Microstructural changes of the white matter in systemic lupus erythematosus patients without neuropsychiatric symptoms: a multi-shell diffusion imaging study.

BACKGROUND: Diffusion kurtosis imaging (DKI) and neurite orientation dispersion and density imaging (NODDI) provide more comprehensive and informative perspective on microstructural alterations of cerebral white matter (WM) than single-shell diffusion tensor imaging (DTI), especially in the detection of crossing fiber. However, studies on systemic lupus erythematosus patients without neuropsychiatric symptoms (non-NPSLE patients) using multi-shell diffusion imaging remain scarce. METHODS: Totally 49 non-NPSLE patients and 41 age-, sex-, and education-matched healthy controls underwent multi-shell diffusion magnetic resonance imaging. Totally 10 diffusion metrics based on DKI (fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity, mean kurtosis, axial kurtosis and radial kurtosis) and NODDI (neurite density index, orientation dispersion index and volume fraction of the isotropic diffusion compartment) were evaluated. Tract-based spatial statistics (TBSS) and atlas-based region-of-interest (ROI) analyses were performed to determine group differences in brain WM microstructure. The associations of multi-shell diffusion metrics with clinical indicators were determined for further investigation. RESULTS: TBSS analysis revealed reduced FA, AD and RK and increased ODI in the WM of non-NPSLE patients (P < 0.05, family-wise error corrected), and ODI showed the best discriminative ability. Atlas-based ROI analysis found increased ODI values in anterior thalamic radiation (ATR), inferior frontal-occipital fasciculus (IFOF), forceps major (F_major), forceps minor (F_minor) and uncinate fasciculus (UF) in non-NPSLE patients, and the right ATR showed the best discriminative ability. ODI in the F_major was positively correlated to C3. CONCLUSION: This study suggested that DKI and NODDI metrics can complementarily detect WM abnormalities in non-NPSLE patients and revealed ODI as a more sensitive and specific biomarker than DKI, guiding further understanding of the pathophysiological mechanism of normal-appearing WM injury in SLE.

Glymphatic abnormality in systemic lupus erythematosus detected by diffusion tensor image analysis along the perivascular space.

OBJECTIVES: This study aimed to evaluate the activity of the glymphatic system in systemic lupus erythematosus (SLE) by a diffusion-based method termed "Diffusion Tensor Image Analysis aLong the Perivascular Space (DTI-ALPS)", and examined its correlations with morphological changes in the brain. METHODS: In this cross-sectional study, forty-five female patients with SLE and thirty healthy controls (HCs) were included. Voxel-based and surface-based morphometric analyses were performed to examine T1 weighted images, and diffusion tensor images were acquired to determine diffusivity along the x-, y-, and z-axes in the plane of the lateral ventricle body. The ALPS-index was calculated. The differences in values between SLE patients and HC group were compared using the independent samples t test or Mann-Whitney U test. For the correlations between the ALPS-index and brain morphological parameters, partial correlation analysis and Pearson's correlation analysis were conducted. RESULTS: SLE patients showed lower values for the ALPS-index in left (1.543 ± 0.141 vs 1.713 ± 0.175, p < 0.001), right (1.428 ± 0.142 vs 1.556 ± 0.139, p < 0.001) and whole (1.486 ± 0.121 vs 1.635 ± 0.139, p < 0.001) brain compared with the HC group. The reduced ALPS-index showed significant positive correlations with gray matter loss. CONCLUSION: The non-invasive ALPS-index could serve as a sensitive and effective neuroimaging biomarker for individually quantifying glymphatic activity in patients with SLE. Glymphatic system abnormality may be involved in the pathophysiologic mechanism underlying central nervous system damage in SLE patients.

Glymphatic System Impairment Contributes to the Formation of Brain Edema After Ischemic Stroke.

BACKGROUND: Blood-brain barrier damage has traditionally been considered to determine the occurrence and development of poststroke brain edema, a devastating and life-threatening complication. However, no treatment strategy targeting blood-brain barrier damage has been proven clinically effective in ameliorating brain edema. METHODS: In mice with stroke models induced by transient middle cerebral artery occlusion (MCAO), the changes in glymphatic system (GS) function impairment were detected by ex vivo fluorescence imaging, 2-photon in vivo imaging, and magnetic resonance imaging within 1 week after MCAO, and the effects of GS impairment and recovery on the formation and resolution of brain edema were evaluated. In addition, in patients with ischemic stroke within 1 week after onset, changes in GS function and brain edema were also observed by magnetic resonance imaging. RESULTS: We found that the extravasation of protein-rich fluids into the brain was not temporally correlated with edema formation after MCAO in mice, as brain edema reabsorption preceded blood-brain barrier closure. Strikingly, the time course of edema progression matched well with the GS dysfunction after MCAO. Pharmacological enhancement of the GS function significantly alleviated brain edema developed on day 2 after MCAO, accompanied by less deposition of Aß (amyloid-ß) and better cognitive function. Conversely, functional suppression of the GS delayed the absorption of brain edema on day 7 after MCAO. Moreover, patients with ischemic stroke revealed a consistent trend of GS dysfunction after reperfusion as MCAO mice, which was correlated with the severity of brain edema and functional outcomes. CONCLUSIONS: GS is a key contributor to the formation of brain edema after ischemic stroke, and targeting the GS may be a promising strategy for treating brain edema in ischemic stroke. REGISTRATION: URL: https://www.chictr.org.cn/showproj.html?proj=162857; Unique identifier: NFEC-2019-189.

Systemic lupus erythematosus-related brain abnormalities in the default mode network and the limbic system: A resting-state fMRI meta-analysis.

BACKGROUND: Systemic lupus erythematosus (SLE) is an immune-mediated and multi-systemic disease which may affect the nervous system, causing neuropsychiatric SLE (NPSLE). Recent neuroimaging studies have examined brain functional alterations in SLE. However, discrepant findings were reported. This meta-analysis aims to identify consistent resting-state functional abnormalities in SLE. METHODS: PubMed and Web of Science were searched to identify candidate resting-state functional MRI studies assessing SLE. A voxel-based meta-analysis was performed using the anisotropic effect-size version of the seed-based d mapping (AES-SDM). The abnormal intrinsic functional patterns extracted from SDM were mapped onto the brain functional network atlas to determine brain abnormalities at a network level. RESULTS: Twelve studies evaluating fifteen datasets were included in this meta-analysis, comprising 572 SLE patients and 436 healthy controls (HCs). Compared with HCs, SLE patients showed increased brain activity in the bilateral hippocampus and right superior temporal gyrus, and decreased brain activity in the left superior frontal gyrus, left middle temporal gyrus, bilateral thalamus, left inferior frontal gyrus and right cerebellum. Mapping the abnormal patterns to the network atlas revealed the default mode network and the limbic system as core neural systems commonly affected in SLE. LIMITATIONS: The number of included studies is relatively small, with heterogeneous analytic methods and a risk of publication bias. CONCLUSIONS: Brain functional alterations in SLE are predominantly found in the default mode network and the limbic system. These findings uncovered a consistent pattern of resting-state functional network abnormalities in SLE which may serve as a potential objective neuroimaging biomarker.

Associations of Serum Testosterone and Sex Hormone-binding Globulin With Incident Arrhythmias in Men From UK Biobank.

CONTEXT: Sex hormones have been identified as cardiovascular risk factors, whereas the relationship between sex hormones and the risk of arrhythmias in men has not yet been well studied in the prospective cohort study. OBJECTIVE: To analyze associations of serum testosterone and SHBG concentrations and calculate free testosterone (cFT) with arrhythmias in men. METHODS: Sex hormones were measured at baseline from UK Biobank. Main outcomes were incidence of atrial fibrillation/flutter (AF), ventricular arrhythmia (VA), and bradyarrhythmia (BA). RESULTS: Of 173 498 men (aged 37-73 years, followed for 11 years), 11 368 had incident AF, 1646 had incident VA, and 4788 had incident BA. Compared with the third quartiles, the lowest category of serum testosterone was associated with increased risks of AF (hazard ratio [HR], 1.06; 95% CI, 1.00-1.12) and BA (HR, 1.11; 95% CI, 1.02-1.20) after multivariable adjustment, but no VA. Likewise, similar associations were found between cFT values and AF and BA events. Furthermore, higher levels of cFT were associated with increased risks of AF (HR, 1.07; 95% CI, 1.02-1.13) and VA (HR, 1.18; 95% CI, 1.01-1.37). Higher SHBG concentrations were associated with increased risks of AF (HR, 1.44; 95% CI, 1.34-1.54), VA (HR, 1.27; 95% CI, 1.07-1.52), and BA (HR, 1.17; 95% CI ,1.05-1.29). CONCLUSIONS: Lower levels of testosterone and cFT were associated with increased risk of AF and BA. Higher cFT levels were associated with increased risk of AF and VA. Higher SHBG levels were associated with increased risk of AF, VA, and BA.

Disrupted resting-state brain functional network properties in non-neuropsychiatric systemic lupus erythematosus patients.

INTRODUCTION: Previous fMRI studies revealed that the abnormal functional connectivity (FC) was related to cognitive impairment in patients with SLE. However, it remains unclear how the disease severity affects the functional topological organization of the whole-brain network in SLE patients without neuropsychiatric symptoms (non-NPSLE). OBJECTIVE: We aim to examine the impairment of the whole-brain functional network in SLE patients without neuropsychiatric symptoms (non-NPSLE), which may improve the understanding of neural mechanism in SLE. METHODS: We acquired resting-state fMRI data from 32 non-NPSLE patients and 32 healthy controls (HC), constructed their whole-brain functional network, and then estimated the topological properties including global and nodal parameters by using graph theory. Meanwhile, we also investigated the differences in intra- and inter-network FC between the non-NPSLE patients and the HC. RESULTS: The non-NPSLE patients showed significantly lower clustering coefficient, global and local efficiency, but higher characteristic path length than the HC. The non-NPSLE patients had significantly lower nodal strength in two regions, ventromedial prefrontal cortex (vmPFC) and anterior PFC (aPFC) than the HC. We found the non-NPSLE patients had significantly lower intra-network FC within frontal-parietal network (FPN) and within default mode network (DMN), and significantly lower inter-network FC between DMN and FPN than the HC. The intra-network FC within DMN was negatively correlated with systemic lupus erythematosus disease activity index (SLEDAI). CONCLUSION: Abnormal whole-brain functional network properties and abnormal intra- and inter-network FC may be related to cognitive impairment and disease degree in the non-NPSLE patients. Our findings provide a network perspective to understand the neural mechanisms of SLE.

Image-based deep learning identifies glioblastoma risk groups with genomic and transcriptomic heterogeneity: a multi-center study.

OBJECTIVES: To develop and validate a deep learning imaging signature (DLIS) for risk stratification in patients with multiforme (GBM), and to investigate the biological pathways and genetic alterations underlying the DLIS. METHODS: The DLIS was developed from multi-parametric MRI based on a training set (n = 600) and validated on an internal validation set (n = 164), an external test set 1 (n = 100), an external test set 2 (n = 161), and a public TCIA set (n = 88). A co-profiling framework based on a radiogenomics analysis dataset (n = 127) using multiscale high-dimensional data, including imaging, transcriptome, and genome, was established to uncover the biological pathways and genetic alterations underpinning the DLIS. RESULTS: The DLIS was associated with survival (log-rank p < 0.001) and was an independent predictor (p < 0.001). The integrated nomogram incorporating the DLIS achieved improved C indices than the clinicomolecular nomogram (net reclassification improvement 0.39, p < 0.001). DLIS significantly correlated with core pathways of GBM (apoptosis and cell cycle-related P53 and RB pathways, and cell proliferation-related RTK pathway), as well as key genetic alterations (del_CDNK2A). The prognostic value of DLIS-correlated genes was externally confirmed on TCGA/CGGA sets (p < 0.01). CONCLUSIONS: Our study offers a biologically interpretable deep learning predictor of survival outcomes in patients with GBM, which is crucial for better understanding GBM patient's prognosis and guiding individualized treatment. KEY POINTS: • MRI-based deep learning imaging signature (DLIS) stratifies GBM into risk groups with distinct molecular characteristics. • DLIS is associated with P53, RB, and RTK pathways and del_CDNK2A mutation. • The prognostic value of DLIS-correlated pathway genes is externally demonstrated.

Conventional MRI Features of Central Nervous System Embryonal Tumor, Not Otherwise Specified in Adults: Comparison with Glioblastoma.

RATIONALE AND OBJECTIVES: The purpose of this study was to explore conventional MRI features that can accurately differentiate central nervous system embryonal tumor, not otherwise specified (CNS ETNOS) from glioblastoma (GBM) in adults. MATERIALS AND METHODS: Preoperative conventional MRI images of 30 CNS ETNOS and 98 GBMs were analyzed by neuroradiologists retrospectively to identify valuable MRI features. Five blinded neuroradiologists independently reviewed all these MRI images, and scored MRI features on a five-point scale. Kendall's coefficient of concordance was used to measure inter-rater agreement. Diagnostic value was assessed by the area under the curve (AUC) of receiver operating curve, and sensitivity and specificity were also calculated. RESULTS: Seven MRI features, including isointensity on T1WI, T2WI, and FLAIR, ill-defined margin, severe peritumoral edema, ring enhancement, and broad-based attachment sign, were helpful for the differential diagnosis of these two entities. Among these features, ring enhancement showed the highest inter-rater concordance (0.80). Ring enhancement showed the highest AUC value (0.79), followed by severe peritumoral edema (0.67). The combination of seven features showed the highest AUC value (0.86), followed by that of three features (ill-defined margin, severe peritumoral edema, and ring enhancement) (0.83). CONCLUSION: Enhancement pattern, peritumoral edema, and margin are valuable for the discrimination between CNS ETNOS and GBM in adults.

Twelve-Month Computed Tomography Follow-Up after Thoracic Endovascular Repair for Acute Complicated Aortic Dissection.

BACKGROUND: To explore the impact of thoracic endovascular aortic repair (TEVAR) on aortic remodeling (AR) and the relationship between AR and complications after TEVAR. METHODS: A total of 56 patients (2 type IIIA aortic dissection [AD] and 54 type IIIB AD) with complicated acute type B aortic dissection suitable for TEVAR were prospectively enrolled. There were 44 men (78%) and 12 women (22%) with an average age of 54 ± 13.8 years. Aortic enhanced computed tomography (CT) was performed pre-TEVAR and 3, 6, and 12 months postoperatively. The morphological changes in AR, namely aortic volume and false lumen thrombosis, were obtained by analyzing the CT data. The effect of TEVAR on AR was determined by the morphological changes in the aorta. The relationship between AR index, false lumen thrombosis, and complications was analyzed. RESULTS: The volume of the thoracic aortic true lumen gradually increased post-TEVAR, whereas the volume of the thoracic aortic false lumen gradually decreased. The volume of abdominal aortic total lumen and false lumen increased 6 months postoperatively. The AR index increased significantly 3 months postoperatively, which was negatively correlated with complications and mortality. The thoracic and abdominal aortic false lumen thrombosis developed gradually after TEVAR, and the degree of thoracic aortic false lumen thrombosis was negatively correlated with complications and mortality. CONCLUSIONS: TEVAR promotes AR. AR index and the degree of thoracic aortic false lumen thrombosis can serve as predictors of complications and mortality.

Curcumin suppresses wilms' tumor metastasis by inhibiting RECK methylation.

Wilms' tumor (WT) is the most common kidney tumor of children. The transformation suppressor gene RECK, which codes membrane-anchored glycoprotein, frequently downregulates multiple matrix metalloproteinases in tumors. And curcumin, which is a polyphenlic compound separated from turmeric, has antitumor effects on various cancers. However, the correlation of WT, RECK and curcumin is still unrevealed. In this study, we evaluated that the methylation degree of RECK was much higher in WT than in adjacent non-tumor tissues. And RECK methylation was closely associated with tumor metastasis in WT patients. After curcumin treatment, the level of RECK methylation was decreased significantly. And the expression of MMP2 and MMP9 was reduced consequently. Moreover, the proliferation, invasion and migration ability of WT cells were suppressed after curcumin treatment. Meanwhile, the apoptosis rate of WT cells was increased simultaneously. In nude mice model, curcumin restrained ability of tumorigenicity and promoted apoptosis of WT cells. Together, our results suggest that the RECK methylation can serve as a prognostic biomarker of WT. Moreover, curcumin could inhibit RECK methylation, thereby abates the expression of MMPs, and suppresses the tumor progression and metastasis of WT.

Morphology-adaptive total variation for the reconstruction of quantitative susceptibility map from the magnetic resonance imaging phase.

Quantitative susceptibility mapping (QSM) is a magnetic resonance imaging technique that quantifies the magnetic susceptibility distribution within biological tissues. QSM calculates the underlying magnetic susceptibility by deconvolving the tissue magnetic field map with a unit dipole kernel. However, this deconvolution problem is ill-posed. The morphology enabled dipole inversion (MEDI) introduces total variation (TV) to regularize the susceptibility reconstruction. However, MEDI results still contain artifacts near tissue boundaries because MEDI only imposes TV constraint on voxels inside smooth regions. We introduce a Morphology-Adaptive TV (MATV) for improving TV-regularized QSM. The MATV method first classifies imaging target into smooth and nonsmooth regions by thresholding magnitude gradients. In the dipole inversion for QSM, the TV regularization weights are a monotonically decreasing function of magnitude gradients. Thus, voxels inside smooth regions are assigned with larger weights than those in nonsmooth regions. Using phantom and in vivo datasets, we compared the performance of MATV with that of MEDI. MATV results had better visual quality than MEDI results, especially near tissue boundaries. Preliminary brain imaging results illustrated that MATV has potential to improve the reconstruction of regions near tissue boundaries.

Cortical thickness reductions associate with abnormal resting-state functional connectivity in non-neuropsychiatric systemic lupus erythematosus.

To detect the abnormal cortical thickness and disrupted brain resting-state functional connectivity (RSFC) in patients with systemic lupus erythematosus (SLE) without neuropsychiatric symptoms (non-NPSLE). Using T1-weighted 3D brain structural data, we first determined the regions with abnormal cortical thickness in a cohort of 33 adult female non-NPSLE patients. By taking brain regions with significantly reduced cortical thickness as the seeds, we calculated their RSFC based on the resting-fMRI data and detected the relationship between the RSFC and cortical thickness in the non-NPSLE patients. Compared to the controls, the non-NPSLE patients showed significantly cortical thinning in the left fusiform gyrus (FUS.L), left lingual gyrus (LING.L), right lingual gyrus (LING.R) and left superior frontal cortex (SFC.L). As for the RSFC, statistical analyses indicated that the abnormal cortical thickness in LING.L is associated with increased RSFC in the left posterior cingulate cortex (PCC.L), and cortical thinning in SFC.L associated with decreased RSFC in left cerebellum 6 (CRBL 6.L) in non-NPSLE patients. In addition, in non-NPSLE patients, the decreased cortical thickness in LING.L was correlated to the increased RSFC in PCC.L, and decreased cortical thickness in SFC.L was correlated to the decreased RSFC in CRBL 6.L. Our findings suggest that the cortical abnormalities may affect brain intrinsic connectivity in non-NPSLE patients.

Brain white matter structural networks in patients with non-neuropsychiatric systemic lupus erythematosus.

Previous neuroimaging studies have revealed cognitive dysfunction in patients with systemic lupus erythematosus (SLE) and suggested that it may be related to disrupted brain white matter (WM) connectivity. However, no study has examined the topological properties of brain WM structural networks in SLE patients, especially in patients with non-neuropsychiatric SLE (non-NPSLE). In this study, we acquired DTI datasets from 28 non-NPSLE patients and 24 healthy controls, constructed their brain WM structural networks by using a deterministic fiber tracking approach, estimated the topological parameters of their structural networks, and compared their group differences. We reached the following results: 1) At the global level, the non-NPSLE patients showed significantly increased characteristic path length, normalized clustering coefficient and small-worldness, but significantly decreased global efficiency and local efficiency compared to the controls; 2) At the nodal level, the non-NPSLE patients had significantly decreased nodal efficiency in regions related to movement control, executive control, and working memory (bilateral precentral gyri, bilateral middle frontal gyri, bilateral inferior parietal lobes, left median cingulate gyrus and paracingulate gyrus, and right middle temporal gyrus). In addition, to pinpointing the injured WM fiber tracts in the non-NPSLE patients, we reconstructed the major brain WM pathways connecting the abnormal regions at the nodal level with the corticospinal tract (CST), superior longitudinal fasciculus-parietal terminations (SLFP), and superior longitudinal fasciculus-temporal terminations (SLFT). By analyzing the diffusion parameters along these WM fiber pathways, we detected abnormal diffusion parameters in the bilateral CST and right SLFT in the non-NPSLE patients. These results seem to indicate that injured brain WM connectivity exists in SLE patients even in the absence of neuropsychiatric symptoms.

[Changes in regional homogeneity of brain activity in patients with diabetic peripheral].

OBJECTIVE: To investigate the abnormalities in regional homogeneity of brain activity in patients with diabetic peripheral neuropathy (DPN) using resting-state functional magnetic resonance imaging (rs-fMRI) and explore the association between brain activity changes and DPN. METHODS: A regional homogeneity (ReHo) approach was used to compare the local synchronization of rs-fMRI signals among 20 patients with painful DPN, 16 patients with painless DPN, and 16 type 2 diabetic patients without DPN (non-DPN group). RESULTS: Compared with the those without DPN, the patients with painful DPN showed high ReHo in the left inferior temporal gyrus and the right central posterior gyrus, and low ReHo in the posterior cingulate gyrus, right inferior parietal gyrus, and the left superior parietal gyrus (P < 0.05);the patients with painless DPN group showed high ReHo in the left inferior temporal gyrus, the right middle temporal gyrus, and the right superior frontal gyrus, and low ReHo in the left thalamus (P < 0.05).No significant differences in ReHo were found between the patients with painful DPN and painless DPN (P>0.05). CONCLUSIONS: The patients with DPN have altered ReHo in multiple brain regions and impairment of a default mode network, for which the left temporal gyrus may serve as a functional compensatory brain area. ReHo disturbance in the central right posterior gyrus may play a central role in the pain symptoms associated with painful DPN.

Connectivity-based parcellation of the nucleus accumbens into core and shell portions for stereotactic target localization and alterations in each NAc subdivision in mTLE patients.

The nucleus accumbens (NAc), an important target of deep brain stimulation for some neuropsychiatric disorders, is thought to be involved in epileptogenesis, especially the shell portion. However, little is known about the exact parcellation within the NAc, and its structural abnormalities or connections alterations of each NAc subdivision in temporal lobe epilepsy (TLE) patients. Here, we used diffusion probabilistic tractography to subdivide the NAc into core and shell portions in individual TLE patients to guide stereotactic localization of NAc shell. The structural and connection abnormalities in each NAc subdivision in the groups were then estimated. We successfully segmented the NAc in 24 of 25 controls, 14 of 16 left TLE patients, and 14 of 18 right TLE patients. Both left and right TLE patients exhibited significantly decreased fractional anisotropy (FA) and increased radial diffusivity (RD) in the shell, while there was no significant alteration in the core. Moreover, relatively distinct structural connectivity of each NAc subdivision was demonstrated. More extensive connection abnormalities were detected in the NAc shell in TLE patients. Our results indicate that neuronal degeneration and damage caused by seizure mainly exists in NAc shell and provide anatomical evidence to support the role of NAc shell in epileptogenesis. Remarkably, those NAc shell tracts with increased connectivities in TLE patients were found decreased in FA, which indicates disruption of fiber integrity. This finding suggests the regeneration of aberrant connections, a compensatory and repair process ascribed to recurrent seizures that constitutes part of the characteristic changes in the epileptic network.

Alterations of white matter structural networks in patients with non-neuropsychiatric systemic lupus erythematosus identified by probabilistic tractography and connectivity-based analyses.

PURPOSE: Systemic lupus erythematosus (SLE) is a chronic inflammatory female-predominant autoimmune disease that can affect the central nervous system and exhibit neuropsychiatric symptoms. In SLE patients without neuropsychiatric symptoms (non-NPSLE), recent diffusion tensor imaging studies showed white matter abnormalities in their brains. The present study investigated the entire brain white matter structural connectivity in non-NPSLE patients by using probabilistic tractography and connectivity-based analyses. METHODS: Whole-brain structural networks of 29 non-NPSLE patients and 29 healthy controls (HCs) were examined. The structural networks were constructed with interregional probabilistic connectivity. Graph theory analysis was performed to investigate the topological properties, and network-based statistic was employed to assess the alterations of the interregional connections among non-NPSLE patients and controls. RESULTS: Compared with HCs, non-NPSLE patients demonstrated significantly decreased global and local network efficiencies and showed increased characteristic path length. This finding suggests that the global integration and local specialization were impaired. Moreover, the regional properties (nodal efficiency and degree) in the frontal, occipital, and cingulum regions of the non-NPSLE patients were significantly changed and negatively correlated with the disease activity index. The distribution pattern of the hubs measured by nodal degree was altered in the patient group. Finally, the non-NPSLE group exhibited decreased structural connectivity in the left median cingulate-centered component and increased connectivity in the left precuneus-centered component and right middle temporal lobe-centered component. CONCLUSION: This study reveals an altered topological organization of white matter networks in non-NPSLE patients. Furthermore, this research provides new insights into the structural disruptions underlying the functional and neurocognitive deficits in non-NPSLE patients.

Non-enhanced MR lymphography of the thoracic duct: improved visualization following ingestion of a high fat meal-initial experience.

PURPOSE: The objective of this study was to compare the clarity of magnetic resonance lymphography (MRL) images of the thoracic duct (TD) obtained from subjects following an overnight fast with those obtained from the same subjects after ingestion of a high fat meal. METHODS: Nineteen healthy volunteers were included in this study. TD images were acquired on a 3·0T MRI system with the imaging sequence of magnetic resonance cholangiopancreatography. TD MRL images were obtained from subjects following an overnight fast and from the same subjects 3-4 h after ingestion of a high fat meal. Images were displayed in maximum intensity projection format and degree of visualization was evaluated using a scoring system. RESULTS: The mean TD score obtained following an overnight fast was significantly lower than the mean TD score obtained 3-4 h after ingestion of a high fat meal (P<0·05). CONCLUSION: The clarity of TD MRL images is improved if subjects have ingested a high fat meal 3-4 h prior to examination.

MRI-based estimation of liver function by intravoxel incoherent motion diffusion-weighted imaging.

PURPOSE: To explore the usefulness of intravoxel incoherent motion (IVIM) to evaluate the hepatic functional reserve as expressed by the model for Child-Pugh class. MATERIALS AND METHODS: IVIM diffusion-weighted imaging (DWI) using 10 different b values were performed on a Philips 3.0T MR scanner in 70 patients with liver cirrhosis and 60 healthy volunteers as the control group. Patients with liver cirrhosis were subdivided into three groups: Child-Pugh class A: 29 cases; Child-Pugh class B: 19 cases; Child-Pugh class C: 22 cases. Pure molecular diffusion (D), pseudo-diffusion (D*), perfusion fraction (f) and apparent diffusion coefficient (ADC) values were calculated, and used to determine liver function, as indicated by the Child-Pugh class. RESULTS: The ICC values of D, D*, f and ADC between two radiologists were 0.997, 0.986, 0.985 and 0.995, respectively. D*, f and ADC values of liver cirrhosis group were significantly lower than control group (P<0.001, P=0.016, P=0.042, respectively). D*, f and ADC values significantly decreased with increasing Child-Pugh scores (p<0.05). Child-Pugh scores were inversely correlated with D* and f values (r=-0.423, r=-0.620, respectively). The areas under the curve (AUCs) of D* and f for evaluating liver function were 0.67-0.90 and 0.78-0.89, respectively. CONCLUSION: IVIM DWI may be a useful image-based method for assessing liver function.

A Novel Method to Locate Intracranial Anatomic Landmarks of Sella Using Three-Dimensional Computed Tomography Reconstruction Images for Endoscopic Endonasal Transsphenoidal Surgery.

OBJECTIVE: To help surgeons to locate the intracranial anatomic landmarks when performing endoscopic endonasal tanssphenoidal surgery using measurements based on three-dimensional computed tomography (CT) reconstruction images. METHOD: High-resolution axial CT images at the thickness of 0.6 mm, and reconstructed 0.41-mm-thick gapless sagittal and coronal CT images were taken from 111 subjects. Using mimics software, first located the points of nasal spine, midpoint of the posterior hard palate and the basic line between them. Then located the medial edge of foramen lacerums, optic canals, midpoints of tuberculum sellae and posterior-inferior sellar floor, measured their distances to nasal spine and angles between the line connecting these structures to nasal spine and the basic line. RESULTS: The mean distance from nasal spine to optic canal is 73.12 ± 4.10 mm, and the corresponding angle is 39.79° ± 3.13°. The distance from the medial edge of foramen lacerum to nasal spine is 79.91 ± 4.01 mm, and the corresponding angle is 23.27° ± 2.89°. The distances from midpoints of the tuberculum sellae and posterior-inferior sellar floor to nasal spine are 76.16 ± 4.56 mm and 82.05 ± 4.81 mm, and the corresponding angles are 34.97° ± 3.24° and 26.39° ± 3.51°, respectively. The distances between both foramen lacerums and optic canals are 22.54 ± 3.25 and 23.44 ± 3.49 mm, respectively. The distance from the midpoint of tuberculum sellae to posterior-inferior sellar floor is 13.33 ± 1.87 mm. CONCLUSION: The current study provides information about intracranial anatomic landmarks, which can help neurosurgeons to locate them and avoid relative complications during endoscopic endonasal transsphenoid surgery. The measurements can be used as surgical indicators to investigate these anatomic landmarks.

Organic Radical Contrast Agents Based on Polyacetylenes Containing 2,2,6,6-Tetramethylpiperidine 1-Oxyl (TEMPO): Targeted Magnetic Resonance (MR)/Optical Bimodal Imaging of Folate Receptor Expressing HeLa Tumors in Vitro and in Vivo(a).

Nitroxides have great potential as magnetic resonance imaging (MRI) contrast agents for tumor detection. Polyacetylenes(PAs) containing 2,2,6,6-tetramethyl-piperidine oxyl (TEMPO) and poly(ethylene glycol) were synthesized via metathesis polymerization of the corresponding substituted acetylenes to be used for targeted bimodal MRI /optical imaging of tumors. The poly(ethylene glycol) in the polyacetylenes enables covalent conjugation of carboxyl fluorescein and folic acid (FA) with hydroxyl groups to develop targeted multifunctional organic radical contrast agents (ORCAs). In vitro studies confirm the excellent binding specificity and subsequent enhanced cellular internalization of the targeted ORCAs (PA-TEMPO-FI-FA) without cytotoxicity. In vivo T1-weighted MRI demonstrates the active tumor targeting ability of PA-TEMPO-FI-FA to generate specific contrast enhancement in mice bearing HeLa tumors. Moreover, longitudinal optical imaging displays high tumor accumulation after 1 h post-injection of PA-TEMPO-FI-FA. These results indicate that multifunctional ORCAs may provide a tumor-targeted delivery platform for further molecular imaging guided cancer therapy.