"Muhammad Ahmad Sultan, Chong Chen, Yingmin Liu, Katarzyna Gil, Karolina Zareba, Rizwan Ahmad","doi":"10.1007/s10334-025-01257-z","DOIUrl":"10.1007/s10334-025-01257-z","url":null,"abstract":"<p><strong>Objective: </strong>To propose and validate an unsupervised MRI reconstruction method that does not require fully sampled k-space data.</p><p><strong>Materials and methods: </strong>The proposed method, deep image prior with structured sparsity (DISCUS), extends the deep image prior (DIP) by introducing group sparsity to frame-specific code vectors, enabling the discovery of a low-dimensional manifold for capturing temporal variations. DISCUS was validated using four studies: (I) simulation of a dynamic Shepp-Logan phantom to demonstrate its manifold discovery capabilities, (II) comparison with compressed sensing and DIP-based methods using simulated single-shot late gadolinium enhancement (LGE) image series from six distinct digital cardiac phantoms in terms of normalized mean square error (NMSE) and structural similarity index measure (SSIM), (III) evaluation on retrospectively undersampled single-shot LGE data from eight patients, and (IV) evaluation on prospectively undersampled single-shot LGE data from eight patients, assessed via blind scoring from two expert readers.</p><p><strong>Results: </strong>DISCUS outperformed competing methods, demonstrating superior reconstruction quality in terms of NMSE and SSIM (Studies I-III) and expert reader scoring (Study IV).</p><p><strong>Discussion: </strong>An unsupervised image reconstruction method is presented and validated on simulated and measured data. These developments can benefit applications where acquiring fully sampled data is challenging.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":"859-871"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12354159/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144078975","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}
Patricia Ulloa, Justus Christian Rudolf, Janina Kremer, Aileen Schmidt, Peter Schramm
{"title":"Influence of orientation, size and shape of the region of interest in diffusion MRI along perivascular spaces index.","authors":"Patricia Ulloa, Justus Christian Rudolf, Janina Kremer, Aileen Schmidt, Peter Schramm","doi":"10.1007/s10334-025-01248-0","DOIUrl":"10.1007/s10334-025-01248-0","url":null,"abstract":"<p><strong>Objective: </strong>Diffusion-tensor imaging (DTI) and diffusion-weighted imaging (DWI) along perivascular spaces (ALPS) index have been proposed as noninvasive techniques to indirectly evaluate the glymphatic system function. However, these techniques are sensitive to examination parameters, limiting inter-study comparability. The definition of the region of interest (ROI) has been identified as the primary weakness of the ALPS method. Therefore, we aimed to determine which ROI characteristics would best promote consistent ALPS index analysis.</p><p><strong>Methods: </strong>We examined 13 healthy volunteers using DTI and DWI to calculate the ALPS index, and compared and determined correlations among 11 different ROI configurations, and tested inter-method reliability.</p><p><strong>Results: </strong>We found significant differences between different ROI configurations in the ALPS index calculation. Considering ROI characteristics and inter-method reliability, a squared ROI is the most suitable. The ICC between ROI configurations showed good-to-excellent inter-method agreement (mean ICC = 0.83). We did not find significant inter-method differences.</p><p><strong>Conclusion: </strong>It is important to standardize the ROI characteristics for consistent ALPS index calculation.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":"761-769"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12497668/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144030858","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}
Riwaj Byanju, Gyula Kotek, Mika W Vogel, Stefan Klein, Juan A Hernandez-Tamames, Dirk H J Poot
{"title":"3D multi-phase balanced non-steady-state free precession acquisition for multi-parameter mapping.","authors":"Riwaj Byanju, Gyula Kotek, Mika W Vogel, Stefan Klein, Juan A Hernandez-Tamames, Dirk H J Poot","doi":"10.1007/s10334-025-01262-2","DOIUrl":"10.1007/s10334-025-01262-2","url":null,"abstract":"<p><strong>Objective: </strong>This study presents the 3D MP-b-nSSFP sequence for multi-parametric mapping.</p><p><strong>Methods: </strong>We evaluate several aspects of the 3D implementation, like the type of RF pulse (selective/non-selective), the readout duration, the undersampling pattern, and the acceleration factor. We use undersampled scans with subspace-constrained reconstruction and extended spiral readouts to achieve clinically acceptable scan times. The repeatability and accuracy of the <math><msub><mi>T</mi> <mn>1</mn></msub> </math> and <math><msub><mi>T</mi> <mn>2</mn></msub> </math> maps are compared with a reference technique in phantom and three volunteer scans.</p><p><strong>Results: </strong>Compared with selective refocusing pulses, we observe lower bias with non-selective pulses, despite modeling the spatially varying effect of the pulses in the fitting process. <math><msub><mi>T</mi> <mn>1</mn></msub> </math> and <math><msub><mi>T</mi> <mn>2</mn></msub> </math> maps obtained from phantom scans were comparable to the nominal values and those from reference scans. <math><msub><mi>T</mi> <mn>1</mn></msub> </math> values in vivo were underestimated compared to the reference scan. The maps with an acquisition matrix of <math><mrow><mn>256</mn> <mo>×</mo> <mn>256</mn> <mo>×</mo> <mn>44</mn></mrow> </math> and resolution <math><mrow><mn>1</mn> <mo>×</mo> <mn>1</mn> <mo>×</mo> <mn>3</mn></mrow> </math> <math><msup><mtext>mm</mtext> <mn>3</mn></msup> </math> were acquired in 11 min.</p><p><strong>Conclusion: </strong>We show that 3D MP-b-nSSFP can be used for multi-parameter mapping within clinically acceptable scan time. Phantom scans show results in good agreement with reference scan results. However, the in vivo scan underestimated <math><msub><mi>T</mi> <mn>1</mn></msub> </math> .</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":"873-893"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12497673/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144143124","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}