Magnetic Resonance in Medicine最新文献

{"title":"Mapping a reproducible water fraction and T₁ using MP2RAGE and variable flip angle quantitative MRI protocols.","authors":"Eden Mama, Rona Shaharabani, José P Marques, Aviv A Mezer","doi":"10.1002/mrm.70096","DOIUrl":"https://doi.org/10.1002/mrm.70096","url":null,"abstract":"<p><strong>Purpose: </strong>Water fraction (WF) estimation, a form of quantitative MRI mapping, is typically performed using the variable flip angle (VFA) approach. In this study, WF estimation was extended to include the magnetization prepared with 2 rapid gradient echoes (MP2RAGE) protocol. The two methods were compared to assess the consistency of WF values across both acquisition strategies.</p><p><strong>Methods: </strong>WF and T₁ maps were calculated using both the VFA and MP2RAGE acquisition protocols. In vivo and phantom datasets were used to assess the comparability of WF estimation between the two methods. Repeatability and reproducibility were evaluated both within each acquisition approach and across the two protocols.</p><p><strong>Results: </strong>High agreement was observed between WF and T₁ maps derived from the VFA and MP2RAGE approaches. The extraction of WF maps from the MP2RAGE protocol was validated, and the consistency of WF estimation across both methods was confirmed.</p><p><strong>Conclusion: </strong>The findings support the use of WF alongside T₁ maps derived from both the VFA and MP2RAGE methods. The ability to obtain reliable WF estimates from either protocol expands the applicability of WF mapping across a broader range of imaging studies.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145280699","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":"Pharmacokinetic modeling strategies for dynamic hyperpolarized urea imaging.","authors":"Keith A Michel, Collin J Harlan, Christopher M Walker, Matthew E Merritt, Yunyun Chen, Stephen Y Lai, James A Bankson","doi":"10.1002/mrm.70117","DOIUrl":"https://doi.org/10.1002/mrm.70117","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate pharmacokinetic modeling methods for quantification of tissue perfusion/permeability with hyperpolarized ¹³C urea.</p><p><strong>Methods: </strong>Three models for quantitative analysis of dynamic HP urea imaging data were proposed and evaluated in numerical simulations and a thyroid cancer mouse model. A multicompartment model resembling the extended Tofts model for DCE-MRI (Model I) and two simplified models were used. The simplified models each eliminate a volume parameter representing vascular (Model II) or impermeable cellular space (Model III). Signal curves were generated from Model I, and models were fit to these synthetic data to quantify the effects of acquisition settings, bias in simplified models, and noise.</p><p><strong>Results: </strong>For Model I, reproducible and accurate results from snapshot imaging occurred at excitation angles of roughly 10 to 40 degrees, with wider ranges of good performance at longer TRs. Models II and III exhibited bias in estimation of the trans-capillary transfer rate constant (k_ve), with high sensitivity in k_ve fitting to variations in the volume parameter not explicitly included. At a peak SNR of 25, k_ve coefficients of variation were 14.6%, 5.53%, and 4.9% for Models I-III, respectively. When vascular input function (VIF) amplitude was jointly estimated, these coefficients of variation increased to 26.9%, 8.86%, and 25.4%. Individual pharmacokinetic parameters exhibit added bias with VIF amplitude fitting, but the k_ve/v_e and k_ve/v_b ratios are independent of VIF scaling and provide accurate results for Models I and III.</p><p><strong>Conclusion: </strong>Our results demonstrate the feasibility and relative performance of pharmacokinetic models for HP urea for quantification of tissue permeability and perfusion.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145280643","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":"7T ¹⁹F/¹H MRI with perfluorocarbon-labeled immune cells in pigs: Pilot results with a dedicated twin-array system with pTX support.","authors":"Maxim Terekhov, Ibrahim A Elabyad, Marwan A Hamid, Farzad Jabbarigargari, Rebekka Grampp, Mohammadreza Keshtkar, Anja Stadtmüller, Gabriele Ulm, Sofia Dembski, Anna Frey, Ulrich Hofmann, Wolfgang R Bauer, Laura M Schreiber","doi":"10.1002/mrm.70105","DOIUrl":"https://doi.org/10.1002/mrm.70105","url":null,"abstract":"<p><strong>Purpose: </strong>Cardiac inflammation plays a key role in many diseases. However, its underlying mechanisms and progression remain poorly understood. Using an ultra-high field (UHF) may increase the sensitivity of MRI of inflammatory processes with ¹⁹F-labeled immune cells. The high Larmor frequency of ¹⁹F (∼95% of that for ¹H-nuclei) leads to similar technical hurdles in acquiring MR images at UHF that originate from the heterogeneity of B₁ ⁺. We aimed to develop a system of transmit/receive (Tx/Rx) arrays exploiting parallel transmit (pTX) technology for B₁ ⁺-shimming to acquire a combination of high-quality anatomical ¹H MR-images of a pig heart and ¹⁹F images of labeled immune cells at 7T.</p><p><strong>Method: </strong>The 16-element twin-arrays for ¹H and ¹⁹F nuclei were designed using electromagnetic simulations with a focus on optimal B₁-shimming and g-factor in the region of the pig heart. pTX support allows for the subject-specific B₁-shimming for ¹H cardiac MRI and transfer of settings for the B₁-shimming to the ¹⁹F twin-array.</p><p><strong>Results: </strong>The twin-array system was implemented and tested in a pig-thorax--shaped phantom, in-vivo in a myocardial infarction pig model, and in an excised heart. A transfer of static B₁+ shimming setting between the ¹H to ¹⁹F arrays was demonstrated. The parallel imaging acceleration of up to a factor 4 was possible with a g-factor <1.3 for both arrays. The 7T MRI of ¹⁹F-labeled immune cells in the heart of the pig was demonstrated both in-vivo and ex-vivo.</p><p><strong>Conclusion: </strong>The 7T MRI of perfluorocarbon-labeled immune cells in a large-animal myocardial infarction model becomes feasible using a novel dedicated twin-arrays system.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145275178","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":"Motion Correction in High-Resolution 3D Brain MRSI Without Water and Lipid Suppression.","authors":"Ziwen Ke, Yibo Zhao, Rong Guo, Yudu Li, Wen Jin, Huixiang Zhuang, Yao Li, Zhi-Pei Liang","doi":"10.1002/mrm.70128","DOIUrl":"https://doi.org/10.1002/mrm.70128","url":null,"abstract":"<p><strong>Purpose: </strong>To develop an effective method for correcting head motion in high-resolution, non-water-suppressed MRSI.</p><p><strong>Methods: </strong>MRSI scans are susceptible to subject motion due to the long data acquisition time required for sufficient spatial-spectral encodings. The problem is more serious in non-water-suppressed MRSI experiments since motion artifacts in the water and lipid signals make their removal even more challenging. To address this problem, we propose a novel motion correction method that detects and discards motion-corrupted k-space data using TR-wise linear navigators. The discarded data are replaced with reconstructed data obtained by reformulating motion correction as a missing data reconstruction problem using sensitivity encodings. Extrinsic priors for water and lipid signals and intrinsic priors for metabolite signals are incorporated in the motion correction process. We evaluated its performance on a spectroscopic phantom and three human groups: (1) five healthy adults performing three different voluntary motion patterns; (2) a healthy child; and (3) a cerebral hemorrhage patient with involuntary movements.</p><p><strong>Results: </strong>In phantom and healthy subjects, the proposed method produced high-quality water images and metabolite maps that closely matched motion-free references, with 10%-20% quantitative gains in image/map quality (higher PSNR/SSIM, lower NRMSE). In the child and patient data, motion artifacts were noticeably reduced, with 20%-30% reductions in NAA linewidth and fitting error in the child, and ˜50% reductions in coefficient-of-variation in the patient.</p><p><strong>Conclusion: </strong>An effective motion-correction technique has been developed for high-resolution non-water-suppressed MRSI. This method has the potential to significantly enhance the robustness and clinical applicability of non-water-suppressed MRSI.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145275191","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":"Increasing the measurable frequency range of magnetic field oscillations with off-resonance spin-lock preparation pulses.","authors":"Fróði Gregersen, Teresa Cunha, Axel Thielscher, Lars G Hanson","doi":"10.1002/mrm.70116","DOIUrl":"https://doi.org/10.1002/mrm.70116","url":null,"abstract":"<p><strong>Purpose: </strong>Oscillatory magnetic fields-arising from, e.g., neuronal currents or induced currents during brain stimulation-can be measured with spin-lock preparation pulses, where the frequency of the measured field matches the amplitude of the spin-lock pulse. The upper frequency limit is thus determined by either the maximum RF amplitude or SAR restrictions. This study aimed to extend the measurable frequency range.</p><p><strong>Theory and methods: </strong>We outline theoretically how off-resonance preparation pulses lead to an extended measurable frequency range of oscillating fields and how to tune them to the frequency of interest, and we discuss how this is related to the theory of two-photon excitation. We use the MR simulator software KomaMRI to simulate our proposed sequence and compare it to phantom measurements, where the oscillatory magnetic field is created from a current in a cable loop around a phantom.</p><p><strong>Results: </strong>The simulations and measurements were consistent, showing that the RF amplitude can be decreased when the off-resonance detuning is increased while being sensitive to the same frequency of the oscillating field. We additionally observed that the effects of the RF inhomogeneities on the measured signal were reduced as the detuning increased.</p><p><strong>Conclusion: </strong>We have shown that the measurable frequency range of magnetic field oscillations can be increased using off-resonance preparation pulses, albeit with a lower sensitivity. We also observed reduced effects from RF inhomogeneities, which can potentially improve neuronal current detection at low frequencies as well.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145251784","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":"Impact of Lower Limb Amputation on Implant Heating During 1.5 T MRI: Assessment of Active and Passive Device.","authors":"Ao Shen, Mir Khadiza Akter, Ziyu Zuo, Lingfei Zhang, Jianfeng Zheng, Michael Steckner, Mingtao Du, Ji Chen","doi":"10.1002/mrm.70123","DOIUrl":"https://doi.org/10.1002/mrm.70123","url":null,"abstract":"<p><strong>Purpose: </strong>This study investigates the impact of lower limb amputation on radiofrequency (RF)-induced heating of active and passive implantable medical devices (AIMDs and PIMDs) in a 1.5 T MRI environment.</p><p><strong>Methods: </strong>High-resolution anatomical models representing various body types and levels of amputation (below-knee and above-knee) were explored in the study. Full-wave electromagnetic simulations were used to assess specific absorption rate (SAR) near modular hip prostheses. The RF-induced lead-tip heating for a clinically relevant peripheral nerve stimulation (PNS) device was evaluated following ISO 10974. Results were normalized using whole-body SAR and averaged B1_+rms. Experimental validation was performed using an anatomically inspired leg phantom with embedded metallic implants.</p><p><strong>Results: </strong>SAR near passive implants increased with implant length and was influenced by the level of amputation. In general, more extensive amputations resulted in reduced SAR due to alterations in tissue geometry. For active implantable medical devices (AIMDs), temperature rise also decreased with greater amputation extent; however, localized heating effects were intensified near the amputation site. Phantom simulation results were in strong agreement with experimental measurements, supporting the accuracy of the modeling approach.</p><p><strong>Conclusion: </strong>Limb amputation significantly alters RF field distribution, affecting RF-induced heating near both active and passive implants. These results highlight the need for amputation-specific safety assessments during MRI to ensure accurate evaluation of heating risks and implant compatibility in amputee patients.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145251724","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":"Rapid flow-artifact-free high-resolution T₂ mapping via multi-shot multiple overlapping-echo detachment imaging.","authors":"Qizhi Yang, Jianfeng Bao, Zurong Ni, Jiechao Wang, Longkun Chen, Shenghen Yu, Zhong Chen, Congbo Cai, Shuhui Cai","doi":"10.1002/mrm.70119","DOIUrl":"https://doi.org/10.1002/mrm.70119","url":null,"abstract":"<p><strong>Purpose: </strong>The aim is to develop a T₂ mapping method with submillimeter spatial resolution, approximately 1-minute acquisition time, large volume coverage, and no extra burden on the console or coil setups. Additionally, to develop an associated approach correcting inter-shot phase variations caused by pulsatile CSF.</p><p><strong>Methods: </strong>Multi-shot (msh-) acquisition scheme was integrated into multiple overlapping-echo detachment imaging (MOLED) to alleviate pitfalls of single-shot MOLED (e.g., excessive voxel size and B₀-induced geometric distortion) from the physical aspect. Discontinuous phase jumps were corrected via deep learning, leveraging the pattern incoherence between desired signal and undesired artifacts. Methodological feasibility was validated with phantoms (at 3 T and 7 T) and humans (at 3 T).</p><p><strong>Results: </strong>Referring to spin-echo (SE), phantom/human results exhibited a mean absolute error of 1.11/0.89 ms, and linear regression of phantom results revealed a slope of 0.994 (R² = 0.995). Referring to turbo SE, msh-MOLED demonstrated good coincidence of structural depiction. In data acquired with different scanners and scanning parameters, errors from CSF-induced inter-shot phase inconsistency were successfully eliminated without autocalibration kernel, navigators, gating equipment, nor time-consuming postprocessing.</p><p><strong>Conclusion: </strong>A T₂ mapping method with submillimeter spatial resolution and high clinical practicality is proposed and validated. Inter-shot phase variation, a nuisance factor to sequences using segmented k-space acquisition, is addressed in a navigator-free and calibrationless manner, retaining the quantification accuracy and acquisition rapidness of msh-MOLED against pulsatile CSF. This work suggests that the trajectory-related ghost artifacts may be removed through specific spatial encoding and image inpainting.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145251699","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":"Time-resolved mapping of myocardial stiffness using 2D multifrequency spiral MR elastography with and without external vibration","authors":"","doi":"10.1002/mrm.70107","DOIUrl":"https://doi.org/10.1002/mrm.70107","url":null,"abstract":"","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"94 6","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.70107","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145230515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of dB/dt-Over-Electric Field Cardiac Magnetostimulation Safety Ratios in 75 Body Models and 18 Gradient Systems.","authors":"Valerie Klein, Jonathan Edmonson, Mathias Davids, Natalie G Ferris, Matthias Gebhardt, Dominik Rattenbacher, Johan S van den Brink, Michael Steckner, Lawrence L Wald, Bastien Guérin","doi":"10.1002/mrm.70130","DOIUrl":"https://doi.org/10.1002/mrm.70130","url":null,"abstract":"<p><strong>Purpose: </strong>The IEC 60601-2-33 standard provides consensus-based safety provisions for MRI equipment. Protection of patients against cardiac stimulation (CS) is based on limiting the maximum E-field induced by MRI gradient coils. In practice, this is achieved by imposing a conservative dB/dt threshold on any gradient waveform. The dB/dt-over-E-field conversion ratio currently used in IEC 60601-2-33 was derived in a homogeneous ellipsoid exposed to a uniform B-field and is 10 (T/s)*(V/m)^-1. This limit is becoming increasingly restrictive in high performance clinical systems. We therefore evaluate dB/dt-over-E-field ratios in realistic body models and coils using state-of-the-art electromagnetic simulations.</p><p><strong>Methods: </strong>We performed two independent simulation studies in a total of 75 realistic body models and 13 commercial gradient systems and derived dB/dt-over-E-field ratios in the heart. We thresholded the E-field maps to mitigate the impact of staircasing artifacts in boundary voxels between the myocardium and the lungs.</p><p><strong>Results: </strong>Thresholding the E-field maps at the 99th percentile E-field value (E99) eliminates staircasing artifacts in both simulation studies. Study #1 predicts a larger range of dB/dt-over-E99 ratios (13-53 (T/s)*(V/m)^-1) than study #2 (12-35 (T/s)*(V/m)^-1). Despite differences in EM solvers, body models, coils, mesh resolution, and post-processing, both studies find similar worst-case ratios of dB/dt-over-E99 of 12-13 (T/s)*(V/m)^-1.</p><p><strong>Conclusion: </strong>Our simulations of dB/dt-over-E-field ratios for cardiac safety in MRI cover a large range of realistic clinical scenarios. An increase of the allowable dB/dt beyond the current CS limit in IEC 60601-2-33 may be feasible.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145239015","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":"Automatic determination of glymphatic flow with the DTI-ALPS-index along the principal axis system in native imaging space corrects for head and fiber orientation.","authors":"Ali Ajouz, Olav Jansen, Lynn Johann Frohwein, Svea Seehafer, Naomi Larsen, Jan-Bernd Hövener","doi":"10.1002/mrm.70082","DOIUrl":"https://doi.org/10.1002/mrm.70082","url":null,"abstract":"<p><strong>Purpose: </strong>The aim of this work is to make the DTI along the perivascular space (DTI-ALPS-index) more robust with respect to region selection and the orientation of the head and fibers. We propose to address this matter by using the principal diffusion directions and an automated, atlas-based region of interest (ROI) placement.</p><p><strong>Methods: </strong>Simulations were used to determine the dependence of the DTI-ALPS-index on the orientations of the head and nerve fibers. Human MRI was performed on 12 healthy volunteers at 3T using a 64 channel head coil (Cima.X Siemens), and the DTI-ALPS-index was calculated along the principal diffusion directions (ALPS-PAS) and along the field of view or laboratory frame (ALPS-LAB). To calculate the DTI-ALPS-index with reduced bias in native space, we developed a novel algorithm for an automatic ROI placement technique. Its calculated index results  were compared to those obtained from a manual ROIplacement in native space and from an existing atlas-based ROI placement. Test-retest scans with varying head rotation were conducted for validation.</p><p><strong>Results: </strong>Simulations showed that ALPS-PAS was more robust toward head and fiber rotations than ALPS-LAB. In vivo, ALPS-PAS yielded a 10% higher index than ALPS-LAB. The automated ROI placement led to a smaller difference in the DTI-ALPS-index between test and retest measurement compared to the manual ROI placement. Stability was enhanced with ALPS-PAS for all ROI placements and varying head rotation.</p><p><strong>Conclusion: </strong>Using the principal components of the diffusion and automated ROI selection increased the measured DTI-ALPS-index, improved the robustness toward head and fiber orientations and eliminated the need for manual region selection.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145232996","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}