Magnetic Resonance in Medicine最新文献

{"title":"Combined angiography and perfusion using radial imaging and arterial spin labeling with structural contrast.","authors":"Thomas W Okell, Joseph G Woods, Mark Chiew","doi":"10.1002/mrm.70073","DOIUrl":"https://doi.org/10.1002/mrm.70073","url":null,"abstract":"<p><strong>Purpose: </strong>To develop a non-contrast MRI method for the simultaneous acquisition of time-resolved 3D angiographic, perfusion, and multi-contrast T₁-weighted structural brain images in a single 6 min acquisition.</p><p><strong>Methods: </strong>The proposed combined angiography and perfusion using radial imaging and arterial spin labeling with structural contrast (CAPRIA+S) pulse sequence uses pseudocontinuous arterial spin labeling to label inflowing blood, an inversion pulse to provide background suppression and T₁-weighted contrast, and a continuous 3D golden ratio spoiled gradient echo readout. Label-control subtraction isolates the blood signal which can be flexibly reconstructed at high/low spatiotemporal resolution for angiography/perfusion imaging. The mean signal retains the static tissue, allowing T₁-weighted structural images to be reconstructed at different effective TIs. CAPRIA+S was compared with conventional time-of-flight angiography, 3D-gradient and spin echo pseudocontinuous arterial spin labeling perfusion imaging, and MPRAGE structural imaging (10 min total) in healthy volunteers.</p><p><strong>Results: </strong>CAPRIA+S gave improved distal vessel visibility and fewer artifacts than time-of-flight angiography, while also providing dynamic information, with blood transit time and dispersion maps. CAPRIA+S perfusion images were comparable to 3D-gradient and spin echo data but without through-slice blurring or artifacts in inferior brain regions. Comparable quantitative cerebral blood flow maps were produced, with CAPRIA+S being significantly more repeatable. Structural CAPRIA+S images were comparable to MPRAGE but also yielded a range of T₁-weighted contrasts and allowed quantitative T₁ maps to be estimated.</p><p><strong>Conclusion: </strong>CAPRIA+S is an efficient single acquisition to provide intrinsically co-registered quantitative information about brain blood flow and structure that has considerable advantages over conventional methods.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145069940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extending real-time MRI of the oral cavity using simultaneous multislice and compressed sensing.","authors":"Isaac Watson, Mike Angus, Elisa Zamboni, David Mitchell, Angelika Sebald, Aneurin J Kennerley","doi":"10.1002/mrm.70085","DOIUrl":"https://doi.org/10.1002/mrm.70085","url":null,"abstract":"<p><strong>Purpose: </strong>To demonstrate a real-time MRI (rtMRI) sequence that can image multiple slices simultaneously and apply them to image the dynamics of the oral cavity. Specifically, we demonstrate the imaging of tongue movement, speech, and swallowing.</p><p><strong>Methods: </strong>We developed a radial rtMRI sequence with multiband excitation. Two sampling schemes were explored: a golden-angle trajectory and a golden-angle trajectory adapted for simultaneous multislice acceleration. Additionally, we developed a compressed sensing reconstruction pipeline. Phantom and in vivo rtMRI data were acquired on a 3 T system using a standard head/neck coil.</p><p><strong>Results: </strong>We show that the proposed technique can acquire rtMRI videos at a range of temporal resolutions (up to 25 ms). Example applications of tongue movement, speech, and swallowing are shown. Additionally, we show that the sequence is robust to changes in slice distance and coil compression level.</p><p><strong>Conclusion: </strong>Combining rtMRI with multiband excitation and compressed sensing reconstruction enables imaging of the oral cavity at high (up to 25 ms) temporal resolution.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145069959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of cardiac diffusion MRI using multiple prospective respiratory motion correction techniques.","authors":"Stephen Jermy, Aaron Hess, Zakariye Ashkir, Betty Raman, Ian Burger, Francesca Little, Ntobeko Ntusi, Ernesta Meintjes, Elizabeth M Tunnicliffe","doi":"10.1002/mrm.70061","DOIUrl":"https://doi.org/10.1002/mrm.70061","url":null,"abstract":"<p><strong>Purpose: </strong>A novel prospective motion correction control system with slice tracking (MNav-CoS) was compared with three other prospective respiratory motion correction techniques in performing free-breathing cardiovascular diffusion tensor imaging (cDTI) acquisitions.</p><p><strong>Methods: </strong>Ten healthy volunteers underwent cDTI using an M2SE sequence. The performance of the proposed MNav-CoS was compared with three respiratory compensation techniques: multiple breath-holds (BH), free breathing with respiratory gating (Gate), and free breathing with single navigator slice tracking (Nav). Data for five diffusion weightings were acquired in a single mid-ventricular slice in end systole. MD, FA, and HA maps were calculated for each technique and combinations of low and high b-values. Data from the respiratory navigators were used to estimate the total amount of cardiac through-plane motion during free breathing.</p><p><strong>Results: </strong>The metrics derived from the diffusion tensor for MNav-CoS with b_low|b_high = 50|450 s/mm² were MD: <math> <semantics><mrow><mn>1</mn> <mo>.</mo> <mn>48</mn> <mo>±</mo> <mn>0.10</mn> <mspace></mspace> <mi>μ</mi> <mi>m</mi> <mo>⁄</mo> <msup><mtext>ms</mtext> <mn>2</mn></msup> </mrow> <annotation>$$ 1.48pm 0.10kern0.3em upmu mathrm{m}/{mathrm{ms}}^2 $$</annotation></semantics> </math> , FA: <math> <semantics><mrow><mn>0</mn> <mo>.</mo> <mn>39</mn> <mo>±</mo> <mn>0.07</mn></mrow> <annotation>$$ 0.39pm 0.07 $$</annotation></semantics> </math> , and HAg: <math> <semantics><mrow><mo>-</mo> <mn>0</mn> <mo>.</mo> <mn>82</mn> <mo>±</mo> <mn>0</mn> <mo>.</mo> <mn>22</mn> <mo>°</mo> <mo>⁄</mo> <mo>%</mo></mrow> <annotation>$$ -0.82pm {0.22}^{{}^{circ}}/% $$</annotation></semantics> </math> . All of the other respiratory compensation techniques produced a similar range of results to the MNav-CoS technique. On average, the free-breathing acquisitions with slice tracking were three times shorter than using BH. The total amount of cardiac through-plane motion during the free-breathing acquisitions ranged from 4 to 10 mm with an average of <math> <semantics><mrow><mn>6</mn> <mo>.</mo> <mn>2</mn> <mo>±</mo> <mn>1</mn> <mo>.</mo> <mn>7</mn> <mspace></mspace> <mtext>mm</mtext></mrow> <annotation>$$ 6.2pm 1.7kern0.3em mathrm{mm} $$</annotation></semantics> </math> .</p><p><strong>Conclusion: </strong>The MNav-CoS technique performed comparably to other commonly used respiratory compensation techniques. Prospective respiratory motion compensation, such as the slice tracking used with MNav-CoS, is a useful tool that offers time-saving benefits and compensates for through-plane motion present during free breathing. These techniques may be beneficial for performing longer cDTI acquisitions providing increased utility in a clinical context.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145069963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing radiofrequency safety of active implants by measuring induced radiofrequency currents using MRI.","authors":"Chiara Hartmann, Mélina Bouldi, Jan M Warnking","doi":"10.1002/mrm.70084","DOIUrl":"https://doi.org/10.1002/mrm.70084","url":null,"abstract":"<p><strong>Purpose: </strong>During MRI in the presence of active wire-like implants, such as deep brain stimulation leads, there is a risk of thermal lesions in tissues adjacent to implant contacts due to radiofrequency currents induced in the wire. Currently, there is no established method to evaluate the radiofrequency (RF) safety of an implant in situ, due to complex interactions between the implant and the electric field inside the patient during MRI. This article presents a method to quantify the RF current in an implant using MRI acquisitions at very low SAR.</p><p><strong>Theory and methods: </strong>To measure RF current in situ, a modified <math> <semantics><mrow><mi>B</mi> <mn>1</mn></mrow> <annotation>$$ B1 $$</annotation></semantics> </math> -mapping sequence is proposed to image the associated perturbation of the <math> <semantics> <mrow> <msubsup><mrow><mi>B</mi></mrow> <mrow><mn>1</mn></mrow> <mrow><mo>+</mo></mrow> </msubsup> </mrow> <annotation>$$ {B}_1^{+} $$</annotation></semantics> </math> field. A forward signal model links the RF current intensity to the MRI signal and is used to fit the RF current from acquired data. Electromagnetic simulations and experiments on a homogeneous phantom are presented for simplified and real implant wires to validate the method.</p><p><strong>Results: </strong>The presented model can correctly reconstruct RF current amplitudes from field maps obtained with detailed electromagnetic simulations, with a normalized RMS error of 4.7%. Phantom experiments show a good linearity between the square of the current measured by MRI and temperature increase ( <math> <semantics> <mrow> <msup><mrow><mi>R</mi></mrow> <mrow><mn>2</mn></mrow> </msup> <mo>></mo> <mn>0</mn> <mo>.</mo> <mn>91</mn></mrow> <annotation>$$ {R}^2>0.91 $$</annotation></semantics> </math> ), demonstrating that the RF current measurements quantitatively represent the effective heating.</p><p><strong>Conclusion: </strong>A method has been developed to quantify the RF current in situ from MRI signals. This method enables to predict the individual heating risk for other MRI sequences performed in the same scanning session.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exact, time-dependent analytical equations for spiral trajectories and matching gradient and density-correction waveforms.","authors":"Guruprasad Krishnamoorthy, James G Pipe","doi":"10.1002/mrm.70053","DOIUrl":"https://doi.org/10.1002/mrm.70053","url":null,"abstract":"<p><strong>Purpose: </strong>To analytically define a spiral waveform and trajectory that match the constraints of gradient frequency, slew rate, and amplitude.</p><p><strong>Theory and methods: </strong>Piecewise analytical solutions for gradient waveforms under the desired constraints are derived using the circle of an involute rather than an Archimedean spiral. Also given are the analytical equations for the time-dependent k-space trajectory and sampling density compensation weights, and analytical expressions for the time dependence of data acquisition in k-space. Open-source software implementing all these equations is shared. Performance is measured against numerically derived solutions to an Archimedean spiral. Scanner implementation is illustrated.</p><p><strong>Results: </strong>The performance of the proposed equations is very similar to that of numerically derived solutions, but this method is much easier to implement and analyze.</p><p><strong>Conclusion: </strong>The proposed method, WHIRLED PEAS (Winding Hybrid Interleaved Radial Lines Encoding Described by Piecewise Exact Analytical Solution), is an easy-to-implement solution for spiral MRI that performs comparable to optimal numerical designs.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal noise lowers the accuracy of rotationally invariant harmonics of diffusion MRI data and their robustness to experimental variations.","authors":"Guillem París, Tomasz Pieciak, Derek K Jones, Santiago Aja-Fernández, Antonio Tristán-Vega, Jelle Veraart","doi":"10.1002/mrm.70035","DOIUrl":"https://doi.org/10.1002/mrm.70035","url":null,"abstract":"<p><strong>Purpose: </strong>Rotational invariants (RIs) are at the root of many dMRI applications. Among others, they are presented as a sensible way of reducing the dimensionality of biophysical models. While thermal noise impact on diffusion metrics has been well studied, little is known on its effect on spherical harmonics-based RI (RISH) features and derived markers. In this work, we evaluate the effect of noise on RISH features and downstream Standard Model Imaging (SMI) estimates.</p><p><strong>Theory and methods: </strong>Using simulated and test/retest multishell MRI data, we assess the accuracy and precision of RISH features and SMI parameters in the presence of thermal noise, as well as its robustness to variations in protocol design. We further propose and evaluate correction strategies that bypass the need of rotational invariant features as an intermediate step.</p><p><strong>Results: </strong>Both RISH features and SMI estimates are impacted by SNR-dependent Rician biases. However, higher-order RISH features are susceptible to a secondary noise-related source of bias, which not only depends on SNR, but also protocol and underlying microstructure. Rician bias-correcting techniques are insufficient to maximize the accuracy of RISH and SMI features, or to ensure consistency across protocols. SMI estimators that avoid RISH features by fitting the model to the directional diffusion MRI data outperform RISH-based approaches in accuracy, repeatability, and reproducibility across acquisition protocols.</p><p><strong>Conclusions: </strong>RISH features are increasingly used in dMRI analysis, yet they are prone to various sources of noise that lower their accuracy and reproducibility. Understanding the impact of noise and mitigating such biases is critical to maximize the validity, repeatability, and reproducibility of dMRI studies.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ex vivo human brain volumetry: Validation of MRI measurements.","authors":"Amy Gérin-Lajoie, Walter Adame-Gonzalez, Eve-Marie Frigon, Liana Guerra Sanches, Anna Nayouf, Denis Boire, Mahsa Dadar, Josefina Maranzano","doi":"10.1002/mrm.70083","DOIUrl":"https://doi.org/10.1002/mrm.70083","url":null,"abstract":"<p><strong>Purpose: </strong>The volume of in vivo human brains is determined with various MRI measurement tools that have not been assessed against a gold standard. The purpose of this study was to validate the MRI brain volumes by scanning ex vivo, in situ specimens, which allows the extraction of the brain after the scan to compare its volume with the gold-standard water displacement method (WDM).</p><p><strong>Methods: </strong>The 3T MRI T₂-weighted, T₁-weighted, and MP2RAGE images of seven anatomical heads fixed with an alcohol-formaldehyde solution were acquired. The gray and white matter were assessed using two methods: (i) a manual intensity-based threshold segmentation using Display (MINC-ToolKit) and (ii) an automatic deep learning-based segmentation tool (SynthSeg). The brains were extracted and their volumes measured with the WDM after the removal of their meninges and a midsagittal cut. Volumes from all methods were compared with the ground truth (WDM volumes) using a repeated-measures analysis of variance.</p><p><strong>Results: </strong>Mean brain volumes, in cubic centimeters, were 1111.14 ± 121.78 for WDM, 1020.29 ± 70.01 for manual T₂-weighted, 1056.29 ± 90.54 for automatic T₂-weighted, 1094.69 ± 100.51 for automatic T₁-weighted, 1066.56 ± 96.52 for automatic magnetization-prepared 2 rapid gradient-echo first inversion time, and 1156.18 ± 121.87 for automatic magnetization-prepared 2 rapid gradient-echo second inversion time. All volumetry methods were significantly different (F = 17.874; p < 0.001) from the WDM volumes, except the automatic T₁-weighted volumes.</p><p><strong>Conclusion: </strong>SynthSeg accurately determined the brain volume in ex vivo, in situ T₁-weighted MRI scans. The results suggested that given the contrast similarity between the ex vivo and in vivo sequences, the brain volumes of clinical studies are most probably sufficiently accurate, with some degree of underestimation depending on the sequence used.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Repeatability of diffusion-weighted arterial spin labeling MRI for mapping blood-brain barrier water exchange rate at different postlabel delays.","authors":"Yufei D Zhu, Quimby N Lee, Xingfeng Shao, Youngkyoo Jung, Danny J J Wang, Audrey P Fan","doi":"10.1002/mrm.70081","DOIUrl":"https://doi.org/10.1002/mrm.70081","url":null,"abstract":"<p><strong>Purpose: </strong>This study sought to determine the intrasession repeatability of the diffusion-weighted (DW) arterial spin labeling (ASL) sequence at different postlabel delays (PLDs).</p><p><strong>Methods: </strong>We first performed numerical simulations to study the accuracy of the two-compartment water exchange rate (Kw) fitting model with added Gaussian noise for DW PLDs at 1500, 1800, and 2100 ms. Ten young, healthy participants then underwent a structural T₁ scan and two intrasession in vivo DW ASL scans at each PLD on a 3T MRI. The Kw, arterial transit time (ATT), and cerebral blood flow maps were linearly registered to the structural images, which were then segmented using FreeSurfer into masks with 35 bilateral gray-matter regions.</p><p><strong>Results: </strong>Simulation results showed that the Kw fitting model performed at an error rate less than 10% at physiological ATTs and Kw values, but that error and bias increased at a PLD of 2100 ms and at ATT ranges where the overall blood signal fraction (A₁) is low. In vivo analysis showed a significant positive correlation between intrasession measurements of regional Kw at a DW PLD of 1800 ms (β = 0.33, p < 0.001) only. Furthermore, a significant positive relationship between Kw and cerebral blood flow was seen at a DW PLD of 1500 ms (β = 0.26, p = 0.005) and DW PLD of 2100 ms (β = 0.39, p = 0.006).</p><p><strong>Conclusion: </strong>Overall, DW ASL provides the strongest intrasession repeatability at a PLD of 1800 ms in young, healthy subjects, and a simulation study shows accurate Kw fits at physiologic range of ATTs and Kw values.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145033644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Few-shot learning for highly accelerated 3D time-of-flight MRA reconstruction.","authors":"Hao Li, Mark Chiew, Iulius Dragonu, Peter Jezzard, Thomas W Okell","doi":"10.1002/mrm.70072","DOIUrl":"https://doi.org/10.1002/mrm.70072","url":null,"abstract":"<p><strong>Purpose: </strong>To develop a deep learning-based reconstruction method for highly accelerated 3D time-of-flight MRA (TOF-MRA) that achieves high-quality reconstruction with robust generalization using extremely limited acquired raw data, addressing the challenge of time-consuming acquisition of high-resolution, whole-head angiograms.</p><p><strong>Methods: </strong>A novel few-shot learning-based reconstruction framework is proposed, featuring a 3D variational network specifically designed for 3D TOF-MRA that is pre-trained on simulated complex-valued, multi-coil raw k-space datasets synthesized from diverse open-source magnitude images and fine-tuned using only two single-slab experimentally acquired datasets. The proposed approach was evaluated against existing methods on acquired retrospectively undersampled in vivo k-space data from five healthy volunteers and on prospectively undersampled data from two additional subjects.</p><p><strong>Results: </strong>The proposed method achieved superior reconstruction performance on experimentally acquired in vivo data over comparison methods, preserving most fine vessels with minimal artifacts with up to eight-fold acceleration. Compared to other simulation techniques, the proposed method generated more realistic raw k-space data for 3D TOF-MRA. Consistently high-quality reconstructions were also observed on prospectively undersampled data.</p><p><strong>Conclusions: </strong>By leveraging few-shot learning, the proposed method enabled highly accelerated 3D TOF-MRA relying on minimal experimentally acquired data, achieving promising results on both retrospective and prospective in vivo data while outperforming existing methods. Given the challenges of acquiring and sharing large raw k-space datasets, this holds significant promise for advancing research and clinical applications in high-resolution, whole-head 3D TOF-MRA imaging.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145033493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volumetric thermometry in moving tissues using stack-of-radial MRI and an image-navigated multi-baseline proton resonance frequency shift method.","authors":"Qing Dai, Shu-Fu Shih, Omar Curiel, Tsu-Chin Tsao, David S Lu, Jason Chiang, Holden H Wu","doi":"10.1002/mrm.70074","DOIUrl":"https://doi.org/10.1002/mrm.70074","url":null,"abstract":"<p><strong>Purpose: </strong>To develop and evaluate a volumetric proton resonance frequency shift (PRF)-based thermometry method for monitoring thermal ablation in moving tissues.</p><p><strong>Methods: </strong>A golden-angle-ordered 3D stack-of-radial MRI sequence was combined with an image-navigated multi-baseline (iNAV-MB) PRF method to reconstruct motion-compensated 3D temperature maps with high spatiotemporal resolution and volumetric coverage. Two radial MRI reconstruction techniques, k-space weighted image contrast filter (KWIC) and golden-angle radial sparse parallel (GRASP) MRI, were implemented and compared within a sliding window reconstruction framework. Ex vivo motion phantom experiments were performed with high-intensity focused ultrasound ablation to evaluate motion tracking and temperature accuracy using input motion waveforms and temperature probe readings as references. In vivo non-heating swine experiments were conducted to assess temperature mapping stability in 3D liver regions of interest.</p><p><strong>Results: </strong>The proposed iNAV-MB thermometry framework achieved volumetric coverage of 24 axial slices (3-mm thickness), in-plane resolution of 1.6 × 1.6 to 1.8 × 1.8 mm², and effective temporal resolution of 0.98 s/volume. In ex vivo high-intensity focused ultrasound experiments, motion tracking achieved correlation coefficients of 0.951 and 0.973, and temporal mean absolute errors were 1.80°C and 1.44°C using KWIC and GRASP, respectively. In vivo experiments demonstrated improvements in voxel-wise temperature temporal SD from a median of 8.03 to 3.85°C (KWIC) and from a median of 7.23 to 2.37°C (GRASP), compared to single-baseline PRF.</p><p><strong>Conclusion: </strong>The proposed stack-of-radial iNAV-MB volumetric PRF thermometry framework can reliably track respiratory motion and map ablation-associated temperature change. This framework has the potential to improve MRI-guided thermal ablation in moving tissues.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145033639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}