bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of MUSE and ssEPI for diffusion-weighted imaging in meningioma: imaging quality and grading accuracy
Authors: Lin Danjie , Zhang Yichao , Liu Sihui , Zhang Jialu , Xue Yunjing , Lin Lin
Published: November 2024

Motivation: DWI is of key importance in evaluating biological behavior of meningioma, but image quality of conventional ssEPI-DWI is unsatisfactory due to susceptibility artifact near the skull. Goal(s): Our goal was to compare the image quality of ssEPI-DWI and MUSE-DWI in meningiomas, and to compare diagnostic accuracy of them in meningiomas grading. Approach: We used a 5-point Likert scale to assess image quality of DWI, and calculated SNR and CNR for quantitative evaluation. Combined models were constructed by using ADC histogram parameters extracted from whole tumor. Results: MUSE-DWI significantly improved imaging quality of DWI, and showed a significantly higher diagnostic accuracy in meningioma grading. Impact: Meningioma is the most commom intracranial tumours. This study revealed that MUSE-DWI, compared with ssEPI-DWI, can improve the imaging quality and grading accuracy of meningiomas, contributing to better clinical evaluation of meningiomas.
Fast-Relaxing Sodium Fraction in Brain Tumors
Authors: Neelsen Christian , Regnery Sebastian , Behl Nicolas , Weckesser Nina , Kurz Felix , Debus Jürgen , Schlemmer Heinz-Peter , Ladd Mark , Paech Daniel , Platt Tanja
Published: November 2024

Motivation: Enhance the specificity of sodium (23Na) imaging in brain tumors. Goal(s): Distinguish intracellular and extracellular sodium distribution in glioblastoma. Approach: We assessed the fraction of fast-relaxing sodium (FT2*s) in 19 glioblastoma patients using a 3D radial 23Na pulse sequence with six echoes at 7T. Results: FT2*s was high in normal appearing white matter resembling expected intracellular behavior, and low in necrotic regions, akin to fluid-like environments. Values for contrast-enhancing tumors and adjacent edema were in between. The differentiation between normal brain tissue and changes in glioblastoma underscores the potential of FT2*s to improve the specificity of sodium imaging in brain tumors. Impact: The study could facilitate the establishment of the fast-relaxing sodium fraction as a diagnostic tool in brain tumors, potentially improving specificity in sodium quantification.
Evaluating the Clinical Utility and Diagnostic Value of High-Resolution Deuterium MRS Imaging (DMRSI) in Patients with Brain Tumor
Authors: Zhu Xiao-Hong , Li Xin , Li Yudu , Aldaraiseh Bashar , Chen Liam , Liang Zhi-Pei , Chen Clark , Ugurbil Kamil , Chen Wei
Published: November 2024

Motivation: Deuterium MRS imaging (DMRSI) can detect Warburg Effect in brain tumors; however, its clinical utility and value in brain tumor diagnosis and treatment has not been investigated. Goal(s): To perform a preliminary investigation in human patients with brain tumor. Approach: High-resolution dynamic DMRSI (HR-DMRSI) study was conducted in brain tumor patients on a 7T clinical scanner with an oral D66-glucose administration; biospecimens taken from DMRSI positive and negative regions were analyzed and compared with the DMRSI and clinical MRI results. Results: HR-DMRSI technology enables detection and characterization of glioma infiltration with a level of precision surpassing traditional imaging modalities. Impact: We clearly demonstrate that 7T high-resolution dynamic deuterium (2H) MRS imaging is able to detect and characterize glioma infiltration in individual human patients with high accuracy and specificity that exceeds conventional imaging modalities available in standard clinical setting.
Optimizing early response assessment in glioblastoma using diffusion imaging on a 1.5T MR-Linac
Authors: Lawrence Liam , Chugh Brige , Stewart James , Ruschin Mark , Theriault Aimee , Detksy Jay , Myrehaug Sten , Maralani Pejman , Tseng Chia-Lin , Soliman Hany , Lim-Fat Mary Jane , Das Sunit , Stanisz Greg , Sahgal Arjun , Lau Angus
Published: November 2024

Motivation: Early response assessment for glioblastoma may be possible using regions of low apparent diffusion coefficient (low-ADC) during MRI-linear accelerator (MR-Linac) treatment, but low-ADC definition has not been optimized. Goal(s): Optimize definition of low-ADC for correlation with progression-free survival. Approach: We defined low-ADC regions from near-daily diffusion-weighted imaging and weekly contrast-enhanced T1-weighted imaging for 41 glioblastoma patients during MR-Linac treatment (3-6 weeks). We compared correlation strength across b-values (800 versus 2000s/mm2) and ADC thresholds (0.7 to 2.0μm2/ms). Results: The optimal b-value/threshold combination was b=800s/mm2 and 1.2μm2/ms (correlation for weeks 2-6). Impact: We showed that early response assessment in glioblastoma during radiotherapy is possible with weekly acquisition of ADC maps and contrast-enhanced T1-weighted imaging on MR-Linacs. Low-ADC regions could serve as targets for radiotherapy dose escalation to potentially extend patient survival.
Investigation of 1H and hyperpolarized 13C spectroscopy-based biomarkers for dual inhibition of TERT and EGFR in GBM cell and animal models.
Authors: Hong Donghyun , Minami Noriaki , Ronen Sabrina
Published: November 2024

Motivation: Inhibiting TERT or its upstream transcription factor GABPB1 can result in tumor growth inhibition. Inhibiting EGFR, upstream of TERT, can also reduce TERT expression. Goal(s): Investigating the combined effects of EGFR and TERT inhibition and assessing whether our MRS-based biomarkers can detect the impact of this combination therapy in cell and animal models. Approach: Proton and hyperpolarized 13C spectroscopy in cell and animal modelsResults: Enhanced inhibition of both cell and tumor growth was observed in our GBM models when TERT/GABPB1 and EGFR were targeted simultaneously. This was associated with a drop in hyperpolarized lactate production from pyruvate. Impact: This study identifies HP lactate as a metabolic biomarker of response to the dual TERT/GABPB1 and EGFR inhibition in cells and animals and points to the value of this biomarker in detecting the added value of this novel combination therapy.
Deep learning enables robust quantification of cerebral blood flow using ASL in the presence of pathology: Application to treated gliomas
Authors: Yang Zhuoqin , Ruffle James , Jäger H Rolf , Nachev Parashkev , Hyare Harpreet , Sokolska Magdalena , Zhang Hui
Published: November 2024

Motivation: The accuracy of cerebral blood flow (CBF) quantification in arterial spin labelling (ASL) may reduce in regions exhibiting pathology-induced signal abnormalities in proton density (PD) images. Goal(s): To develop an algorithm for improved CBF quantification by correcting signal abnormalities in PD images due to pathology. Approach: To correct signal abnormalities, an image-inpainting algorithm based on deep learning (DL) was developed using healthy subject data. The algorithm was demonstrated with an application to patients post tumour treatment. Results: The developed DL algorithm was able to effectively correct signal abnormalities, resulting in improved CBF maps. Impact: The improvement in CBF accuracy through DL-corrected PD images may aid clinicians in their assessment of patients. This study demonstrates the potential benefit of the proposed method in an example application of monitoring tumour recurrence post treatment with ASL.
Decoding Visual Information from fMRI Data: A Multimodal Approach to Image and Caption Reconstruction
Authors: Ferrante Matteo , Boccato Tommaso , Ozcelik Furkan , VanRullen Rufin , Toschi Nicola
Published: November 2024

Motivation: The study addresses the challenge of decoding and reconstructing visual experiences from fMRI data, an area yet to be mastered in neuroscience. Goal(s): We propose a methodology that deciphers brain activity patterns and renders these into visual and textual representations. Approach: We trained a linear model to map brain activity to image latent represenations. This informed a generative image-to-text transformer and a visual attribute-focused regression model, culminating in the creation of photorealistic images using a text-to-image diffusion model. Results: The model effectively combined high-level semantic understanding and low-level visual details, producing plausible reconstruction images from fMRI data. Impact: Our findings enhance our understanding of visual processing in the brain, with significant implications for integrating artificial intelligence (AI) with neuroscience.
Pretreatment arterial spin labelling combined with depth of invasion predict disease progression in nonmetastatic NPC after IMRT
Authors: Yang Fan , Wei Haoran , Yu Xiaoduo , Lin Meng , Zhang Hongmei
Published: November 2024

Motivation: Arterial spin labeling (ASL) showed the promising value in diagnosis and early treatment outcome prediction in head and neck. Whether ASL combined with tumor invasion depth could help predicting disease progression needs further investigate. Goal(s): To explore the value of CBF derived from ASL and depth of invasion in predicting 3-year disease progression in NPC. Approach: Prospective inclusion of consecutive patients with regular follow-up. Selection of appropriate statistical methods to construct and compare models. Results: CBF and tumor invasion depth are significantly correlated with progression-free survival, and both of them could help predicting 3-year disease progression. Impact: ASL and tumor infiltration depth shown for the first time to predict disease progression in NPC, which could help with clinical treatment decisions.
Intensity normalization of ASL measured perfusion improves reproducibility and treatment evaluation in glioblastoma patients
Authors: Zhou Limin , Wang Yiming , Udayakumar Durga , Pinho Marco , Youssef Michael , Maldjian Joseph , Madhuranthakam Ananth
Published: November 2024

Motivation: Chemoradiation in patients with glioblastoma (GBM) causes a 10-13% perfusion decrease in normal appearing tissue, confounding reproducibility of ASL measurements and longitudinal treatment evaluations. This confounds intra-patient and inter-patient comparisons, irrespective of perfusion variations from tumor progression/response. Goal(s): To improve ASL measurement reproducibility and longitudinal treatment assessment in GBM patients using intensity normalization methods. Approach: Different normalization methods were applied to ASL measured perfusion in a prospective study for reproducibility analyses and response assessment. Results: Intensity normalization of ASL measured perfusion in GBM patients improved reproducibility enabling longitudinal treatment evaluation for intra- and inter-patient comparisons. Impact: Intensity normalization of ASL reduces variability, improves reproducibility, and enables accurate quantitative intra- and inter-patient comparison. This can play an important role in evaluating treatment response assessment and building predictive models with ASL across different studies and sites.
In vivo CEST-MRI Parameters correlate to Transcriptome and Metabolic Features in Breast Lesions
Authors: Udayakumar Durga , Wang Xiaojing , Cai Ling , Xi Yin , Seiler Stephen , Sahoo Sunati , Dimitrov Ivan , Keupp Jochen , Vinogradov Elena
Published: November 2024

Motivation: CEST-MRI could provide biochemical and molecular information on breast lesions before detection of physiological and anatomical changes. Goal(s): Our goal is to identify suitable in vivo CEST-MRI biomarker candidates. Approach: 12 patients with 6 benign and 8 malignant lesions (pathology confirmed) who had concurrent CEST-MRI, transcriptome, and metabolomic data were included. Results: Expression of several genes and metabolites correlated with MTRasym values (P<0.05) at 1, 2, and 3.5 ppm. At 1 and 2 ppm, DNA damage, cell cycle, stress response, and small molecule metabolic processes were prominently represented. Specific metabolites (e.g., Citrate/Isocitrate, glucuronate) showed significant correlations at 1, 2, and 3.5 ppm. Impact: In vivo CEST-MRI parameters are reflective of transcriptome and metabolomic features in breast lesions. This provides molecular information, potentially before the detection of physiological and anatomical changes, and could facilitate accurate prediction of response to therapy allowing earlier interventions.
Radiogenomics reveals tumor heterogeneity associated with the response to neoadjuvant chemotherapy in luminal breast cancer
Authors: Sun Shiyun , You Chao , Gu Yajia
Published: November 2024

Motivation: There is an urgent clinical need to develop predictive biomarkers that can help identify proper candidates for neoadjuvant chemotherapy (NAC) in luminal breast cancer. Goal(s): To develop tailored prediction model for response to NAC, identify stable predictive features shared between Eastern and Western populations and reveal their biological interpretability. Approach: Multiscale radiomic features, multiple feature selection methods and classifiers, bioinformatics analysis, three independent cohorts. Results: The combination of "high-frequency features-XGBoost" demonstrated the best predictive performance for NAC response. Four multiscale radiomic features were identified as stable and discriminative predictive features between Eastern and Western populations, which associated with the immune-related and PPAR pathways. Impact: We proposed a more rigorous approach to ensure the robustness of radiomic features and explored the stable predictive features and their biological significance across different populations of luminal breast cancer. It will capture the interest of radiologist and clinicians.
Medical physics mentoring through a RAD-AID International partnership with Intermed Hospital in Mongolia: Development and initial visit
Authors: Weygand Joseph , Shagdarsuren Batnasan , Munkhtuvshin Tamir , Bold Bayarbaatar , Khurelsukh Khulan , Suliman Eman , Bryant John , Redler Gage , Musall Benjamin , McVorran Shauna , Salzillo Travis , Mohammed Sharon , Mollura Daniel
Published: November 2024

Motivation: Despite wide application in high-income countries, MRI is largely underutilized in low- and middle-income countries3 (LMIC’s). One reason is a lack of expertise in MRI physics in LMIC’s. RAD-AID International is an organization engaged in radiological outreach and is active in over twenty countries. Goal(s): In this abstract, a roadmap for an MRI physics mentorship partnership is presented and illustrated at a private hospital in Northeast Asia. Approach: A physicist volunteering for RAD-AID International visited Intermed Hospital in Mongolia. Results: He taught the basics of MRI physics, optimized their imaging protocols, and established a quality assurance program. Collaboration will be ongoing. Impact: MRI is underutilized in low-resource settings. One impediment to its utilization is lack of physics expertise. In this work, a roadmap is presented whereby a philanthropic organization partners with an Asian hospital to better incorporate physics concepts into clinic practice.
Enhancing Motion Correction in T1-Weighted Abdominal MRI Through Outlier Removal and Overlapping Binning
Authors: Su Michelle , Ariyurek Cemre , Chow Jeanne , Afacan Onur , Kurugol Sila
Published: November 2024

Motivation: Respiratory motion creates blurring artifacts in abdominal MRIs for the liver and kidneys, preventing identification of tumors and blood vessels and optimal treatment administration. Goal(s): We aimed to increase respiratory data density, decrease motion, and maximize data utilization in each motion-state. Approach: We proposed a motion-correction method to remove respiratory irregularities and sort data into overlapping motion-states. We compared signal density and conspicuity of artifacts and organ structures for images reconstructed from the proposed and traditional methods. Results: Compared with the traditional method, the proposed method consistently increased data density by over 50% and produced more motion-robust images for inhale-states of irregular-breathing patients. Impact: Our proposed motion-correction method for T1-weighted abdominal MRIs increases respiratory data density to improve visibility of liver and kidney vessels and boundaries, supporting treatment for irregular-breathing and pediatric patients. This method may enhance dynamic contrast-enhanced MRI with temporal resolution constraints.
Dynamic alterations in spontaneous neural activity in patients with attention-deficit/hyperactivity disorder: a resting-state fMRI study
Authors: Hu Rui , Du Wei , Tan Fan , Wu Yong , Chen Wen , Miao Yanwei
Published: November 2024

Motivation: The dALFF and dfALFF of ADHD have not been fully revealed and publicized. Goal(s): We investigate dALFF and dfALFF in ADHD and further explore whether dALFF and dfALFF can be used to test the feasibility of differentiating ADHD from HC. Approach: The ALFF and fALFF methods were combined with sliding-window approaches to investigate the abnormal time-varying local brain activity of ADHD. Results: ADHD showed statistically significant differences in dALFF and dfALFF. Clinical scores and executive function were correlated with the quantitative values of dynamic differential brain regions. ADHD and HC can be effectively distinguished using an auxiliary diagnostic model based on random forest. Impact: From the perspective of dynamic local brain activity, this study provides insight into the brain dysfunction of ADHD. Understanding dALFF/dfALFF variability can be helpful in understanding neurophysiological mechanisms and possibly guiding ADHD diagnosis.
First demonstration of arterial spin labeling on a 1.5T MR-Linac for characterizing glioblastoma perfusion dynamics
Authors: Lawrence Liam , Chugh Brige , Stewart James , Ruschin Mark , Theriault Aimee , Detksy Jay , Myrehaug Sten , Maralani Pejman , Tseng Chia-Lin , Soliman Hany , Lim-Fat Mary Jane , Das Sunit , Sahgal Arjun , Lau Angus
Published: November 2024

Motivation: Glioblastoma is a highly vascularized brain tumor. Changes in perfusion could guide treatment adaptation, but the dynamics of blood flow changes in glioblastoma during radiotherapy are poorly understood. Goal(s): We sought to characterize changes in glioblastoma cerebral blood flow during radiotherapy. Approach: We acquired twice-weekly arterial spin labeling (ASL) MRI in 22 glioblastoma patients during radiotherapy on a 1.5T MRI-linear accelerator (MR-Linac) and evaluated changes in cerebral blood flow. Results: We provided the first demonstration of MR-Linac ASL. Tumor cerebral blood flow tended to decrease during radiotherapy. Highly-perfused tumor regions showed the greatest change. Impact: We showed that frequent perfusion imaging on MRI-linear accelerators is feasible and that blood flow in highly-perfused regions of human glioblastoma tends to decrease during radiotherapy. Radiotherapy with dose escalation to highly perfused tumor regions likely requires target adaptation.
Comparing APT-weighted MTRasym and LD-mapping for personalized radiotherapy target delineation of glioblastoma: A prospective pilot study.
Authors: Tang Patrick , Smits Marion , Nout Remi , van Rij Caroline , Slagter Cleo , Swaak-Kragten Annemarie , Romero Alejandra Méndez , Warnert Esther
Published: November 2024

Motivation: Microscopic tumor infiltration in glioblastoma cannot be depicted on conventional MRI. Therefore, the clinical target volume (CTV) for radiotherapy consists of the gross tumor volume (GTV) plus a 15-mm safety margin. This large expansion increases the risk of radiation-induced side-effects. Goal(s): To explore the potential of APTw-CEST MRI for improved GTV delineation, ultimately enabling a CTV-margin reduction. Approach: Radiotherapy planning MRI-acquisition included an APTw-CEST MRI-sequence. GTVs based on APTw MTRasym or LD-maps were defined and compared to the conventional GTVs and CTVs. Results: Both APTw-CEST MRI-based GTVs were similar in size, significantly larger than the GTV, and significantly smaller than the CTV. Impact: This prospective pilot study integrates APTw-CEST MRI into glioblastoma radiotherapy planning, enabling a reduction of the 15-mm CTV-margin, and construction of a personalized target area that only targets tumor infiltration. This minimizes radiation-induced side-effects and thus improves quality of life.
Super-paramagnetic iron oxide nanoparticles improve liver tumor visualization throughout online MRI-guided liver stereotactic radiotherapy
Authors: Lee Danny , Oh Seungjong , Kirichenko Alexander
Published: November 2024

Motivation: Can we provide superior liver tumor visualization for online adaptive planning? MRI enables direct visualization of tumor and organs-at-risk (OAR). However, MRI contrast agents are often required to differentiate primary and metastatic liver malignant lesions from functional hepatic parenchyma. Goal(s): We employed super-paramagnetic iron oxide nanoparticles (SPION) as an MRI contrast agent. Approach: SPION enhanced the liver-to-tumor contrast ration for rapid and accurate delineation of tumors and functional hepatic parenchyma throughout the entire treatment course. Results: This study is the first to report the efficiency of a single SPION injection for multi-fractionated MRI-guided liver stereotactic body radiotherapy on a 1.5T Elekta MR-Linac. Impact: A single SPION injection significantly improved the tumor-to-liver contrast, and it was maintained throughout multi-fraction MRI-guided liver SBRT to provide rapid and accurate contouring tumor lesions from functional liver parenchyma for online adaptive planning.
Technical validation of DWI in the abdomen using different motion compensation techniques on a 1.5T MR-Linac
Authors: Baas Koen , Visser Sabine , van Pelt Vivian , McHugh Damien , Thorwarth Daniela , Wetscherek Andreas , Schakel Tim , Kruiskamp Marijn , Wang Jihong , Nowee Marlies , van der Heide Uulke , Paulson Eric , van Houdt Petra
Published: November 2024

Motivation: The apparent diffusion coefficient (ADC), derived from diffusion-weighted imaging (DWI), is a promising quantitative biomarker for treatment response during radiotherapy. However, DWI in the abdomen is complicated by respiratory motion. Goal(s): To compare the repeatability of the ADC acquired with different motion compensation techniques on a 1.5T MR-linac. Approach: A phantom and test-retest study (26 healthy volunteers) were performed, evaluating four DWI acquisitions (free breathing, navigator-triggered, and both repeated with an abdominal compression belt). Results: From the 11 datasets analyzed so far, absolute ADC values and repeatability were comparable between the acquisitions in healthy regions of the liver, spleen and kidney. Impact: This study initiates defining the optimal DWI acquisition strategy to measure treatment-related ADC changes of abdominal tumors on an MR-linac.
Longitudinal ADC changes in prostate cancer patients treated with hypofractionated radiotherapy with 1.5T MR-Linac
Authors: Wong Oi Lei , Yuan Jing , Poon Darren , Chiu Sin Tin , Yang Bin , Xue Cindy , Chiu George , Cheung Kin Yin
Published: November 2024

Motivation: Additional functional information from DWI is one of the major advantages of MR-Linac over conventional radiation therapy techniques, and is sparsely studied. Goal(s): To monitor the ADC change during the course of hypofractionated radiation therapy in prostate cancer using a 1.5T MR-Linac. Approach: For each patient, a prostate DWI-EPI scan was acquired immediately after each of the 5 hypofractionated radiation therapy sessions. The ADC maps were generated and compared among the fractions using the Kruskal-Wallis test. Results: No significant ADC change among fractions might indicate that monitoring ADC alone might be insufficient to reflect the early treatment response. Impact: Biological radiotherapy treatment planning has been proposed for decades, but was hindered by lack of tools that could provide functional information with spatial interpretation. The study results shed light on potential use of DWI for early treatment monitoring using MR-Linac.
4D Lung MRI with Isotropic Resolution on a 1.5T MR-Linac using a Self-Navigated 3D Radial Kooshball Acquisition and Sparse Motion Reconstruction
Authors: Wu Can , Jogi Sandeep , Otazo Ricardo
Published: November 2024

Motivation: Current 4D MRI methodology on the MR-Linac is based on stack-of-stars acquisition, which has limited resolution along the slice dimension and can compromise the performance of motion assessment. Goal(s): To develop 4D lung MRI with isotropic-resolution on a 1.5T MR-Linac using 3D radial kooshball acquisition with respiratory self-navigation. Approach: Stack-of-stars and kooshball acquisitions were performed on a healthy volunteer. Motion-resolved 4D MRI was reconstructed using XD-GRASP and then compared in terms of image quality and motion characteristics. Results: Stack-of-stars acquisition underestimated motion due to limited resolution in the slice dimension. Kooshball acquisition provided isotropic-resolution that allows for improved visualization of smaller pulmonary structures. Impact: 4D MRI with isotropic spatial resolution has the potential to enhance treatment planning and adaptation for lung cancer patients receiving radiation therapy on the MR-Linac system.
Using Ventilation and Perfusion MRI at a 0.35 T MR-Linac to Predict Radiation-Induced Pneumonitis in Lung Cancer Patients
Authors: Klaar Rabea , Rabe Moritz , Stüber Anna , Corradini Stefanie , Eze Chukwuka , Belka Claus , Landry Guillaume , Kurz Christopher , Dinkel Julien
Published: November 2024

Motivation: Early predictors of radiation-induced pneumonitis in patients receiving MR-guided radiotherapy allowing a closer follow up and taking early countermeasures to avoid a severe disease progression have not yet been identified. Goal(s): We aimed at finding functional MR-based biomarkers acquired during treatment that allows the prediction of radiation-induced pneumonitis (RP) for lung cancer patients directly after MR-guided radiotherapy. Approach: For 19 patients, ventilation- and perfusion-maps were acquired using a non-contrast enhanced free-breathing technique and investigated in different regions of the irradiated lung. Results: Changes over treatment in the ventilation around the tumor significantly separate between RP and non-RP group. Impact: The acquisition of additional functional lung imaging during MR-guided radiotherapy requires little effort while offering the opportunity to identify lung cancer patients at risk of developing radiation-induced pneumonitis right after treatment and to take early countermeasures to avoid severe complications.
Model-Based Rapid 3D Passive Needle Localization for Automatic Slice Positioning in MR-Guided Interventions
Authors: Faust Jonas , Polak Daniel , Krafft Axel , Speier Peter , Ooms Nathan , Roll Jesse , Krieger Joshua , Ladd Mark , Maier Florian
Published: November 2024

Motivation: For MR-guided needle interventions, rapid 3D needle localization enables automatic realignment of 2D real-time imaging slices with the device during the procedure. Goal(s): To investigate a model-based approach for rapid 3D needle localization that does not require prepositioned tracking slices. Approach: 3D k-space data was radially acquired before and after needle placement. Two algorithms to extract position and orientation of the needle were introduced and compared (artifact model fit to undersampled subtraction k-space/image). Results: Model-based rapid 3D needle localization was successfully demonstrated in-vivo (k-space-based offline localization error 4.3mm for FOV of (256cm)3 in 1.1s combined acquisition and localization time using 64 k-space spokes). Impact: Model-based rapid 3D passive needle localization shows potential to improve the workflow of MR-guided needle interventions, allowing for automatic alignment of 2D real-time imaging slices with the needle trajectory.
Feasibility of 3D Visualization and 3D Catheter Tracking for Enhanced MRI-Guidance of Cardiac Catheterization
Authors: Kowalik Grzegorz , Kerfoot Eric , Neji Radhouene , Kunze Karl , Moon Tracy , Mellor Nina , Razavi Reza , Pushparajah Kuberan , Roujol Sébastien
Published: November 2024

Motivation: MRI-guidance of cardiac catheterisation is currently performed using one or multiple 2D imaging planes, which may be suboptimal for catheter navigation in congenital heart disease patients with complex anatomies. Goal(s): To develop a robust real-time 3D catheter tracking method and 3D visualisation strategy for improved MRI-guidance of cardiac catheterisation procedures. Approach: Fast 3D screening through projection imaging combined with advanced post-processing strategies were developed for real-time 3D catheter tracking and enhanced 3D visualisation. The method was evaluated in patients. Results: This approach was demonstrated in three patients and was able to successfully track and visualise the catheter in 3D. Impact: Our approach show promise for enhanced catheter navigation and visualisation during MRI-guided cardiac catheterization and may contribute to reduce procedural time and outcome.
Clinical Feasibility of MRI-guided Robotic and Percutaneous In-Bore Prostate Biopsies at 0.55T
Authors: Kaur Tejinder , Jiang Yun , Seiberlich Nicole , Hussain Hero , Wells Shane , Caoili Elaine , Gulani Vikas
Published: November 2024

Motivation: MR-guided prostate biopsies are important for sampling indeterminate lesions and are performed at 1.5 or 3T.There are potential advantages of performing interventions on lower field scanners due to their potential to decrease needle artifact width, larger bores to accommodate hardware, improved imaging in presence of metallic implants, and patient comfort. However, lesion/needle visualization, SNR, and ability to target lesions could be challenging at lower fields. Goal(s): To assess feasibility of MRI-guided prostate biopsies on a low field scanner. Approach: We performed 5 in-vivo biopsies and did histopathological correlation. Results: We performed successful biopsies and high volume disease was found in all cases. Impact: Successful lesion visualization and percutaneous and transrectal prostate biopsies are possible on high access, wide bore 0.55 T scanners, widening the clinical feasibility and utility of in-bore MRI guided intervention.
Clinical Application of Semi-Automatic Device Guidance in MR-Guided Transperineal Prostate Interventions: Biopsy and Cryoablation
Authors: Lilieholm Thomas , Block Walter , Koepsel Erica Knavel
Published: November 2024

Motivation: In the prostate, transperineal needle placement is often assisted with trajectory guides and imaging. Improper placement necessitates needle reinsertion, increasing procedure time and complication risk. Presented here is a straightforward platform tested in multiple biopsy and cryoablation procedures. Previous work demonstrated feasibility in a single MR-guided focal biopsy. Goal(s): To demonstrate the platform’s technical feasibility across greater procedural types and numbers. Approach: The proposed techniques were performed on consented patients. These procedures included prostate cryoablations, biopsies, and fluid aspirations. Results: 12 procedures were performed- 6 cryoablations, 5 biopsies, and 1 fluid aspiration. Technical success was achieved in every procedure. Impact: Using the proposed methodology, all 12 prostate procedures achieved technical success. With the platform’s support, a median procedure saw satisfactory needle placement in 83.7% of initial insertions, requiring no further adjustment. This can reduce procedure times and complication risks.
Rapid Specific Absorption Rate Estimation of High-Field MRI via 3D U-net Architectures for MRI Safety
Authors: Wang Xi , Jia Xiaofan , Huang Shao Ying , Yucel Abdulkadir C.
Published: November 2024

Motivation: Advancements in MRI technology towards high fields demand rapid and accurate SAR estimation tools for enhancing MRI safety, currently hindered by the computational cost of conventional physics-based simulators. Goal(s): The goal is to develop an efficient machine learning framework capable of estimating subject-specific SAR values rapidly. Approach: The study employs 3D U-net deep learning models with their variants to achieve rapid and accurate SAR estimations. Results: The proposed neural network model provides SAR estimations within 183ms, achieving approximately 10,000x acceleration over traditional physics-based simulators, with a mean relative error of 7.6%. Impact: The near real-time accurate SAR estimation achieved by proposed machine learning framework will allow (i) checking patient-specific SAR while patient is lying in the MRI machine and (ii) performing ultra-fast optimization and uncertainty quantification studies while designing new high-field coils.
Impact of RF imperfections on MRF-based and reference B1+ mapping methods with a commercial 1Tx/32Rx head coil
Authors: Lutz Max , Silemek Berk , Seifert Frank , Aigner Christoph , Orzada Stephan , DelaBarre Lance , Schaeffter Tobias , Schmitter Sebastian
Published: November 2024

Motivation: Magnetic Resonance Fingerprinting (MRF) and preparation-based reference B1+ mapping approaches yielded an unexpected B1+ offset. Goal(s): Identify the origin of the B1+ offset. Approach: Pick-up coil measurements to evaluate the actual RF pulse shape using a commercial 1Tx/32Rx head-coil at 7T. Results: For the preparation-based B1+ mapping method with rectangular pulses, longer RF rise times (~100 µs) and phase variations (~10°) were observed. Furthermore, during the 21s-long MRF acquisition using sinc-pulses, an increased RF amplitude (~2.5%) was observed. By incorporating the measured RF alterations, the B1+ offset could be substantially reduced. Impact: Unidentified effects of the RF transmission such as deviation in envelope and temporal instability affect measurements. Characterizing the RF transmission enables quantification and correction of these deviations.
Evaluation of a Numerical Approach Alternative to MR Thermometry in the Safety Validation of Multi-Channel RF Coils
Authors: Sadeghi-Tarakameh Alireza , Schmidt Simon , Waks Matt , Lagore Russell , Zulkarnain Nur Izzati Huda , Wu Xiaoping , Adriany Gregor , Metzger Gregory , Ugurbil Kamil , Eryaman Yigitcan
Published: November 2024

Motivation: The existing safety validation process for multi-channel RF coils requires MR thermometry tests, which are difficult to carry out. Goal(s): To propose an alternative approach to MRT in the validation process of multi-channel RF coils. Approach: The simulated B1+ error was measured and propagated to the SAR error using Monte-Carlo simulations. To validate this approach MRT experiments were conducted with a 16-channel body coil at 10.5T, and the measured SAR errors were compared against the predicted ones. Results: For two different excitation patterns, measured SAR errors were 36% and 40%, while predicted SAR errors were 49% and 46%, respectively. Impact: The new strategy presented replaces MR Thermometry in the safety validation process of multi-channel RF coils. This approach can simplify and accelerate the development and testing of innovative multi-channel RF coils which are essential for UHF MRI applications.
Hepatitis C virus infection is associated with elevated bone marrow adiposity in the proximal femur: A preliminary study
Authors: Jones Brandon , Clark Makayla , Vu Brian-Tinh , Kamona Nada , Tang Sisi , Grewal Rasleen , Cottrell Christiana , Re Vincent Lo , Rajapakse Chamith
Published: November 2024

Motivation: Hepatitis C (HCV) has been linked to osteoporosis and elevated risk of fracture in retrospective studies. Goal(s): To perform the first investigation of bone marrow adiposity in a cohort of patients with chronic HCV infection. Approach: A total of 33 patients with HCV and 42 age-, sex-, and race-matched HCV-uninfected controls were recruited for MRI. Proximal femur bone marrow adiposity was assessed via chemical-shift-encoded MRI from multi-echo gradient-echo sequences. Results: The HCV group had elevated marrow adiposity in the proximal femur (80.4 ± 6.6% vs 74.9 ± 9.1%, P=0.0045) compared to controls, suggesting impairment of the trabecular network. Impact: HCV was associated with elevated bone marrow adiposity compared to uninfected controls. MRI quantification of hip fat fraction enables investigation into the pathogenesis of increased fracture risk for patients with Hepatitis C infection.
Accelerated high-resolution deep learning reconstructed turbo spin echo MRI of the knee at ultra-high field strength
Authors: Marth Adrian , Feuerriegel Georg , Goller Sophia , Sommer Stefan , Sutter Reto , Nanz Daniel , von Deuster Constantin
Published: November 2024

Motivation: High-resolution 7T-MRI using Turbo-Spin-Echoes requires high acceleration factors for reasonable scan times. Deep-Learning (DL) algorithms enable increased data under-sampling compared to state-of-the-art reconstructions. Goal(s): To explore the feasibility of undersampled data acquisition in combination with DL-reconstruction for high-resolution T1- and PD-weighted knee MRI. Approach: Volunteers underwent twofold, threefold and fourfold-accelerated 7T knee MRI with and without DL image reconstruction. Three readers rated various aspects of image quality. Results: Image quality was rated significantly superior for fourfold-accelerated DL reconstructed images compared to images without DL reconstruction, while compared to twofold and threefold accelerated images, no image quality difference was observed. Impact: This study successfully employed DL reconstructions at ultra-high field strength with promising results regarding image quality compared to conventional image reconstruction. Therefore, DL reconstructions at fourfold acceleration allows an efficient reduction in acquisition time, while still delivering high-quality images.
UTE-Based DW-SSFP for Musculoskeletal MRI
Authors: Jung Kwan-Jin
Published: November 2024

Motivation: Fiber tracking of ligaments suffer from a low signal due to their fast T2 relaxation during a long echo time in spin-echo EPI diffusion sequences. Goal(s): Shorten the echo time of the diffusion sequence and acquire in 3D. Approach: Use a 3D spiral-in readout in a DW-SSFP sequence. Results: The 3D spiral-in readout features an enhanced signal, shorter TR or TE, a wider interval for diffusion gradients, reduced geometric distortion, and a minimized echo time shift. It is demonstrated for tracts of knee ligaments using ex vivo hind limbs of piglets. Impact: The proposed diffusion imaging sequence provides a high sensitivity to musculoskeletal tissue with short T2 relaxation times. This will be useful in studying the muscles, tendons, ligaments, and cartilage.
Application of diffusion microstructure imaging in thigh muscle
Authors: Wang Yiou , Qiu Ziru , Deng Kan , Chan Queenie , Zhang Zhongping , Zhang Xinyuan , Zhang Xiaodong
Published: November 2024

Motivation: Diffusion microstructure imaging (DMI) obtains the distribution of three microstructure compartments of each voxel[1], and more specifically understands the microstructure integrity of tissues. Goal(s): Quantitative detection of the correlation between the microstructure parameters of thigh muscle and its fat infiltration degree and its relationship with the body composition of healthy individuals. Approach: We used DMI and mDIXON quant sequences to measure microstructural parameters and fat fraction (FF) of thigh muscle in healthy individuals, and to assess the value of DMI in thigh muscle imaging. Results: DMI parameters differed significantly during aging and were significantly correlated with intramuscular FF. Impact: The change of DMI parameters is a sensitive indicator of the physiological changes of muscle fiber structure during aging, which may suggest the microstructure characteristics of local metabolic changes in the body during aging.
Quantification of the anisotropic biomechanical properties of the lower leg muscles during muscle contraction using MR elastography and DTI
Authors: Majd Mahsa Salimi , Tzschätzsch Heiko , Yang Yang , Meyer Tom , Görner Steffen , Jaitner Noah , Agres Alison , Braun Jürgen , Sack Ingolf , Guo Jing
Published: November 2024

Motivation: Determining the in vivo mechanical properties of synergist muscles is challenging. Goal(s): In this study, we developed an anisotropic inversion method for MR elastography (MRE) to quantify biomechanical parameter changes in lower leg muscles during passive plantarflexion and dorsiflexion. Approach: Based on DTI and multifrequency MRE in 13 male volunteers, stiffness reconstruction was performed after aligning MRE with DTI coordinate systems. Isotropic shear wave speed (ciso) and anisotropic shear wave speed, parallel (c$$$_{\parallel}$$$) and perpendicular (c$$$_{\perp}$$$) to the fiber orientation were obtained. Results: Our findings showed significant changes of biophysical properties during muscle movements, particularly c$$$_{\parallel}$$$ and c$$$_{\perp}$$$ are more sensitive than ciso.Impact: Anisotropic muscle stiffness measured by DTI-MRE provides a consistent biomarker sensitive to changes in muscle structure and alignment altered by passive muscle movements such as plantarflexion and dorsiflexion.
Multiband Real-Time MRI at high frame rate (80fps) for studying the kinematics of joint movement in health and disease.
Authors: Watson Isaac , Zamboni Elisa , McStravick James , Zambolin Fabio , Trefzer Martin , Sebald Angelika , McPhee Jamie , Kennerley Aneurin
Published: November 2024

Motivation: Our research addresses the need for improved imaging techniques to assess joint kinematics in orthopedic and neuro-pathological conditions, with a focus on osteoarthritis. Goal(s): The goal of this project is to investigate the capability of real-time MRI to assess joint mobility and function to aid clinical diagnosis and health/exercise research. Approach: We use a multi-band real-time MRI sequence, capturing joint movement at 80 frames per second in various body parts, including the mouth, temporo-mandibular joint, thumb, knee, and foot/ankle. Results: We demonstrate the feasibility of real-time MRI, offering detailed kinematic information while retaining soft tissue contrast. Impact: Our real-time MRI technique, capturing joint motion at 80 frames per second, can empower clinical diagnostics and health research related to joint kinematics. It offers precise, dynamic insights into joint function, potentially improving patient care and advancing scientific understanding.
Ultrafast Deep Learning vs. Wave-CAIPI 3D FLAIR for Clinical Evaluation and Quantitative Assessment of White Matter Lesions
Authors: Fujita Shohei , Nickel Marcel , Lo Wei-Ching , Clifford Bryan , Conklin John , Huang Susie
Published: November 2024

Motivation: Deep learning (DL) reconstructions show promise in accelerating MRI yet have not been extensively validated clinically, particularly for 3D sequences. Goal(s): To evaluate the diagnostic quality of DL-based 3D FLAIR compared to Wave-CAIPI-accelerated FLAIR in a clinical setting. Approach: This prospective study included 26 patients undergoing evaluation for demyelinating disease with Wave-CAIPI-FLAIR and a resolution-matched 6-fold-under-sampled Cartesian FLAIR acquisition with DL reconstruction. Results: DL-FLAIR reduced scan time (1:53 vs. 2:50) and showed better image quality with higher SNR/CNR, greater lesion conspicuity, and reduced noise compared to Wave-CAIPI-FLAIR, with high agreement in lesional and regional brain volumes between both methods. Impact: Deep learning reconstruction of 3D-FLAIR provides 30% less acquisition time and improved subjective image quality compared to a state-of-the-art accelerated technique. The excellent agreement in quantitative lesion and regional brain volumes suggests robustness for use in clinical and research studies.
High-Resolution Sodium MRI of Human Gliomas at 3T Using Physics-Based Generative AI
Authors: Raymond Catalina , Feiweier Thorsten , Clifford Bryan , Meyer Heiko , Zhong Xiaodong , Han Fei , Kolkovsky Alfredo Lopez , Cho Nicholas , Sanvito Francesco , Oshima Sonoko , Salamon Noriko , Everson Richard , Cloughesy Timothy , Ellingson Benjamin
Published: November 2024

Motivation: Sodium MRI is a promising technique for understanding the brain tumor microenvironment. However, sodium MRI at 3T suffers from extremely low SNR, resulting in compromised resolution and long acquisition times. Goal(s): Our goal is to create a high-resolution sodium MRI at 3T using generative AI to improve biological characterization, treatment monitoring, and surgical planning for brain tumor patients. Approach: We developed a physics-informed synthetic dataset to train an anatomically-constrained GAN for high-resolution neuroimaging of brain tumors. Results: When applied to brain tumor patients' images, the synthetic-sodium MRI improved resolution, SNR, and correlated with expression of sodium-proton exchanger (NHE1) on image-guided biopsy. Impact: High-resolution sodium neuroimaging at 3T using physics-informed anatomically-constrained GAN has the potential to make multinuclear MRI feasible in the clinical environment, leading to conceivable improvements in diagnosis, monitoring, treatment, and our understanding of the biology of brain tumors.
MRI-derived Vascular Permeability and Cell Density Habitats for Prediction of Isocitrate Dehydrogenase Mutation in Gliomas
Authors: Liu Ping , Zhen Wanyi , Jiang Guihua
Published: November 2024

Motivation: Accurate preoperative identification of isocitrate dehydrogenase (IDH) mutation is crucial for improving patients’ management in clinical practice. Intratumor heterogeneity in gliomas limits the accurate determination of IDH mutation to some extent. Goal(s): T1-CE-derived BBB permeability and DWI-derived cell density habitat imaging may enable more precise prediction of IDH mutation by parcellating similar voxels using a clustering method. Approach: We developed and validated imaging habitats based on T1-CE and DWI to predict IDH mutation by localized mapping of tumor heterogeneity. Results: The damaged vascular and hypocellular imaging habitat performed best and robust to predict the IDH mutation, and was considered as the sensitive habitat. Impact: Fully recognizing and exploiting this heterogeneity can contribute to improving the prediction accuracy of IDH mutation status, providing more precise treatment and management strategies, and ultimately improving survival and quality of life.
Preoperative personalized 3D printing technology enhanced glioblastoma patient survival by improving fractal dimensions of wound surface
Authors: xi huaze , zhou junlin
Published: November 2024

Motivation: This study sought to forecast the prognosis of glioblastoma patients by conducting a retrospective analysis of their fractal dimensions (FD) from postoperative multimodal MRI and radiomics features within surgical regions. Additionally, it aimed to assess the potential for improving clinical therapeutic outcomes using preoperative personalized three dimensional (3D)-printing technology. Goal(s): Exploring whether personalised 3D-printing technology can improve surgical precision and thus prolong survival in glioblastoma patientsApproach: Using questionnaires, radiomics, and FD to evaluate whether preoperative 3D-printing technology improves postoperative outcomes and survivalResults: The FD of surgical regions was associated with overall survival, and preoperative 3D-printing improves patient prognosis and prolongs survivalImpact: Multimodal magnetic resonance imaging radiomics and fractal dimension can predict patient survival by analyzing postoperative images, while personalized 3D printing technology can improve surgical accuracy, reduce the fractal dimension of the surgical regional, and prolong the overall survival of patients