An ill-posed inverse problem in quantitative susceptibility mapping (QSM) is usually solved using a regularization and optimization solver, which is time consuming considering the three-dimensional volume data. Howe...An ill-posed inverse problem in quantitative susceptibility mapping (QSM) is usually solved using a regularization and optimization solver, which is time consuming considering the three-dimensional volume data. However, in clinical diagnosis, it is necessary to reconstruct a susceptibility map efficiently with an appropriate method. Here, a modified QSM reconstruction method called weighted total variation using split Bregman (WTVSB) is proposed. It reconstructs the susceptibility map with fast computational speed and effective artifact suppression by incorporating noise-suppressed data weighting with split Bregman iteration. The noise-suppressed data weighting is determined using the Laplacian of the calculated local field, which can prevent the noise and errors in field maps from spreading into the susceptibility inversion. The split Bregman iteration accelerates the solution of the Ll-regularized reconstruction model by utilizing a preconditioned conjugate gradient solver. In an experiment, the proposed reconstruction method is compared with truncated k-space division (TKD), morphology enabled dipole inversion (MEDI), total variation using the split Bregman (TVSB) method for numerical simulation, phantom and in vivo human brain data evaluated by root mean square error and mean structure similarity. Experimental results demonstrate that our proposed method can achieve better balance between accuracy and efficiency of QSM reconstruction than conventional methods, and thus facilitating clinical applications of QSM.展开更多
Objective To investigate the changes of lateral geniculate body (LGB) in the normal aging brain using quantitative susceptibility mapping (QSM) technique. Methods Magnetic resonance (MR) phase and magnitude imag...Objective To investigate the changes of lateral geniculate body (LGB) in the normal aging brain using quantitative susceptibility mapping (QSM) technique. Methods Magnetic resonance (MR) phase and magnitude images were acquired from enhanced gradient echo T2 star weighted angiography sequence with 16 echoes on 3.0T MR system using the head coil with 32 channels. Morphology Enabled Dipole Inversion (MEDI) method was applied for QSM, and the susceptibility value of LGB was measured by region of interest (ROI) drawn manually on three orthogonal planes. Results LGB of the middle-aged group had a higher susceptibility value (0.16±0.05 ppm) than that of the youth group (0.12±0.05 pprn) and elderly group (0.13±0.03 ppm) (all P〈0.05). Partial correlation analysis demonstrated that there was significantly positive correlation between susceptibility value and age in the youth group (r=0.71, P〈0.05). Conclusion LGB could clearly be identified on QSM in the brain in vivo.展开更多
Quantitative susceptibility mapping(QSM)is an advanced post‐processing technique in magnetic resonance imaging that offers precise measurements of tissue magnetic susceptibility with impressive spatial resolution and...Quantitative susceptibility mapping(QSM)is an advanced post‐processing technique in magnetic resonance imaging that offers precise measurements of tissue magnetic susceptibility with impressive spatial resolution and sensitivity.This review examines the potential of QSM as a biomarker for early detection and monitoring of amyotrophic lateral sclerosis(ALS).Since 2015,studies have consistently reported increased QSM values in the motor regions of individuals with ALS,indicating significant iron deposition.Iron accumulation is associated with dysfunction of the upper motor neurons and faster disease progression.Notably,increased QSM values were also observed in the critical subcortical areas responsible for motor function and cognitive control.However,standardizing optimized protocols,including background field removal algorithms,phase unwrapping approaches,and methods for final susceptibility map reconstruction,has the potential to enhance the consistency and reliability of QSM as an ALS biomarker.Overall,the current body of evidence strongly supports QSM in detecting iron dysregulation associated with neurodegeneration in both motor and extra‐motor regions in ALS.Furthermore,QSM's remarkable sensitivity to early pathological iron changes and its high specificity in distinguishing ALS positions make it a promising diagnostic and progression‐tracking biomarker.展开更多
To the Editor:With the aging of the population,the prevalence of Alzheimer’s disease(AD)has increased significantly.Mild cognitive impairment(MCI)is the transition period between normal aging and dementia.[1]Quantita...To the Editor:With the aging of the population,the prevalence of Alzheimer’s disease(AD)has increased significantly.Mild cognitive impairment(MCI)is the transition period between normal aging and dementia.[1]Quantitative susceptibility mapping(QSM)allows for the direct measurement of iron metabolism disorders and iron deposition in AD brain tissue,represented as susceptibility(SUS).Voxel-based morphometry(VBM)is widely applied to evaluate gray and white matter lesions in the brain,reflecting differences in the corresponding anatomical structures by quantitatively calculating and analyzing the density or volume of brain gray/white matter for each voxel in the T1WI three-dimensional magnetization prepared rapid acquisition gradient echo(T1WI-3D-MP RAGE)sequence.Herein,we investigated the difference in brain microstructural changes in patients with AD and MCI using QSM and VBM,combined with neuropsychological test results,to evaluate the diagnostic value of QSM and VBM.展开更多
This study aimed to explore the value of deep learning(DL)-assisted quantitative susceptibility mapping(QSM)in glioma grading and molecular subtyping.Forty-two patients with gliomas,who underwent preoperative T2 fluid...This study aimed to explore the value of deep learning(DL)-assisted quantitative susceptibility mapping(QSM)in glioma grading and molecular subtyping.Forty-two patients with gliomas,who underwent preoperative T2 fluid-attenuated inversion recovery(T2 FLAIR),contrast-enhanced T1-weighted imaging(T1WI+C),and QSM scanning at 3.0T magnetic resonance imaging(MRI)were included in this study.Histopathology and immunohistochemistry staining were used to determine glioma grades,and isocitrate dehydrogenase(IDH)1 and alpha thalassemia/mental retardation syndrome X-linked gene(ATRX)subtypes.Tumor segmentation was performed manually using Insight Toolkit-SNAP program(www.itksnap.org).An inception convolutional neural network(CNN)with a subsequent linear layer was employed as the training encoder to capture multi-scale features from MRI slices.Fivefold cross-validation was utilized as the training strategy(seven samples for each fold),and the ratio of sample size of the training,validation,and test dataset was 4:1:1.The performance was evalu-ated by the accuracy and area under the curve(AUC).With the inception CNN,single modal of QSM showed better perfor-mance in differentiating glioblastomas(GBM)and other grade gliomas(OGG,grade II–III),and predicting IDH1 mutation and ATRX loss(accuracy:0.80,0.77,0.60)than either T2 FLAIR(0.69,0.57,0.54)or T1WI+C(0.74,0.57,0.46).When combining three modalities,compared with any single modality,the best AUC/accuracy/F1-scores were reached in grading gliomas(OGG and GBM:0.91/0.89/0.87,low-grade and high-grade gliomas:0.83/0.86/0.81),predicting IDH1 mutation(0.88/0.89/0.85),and predicting ATRX loss(0.78/0.71/0.67).As a supplement to conventional MRI,DL-assisted QSM is a promising molecular imaging method to evaluate glioma grades,IDH1 mutation,and ATRX loss.展开更多
Background and Purpose:With the increasing prevalence of cerebrovascular risk factors in young adults,accurate differentiation of multiple sclerosis(MS)from cerebral small vessel disease(SVD)remains challenging becaus...Background and Purpose:With the increasing prevalence of cerebrovascular risk factors in young adults,accurate differentiation of multiple sclerosis(MS)from cerebral small vessel disease(SVD)remains challenging because of the significant overlap in the appearance of white matter lesions on conventional magnetic resonance(MR)images.The purpose of this study was to use quantitative susceptibility mapping(QSM)to differentiate patients with MS from patients with SVD.Materials and Methods:Thirty-two patients with relapsing-remitting MS and 40 patients with SVD were selected in this institution review board-approved retrospective study.All patient examinations included QSM and T2-weighted FLAIR(T2w).All T2w hyperintense lesions were analyzed on QSM for susceptibility relative to normal-appearing white matter and were evaluated for the presence of hyperintense rims and the central vein sign.Receiver operating characteristic(ROC)curve analysis was performed to assess the diagnostic accuracy of differentiating MS patients from SVD patients.Results:The mean susceptibility value of SVD lesions was significantly lower than MS lesions(2.31±9.68 ppb vs.27.77±20.27 ppb,p<0.001).Of MS patients and MS lesions,68.8%and 22.2%had hyperintense rims on QSM,respectively.Of MS patients and MS lesions,75%and 37.6%had a central vein sign on QSM,respectively.Lesion susceptibility values allowed accurate differentiation MS from SVD with an area under the ROC curve(AUC)=0.848 for lesion differentiation,AUC=0.999 for patient differentiation,and an optimal cut-off susceptibility value of 14.88 ppb.Conclusions:Magnetic susceptibility measured using QSM allows accurate differentiation of MS patients from SVD patients.展开更多
Mesenchymal stromal cell transplantation is an effective and promising approach for treating various systemic and diffuse diseases.However,the biological characteristics of transplanted mesenchymal stromal cells in hu...Mesenchymal stromal cell transplantation is an effective and promising approach for treating various systemic and diffuse diseases.However,the biological characteristics of transplanted mesenchymal stromal cells in humans remain unclear,including cell viability,distribution,migration,and fate.Conventional cell tracing methods cannot be used in the clinic.The use of superparamagnetic iron oxide nanoparticles as contrast agents allows for the observation of transplanted cells using magnetic resonance imaging.In 2016,the National Medical Products Administration of China approved a new superparamagnetic iron oxide nanoparticle,Ruicun,for use as a contrast agent in clinical trials.In the present study,an acute hemi-transection spinal cord injury model was established in beagle dogs.The injury was then treated by transplantation of Ruicun-labeled mesenchymal stromal cells.The results indicated that Ruicunlabeled mesenchymal stromal cells repaired damaged spinal cord fibers and partially restored neurological function in animals with acute spinal cord injury.T2*-weighted imaging revealed low signal areas on both sides of the injured spinal cord.The results of quantitative susceptibility mapping with ultrashort echo time sequences indicated that Ruicun-labeled mesenchymal stromal cells persisted stably within the injured spinal cord for over 4 weeks.These findings suggest that magnetic resonance imaging has the potential to effectively track the migration of Ruicun-labeled mesenchymal stromal cells and assess their ability to repair spinal cord injury.展开更多
Susceptibility weighted imaging(SWI)is a recently developed magnetic resonance imaging(MRI)technique that is increasingly being used to narrow the differential diagnosis of many neurologic disorders.It exploits the ma...Susceptibility weighted imaging(SWI)is a recently developed magnetic resonance imaging(MRI)technique that is increasingly being used to narrow the differential diagnosis of many neurologic disorders.It exploits the magnetic susceptibility differences of various compounds including deoxygenated blood,blood products,iron and calcium,thus enabling a new source of contrast in MR.In this review,we illustrate its basic clinical applications in neuroimaging.SWI is based on a fully velocity-compensated,high-resolution,three dimensional gradientecho sequence using magnitude and phase images either separately or in combination with each other,in order to characterize brain tissue.SWI is particularly useful in the setting of trauma and acute neurologic presentations suggestive of stroke,but can also characterize occult low-flow vascular malformations,cerebral microbleeds,intracranial calcifications,neurodegenerative diseases and brain tumors.Furthermore,advanced MRI post-processing technique with quantitative susceptibility mapping,enables detailed anatomical differentiation based on quantification of brain iron from SWI raw data.展开更多
Brain radiomics can reflect the characteristics of brain pathophysiology.However,the value of T1-weighted images,quantitative susceptibility mapping,and R2*mapping in the diagnosis of Parkinson’s disease(PD)was under...Brain radiomics can reflect the characteristics of brain pathophysiology.However,the value of T1-weighted images,quantitative susceptibility mapping,and R2*mapping in the diagnosis of Parkinson’s disease(PD)was underestimated in previous studies.In this prospective study to establish a model for PD diagnosis based on brain imaging information,we collected high-resolution T1-weighted images,R2*mapping,and quantitative susceptibility imaging data from 171 patients with PD and 179 healthy controls recruited from August 2014 to August 2019.According to the inclusion time,123 PD patients and 121 healthy controls were assigned to train the diagnostic model,while the remaining 106 subjects were assigned to the external validation dataset.We extracted 1408 radiomics features,and then used data-driven feature selection to identify informative features that were significant for discriminating patients with PD from normal controls on the training dataset.The informative features so identified were then used to construct a diagnostic model for PD.The constructed model contained 36 informative radiomics features,mainly representing abnormal subcortical iron distribution(especially in the substantia nigra),structural disorganization(e.g.,in the inferior temporal,paracentral,precuneus,insula,and precentral gyri),and texture misalignment in the subcortical nuclei(e.g.,caudate,globus pallidus,and thalamus).The predictive accuracy of the established model was 81.1±8.0%in the training dataset.On the external validation dataset,the established model showed predictive accuracy of 78.5±2.1%.In the tests of identifying early and drug-naïve PD patients from healthy controls,the accuracies of the model constructed on the same 36 informative features were 80.3±7.1%and 79.1±6.5%,respectively,while the accuracies were 80.4±6.3%and 82.9±5.8%for diagnosing middle-to-late PD and those receiving drug management,respectively.The accuracies for predicting tremor-dominant and non-tremor-dominant PD were 79.8±6.9%and 79.1±6.5%,respectively.In conclusion,the multiple-tissue-specific brain radiomics model constructed from magnetic resonance imaging has the ability to discriminate PD and exhibits the advantages for improving PD diagnosis.展开更多
In quantitative susceptibility mapping(QSM),the background field removal is an essential data acquisition step because it has a significant effect on the restoration quality by generating a harmonic incompatibility in...In quantitative susceptibility mapping(QSM),the background field removal is an essential data acquisition step because it has a significant effect on the restoration quality by generating a harmonic incompatibility in the measured local field data.Even though the sparsity based first generation harmonic incompatibility removal(1GHIRE)model has achieved the performance gain over the traditional approaches,the 1GHIRE model has to be further improved as there is a basis mismatch underlying in numerically solving Poisson’s equation for the background removal.In this paper,we propose the second generation harmonic incompatibility removal(2GHIRE)model to reduce a basis mismatch,inspired by the balanced approach in the tight frame based image restoration.Experimental results shows the superiority of the proposed 2GHIRE model both in the restoration qualities and the computational efficiency.展开更多
Structural brain changes indicative of dementia occur up to 20 years before the onset of clinical symptoms. Efforts to modify the disease process after the onset of cognitive symptoms have been unsuccessful in recent ...Structural brain changes indicative of dementia occur up to 20 years before the onset of clinical symptoms. Efforts to modify the disease process after the onset of cognitive symptoms have been unsuccessful in recent years. Thus, future trials must begin during the preclinical phases of the disease before symptom onset. Age related cognitive decline is often the result of two coexisting brain pathologies: Alzheimer's disease(amyloid, tau, and neurodegeneration) and vascular disease. This review article highlights some of the common neuroimaging techniques used to visualize the accumulation of neurodegenerative and vascular pathologies during the preclinical stages of dementia such as structural magnetic resonance imaging, positron emission tomography, and white matter hyperintensities. We also describe some emerging neuroimaging techniques such as arterial spin labeling, diffusion tensor imaging, and quantitative susceptibility mapping. Recent literature suggests that structural imaging may be the most sensitive and cost-effective marker to detect cognitive decline, while molecular positron emission tomography is primarily useful for detecting disease specific pathology later in the disease process. Currently, the presence of vascular disease on magnetic resonance imaging provides a potential target for optimizing vascular risk reduction strategies, and the presence of vascular disease may be useful when combined with molecular and metabolic markers of neurodegeneration for identifying the risk of cognitive impairment.展开更多
Objective:Ceruloplasmin(CP),a key human ferroxidase,can maintain the iron balance in the brain,and the familial hypoceruloplasminemia might be rare.Ceruloplasmin reduction is one of the most common features in Wilson&...Objective:Ceruloplasmin(CP),a key human ferroxidase,can maintain the iron balance in the brain,and the familial hypoceruloplasminemia might be rare.Ceruloplasmin reduction is one of the most common features in Wilson's disease.Some patients with hypoceruloplasminemia do not fulfill the criteria for the diagnosis of Wilson's disease or other known diseases.Moreover,these patients always suffer from various degrees of abnormal brain iron deposition.We sought to investigate the genetic basis of nonWilson's disease hypoceruloplasminemia using whole-exome sequencing.Methods:We recruited four patients with non-Wilson's disease hypoceruloplasminemia,who visited the Department of Neurology,Shanghai First People's Hospital,China from December 2010 to February 2011.Three of them were from the same pedigree,and the other patient shared no blood relation with the others.Iron deposition in the brain was assessed using quantitative susceptibility mapping and peripheral blood DNA was extracted.The part of the exons'genome were sequenced using the NimbleGen Sequence Capture Array and high-throughput sequencing technologies.Intersection analysis at the single nucleotide polymorphism(SNP)loci was carried out.The selected loci were verified with Sanger sequencing.Results:Magnetic resonance imaging revealed that the magnetic susceptibility in the globus pallidus,which showed with a high signal intensity,was apparently higher in three patients than that in the normal controls,indicating the presence of abnormal iron deposition in the brain.The whole-exome sequencing and Sanger sequencing primarily excluded the possibility of mutations in the CP,ATP7B,and ATP7A genes that may impact ceruloplasmin levels.The four patients presented the homozygous mutation c.3611A>C in the C12orf51 gene;this was suspected to be a causative mutation after excluding SNP loci that were the same as those in the common population,as per The 1000 Genomes Project.Conclusion:Non-Wilson's disease hypoceruloplasminemia showed varying degrees of abnormal iron deposition in the brain,and was possibly associated with the c.3611A>C mutation in C12orf51.How copper and iron regulate the levels of one another in the body is still not fully understood.The reduction of ceruloplasmin levels and brain iron deposition probably participated in the occurrence and development of neurodegenerative diseases.Following the combination of pre-existing techniques with a new generation of gene sequencing,the early diagnosis,prevention,and treatment of non-Wilson's disease hypoceruloplasminemia and other neurodegenerative diseases can be achieved.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11474236,81671674,and 11775184)the Science and Technology Project of Fujian Province,China(Grant No.2016Y0078)
摘要An ill-posed inverse problem in quantitative susceptibility mapping (QSM) is usually solved using a regularization and optimization solver, which is time consuming considering the three-dimensional volume data. However, in clinical diagnosis, it is necessary to reconstruct a susceptibility map efficiently with an appropriate method. Here, a modified QSM reconstruction method called weighted total variation using split Bregman (WTVSB) is proposed. It reconstructs the susceptibility map with fast computational speed and effective artifact suppression by incorporating noise-suppressed data weighting with split Bregman iteration. The noise-suppressed data weighting is determined using the Laplacian of the calculated local field, which can prevent the noise and errors in field maps from spreading into the susceptibility inversion. The split Bregman iteration accelerates the solution of the Ll-regularized reconstruction model by utilizing a preconditioned conjugate gradient solver. In an experiment, the proposed reconstruction method is compared with truncated k-space division (TKD), morphology enabled dipole inversion (MEDI), total variation using the split Bregman (TVSB) method for numerical simulation, phantom and in vivo human brain data evaluated by root mean square error and mean structure similarity. Experimental results demonstrate that our proposed method can achieve better balance between accuracy and efficiency of QSM reconstruction than conventional methods, and thus facilitating clinical applications of QSM.
基金Supported by the National Natural Science Foundation of China(81171319)Nursery Fund of PLA General Hospital(13KMM41)
摘要Objective To investigate the changes of lateral geniculate body (LGB) in the normal aging brain using quantitative susceptibility mapping (QSM) technique. Methods Magnetic resonance (MR) phase and magnitude images were acquired from enhanced gradient echo T2 star weighted angiography sequence with 16 echoes on 3.0T MR system using the head coil with 32 channels. Morphology Enabled Dipole Inversion (MEDI) method was applied for QSM, and the susceptibility value of LGB was measured by region of interest (ROI) drawn manually on three orthogonal planes. Results LGB of the middle-aged group had a higher susceptibility value (0.16±0.05 ppm) than that of the youth group (0.12±0.05 pprn) and elderly group (0.13±0.03 ppm) (all P〈0.05). Partial correlation analysis demonstrated that there was significantly positive correlation between susceptibility value and age in the youth group (r=0.71, P〈0.05). Conclusion LGB could clearly be identified on QSM in the brain in vivo.
摘要Quantitative susceptibility mapping(QSM)is an advanced post‐processing technique in magnetic resonance imaging that offers precise measurements of tissue magnetic susceptibility with impressive spatial resolution and sensitivity.This review examines the potential of QSM as a biomarker for early detection and monitoring of amyotrophic lateral sclerosis(ALS).Since 2015,studies have consistently reported increased QSM values in the motor regions of individuals with ALS,indicating significant iron deposition.Iron accumulation is associated with dysfunction of the upper motor neurons and faster disease progression.Notably,increased QSM values were also observed in the critical subcortical areas responsible for motor function and cognitive control.However,standardizing optimized protocols,including background field removal algorithms,phase unwrapping approaches,and methods for final susceptibility map reconstruction,has the potential to enhance the consistency and reliability of QSM as an ALS biomarker.Overall,the current body of evidence strongly supports QSM in detecting iron dysregulation associated with neurodegeneration in both motor and extra‐motor regions in ALS.Furthermore,QSM's remarkable sensitivity to early pathological iron changes and its high specificity in distinguishing ALS positions make it a promising diagnostic and progression‐tracking biomarker.
基金supported by“1+X”program for Clinical Competency Enhancement–Improvement of Clinical Technology Project,The Second Hospital of Dalian Medical University(No.2022LCJSGC04)“Xingliao Talent Plan”Medical Master Project of Liaoning Province(No.YXMJ-QN-16)Fundamental Scientific Research Project of Liaoning Provincial Department of Education(No.LJ212410161028).
摘要To the Editor:With the aging of the population,the prevalence of Alzheimer’s disease(AD)has increased significantly.Mild cognitive impairment(MCI)is the transition period between normal aging and dementia.[1]Quantitative susceptibility mapping(QSM)allows for the direct measurement of iron metabolism disorders and iron deposition in AD brain tissue,represented as susceptibility(SUS).Voxel-based morphometry(VBM)is widely applied to evaluate gray and white matter lesions in the brain,reflecting differences in the corresponding anatomical structures by quantitatively calculating and analyzing the density or volume of brain gray/white matter for each voxel in the T1WI three-dimensional magnetization prepared rapid acquisition gradient echo(T1WI-3D-MP RAGE)sequence.Herein,we investigated the difference in brain microstructural changes in patients with AD and MCI using QSM and VBM,combined with neuropsychological test results,to evaluate the diagnostic value of QSM and VBM.
基金supported in part by Science and Technology Commission of Shanghai Municipality(grant number 18411967300,20ZR1407800)Shanghai Municipal Science and Technology Major Project(2018SHZDZX01)the National Natural Science Foundation of China(81873893).
摘要This study aimed to explore the value of deep learning(DL)-assisted quantitative susceptibility mapping(QSM)in glioma grading and molecular subtyping.Forty-two patients with gliomas,who underwent preoperative T2 fluid-attenuated inversion recovery(T2 FLAIR),contrast-enhanced T1-weighted imaging(T1WI+C),and QSM scanning at 3.0T magnetic resonance imaging(MRI)were included in this study.Histopathology and immunohistochemistry staining were used to determine glioma grades,and isocitrate dehydrogenase(IDH)1 and alpha thalassemia/mental retardation syndrome X-linked gene(ATRX)subtypes.Tumor segmentation was performed manually using Insight Toolkit-SNAP program(www.itksnap.org).An inception convolutional neural network(CNN)with a subsequent linear layer was employed as the training encoder to capture multi-scale features from MRI slices.Fivefold cross-validation was utilized as the training strategy(seven samples for each fold),and the ratio of sample size of the training,validation,and test dataset was 4:1:1.The performance was evalu-ated by the accuracy and area under the curve(AUC).With the inception CNN,single modal of QSM showed better perfor-mance in differentiating glioblastomas(GBM)and other grade gliomas(OGG,grade II–III),and predicting IDH1 mutation and ATRX loss(accuracy:0.80,0.77,0.60)than either T2 FLAIR(0.69,0.57,0.54)or T1WI+C(0.74,0.57,0.46).When combining three modalities,compared with any single modality,the best AUC/accuracy/F1-scores were reached in grading gliomas(OGG and GBM:0.91/0.89/0.87,low-grade and high-grade gliomas:0.83/0.86/0.81),predicting IDH1 mutation(0.88/0.89/0.85),and predicting ATRX loss(0.78/0.71/0.67).As a supplement to conventional MRI,DL-assisted QSM is a promising molecular imaging method to evaluate glioma grades,IDH1 mutation,and ATRX loss.
摘要Background and Purpose:With the increasing prevalence of cerebrovascular risk factors in young adults,accurate differentiation of multiple sclerosis(MS)from cerebral small vessel disease(SVD)remains challenging because of the significant overlap in the appearance of white matter lesions on conventional magnetic resonance(MR)images.The purpose of this study was to use quantitative susceptibility mapping(QSM)to differentiate patients with MS from patients with SVD.Materials and Methods:Thirty-two patients with relapsing-remitting MS and 40 patients with SVD were selected in this institution review board-approved retrospective study.All patient examinations included QSM and T2-weighted FLAIR(T2w).All T2w hyperintense lesions were analyzed on QSM for susceptibility relative to normal-appearing white matter and were evaluated for the presence of hyperintense rims and the central vein sign.Receiver operating characteristic(ROC)curve analysis was performed to assess the diagnostic accuracy of differentiating MS patients from SVD patients.Results:The mean susceptibility value of SVD lesions was significantly lower than MS lesions(2.31±9.68 ppb vs.27.77±20.27 ppb,p<0.001).Of MS patients and MS lesions,68.8%and 22.2%had hyperintense rims on QSM,respectively.Of MS patients and MS lesions,75%and 37.6%had a central vein sign on QSM,respectively.Lesion susceptibility values allowed accurate differentiation MS from SVD with an area under the ROC curve(AUC)=0.848 for lesion differentiation,AUC=0.999 for patient differentiation,and an optimal cut-off susceptibility value of 14.88 ppb.Conclusions:Magnetic susceptibility measured using QSM allows accurate differentiation of MS patients from SVD patients.
基金supported by the National Key R&D Program of China,Nos.2017YFA0104302(to NG and XM)and 2017YFA0104304(to BW and ZZ)
摘要Mesenchymal stromal cell transplantation is an effective and promising approach for treating various systemic and diffuse diseases.However,the biological characteristics of transplanted mesenchymal stromal cells in humans remain unclear,including cell viability,distribution,migration,and fate.Conventional cell tracing methods cannot be used in the clinic.The use of superparamagnetic iron oxide nanoparticles as contrast agents allows for the observation of transplanted cells using magnetic resonance imaging.In 2016,the National Medical Products Administration of China approved a new superparamagnetic iron oxide nanoparticle,Ruicun,for use as a contrast agent in clinical trials.In the present study,an acute hemi-transection spinal cord injury model was established in beagle dogs.The injury was then treated by transplantation of Ruicun-labeled mesenchymal stromal cells.The results indicated that Ruicunlabeled mesenchymal stromal cells repaired damaged spinal cord fibers and partially restored neurological function in animals with acute spinal cord injury.T2*-weighted imaging revealed low signal areas on both sides of the injured spinal cord.The results of quantitative susceptibility mapping with ultrashort echo time sequences indicated that Ruicun-labeled mesenchymal stromal cells persisted stably within the injured spinal cord for over 4 weeks.These findings suggest that magnetic resonance imaging has the potential to effectively track the migration of Ruicun-labeled mesenchymal stromal cells and assess their ability to repair spinal cord injury.
摘要Susceptibility weighted imaging(SWI)is a recently developed magnetic resonance imaging(MRI)technique that is increasingly being used to narrow the differential diagnosis of many neurologic disorders.It exploits the magnetic susceptibility differences of various compounds including deoxygenated blood,blood products,iron and calcium,thus enabling a new source of contrast in MR.In this review,we illustrate its basic clinical applications in neuroimaging.SWI is based on a fully velocity-compensated,high-resolution,three dimensional gradientecho sequence using magnitude and phase images either separately or in combination with each other,in order to characterize brain tissue.SWI is particularly useful in the setting of trauma and acute neurologic presentations suggestive of stroke,but can also characterize occult low-flow vascular malformations,cerebral microbleeds,intracranial calcifications,neurodegenerative diseases and brain tumors.Furthermore,advanced MRI post-processing technique with quantitative susceptibility mapping,enables detailed anatomical differentiation based on quantification of brain iron from SWI raw data.
基金supported by the National Natural Science Foundation of China, Nos.82001767(to XJG), 81971577(to MMZ), 82171888(to XJX)the Natural Science Foundation of Zhejiang Province of China, Nos.LQ21H180008(to XJG), LQ20H180012(to MX)+1 种基金the China Postdoctoral Science Foundation, Nos.2021T140599(to XJG), 2019M662082(to XJG)the 13th Five-year Plan for National Key Research and Development Program of China, No.2016YFC1306600(to MMZ)
摘要Brain radiomics can reflect the characteristics of brain pathophysiology.However,the value of T1-weighted images,quantitative susceptibility mapping,and R2*mapping in the diagnosis of Parkinson’s disease(PD)was underestimated in previous studies.In this prospective study to establish a model for PD diagnosis based on brain imaging information,we collected high-resolution T1-weighted images,R2*mapping,and quantitative susceptibility imaging data from 171 patients with PD and 179 healthy controls recruited from August 2014 to August 2019.According to the inclusion time,123 PD patients and 121 healthy controls were assigned to train the diagnostic model,while the remaining 106 subjects were assigned to the external validation dataset.We extracted 1408 radiomics features,and then used data-driven feature selection to identify informative features that were significant for discriminating patients with PD from normal controls on the training dataset.The informative features so identified were then used to construct a diagnostic model for PD.The constructed model contained 36 informative radiomics features,mainly representing abnormal subcortical iron distribution(especially in the substantia nigra),structural disorganization(e.g.,in the inferior temporal,paracentral,precuneus,insula,and precentral gyri),and texture misalignment in the subcortical nuclei(e.g.,caudate,globus pallidus,and thalamus).The predictive accuracy of the established model was 81.1±8.0%in the training dataset.On the external validation dataset,the established model showed predictive accuracy of 78.5±2.1%.In the tests of identifying early and drug-naïve PD patients from healthy controls,the accuracies of the model constructed on the same 36 informative features were 80.3±7.1%and 79.1±6.5%,respectively,while the accuracies were 80.4±6.3%and 82.9±5.8%for diagnosing middle-to-late PD and those receiving drug management,respectively.The accuracies for predicting tremor-dominant and non-tremor-dominant PD were 79.8±6.9%and 79.1±6.5%,respectively.In conclusion,the multiple-tissue-specific brain radiomics model constructed from magnetic resonance imaging has the ability to discriminate PD and exhibits the advantages for improving PD diagnosis.
基金The research of the first author is supported in part by the NSFC Youth Program 11901338The research of the second author is supported by the Hong Kong Research Grant Council(HKRGC)GRF 16306317 and 16309219+2 种基金The research of the third author is supported by the NSFC Youth Program 11901436 and the Fundamental Research Program of Science and Technology Commission of Shanghai Municipality(20JC1413500)The research of the fourth author is supported by the NSFC grant 11831002The research of the fifth author is supported by the National Natural Science Foundation of China Youth Program grant 11801088 and the Shanghai Sailing Program(18YF1401600).
摘要In quantitative susceptibility mapping(QSM),the background field removal is an essential data acquisition step because it has a significant effect on the restoration quality by generating a harmonic incompatibility in the measured local field data.Even though the sparsity based first generation harmonic incompatibility removal(1GHIRE)model has achieved the performance gain over the traditional approaches,the 1GHIRE model has to be further improved as there is a basis mismatch underlying in numerically solving Poisson’s equation for the background removal.In this paper,we propose the second generation harmonic incompatibility removal(2GHIRE)model to reduce a basis mismatch,inspired by the balanced approach in the tight frame based image restoration.Experimental results shows the superiority of the proposed 2GHIRE model both in the restoration qualities and the computational efficiency.
摘要Structural brain changes indicative of dementia occur up to 20 years before the onset of clinical symptoms. Efforts to modify the disease process after the onset of cognitive symptoms have been unsuccessful in recent years. Thus, future trials must begin during the preclinical phases of the disease before symptom onset. Age related cognitive decline is often the result of two coexisting brain pathologies: Alzheimer's disease(amyloid, tau, and neurodegeneration) and vascular disease. This review article highlights some of the common neuroimaging techniques used to visualize the accumulation of neurodegenerative and vascular pathologies during the preclinical stages of dementia such as structural magnetic resonance imaging, positron emission tomography, and white matter hyperintensities. We also describe some emerging neuroimaging techniques such as arterial spin labeling, diffusion tensor imaging, and quantitative susceptibility mapping. Recent literature suggests that structural imaging may be the most sensitive and cost-effective marker to detect cognitive decline, while molecular positron emission tomography is primarily useful for detecting disease specific pathology later in the disease process. Currently, the presence of vascular disease on magnetic resonance imaging provides a potential target for optimizing vascular risk reduction strategies, and the presence of vascular disease may be useful when combined with molecular and metabolic markers of neurodegeneration for identifying the risk of cognitive impairment.
基金upported by the National Natural Science Foundation of China(Grant Nos.81071065 and 81671103 to WXP)Shanghai Jiao Tong University School of Medicine’s Brain Innovative Plan 2015。
摘要Objective:Ceruloplasmin(CP),a key human ferroxidase,can maintain the iron balance in the brain,and the familial hypoceruloplasminemia might be rare.Ceruloplasmin reduction is one of the most common features in Wilson's disease.Some patients with hypoceruloplasminemia do not fulfill the criteria for the diagnosis of Wilson's disease or other known diseases.Moreover,these patients always suffer from various degrees of abnormal brain iron deposition.We sought to investigate the genetic basis of nonWilson's disease hypoceruloplasminemia using whole-exome sequencing.Methods:We recruited four patients with non-Wilson's disease hypoceruloplasminemia,who visited the Department of Neurology,Shanghai First People's Hospital,China from December 2010 to February 2011.Three of them were from the same pedigree,and the other patient shared no blood relation with the others.Iron deposition in the brain was assessed using quantitative susceptibility mapping and peripheral blood DNA was extracted.The part of the exons'genome were sequenced using the NimbleGen Sequence Capture Array and high-throughput sequencing technologies.Intersection analysis at the single nucleotide polymorphism(SNP)loci was carried out.The selected loci were verified with Sanger sequencing.Results:Magnetic resonance imaging revealed that the magnetic susceptibility in the globus pallidus,which showed with a high signal intensity,was apparently higher in three patients than that in the normal controls,indicating the presence of abnormal iron deposition in the brain.The whole-exome sequencing and Sanger sequencing primarily excluded the possibility of mutations in the CP,ATP7B,and ATP7A genes that may impact ceruloplasmin levels.The four patients presented the homozygous mutation c.3611A>C in the C12orf51 gene;this was suspected to be a causative mutation after excluding SNP loci that were the same as those in the common population,as per The 1000 Genomes Project.Conclusion:Non-Wilson's disease hypoceruloplasminemia showed varying degrees of abnormal iron deposition in the brain,and was possibly associated with the c.3611A>C mutation in C12orf51.How copper and iron regulate the levels of one another in the body is still not fully understood.The reduction of ceruloplasmin levels and brain iron deposition probably participated in the occurrence and development of neurodegenerative diseases.Following the combination of pre-existing techniques with a new generation of gene sequencing,the early diagnosis,prevention,and treatment of non-Wilson's disease hypoceruloplasminemia and other neurodegenerative diseases can be achieved.