Magnetic Resonance Materials in Physics, Biology and Medicine最新文献

{"title":"<ArticleTitle xmlns:ns0=\"http://www.w3.org/1998/Math/MathML\">Longitudinal relaxation rate ( <ns0:math><ns0:msub><ns0:mi>R</ns0:mi> <ns0:mn>1</ns0:mn></ns0:msub> </ns0:math> ) in lung: a systematic review and meta-analysis.","authors":"Lucy Edwards, Geoff J M Parker, John C Waterton, Marta Tibiletti","doi":"10.1007/s10334-025-01259-x","DOIUrl":"10.1007/s10334-025-01259-x","url":null,"abstract":"<p><strong>Objective: </strong>The lung magnetic resonance longitudinal relaxation rate <math><msub><mi>R</mi> <mn>1</mn></msub> </math> varies with disease but reported values in healthy subjects (HS) also differ markedly between studies.</p><p><strong>Objective: </strong>To evaluate the reported values and variances of observed <math><msub><mi>R</mi> <mn>1</mn></msub> </math> accounting for field strength <math><msub><mi>B</mi> <mn>0</mn></msub> </math> , acquisition method, and disease.</p><p><strong>Materials and methods: </strong>A systematic literature search was performed to identify studies quantifying <math><msub><mi>R</mi> <mn>1</mn></msub> </math> or its reciprocal <math><msub><mi>T</mi> <mn>1</mn></msub> </math> . The relationship between field strength and observed R₁ was analysed in all healthy subject data. Data were fit to the heuristic equation <math> <mrow><msub><mi>R</mi> <mn>1</mn></msub> <mo>=</mo> <mi>B</mi> <mrow></mrow> <mo>∗</mo> <msubsup><mrow><mo>(</mo> <mi>B</mi></mrow> <mrow><mn>0</mn></mrow> <mi>A</mi></msubsup> <mrow><mo>)</mo></mrow> </mrow> </math> . The variances between-study <math><mrow><mi>bs</mi></mrow> </math> , within-study-between-subject <math><mrow><mi>wsbs</mi></mrow> </math> , and within-study-within-subject <math><mrow><mi>wsws</mi></mrow> </math> , in HS were assessed. Linear correlation between observed R₁ and TE was also investigated.</p><p><strong>Results: </strong>Fifty-nine papers were selected, 50 quantifying R₁ in HS and 20 in disease, representing 1559 human and non-human subjects, with <math><msub><mi>B</mi> <mn>0</mn></msub> </math> ranging from 0.2 T to 9.4 T. In HS, the result of the fit on all healthy subjects was A = -0.227 ± 0.020 s^-1 T^-1, B = 0.923 ± 0.014 s^-1 with variance components <math><mrow><mi>b</mi> <mi>s</mi> <mo>></mo> <mi>w</mi> <mi>s</mi> <mi>b</mi> <mi>s</mi> <mo>></mo> <mi>w</mi> <mi>s</mi> <mi>w</mi> <mi>s</mi></mrow> </math> . The reference values for R₁ at <math><msub><mi>B</mi> <mn>0</mn></msub> </math> between 0.55 T and 7 T were derived. For inversion recovery with gradient echo readout at 1.5 T, a previously observed negative relationship between <math><msub><mi>R</mi> <mn>1</mn></msub> </math> and TE was confirmed.</p><p><strong>Discussion: </strong>We provide reference values for lung <math><msub><mi>R</mi> <mn>1</mn></msub> </math> across all commonly used field strengths. The variation in HS lung observed <math><msub><mi>R</mi> <mn>1</mn></msub> </math> reported in different studies in different centres likely reflects methodological differences. Investigators wishing to compare lung <math><msub><mi>R</mi> <mn>1</mn></msub> </math> values with previous reports should take account of this irreproducibility, and multicentre projects should standardise to minimise between-centre variance.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":"747-760"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12497672/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144078972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Explainable radiomics based on association of histopathological cell density and multiparametric MR radiomic features for high-risk stratification of prostate cancer patients.","authors":"Yusuke Shibayama, Hidetaka Arimura, Yukihisa Takayama, Fumio Kinoshita, Dai Takamatsu, Akihiro Nishie, Satoshi Kobayashi, Takashi Matsumoto, Masaki Shiota, Masatoshi Eto, Yoshinao Oda, Kousei Ishigami","doi":"10.1007/s10334-025-01250-6","DOIUrl":"10.1007/s10334-025-01250-6","url":null,"abstract":"<p><strong>Objective: </strong>This study aimed to develop an explainable radiomics model for stratifying prostate cancer (PCa) patients with high-risk disease via investigation of the association between cell density (CD) in the PCa region on histopathological images and multiparametric MR (mpMR) radiomics features.</p><p><strong>Materials and methods: </strong>137,970 radiomic features were calculated from mpMR images (101 PCa regions of 44 patients), and joint histograms (JHs) were derived from dynamic contrast-enhanced (DCE) images for each PCa region. The association between CD on histopathological images and its corresponding mpMR radiomic features in PCa regions for various grade groups and the three risk groups was evaluated using Spearman's correlation coefficient. To validate the potential of the radiomic-feature-CD association, we developed the radiomics model for stratifying patients into low/intermediate-risk and high-risk groups.</p><p><strong>Results: </strong>There were moderate correlations of the CD with a DCE-based texture feature (WV_HH_1st_GLSZM_ZP) (ρ = 0.609, p = 0.024) and DCE-JH feature (JH_WV_HL_1st versus 5th-1st_Hist_STD) (ρ = 0.609, p = 0.024) in the high-risk group. The radiomics model had an accuracy of 0.920 for stratifying the patients of a test dataset into the low/intermediate-risk and high-risk groups.</p><p><strong>Conclusion: </strong>The association between CD and mpMR features can be leveraged to develop the explainable radiomics for the high-risk stratification of patients with PCa.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":"803-815"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144017436","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":"Toward accessible MRI: SDR4MR, a simple RF pulse monitoring technique using an inexpensive software-defined radio.","authors":"Kouame Ferdinand Kouakou, Anita Paisant, Christophe Aube, Hervé Saint-Jalmes","doi":"10.1007/s10334-025-01249-z","DOIUrl":"10.1007/s10334-025-01249-z","url":null,"abstract":"<p><strong>Objective: </strong>This study evaluated the applicability and performance of the SDR4MR method at 1.5 T and 3 T across different acquisition scenarios in a clinical environment.</p><p><strong>Materials and methods: </strong>The SDR4MR hardware consists of a broadband receiver coil connected to a software-defined radio (SDR) via optional RF attenuators. The SDR stick is plugged into the computer's USB port, which runs the SDR software and a Mathematica script to decode the RF pulse sequence. Several MRI pulse sequences were recorded: (i) a multi-echo multi-slice spin echo sequence to check the SDR4MR configuration on a well-known simple sequence; (ii) 2D and 3D sequences for which detailed information is not available in the user interface.</p><p><strong>Results: </strong>The measured RF pulse sequences have been drawn in the style of illustrations found in MRI textbooks. Sequence times and amplitudes were estimated, and sequence details not described in the MRI user interface were retrieved.</p><p><strong>Conclusion: </strong>The present study demonstrated the implementation of SDR4MR on clinical scanners. This easy-to-use configuration enables precise monitoring of RF pulse sequences. This method could be further improved by taking advantage of advances in SDR hardware and software.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":"895-903"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12497666/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144020619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accuracies of four simulation approaches in reproducing motion artifacts and morphometric parameter biases.","authors":"Bingbing Zhao, Yichen Zhou, Xiaopeng Zong","doi":"10.1007/s10334-025-01246-2","DOIUrl":"10.1007/s10334-025-01246-2","url":null,"abstract":"<p><strong>Objective: </strong>Despite widespread uses in MRI research, the relative accuracies of different motion artifact simulation approaches in reproducing artifacts and artifact-induced changes (AIC) of morphometric parameters in structural MRI remain largely unknown. We aim to evaluate the performances of four simulation approaches in reproducing artifacts and AIC of brain morphometric parameters.</p><p><strong>Methods: </strong>Within-session repeated T₁-weighted scans were acquired on ten volunteers with their heads remaining still or undergoing intentional motion monitored by fat navigators. Four simulation approaches were adopted, which differed in terms of whether channel-combined magnitude image or complex multi-channel k-space data were utilized, and whether motion effects were introduced by modifying k-space data value (MDV) or modifying k-space coordinates and data phase (MCP). By means of simulation, the dependence of morphometric parameter changes on motion pattern and severity was studied.</p><p><strong>Results: </strong>Multi-channel k-space database simulation achieved higher artifact similarity and AIC consistency with measured motion scan images than magnitude image-based simulation. MDV- and MCP-based simulations achieved comparable results. From k-space database simulation employing MDV, the motion-induced biases in morphometric parameters were found to vary linearly with motion severity with motion pattern-dependent slopes.</p><p><strong>Conclusions: </strong>Simulations based on multi-channel complex k-space data outperformed those based on channel-combined magnitude images in reproducing artifacts and AICs. Head motion caused imaging artifacts and systematic biases in morphometric parameters which can be equally reproduced by simulations using two different motion effect introduction strategies.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":"845-858"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143971440","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":"Evaluation of tractography parameters for dentato-rubro-thalamic tract reconstruction during pediatric posterior fossa tumor surgery.","authors":"Pien E J Jellema, Karina J Kersbergen, Eelco W Hoving, Maarten H Lequin, Kirsten M van Baarsen, Thomas Lindner, Wouter P Nieuwenhuis, Alberto De Luca, Jannie P Wijnen","doi":"10.1007/s10334-025-01297-5","DOIUrl":"https://doi.org/10.1007/s10334-025-01297-5","url":null,"abstract":"<p><strong>Objective: </strong>Intraoperative fiber tractography can help neurosurgeons in localizing eloquent tracts potentially displaced by tumors. In pediatric posterior fossa tumor (pPFT) patients, disturbances to the eloquent dentato-rubro-thalamic tract (DRTT) might contribute to cerebellar mutism syndrome. This study investigates the effect of fiber tractography parameters on DRTT reconstruction in pre- and intraoperative settings.</p><p><strong>Methods: </strong>T1-weighted and diffusion MRI data were acquired from ten pPFT patients and two healthy volunteers. The patients were scanned pre- and intraoperatively. The DRTT was reconstructed using multiple fiber orientation distribution (FOD) and angle thresholds. An expert panel evaluated tract reconstructions to identify optimal parameters in our dataset. The corticospinal tract (CST) served as a control. Relative tract volumes of the DRTT and the CST were calculated.</p><p><strong>Results: </strong>Diffusion MRI data were sufficient for reliable DRTT reconstruction in healthy volunteers. In most pPFT patients, an FOD of 0.01 and a 60° angle threshold were evaluated as optimal for DRTT reconstruction in our dataset. Preoperative DRTT reconstructions showed more reconstructed streamlines and larger relative volumes, particularly in non-decussating tracts. CST reconstructions remained consistent across both timepoints.</p><p><strong>Discussion: </strong>DRTT reconstruction is feasible in pPFT patients before and during surgery. However, inter-subject variability suggests that some patients may require adjusted thresholds for optimal results.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145199772","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":"BOLD fMRI at 9.4T with 3D stack-of-spirals readouts.","authors":"Alejandro Monreal-Madrigal, Denizhan Kurban, Desmond H Y Tse, Dimo Ivanov, Nicolas Boulant, Benedikt A Poser","doi":"10.1007/s10334-025-01298-4","DOIUrl":"https://doi.org/10.1007/s10334-025-01298-4","url":null,"abstract":"<p><strong>Objective: </strong>To investigate the use of spiral readouts for sub-millimeter BOLD fMRI at 9.4T and to verify simulations of the BOLD point spread function (PSF) with functional experiments.</p><p><strong>Materials and methods: </strong>Spiral readouts were evaluated through simulations and functional experiments to test their performance in sub-millimeter BOLD fMRI. Both spiral-out and spiral-in readout strategies were considered, with attention to echo time (TE) relative to T₂*.</p><p><strong>Results: </strong>We confirmed that a TE shorter than T₂* can be employed for spiral-out readouts without compromising BOLD sensitivity. The use of shorter TE provided a reduced repetition time (TR), improved temporal signal-to-noise ratio (tSNR), and minimized off-resonance effects.</p><p><strong>Discussion: </strong>Spiral-in readouts were found to be mainly useful for lower-resolution applications at ultra-high field (UHF). In contrast, segmented spiral-out readouts demonstrated strong potential for mesoscopic BOLD fMRI at ultra-high fields (> 7T).</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145186214","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":"Book of Abstracts ESMRMB 2025 Online 41st Annual Scientific Meeting 8-11 October 2025.","authors":"","doi":"10.1007/s10334-025-01278-8","DOIUrl":"https://doi.org/10.1007/s10334-025-01278-8","url":null,"abstract":"","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145191983","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":"Free-running time-resolved first-pass myocardial perfusion using a multi-scale dynamics decomposition: CMR-MOTUS.","authors":"Thomas E Olausson, Maarten L Terpstra, Niek R F Huttinga, Casper Beijst, Niels Blanken, Dominika Suchá, Teresa Correia, Birgitta K Velthuis, Cornelis A T van den Berg, Alessandro Sbrizzi","doi":"10.1007/s10334-025-01291-x","DOIUrl":"https://doi.org/10.1007/s10334-025-01291-x","url":null,"abstract":"<p><strong>Objective: </strong>First-pass myocardial perfusion involves several types of dynamics, including cardiac motion, respiratory motion, bulk motion and contrast agent inflow. To accurately quantify the initial inflow of the contrast agent, high spatiotemporal resolution MR imaging must be obtained. To achieve this, we present a novel approach, named CMR-MOTUS, for the reconstruction of time-resolved free-running first-pass myocardial perfusion by jointly estimating high-quality motion fields and contrast-varying images.</p><p><strong>Materials and methods: </strong>We propose CMR-MOTUS, which extends the MR-MOTUS framework by integrating a contrast-varying reference image with a low-rank plus sparse decomposition to capture additional dynamics such as blood flow and contrast agent inflow. This joint reconstruction framework alternates between solving for time-dependent image contrast changes and motion fields, eliminating the need for a pre-acquisition motion-static reference image. The method was tested on simulations and in-vivo datasets.</p><p><strong>Results: </strong>In simulations, CMR-MOTUS showed improved image similarity and motion field accuracy compared to state-of-the-art methods. In in-vivo tests, the methods effectively captured cardiac and respiratory motion dynamics, resulting in cine images with sharper features than state-of-the-art.</p><p><strong>Discussion: </strong>CMR-MOTUS presents significant advantages by modelling motion and contrast dynamics in the reconstruction of first-pass myocardial perfusion. The framework enables a data-efficient free-running workflow since the entire acquisition is correlated with high-quality motion fields. This approach has the potential to enhance the diagnostic value of cardiac MRI but needs further clinical validations.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145125030","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":"MDFNet: a multi-dimensional feature fusion model based on structural magnetic resonance imaging representations for brain age estimation.","authors":"Chenxiao Zhang, Pengzhi Nan, Limei Song, Yuhao Wang, Kaile Su, Qiang Zheng","doi":"10.1007/s10334-025-01294-8","DOIUrl":"https://doi.org/10.1007/s10334-025-01294-8","url":null,"abstract":"<p><strong>Objectives: </strong>Brain age estimation plays a significant role in understanding the aging process and its relationship with neurodegenerative diseases. The aim of the study is to devise a unified multi-dimensional feature fusion model (MDFNet) to enhance the brain age estimation solely on structural MRI but with a diverse representation of whole brain, tissue segmentation of gray matter volume, node message passing of brain network, edge-based graph path convolution of brain connectivity, and demographic data.</p><p><strong>Materials and methods: </strong>The MDFNet was developed by devising and integrating a whole-brain-level Euclidean-Convolution channel (WBEC-channel), a tissue-level Euclidean-convolution channel (TEC-channel), a Graph-convolution channel based on node message passing (nodeGCN-channel) and an edge-based graph path convolution channel on brain connectivity (edgeGCN-channel), and a multilayer perceptron (MLP) channel for demographic data (MLP-channel) to enhance the multi-dimensional feature fusion. The MDFNet was validated on 1872 healthy subjects from four public datasets, and applied to an independent cohort of Alzheimer's Disease (AD) patients. The interpretability analysis and normative modeling of the MDFNet in brain age estimation were also performed.</p><p><strong>Results: </strong>The MDFNet achieved a superior performance of Mean Absolute Error (MAE) of 4.396 ± 0.244 years, a Pearson Correlation Coefficient (PCC) of 0.912 ± 0.002, and a Spearman's Rank Correlation (SRCC) of 0.819 ± 0.015 when comparing with the state-of-the-art deep learning models. The AD group exhibited a significantly greater brain age gap (BAG) than health group (P < 0.05), and the normative modeling also exhibited a significantly higher mean Z-scores of AD patients than healthy subjects (P < 0.05). The interpretability was also visualized at both the group and individual level, enhancing the reliability of the MDFNet.</p><p><strong>Conclusions: </strong>The MDFNet enhanced the brain age estimation solely on structural MRI by employing a multi-dimensional feature integration strategy.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145081044","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":"Upright 0.5 T open MR defaecating proctography proof of concept study: the inter- and intra-rater variability of pelvic floor measures using seated proctography.","authors":"Rashed Sobhan, Paul M Glover, Penny A Gowland, Rahul Munyal, Olivier E Mougin, Christopher G D Clarke","doi":"10.1007/s10334-025-01296-6","DOIUrl":"https://doi.org/10.1007/s10334-025-01296-6","url":null,"abstract":"<p><strong>Objective: </strong>We tested the feasibility, data quality, and reliability of an upright magnetic resonance defaecating proctography (uMRDP) technique using an Open 0.5 T ASG MRI scanner.</p><p><strong>Materials and methods: </strong>Eight healthy volunteers (2 males) performed seated defaecation on a purpose-built radio-frequency commode coil in an Open scanner. An optimised T2-weighted HASTE sequence captured dynamic changes during all three phases of the Kegel manoeuvre. Inter- and intra-rater variability was measured from the pelvic floor (PF) metrices (M-line, H-line, distances of landmarks) extracted by two radiologists.</p><p><strong>Results: </strong>All relevant PF landmarks could be identified and metrices were extracted with acceptable inter- and intra-rater variability. Intra-rater variation was marginal, with relative absolute differences ranging from 5 to 21% and 3.2-44%. Inter-rater variability was reported using correlation and Bland-Altman plots. Correlation between raters was satisfactory, with r² > 0.93, and bias ranged from - 1.8 to 0.65 mm. Moreover, the limit of agreement in the Bland-Altman plot ranged from 5.8 to 20.4 mm, indicating satisfactory precision.</p><p><strong>Discussion: </strong>The proposed uMRDP technique can be used as a feasible and reliable alternative to supine MRDP, without the necessity of gadolinium injection and bowel preparation. It can capture defaecation in a regular seated posture and can provide information complementary to standard-of-care fluoroscopic proctography for clinicians.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145054287","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}