bluuebunny/crossref_metadata_2025 huggingface dataset:
Prognosticating Maternal and Neonatal Outcomes in Placenta Accreta Spectrum Disorders by Combining Placental Perfusion and MRI Features
Authors: Zhang* Jin , Kong* Lingnan , Qu Feifei , Chen Ting , Zhou Xin , Ge Zhiping , Jin Bai , Zhang# Xuan , Zhao# Meng
Published: November 2024

Motivation: The factors to predict adverse maternal and neonatal outcomes in patients with placenta accreta spectrum disorders needed identification. Goal(s): This study aimed to identify appropriate predictive indicators using magnetic resonance imaging (MRI) and intravoxel incoherent motion (IVIM) parameters. Approach: The study examined the association between various influencing factors (clinical risk factors, MRI features, and IVIM parameters) and adverse outcomes using univariate and multivariate analyses. Results: Independent predictors of a poor prognosis included previous cesarean sections, low-signal-intensity bands on T2WI, and D value. Impact: The components of the prediction model in this study were more comprehensive and improved the prediction efficiency. The study analyzed the relationship between f value and postpartum hemorrhage and further examined the importance of IVIM in predicting adverse outcomes.
Radiomic Features of Placental Magnetic Resonance Imaging Identify Adverse Pregnancy Outcomes: A Pilot Study
Authors: Do Quyen , Xi Yin , Lewis Matthew , Fei Baowei , Spong Catherine , Twickler Diane , Herrera Christina
Published: November 2024

Motivation: Chronic hypertension (cHTN) is a significant obstetric condition with increased risk of adverse outcomes. Radiomic analysis of MR images may be able to predict outcomes before development of clinical findings. Goal(s): Our goal was to compare MR T2W radiomic features among 4 clinical outcomes: normal, cHTN, preeclampsia with severe features, and small for gestational age (SGA). Approach: We applied ROI-based radiomics analysis on prospectively collected T2W MR images in normal and cHTN pregnancies. Results: We found that MR T2W radiomic features as early as 16 weeks can identify those patients who develop preeclampsia with severe features and whose infants are born SGA. Impact: We demonstrated that MR T2W radiomic features as early as 16 weeks can identify those patients who develop preeclampsia with severe features and whose infants are born small for gestational age.
Classification of MRI-only suspicious breast lesions: Development and validation of a nomogram combining MRI features and ADC-based histogram
Authors: Li Xue , Chen Min , Jiang Lei , Li Chunmei , Zheng Dandan
Published: November 2024

Motivation: MRI-only lesions tend to be small in size and often have limited specific morphologic features on MRI, posing a significant diagnostic challenge for clinicians. Goal(s): A simple, objective, and noninvasive approach is required to improve the diagnostic accuracy of MRI-only lesions. Approach: We aimed to develop and validate a nomogram combining clinicoradiologic features and ADC-based histogram parameters for MRI-only suspicious lesions. Results: Our results showed that ADC entropy in histogram parameters and kinetic pattern in clinicoradiologic parameters were identified as the most valuable predictors for differentiating MRI-only lesions, and a nomogram combining them exhibited better diagnostic performance than the two variables alone. Impact: A nomogram combining ADC entropy and kinetic pattern, as a simple, objective, and noninvasive tool, displays satisfactory diagnostic performance for MRI-only suspicious lesions and may be utilised to avoid unnecessary biopsy.
IVIM diffusion parameter highlights placental microstructural damage in patients with previous SARS-CoV-2 pregnancy infection
Authors: Maiuro Alessandra , Ercolani Giada , Celli Veronica , Porpora Maria Grazia , Catalano Carlo , Giancotti Antonella , Manganaro Lucia , Capuani Silvia
Published: November 2024

Motivation: Currently, no study has investigated the role of diffusion-MRI to assess the placenta of women getting SARS-CoV-2 infection. Goal(s): To study the placental tissues abnormalities due to the infection. Approach: Pregnant women COVID-19 group (n=14) and pre-pandemic healthy women (n=19) were investigated using IVIM protocol at 1.5T. Results: D was significantly higher in the COVID-19 compared to that of the age-matched healthy group. No-significant difference between f values was found in the two groups suggesting no-specific microstructural damage with no-perfusion alteration. A significant negative correlation was found between D and GA only in the COVID-19 reflecting a possible senescence process due to COVID-19. Impact: Diffusion MRI underline higher D value in SARS-Cov-2 compared to healthy placentas, which can be explained as a microstructural deterioration of the placental tissue. Further investigations will allow us better to understand the effects of SARS-Cov-2 infection on human tissues.
Monitoring treatment response of nasopharyngeal carcinoma to vascular normalization with Amide Proton Transfer Imaging
Authors: Yu Jing , Cheng Yong , Wu Peng , Gao Bo
Published: November 2024

Motivation: The effectiveness of anti-angiogenesis therapy in patients with advanced nasopharyngeal carcinoma is not optimal, and early monitoring of treatment effectiveness can reduce unnecessary treatment for patients. Goal(s): The focus of this study was to ascertain whether Amide Proton Transfer- Magnetic Resonance Imaging (APT-MRI) could be effectively used to evaluate tumor response at an early stage. Approach: The research involved an examination of the correlation between APTw values and tumor cell proliferation, achieved by subjecting preclinical models to diverse antiangiogenic therapies. Results: The results of our study demonstrated a marked positive correlation between APTw and the expression of Ki67, a tumor proliferation marker. Impact: This study is useful for the clinical application of anti-angiogenesis therapy. The study provides an in-depth exploration of the mechanisms and efficacy of this therapeutic approach, offering a comprehensive understanding that is crucial for its successful implementation in clinical practice.
Model selection criteria for data-driven determination of 1H-MRS basis-set composition.
Authors: Davies-Jenkins Christopher , Simicic Dunja , Zöllner Helge , Oeltzschner Georg
Published: November 2024

Motivation: The composition of metabolite basis sets impacts their estimates, but no consensus or objective methods exist to decide which compounds should be included or excluded for a particular dataset. Goal(s): To develop an objective, data-driven procedure for determining basis-set composition. Approach: An iterated fitting algorithm uses information criteria scores to select the most appropriate metabolite basis functions directly from the data. We tested two “stopping conditions” using in-vivo-like simulated spectra. Results: The algorithm correctly, consistently identified large parts of the ground-truth set. Stopping conditions set reliable bounds on the basis-set composition. Refinement for low-concentration compounds is expected to further improve accuracy. Impact: Model selection for data-driven assessment of basis set composition has the potential to provide objective criteria and remove operator bias of linear-combination modeling. This may reduce analytic variability and help establish practices for low-concentration and pathology-specific metabolites.
In vivo data-driven discovery of tissue's constitutive relations: proof of concept on a thigh muscle
Authors: Heesterbeek David , van Riel Max , Froeling Martijn , van Leeuwen Tristan , van den Berg Cornelis , Sbrizzi Alessandro
Published: November 2024

Motivation: Over simplified constitutive relations limit the applicability of in vivo biomechanical analysis of tissue. Goal(s): To develop a data-driven framework for discovering potentially more accurate in vivo constitutive relations using displacement fields and pressure measurements obtained in a simple acquisition/reconstruction setup. Approach: An inflatable pressure cuff is used to deform the thigh muscle during an MRI scan. Time-resolved images and displacement fields are reconstructed directly from k-space and used to extract strain information. This information allows for the discovery of potentially more accurate constitutive relations. Results: An anisotropic constitutive relation for the hamstring is found. Numerical tests suggest the validity of the method. Impact: Data-driven discovery of tissue’s constitutive relations could help to better characterise its mechanical properties. We demonstrated in this proof of concept study that information acquired during simple dynamic loading experiments allows reconstruction of constitutive relations that include muscle anisotropy.
Characterize the Membrane Phospholipids 31P MRS Signal in Human Brain at 7T
Authors: Ren Jimin , Johnson Talon , Henning Anke
Published: November 2024

Motivation: Human brain 31P-MR spectra often show a broad membrane phospholipid (MPL) signal, which has an intensity far exceeding all other sharp signals combined and a linewidth of ~ 15 ppm. Despite its spectral dominance and distortive effect on the sharp 31P peaks, this MPL signal has received little NMR characterization. Goal(s): Measure MPL T2 relaxation time, estimate its concentration, and demonstrate MPL chemical exchange effect. Approach: Chemical exchange was measured by inversion-recovery method, and T2 by varying the delayed time of FID-sampling. Results: MPL has a short T2 (0.1 ms), and high concentration (1.2 M), and present with internal chemical exchange within its structure. Impact: MPL signals can be selectively detected using 31P MRS in the human brain. High concentration of MPL in the order of 1M may provide a valuable surrogate point for studying demyelination process in neurodegenerative diseases such as multiple sclerosis (MS).
Improving Outcomes in Deep Brain Stimulation: A Comparative Study of 7T versus 3T Targeting
Authors: Middlebrooks Erik , Zhou Xiangzhi , Tao Shengzhen , Greco Elena , Okromelidze Lela , Patel Vishal , Grewal Sanjeet
Published: November 2024

Motivation: 7T MRI offers improved image quality for deep brain stimulation (DBS) targeting, but greater distortion and artifacts that could lead to inaccurate targeting. Goal(s): Our goal was to compare outcomes in DBS for essential tremor between patients targeted using 3T versus 7T MRI. Approach: Retrospective comparison of DBS patients with ET was performed with patients targeted using 3T versus 7T MRI. We assessed differences in tremor improvement, adverse events, and electrode positioning. Results: ET DBS patients targeted with 7T had significantly greater tremor control compared to 3T, as well as lower stimulation currents and improved electrode precision. Impact: Despite challenges of 7T MRI in surgical planning, outcomes in DBS for ET were improved by use of 7T MRI versus 3T MRI, including better tremor control, reduced stimulation currents, and greater precision.
Association of carotid stiffness and pulsatility using single-slice oblique-sagittal PC-MRI with cognitive impairment in elderly adults
Authors: Tang Jianing , Zhao Tianrui , Joe Elizabeth , Pahlavian Soroush , Chui Helena , Yan Lirong
Published: November 2024

Motivation: Arterial stiffening and pulsatility serve as important markers of vascular dysfunction. Oblique-sagittal PC-MRI (OS PC-MRI) is a technique that provides a one-stop-shop approach for multiple vascular metrics. Goal(s): This study aims to investigate the association of carotid vascular metrics measured by OS PC-MRI with cognitive impairment and cerebral perfusion in an elderly cohort. Approach: OS PC-MRI data were collected on 40 elderly participants, who also underwent cognitive tests. Cerebral perfusion was measured using 3D pCASL. Pulse wave velocity(cPWV), pulsatility index(PI), and damping factor(DF) were calculated. Results: Our results showed increased cPWV and reduced cDF were associated with cognitive impairment and reduced cerebral perfusion. Impact: OS PC-MRI measures multiple vascular metrics including cPWV, PI, and cDF within two minutes, which shows strong associations with cognitive impairment and cerebral perfusion, consistent with previous findings. This study suggests OS PC-MRI could be promising to study vascular dysfunction.
Wide-spectrum framework in Disorders of Arousal: combined resting state connectivity and metabolic study of cingulate cortex
Authors: Cantoni Elena , Sighinolfi Giovanni , Rochat Magali , Mitolo Micaela , Greta Mainieri , Venturi Greta , Bianchini Claudio , Cirignotta Lorenzo , Bartiromo Fiorina , Vornetti Gianfranco , Manners David , Provini Federica , Lodi Raffaele , Tonon Caterina
Published: November 2024

Motivation: A comprehensive framework for the characterization of Disorders of Arousal (DoA) in adulthood is lacking, and the brain metabolic and functional mechanisms underlying this disorder are still unknown. Goal(s): To fill this gap, we aimed to quantitatively investigate the cingulate cortex in DoA through advanced brain MRI, combined with thorough neuropsychological evaluations. Approach: We collected and compared resting-state, 1H-MRS and clinical data from adult patients diagnosed with DoA and a matched group of healthy controls. Results: We identified metabolic and functional alterations in regions involving the limbic system and changes in the connectivity of the sensorimotor network crucial for understanding the pathology. Impact: Through a combined MR imaging investigation and psychological assessments, we extracted results in the form of brain metabolic and functional quantitative markers that advance our knowledge on the brain alterations underlying Disorders of Arousal.
Changed excitation-inhibition balance and dynamic functional connectivity provide evidence for sensory deprivation theory in presbycusis
Authors: Su Meixia , Li Ning , Li Fuyan , Li Xiao , Edden Richard , Chen Weibo , Ren Fuxin , Gao Fei
Published: November 2024

Motivation: To learn more about neurophysiological changes in the cognitive-ear link in presbycusis. Goal(s): To explore the role of excitation-inhibition (EI) balance and dynamic functional connectivity (dFC) in mediating the associations between hearing loss and cognitive impairment in presbycusis patients. Approach: MRS in the auditory cortex and resting-state fMRI of whole brain in 98 presbycusis patients and 60 healthy controls were assessed. Results: EI balance and dFC indices were statistically different between presbycusis patients and healthy controls. Hearing loss can affect cognition via a bottom-up route from ear to cognitive in a neurochemical and dFC way in presbycusis. Impact: Shifted EI balance and dFC abnormalities play important roles in cognitive-ear link reorganization and provide evidence for sensory deprivation theory, and they can serve as a potential neuroimaging marker for predicting cognitive impairment in presbycusis patients.
Structural alterations in Spinocerebellar Ataxia Type 3: A 3T baseline and longitudinal MRI study of cerebellar peduncles and cerebral pathways
Authors: Ferreira Mónica , Wegner Philipp , Theisen Jahn , Klockgether Thomas , Faber Jennifer
Published: November 2024

Motivation: The first gene-silencing trials for Spinocerebellar Ataxia Type-3 (SCA3) highlights the need for non-invasive biomarkers. Goal(s): We aim to evaluate white matter (WM) tract integrity, identify early-alterations before clinical onset (preSCA3) and track disease progression over time. Approach: Analyze fractional anisotropy (FA) and mean diffusivity (MD) in WM tracts of healthy controls, preSCA3, and SCA3 patients at cross-sectional and longitudinal visits by employing a global and along-tract analysis. Results: While longitudinal analysis did not show relevant changes, alterations in preSCA3 in FA and MD were observed in all cerebellar peduncles and in the dentato-rubro-thalamo-cortical-tract, indicating their potential as promising stratification-biomarkers before clinical onset. Impact: This study offers a promising approach to differentiate early-stage SCA3 before clinical onset from healthy subjects, addressing clinical scale limitations. It underscores the potential of imaging biomarkers and the necessity for further research on disease progression modeling.
Subcortical Shape Abnormalities in Maintenance Hemodialysis Patients with Sleep Disorder
Authors: Jiang Yuhan , Miao Yanwei , Wu Jianlin
Published: November 2024

Motivation: Hemodialysis (HD) patients can cause alterations in brain structure, and often experience cognitive and sleep disorders (SD). However, the mechanism of SD in HD patients is not fully understood. Goal(s): We aimed to assess the changes in subcortical structures of HD patients with SD and to explore the associations with cognitive. Approach: Volumetric and vertex-wise shape analysis approaches were used to investigate the 14 subcortical structural abnormalities. Results: Hemodialysis patients with sleep disorder exhibited significant surface reduction on the right hippocampus. Impact: Atrophy of subcortical structures was observed in the hemodialysis patients. Right hippocampus atrophy is closely associated with sleep disorder, emphasizing the role of hippocampus as viable predictor.
Microscopic diffusion anisotropy as a predictor of cognitive decline in asymptomatic adults
Authors: Shin Hyeong-Geol , Sasannia Sarvin , Mahmud Sarara , Matsyuk Mykola , Wang Shimeng , Zhang Jinwei , Szczepankiewicz Filip , Li Xu , Prince Jerry , Knutsson Linda , van Zijl Peter , Nyquist Paul
Published: November 2024

Motivation: Conventional diffusion MRI metrics like FA have limitations in assessing WMH lesions due to fiber orientation dispersion. Goal(s): To improve MRI sensitivity to white matter integrity in WMH and assess its clinical relevance in predicting preclinical cognitive decline using advanced diffusion MRI. Approach: FA and μFA maps were acquired in 54 adults using tensor-valued diffusion MRI and their quantitative correlation with cognitive decline were evaluated in WMH lesion and penumbra. Results: While both μFA and FA differentiated WMH from other white matter regions, μFA demonstrated greater sensitivity to predict cognitive decline, suggesting its added specificity to probe white matter integrity in WMH. Impact: Enhanced sensitivity of μFA to subtle white matter integrity and clinical aspect may offer better understanding of underlying histopathological alterations in white WMH, helping earlier detection of cerebrovascular pathology and aiding efforts to identify at-risk individuals and guide timely interventions.
Association of Asian Parkinson's Disease risk variant rs9638616 with brain structural and functional changes
Authors: Welton Thomas , Teo Thomas
Published: November 2024

Motivation: The genetic variant rs9638616, is associated with Parkinson’s Disease (PD) risk in Asian populations. Goal(s): To provide insight into the neural correlates of rs9638616 in Asian PD, to inform risk models and idiopathic PD aetiology. Approach: Using imaging and genotyping data from 116 early-PD patients and 57 controls of Chinese ethnicity, we performed voxelwise analyses to assess rs9638616 T-allele association with brain microstructure, morphology and function. Results: Our results suggest that rs9638616 may confer PD risk in Asian cohorts via lower white matter fractional anisotropy and reduced supplementary motor area functional connectivity. Impact: In an imaging-genetics analysis, the Asian PD risk variant rs9638616 was associated with altered brain structure/function. This rationalises rs9638616’s role in PD risk, and may be useful in improving PD stratification and risk modeling.
Fast SMWI : Optimizing Classifier with FOV reduction simulation
Authors: Youn Jonghyo , Park Juhyung , Ji Sooyeon , Choi Jaewoo , Heo Hwan , Lee MyeongOh , Song Soohwa , Shin Donghoon , Kim Eung Yeop , Lee Jongho
Published: November 2024

Motivation: SMWI is an advanced SWI method capable of detecting nigral hyperintensity in the substantia nigra. Due to the long scan time, a reduced FOV sequence was proposed to decrease the scan time from 4min 15sec to 2min 45sec, along with the application of denoising techniques. However, when evaluated with the original classifier, the results showed changes, reporting increased FN, which may be a problem in clinic. Goal(s): Maintaining diagnostic results for the reduced FOV with denoised SMWI images. Approach: Optimizing classifier to denoised FOV-simulated SMWI images. Results: The diagnostic result of denoised FOV 64.5% SMWI images is comparable to FOV 100% SMWI images. Impact: The diagnostic result of denoised FOV 64.5% SMWI images is comparable to FOV 100% SMWI images with the optimizing classifier based on denoised FOV-simulated SMWI images.
The value of radiomics models based on DTI and DWI sequences in identifying cervical adenocarcinoma and squamous cell carcinoma
Authors: Tian Shifeng , Zhang Hanyue , Ma Changjun , Liu Ailian
Published: November 2024

Motivation: To explore the feasibility of differentiating pathological types of cervical adenocarcinoma and squamous cell carcinoma by radiomics models based on DTI and DWI sequences. Goal(s): To explore the value of radiomics models based on DTI and DWI sequences in differentiating pathological types of cervical adenocarcinoma and squamous cell carcinoma. Approach: Based on the DTI and DWI sequence images of cervical cancer patients , this study quantitatively analyzed the differences in the radiomics feature parameters of adenocarcinoma and squamous cell carcinoma. Results: The radiomics models based on DTI and DWI sequences are valuable in differentiating the pathological types of cervical adenocarcinoma and squamous cell carcinoma. Impact: Radiomics can transform images into data that can be mining, providing a non-invasive and effective auxiliary method for determining tumor heterogeneity before clinical treatment of cervical cancer, guiding clinical practice, and enabling patients to achieve personalized diagnosis and treatment.
Spatio-temporal Consistency Analysis of Cerebral Small Vessel Disease: A fMRI study
Authors: Yang Jie , Liu Yujian , Hang Yantao , Wu Hengping , Zheng Chunyan , Chen Meining , Zhang Qin , Zhong Jianquan
Published: November 2024

Motivation: Cerebral small vessel disease (SVD) affects older adults, but traditional approaches have limited understanding of the neural mechanisms of SVD. Goal(s): To explore the effects of SVD on brain regions and its relationship to cognitive decline by FOCA method. Approach: MRI data from 42 SVD patients and 38 controls were analyzed using FOCA values, and the correlation between FOCA values of SVD patients and SVD score was explored. Results: Different FOCA value changes in SVD patients were associated with regions of cognitive function. Impact: This study has the potential to improve our understanding of the neural mechanisms of SVD, suggesting that FOCA values provide a new method to analyzing changes in cognitive function.
Location matters: Altered interhemispheric homotopic connectivity in post-stroke dyskinesia
Authors: Zhao Changjiang , Xu Haibo , Yu Chengxin , Gao Lei , Pan Junlong , Chen Long , Zhang Can , Chen Jiangjin , Zhu Li , Xiong Xiong , Zhao Xiance
Published: November 2024

Motivation: How stroke at different locations affects homotopic connectivity remains incompletely understood. Goal(s): This study aimed to examine how motor deficits resulting from acute stroke in different brain regions impact homotopic connectivity. Approach: Patients with dyskinesia were included and divided into 4 demographically matched subgroups by stroke location: frontoparietal, radiation coronal, basal ganglia, and brain stem. Additional 37 matched healthy controls were also recruited. Interhemispheric homotopic functional and structural connectivity was obtained by resting-state functional MRI and diffusion tensor imaging. Results: Our results suggest that post-stroke motor deficits in different regions implicate different links from cortical to subcortical areas. Impact: Alterations in lesion topography and regional functional homotopy provide new insights into the understanding of neural basis of motor disorders and also inform potential individualized precisive targets.
Correlations between cognitive reserve, brain and cerebrospinal fluid volume in mild cognitive impairment patients
Authors: Yang Wenxia , Zhou Liang , Zhang Jing
Published: November 2024

Motivation: Cognitive reserve (CR), which can preserve cognitive function despite underlying neuropathology, explains at least some variability in cognitive performance. Goal(s): To explore the effect of CR on brain and CSF volume in patients with MCI and healthy elders (HC). Approach: The study population included 31 HC and 50 MCI patients were collected in this study to obtain high-resolution 3D-T1 structure images, cognitive function and composite CR scores. Results: The results showed that cognitive reserve was significantly associated with cognitive performance. Some brain and CSF volumes correlate with cognitive reserve. Cognitive reserve affects cognitive performance by reducing the volume of the right parahippocampal gyrus. Impact: Our study provides evidence that CR protects neurocognitive function in the preclinical stages of AD, particularly in the right parahippocampal gyrus, through mechanisms that modulate brain and CSF volume.
Improve conspicuity of distal small vessels in velocity-selective ASL MRA using variable flip angle readout
Authors: Liu Lixin , Wang Lili , Chu Ying Hua , Liu Wenjin , Li Hao , Chen Zhensen , Wang He
Published: November 2024

Motivation: The conventional velocity-selective ASL-based (VSASL) MRA's acquisition efficiency is low since a long waiting time is used for blood refreshing. A large turbo factor for acquisition window can be used, but will lead to image blurring and degraded depiction of small vessels. Goal(s): To explore the potential of variable flip angle (VFA) strategy for improving conspicuity of distal small vessels in VSASL MRA. Approach: Four VFA strategies were designed and compared with constant FA in vessel visualization. Vessel sharpness of ACA, MCA and PCA was calculated. Results: Compared to constant FA, VFA has higher sharpness and can reduce the blurring of small vessels. Impact: The sharpness was higher for VFA than constant FA, suggesting the effectiveness of the VFA strategy in reducing blurring and improving the conspicuity of distal small vessels for VSASL MRA.
A Single Oscillating Waveform-based Gradient Delay Estimation
Authors: Li Bo , Taso Manuel , Chang Yulin , Detre John , Wang Ze
Published: November 2024

Motivation: The study was motivated by substantially reducing the calibration scan time for gradient delay estimation in spiral imaging. Goal(s): we only acquire a single spiral readout along each channel for delay estimation, which enables a substantial reduction in the calibration scan time. Approach: Our proposed method of SODA estimates the delay by calculating the relative shift between the MR spectrums required in a single scan as the k-space trajectory progresses from the negative kx direction to the positive kx direction and vice versa, i.e., from +kx to -kx. Results: The delay values demonstrated robust agreement and consistency between SODA and the reference. Impact: The SODA method delivers accurate delay estimates within extremely short scan time (about 50 ms). This technique can seamlessly integrate with any host sequence to correct k-space location errors stemming from gradient delays.
Modeling fat-water R1 relaxation in Fat DESPOT from complex signal
Authors: Bider Renée-Claude , Ciobanu Cristian , Campos-Pazmiño Jorge , McNabb Evan , Fortier Véronique , Levesque Ives
Published: November 2024

Motivation: Fat DESPOT, a fat and water R1 mapping technique, has been proposed to image tumor hypoxia through the oxygen-induced change in fat R1. Goal(s): Using the complex signal for Fat DESPOT doubles the usable data for each acquisition, reducing the total number of acquisitions required and scan time. Approach: The published magnitude approach to fat DESPOT was compared to the complex approach in simulations and phantom experiments. Results: Compared to the magnitude approach, the complex approach to Fat DESPOT increased the precision and accuracy of fat R­1 estimates in simulations and phantom experiments and increased the accuracy of PDFF in phantom experiments. Impact: This study suggests that the complex approach to fat DESPOT R1 measurements could reduce imaging time without compromising PDFF or R­1f estimates. It could therefore offer sensitive and versatile R1-based tumor hypoxia mapping in potentially clinically feasible scan times.
Improved 3D-EPI with motion and FID-navigated field correction
Authors: Utkur Mustafa , Wallace Tess , Kober Tobias , Kurugol Sila , Afacan Onur
Published: November 2024

Motivation: Previous studies have demonstrated field correction with 3D-EPI for fMRI and SWI, but ideal correction would account for both field inhomogeneities and motion. Goal(s): We aimed to investigate the limits of simultaneous motion and field correction with 3D-EPI. Approach: Our approach was to acquire in vivo data with controlled head motion. Volunteers were directed to rotate their heads 4-8 degrees and move left/right during scanning. We performed correction for field inhomogeneities using FID navigators after rigid motion registration. Results: Analysis across varying rotation degrees showed the ability to successfully correct both motion and field distortions in 3D-EPI using FID navigators. Impact: This simultaneous motion and field correction technique could enable high-resolution artifact-free 3D-EPI for fMRI studies. By correcting head motion and field inhomogeneities concurrently, the approach opens possibilities for investigating new research questions dependent on artifact-free imaging with substantial subject motion.
Distortion-free Diffusion Imaging Using BUDA-gSlider on the Connectome 2.0 System
Authors: Cho Jaejin , Liu Qiang , Jun Yohan , Fujita Shohei , Yong Xingwang , Kim Tae Hyung , Mahmutovic Mirsad , Keil Boris , Jaimes Camilo , Gee Michael , Huang Susie , Bilgic Berkin
Published: November 2024

Motivation: High-performance gradients of the Connectome 2.0 system drastically improve diffusion and imaging encoding to enable submillimeter diffusion imaging with high geometric fidelity. Goal(s): To enable high-resolution, distortion-free diffusion imaging with adequate SNR. Approach: Distortion-free BUDA-gSlider acquisition was deployed on the Connectome 2.0 system, and was compared against acquisitions using gradients derated to the level of clinical systems. Results: The Connectome 2.0 system provides improved diffusion-weighted images with higher SNR and geometric fidelity, particularly at submillimeter resolutions. Impact: High-performance Connectome 2.0 gradients enable high-resolution, distortion-free diffusion-weighted imaging with improved SNR at submillimeter resolutions.
Amide proton transfer imaging corrected by apparent diffusion coefficient to detect response of chemotherapy in bone and soft tissue sarcomas
Authors: Sagiyama Koji , Kamitani Takeshi , Yamasaki Yuzo , Hino Takuya , Tabata Kosuke , Yabuuchi Hidetake , Ishigami Kousei , Endo Makoto , Mori Taro , Oda Yoshinao
Published: November 2024

Motivation: Evaluating the response to chemotherapy based on volume changes is often difficult in bone and soft tissue sarcomas; therefore, new molecular imaging techniques are required. Goal(s): To investigate whether amide proton transfer (APT) imaging combined with apparent diffusion coefficient (ADC) accurately reflects treatment efficacy in bone and soft tissue sarcomas. Approach: An MRI was performed before and after chemotherapy in 12 patients who received preoperative chemotherapy. Tumor volume, APT, and ADC were compared before and after treatment and correlated with postoperative pathology specimens. Results: Only APT imaging with ADC correction correctly reflected the effect of preoperative chemotherapy. Impact: The present study demonstrates that a new molecular imaging technique can accurately determine the efficacy of chemotherapy for bone and soft tissue sarcomas. This will help to determine the optimal course of treatment and improve patient prognosis.
A generalized QUCESOP method for amide and NOE quantification in rat brain tumor
Authors: Wang Yi , Fan Yang , Song Xiaolei , Gao Jia-Hong
Published: November 2024

Motivation: Current CEST quantification methods only calculated the fractional concentration fb and the exchange rate kb for each solute pool, but consider R2b as a constant. Goal(s): To quantify the change of b, kb and R2b corresponding to the amide and NOE pool in brain tumor imaging of rats. Approach: Partial Z-spectra around the target frequency offsets were acquired using several saturation amplitudes, and the QUCESOP method was employed to fit the parameters of the amide solute and the “NOE solute” respectively. Results: Tumor exhibited higher R2b and lower fb for “NOE solute”, with a slightly-elevated amide pool size, compared with the normal tissue. Impact: Tumor displayed an increase of R2b and a decrease of fb for the “NOE solute”, that originated from the aliphatic protons on the macromolecular pool. The larger R2b may reflect the increased cell density in the tumor region.
A unified framework of tumor segmentation and response assessment in patients with malignant gliomas using structural and APT-weighted MRI
Authors: Wang Puyang , Huang Qianqi , Wu Jingpu , Liu Mingchao , Chai Keyi , Zou Yunfan , Zhou Jinyuan , Jiang Shanshan
Published: November 2024

Motivation: Amide protein transfer-weighted (APTw) MRI has been validated to accurately detect recurrent malignant gliomas across different studies. However, APTw image interpretation is time consuming and requires professional knowledge. Goal(s): Our goal was to develop a reliable, automated imaging diagnostic tool to assess malignant glioma response to therapies are urgently needed. Approach: We developed and verified a unified CNN-based deep-learning framework for both tumor segmentation and tumor progression assessment by adding APTw MRI data to structural MR images as model input. Results: The use of APTw images can improve not only diagnostic accuracy but also segmentation performance to structural MRIs. Impact: The proposed deep-learning method could be a highly efficient solution that could help clinical experts to make precise diagnoses for patients with post-treatment gliomas.
A reassessment of quasi-steady-state enhanced T1 normalization in quantitative CEST analysis
Authors: Sun Phillip
Published: November 2024

Motivation: Correction of T1 contribution in quantitative CEST MRI often assumes an equilibrium CEST signal. However, most CEST scans were not and will unlikely to be performed under equilibrium conditions. Goal(s): To investigate T1 correction and improve CEST quantification using CEST scans under practical scan (non-equilibrium) protocols. Approach: We performed numerical simulation and in vivo experiments to evaluate T1 correction without and with quasi-steady-state analysis. Results: Our study demonstrated that QUASS postprocessing enhances the accuracy of T1 correction with the AREX metric independent of the RF saturation time, relaxation delay, and T1. Impact: Our study provides a practical qCEST solution that lays the foundation for future clinical translation to improve the quantification and specificity of CEST imaging.
Challenges for in-vivo hepatic GlycoNOE on human subjects at 7T
Authors: Poli Simone , Buser Angeline Laura , Herzig David , Bally Lia , Kreis Roland
Published: November 2024

Motivation: The GlycoNOE technique promises advantages compared to GlycoCEST and spectroscopic methods for fast non-invasive determination of hepatic glycogen content on standard MRI systems. Goal(s): Establish a robust glycoNOE technique at 7T for hepatic glycogen quantification in humans. Approach: A single-voxel MRS technique was combined with CEST modules and tested in vitro and in human subjects together with standard 13C-MRS. Results: The method gave excellent results in vitro, but in vivo the failure rate was substantial and shows that further refinements of the method are needed to provide robust measurements of hepatic glycogen in human subjects, especially in pathological conditions. Impact: The GlycoNOE technique promises advantages compared to GlycoCEST and spectroscopic methods for determining hepatic glycogen content in vivo. Lack of robustness as implemented for a combined CEST-spectroscopy technique hinders its use in humans.
Comparison of fast quantitative magnetization transfer imaging methods on a 1.5 T MR-Linac
Authors: Tran Brandon , Lawrence Liam , Chan Rachel , Stewart James , Ruschin Mark , Theriault Aimee , Detsky Jay , Myrehaug Sten , Maralani Pejman , Tseng Chia-Lin , Soliman Hany , Sahgal Arjun , Lau Angus
Published: November 2024

Motivation: Quantitative magnetization transfer (qMT) could guide radiotherapy on MRI-linear accelerators (MR-Linacs), but limited scan time requires a fast sequence. Fast 3D qMT is possible with balanced steady-state free precession (bSSFP) or echo-planar imaging (EPI), but which method is superior is unclear. Goal(s): Our goal was to determine whether bSSFP or EPI qMT on a 1.5T MR-Linac was best for imaging glioblastoma patients. Approach: Eight patients were scanned using both methods. Repeatability in normal tissue and magnitude of tumor changes were compared. Results: A 2 minute 20 second EPI qMT scan was more repeatable than bSSFP qMT and detected greater tumor changes. Impact: The improvement in quantitative magnetization transfer acquisition speed through using 3D EPI enables integration into MR-Linac radiotherapy workflows, an unmet need as qMT can detect white matter changes which could be used to assess tumor response during treatment.
A Simple Approach for Quantifying T1 and Macromolecular Proton Fraction from Rapid Inversion Recovery with 3D stack-of-spiral FLASH readout
Authors: Hu Zhen , Zhu Dan , Li Yuguo , Xu Jiadi , Qin Qin
Published: November 2024

Motivation: Simultaneous Quantification of T1 and macromolecular proton fraction (fm) is desired but current methods are time consuming. Goal(s): To develop an approach for quantitative mapping of both apparent T1 and fM from inversion recovery (IR) curves. Approach: IR curves with efficient 3D stack-of-spiral FLASH readout were fitted with a monoexponential function, extracting both the apparent T1 and the inversion degree with the latter to determine fm. This method was evaluated through theory, simulation, phantom, and brain experiments. Results: This study demonstrated a simple and rapid approach for 3D mapping of both apparent T1 and fm. Impact: A simple and rapid approach for quantitative mapping of both apparent T1 and macromolecular proton fraction (fm) will help understanding the T1 contrast mechanism and facilitate developing pathological biomarkers for various clinical applications.
Investigating the feasibility of reverse cross polarization for the development of a new myelin detection technique in MRI
Authors: Ensworth Alex , Knight Cariad-Arianna , Kozlowski Piotr , Laule Cornelia , MacKay Alex , Michal Carl
Published: November 2024

Motivation: The potential of phosphorous MRI to enhance in vivo myelin detection and improve neurodegenerative disease diagnosis inspired our project. However, the challenge lies in transferring the solid phosphorus signal to aqueous protons for MRI measurement. Goal(s): To demonstrate the feasibility of detecting an aqueous proton signal originating from myelin phosphorous, providing a proof of principle result. Approach: We employed gradients in solid-state NMR experiments to investigate signal transfer between aqueous proton signal originating from myelin phosphorous, incorporating encoding and decoding gradients. Results: While individual transfer steps were successful, the complete transfer experiment yielded an unexpected negative result, indicating that further investigation is needed. Impact: The successful transfer of signal from phosphorous in myelin to aqueous hydrogen would lead to a new method for direct myelin detection. This could potentially offer earlier and more direct measurements of demyelination, benefiting those with neurodegenerative diseases.
Accelerating CEST MRI using Data-Driven Z-Spectral Compressed Sensing
Authors: Xu Haipeng , Gong Tao , Chen Lin
Published: November 2024

Motivation: CEST MRI requires the collection of multiple saturated images with different saturation offsets, resulting in prolonged scan times, which hinders its clinical applications. Goal(s): we aim to reduce the scan time of CEST MRI by recovering the undersampled Z-spectrum to full-sampling counterpart using data-driven Z-spectral compressed sensing method. Approach: The modified U-Net was employed for Z-spectral recovery. Training data were generated using Bloch equation. Numerical simulations and in vivo experiments on rat brains were conducted to validate the proposed method. Results: The results demonstrate that our method outperformed conventional interpolation methods, and threefold undersampling rate can be achieved without discernible degradation in quantification. Impact: The proposed method can efficiently reduce the scan time of CEST MRI, potentially facilitating its clinical applications.
Simultaneous Measurement of CEST and $$$T_1$$$ using Model-based Multi-Pool-Lorentzian Look-Locker Reconstruction
Authors: Huemer Markus , Scholand Nick , Mackner Daniel , Stilianu Clemens , Zaiss Moritz , Stollberger Rudolf
Published: November 2024

Motivation: Conventional quantitative CEST experiments require the additional determination of $$$T_1$$$. CEST sequences include $$$T_1$$$ relaxation periods that can be exploited to estimate $$$T_1$$$ simultaneously to the CEST parameters. Goal(s): The development of a technique for efficient simultaneous quantification of CEST contrast and $$$T_1$$$. Approach: Integration of a FLASH acquisition train after conventional CEST saturations. Simultaneous CEST contrast and $$$T_1$$$ fitting is achieved by extending the Lorentzian model of the CEST spectrum with a Look-Locker model for the FLASH readout. Results: The proof-of-concept was implemented, and first results are demonstrated in a two pools phantom and a four pool in vivo study. Impact: The presented technique enables calculating $$$T_1$$$ corrected quantitative CEST results from one measurement. This simplifies the application of the apparent exchange-dependent relaxation ($$$MTR_{AREX}$$$), the quasi-steady-state$$$\;$$$contrast and other CEST metrics, which require a $$$T_1$$$ map, making them more accessible.
Neural Bloch-McConnell fitting (NBMF): unsupervised test-time learning of clinical semisolid MT/CEST MRF reconstruction
Authors: Finkelstein Alex , Vladimirov Nikita , Weinmüller Simon , Zaiss Moritz , Perlman Or
Published: November 2024

Motivation: MRF-based quantification of semi-solid MT/CEST proton-exchange requires a computationally demanding dictionary synthesis/matching. Recently reported unsupervised learning alternatives were incompatible with pulsed clinical CEST and multi-pool imaging. Goal(s): To develop a training-set-free MRF reconstruction method, learning directly from the acquired data via pulsed-saturation-compatible physical modeling. Approach: A differentiable multi-pool Bloch-McConnel simulator was designed and embedded within a test-time learning framework. Validation was performed using L-arginine phantoms and a human subject at 3T. Results: The method enabled quantitative MT/CEST reconstruction in ~1 minute. The resulting maps were highly correlated with ground-truth in-vitro (Pearson’s r>0.95). In-vivo, semi-solid volume fractions were in agreement with MRF-based maps (r~0.8). Impact: A one-stop-shop for semisolid MT and CEST MRF reconstruction was developed, enabling a training-set-free rapid quantification of exchange parameters on clinical scanners. This accessible approach could help a variety of Bloch-fitting applications to benefit from deep learning through differentiable spin-physics.
Analytical solution of the Bloch-McConnell equations for steady-state CEST Z-spectra
Authors: Shaghaghi Mehran , Cai Kejia
Published: November 2024

Motivation: Fitting CEST-MRI spectra using numerical methods is currently a time-consuming process, involving various approximations for initial parameters to expedite the process. Goal(s): We aimed to derive the exact analytical expression for CEST Z-spectra of a two-pool exchange system. Approach: We directly solved the Bloch-McConnell differential equations in matrix form for a two-pool exchange system to determine water magnetization under a steady-state saturation over the entire Z-spectrum. Results: The analytical solution accurately reproduces spectra obtained through numerical methods. It allows fitting for physical parameters of the exchange system (like the exchange rate) as demonstrated by fitting simulated CEST spectra. Impact: The analytical solution significantly reduces fitting time compared to the numerical methods used for fitting CEST Z-spectra. This solution has been demonstrated for the determination of physical parameters in the exchange system with fewer assumptions.
Self-Supervised Low-rank plus Sparse Network for Radial MRI Reconstruction
Authors: Mancu Andrei , Huang Wenqi , Cruz Gastao Lima da , Rückert Daniel , Hammernik Kerstin
Published: November 2024

Motivation: Physics-guided self-supervised approaches have proven to be useful in MR image reconstruction from limited Cartesian measurements. However, the potential of radially-sampled k-space data remains largely unexplored. Goal(s): In this context, we introduce a self-supervised learning approach to reconstruct dynamic images from sparsely-sampled radial cardiac data. Approach: The proposed model integrates a novel low-rank and sparse regularizer in its iterative framework to better exploit the characteristics of dynamic images. Results: Our method is compared to iterative reconstruction techniques and other deep neural network approaches in supervised and self-supervised tasks, where the proposed model achieves the best performance for a single and four heartbeat reconstruction. Impact: Self-supervised models for radially sampled cardiac measurements can now be efficiently trained on limited amounts of data to reliably reconstruct high-contrast and low artifact dynamic MR images, even at high acceleration rates for faster acquisition speed.
Deep Learning-Based High Frequency Constrained Fast Image Reconstruction for 4D Cardiac MRI
Authors: Deb Ashmita , Kara Danielle , Robakowski Mary , Potdar Ojas , Chen David , Nguyen Christopher
Published: November 2024

Motivation: Online image reconstructions for prospectively undersampled cardiac MRI data are noisy as the naïve approach fails to remove undersampling artifacts. Compressed sensing (CS) reconstruction reduces artifacts but is time and memory intensive, making it an offline reconstruction option only. Goal(s): Our aim was to address these constraints by training a Deep Learning (DL) model to obtain high resolution online reconstructions. Approach: We achieved this by implementing a spatiotemporal UNET with a weighted high frequency loss. Results: We found the results of the DL model comparable to the CS reconstruction in image quality, with lower computational cost, making it suitable for online reconstructions. Impact: Our image denoising Deep Learning (DL) model showed similar results to the time consuming, more computationally expensive compressed sensing (CS) reconstruction (gold standard), thus demonstrating its potential for online reconstruction of prospectively undersampled cardiac MRI data.