Cerebral perfusion changes of the basal ganglia and thalami in full-term neonates with hypoxic-ischaemic encephalopathy: a three-dimensional pseudo continuous arterial spin labelling perfusion magnetic resonance imaging study.

BACKGROUND: Neonatal hypoxic-ischemic encephalopathy (HIE) is one of the common causes of neurological injury in full-term neonates following perinatal asphyxia. The conventional magnetic resonance technique has low sensitivity in detecting variations in cerebral blood flow in patients with HIE. OBJECTIVE: This article evaluates the clinical diagnostic value of three-dimensional pseudo-continuous arterial spin labelling (3-D pcASL) perfusion magnetic resonance imaging (MRI) for early prediction of neurobehavioral outcomes in full-term neonates with HIE. MATERIALS AND METHODS: All neonates diagnosed with HIE underwent MRI (conventional and 3-D pcASL perfusion MRI). Cerebral blood flow values were measured in the basal ganglia (caudate nuclei, lenticular nuclei), thalami and white matter regions (frontal lobes, corona radiata). After 1-month follow-up, the Neonatal Behavioral Neurological Assessment scores were used to divide patients into favourable outcome group versus adverse outcome group. RESULTS: Twenty-three patients were enrolled in this study. There were no statistical differences between the symmetrical cerebral blood flow values of bilateral basal ganglia, thalami and white matter regions. However, the cerebral blood flow values of grey matter nuclei were higher than the white matter regions. The average value of cerebral blood flow in the basal ganglia and thalami in the adverse outcome group was 37.28±6.42 ml/100 g/min, which is greater than the favourable outcome group (22.55 ± 3.21 ml/100 g/min) (P<0.01). The area under the curve (AUC) of 3-D pcASL perfusion MRI was 0.992 with a cutoff value of 28.75 ml/100 g/min, with a Youden's index of 0.9231. The sensitivity and specificity were 92.3% and 100%, respectively. CONCLUSION: The 3-D pcASL demonstrated higher perfusion alteration in the basal ganglia and thalami of neonatal HIE with adverse outcomes. The 3-D pcASL perfusion MRI has the potential to predict neurobehavioral outcomes of neonates with HIE.

Decreased Functional Connectivity of Vermis-Ventral Prefrontal Cortex in Bipolar Disorder.

Objectives: To investigate changes in functional connectivity between the vermis and cerebral regions in the resting state among subjects with bipolar disorder (BD). Methods: Thirty participants with BD and 28 healthy controls (HC) underwent the resting state functional magnetic resonance imaging (fMRI). Resting-state functional connectivity (rsFC) of the anterior and posterior vermis was examined. For each participant, rsFC maps of the anterior and posterior vermis were computed and compared across the two groups. Results: rsFC between the whole vermis and ventral prefrontal cortex (VPFC) was significantly lower in the BD groups compared to the HC group, and rsFC between the anterior vermis and the middle cingulate cortex was likewise significantly decreased in the BD group. Limitations: 83.3% of the BD participants were taking medication at the time of the study. Our findings may in part be attributed to treatment differences because we did not examine the effects of medication on rsFC. Further, the mixed BD subtypes in our current study may have confounding effects influencing the results. Conclusions: These rsFC differences of vermis-VPFC between groups may contribute to the BD mood regulation.

Quantitative spectral CT evaluation of kidney tumors with the stretched-exponential nonlinear regression analysis model.

BACKGROUND: This study aimed to use the stretched-exponential nonlinear regression analysis model to explore the value of the energy spectral curve in the differential diagnosis of clear cell renal cell carcinoma (ccRCC), minimal fat renal angiomyolipoma (RAML), and hypovascular renal cell carcinoma. METHODS: Sixty-five cases with renal tumors were enrolled retrospectively who had undergone a preoperative multiphase spectral CT scan of the kidney in pre-enhance and double-phase enhanced scanning. The normalized iodine concentrations (NIC) of these lesions, normal renal cortex, and psoas major were measured and calculated. The spectral curves of these lesions and normal tissues were analyzed to calculate the stretched-exponential index (α) and b value with the stretched-exponential nonlinear regression analysis model (y=-b·Xα). The differences between α, b value, and NIC of these lesions and normal tissues in pre-enhance and two enhanced phases were compared using one-way ANOVA. The correlation between α, b value, and NIC was evaluated using the Pearson coefficient test, with significance assigned at the 5% level. RESULTS: There was no significant difference in α value between the groups in pre-enhance scanning. In the Cortical phase (CP), there were no significant differences in NIC and α value between minimal fat RAML and hypovascular renal cell carcinoma, or between ccRCC and the normal renal cortex. However, in the nephrographic phase (NP), a significant difference in α value was found between minimal fat RAML and hypovascular renal cell carcinoma, but no difference in NIC between them. In NP, there were significant differences in NIC and α values between ccRCC and the normal renal cortex. In CP and NP, there were significant differences between the psoas major and other groups in all parameters. For b value, in pre-enhance scanning, there was a significant difference between the psoas major and other groups, and between ccRCC and the normal renal cortex. There was no significant difference between other groups. After enhancement, in CP and NP, significant differences were observed between the psoas major and other groups in b value, but no significant differences were observed between all renal tumors and the normal renal cortex. A linear correlation was found between α values and NIC in CP (r=0.780, P=0.00) and NP (r=0.693, P=0.00). The b values and NIC had a low correlation in CP, with no correlation in NP. CONCLUSIONS: Quantitative spectral CT with the stretched-exponential nonlinear regression analysis model may enhance the differential diagnosis ability for renal tumors. Its clinical value remains to be further explored in other types of soft tissue lesions.

Impact of low serum hemoglobin on development of contrast-induced nephropathy (CIN) in patients with hepatocellular carcinoma (HCC) following transarterial chemoembolisation (TACE).

OBJECTIVES: To assess the association between low hemoglobin (Hb) level and development of contrast-induced nephropathy (CIN) for hepatocellular carcinoma (HCC) patients after transarterial chemoembolization (TACE). METHODS: A retrospective analysis was performed on 284 patients undergoing 503 consecutive sessions of TACE. Propensity score matching (PSM) analysis was used to reduce the influence of the difference in variables in normal and low hemoglobin groups. Risk factors of CIN were assessed by univariate and multivariate logistic regression analysis. The relation between Hb level and CIN development was analyzed by receiver operating characteristic (ROC) curve. RESULTS: CIN developed in 5.6% patients after TACE. Multivariate logistic regression analysis showed that hypertension, Hb and serum creatinine (Scr) were independent risk factors for the development of post-TACE CIN. Grouped by normal or low Hb, the incidence of CIN was 14.6% (16/110) in the low Hb group and 3.4% (4/116) in the normal Hb group after PSM. Multivariate logistic regression analysis revealed that Hb, lymphocyte count, and neutrophil to lymphocyte ratio (NLR) were independent risk factors for the development of post-TACE CIN. The optimal cut-off point at which the Hb concentration resulted in a high probability of developing CIN was 105.5 g/L in males. CONCLUSIONS: Low Hb is an independent risk factor for post-TACE CIN. Therefore, HCC patients with low Hb levels should be closely monitored before and during TACE.

Comparison of Field-of-view Optimized and Constrained Undistorted Single Shot With Conventional Intravoxel Incoherent Motion Diffusion-Weighted Imaging for Measurements of Diffusion and Perfusion in Vertebral Bone Marrow.

BACKGROUND AND PURPOSE: A limited number of studies have used the intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) approach on bone marrow. The purpose of this study was to qualitatively and quantitatively compare the clinical value of IVIM based on field-of-view optimized and constrained undistorted single shot (FOCUS) with the standard single-shot echo-planar imaging (ss-EPI) in the vertebral bone marrow. MATERIALS AND METHODS: Twenty healthy volunteers underwent ss-EPI and FOCUS IVIM-DWI of the lumbar spine. Intravoxel incoherent motion parameters (the apparent diffusion coefficient [ADC], true diffusion coefficient [D], pseudodiffusion coefficient [D*], and perfusion fraction [f]) were calculated. RESULTS: The FOCUS IVIM protocol allowed for measurement of ADC, D, D*, and f in all volunteers: ADC, 0.28 ± 1.33 ×10-3 mm2/s; D = 0.25 ± 3.98 ×10-3 mm2/s, f = 0.36 ± 4.01; and D* = 102.16 ± 71.21 ×10-3 mm2/s. There were no significant differences between the values of ADC, D, and f obtained with ss-EPI and FOCUS. The D* was significantly different (P < 0.05) between ss-EPI and FOCUS IVIM. Image quality assessments showed that the image qualities of FOCUS were superior to ss-EPI (P < 0.001). CONCLUSIONS: As a high-resolution IVIM-DWI technique, the FOCUS technique has potential clinical utility in evaluating the diffusion and perfusion in the vertebral bone marrow.

Differentiating atypical hemangiomas and vertebral metastases: a field-of-view (FOV) and FOCUS intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) study.

PURPOSE: Some atypical vertebral hemangiomas (VHs) may mimic metastases on routine MRI and can result in misdiagnosis and ultimately to additional imaging, biopsy and unnecessary costs. The purpose of this study is to assess the utility of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) on account of field-of-view optimized and constrained undistorted single shot (FOCUS) in distinguishing atypical VHs and vertebral metastases. METHODS: A total of 25 patients with vertebral metastases and 25 patients with atypical VHs were confirmed by clinical follow-up or pathology. IVIM-DWI imaging was performed at different b values (0, 30, 50, 100, 150, 200, 400, 600, 800, 1000 mm2/s). IVIM parameters [the true diffusion coefficient (D), pseudodiffusion coefficient (D*), standard apparent diffusion coefficient (ADC), and perfusion fraction (f)] were calculated and compared between two groups by using Student's t test. A receiver operating characteristic analysis was performed. RESULTS: Quantitative analysis of standard ADC and D parameters showed significantly lower values in vertebral metastases when compared to atypical hemangiomas [ADC value: (0.70 ± 0.12) × 10-3 mm2/s vs (1.14 ± 0.28) × 10-3 mm2/s; D value: (0.47 ± 0.07) × 10-3 mm2/s vs (0.76 ± 0.14) × 10-3 mm2/s, all P < 0.01]. The sensitivity and specificity of D value were 93.8% and 92.3%, respectively. CONCLUSION: The standard ADC value and D value may be used as an indicator to distinguish vertebral metastases from atypical VHs. FOCUS IVIM-derived parameters provide potential value in the quantitatively differentiating vertebral metastases from vertebral atypical hemangiomas.

Prevention and control measures in radiology department for COVID-19.

Since a novel coronavirus was discovered from a cluster of patients with emerging pneumonia of unknown etiology in Wuhan, China, it has spread rapidly through droplet and contact transmission. Recently, the novel coronavirus pneumonia which was named COVID-19 by the World Health Organization (WHO) has been raised as a worldwide problem. Radiological examinations were confirmed as effective methods for the screening and diagnosis of COVID-19. It is reported that some radiologists and radiological technologists were infected when giving examinations to the patients with COVID-19. In order to reduce the infection risk of medical staff in radiology department, we summarized the experience on prevention and control measures in radiology department for COVID-19, aiming to guide the prevention and practical work for radiologists and radiological technologists. KEY POINTS: • The novel coronavirus spreads rapidly through droplet and contact transmission. • Radiologists and radiological technologists were possibly infected by patients. • Prevention and control measures in radiology department for COVID-19 are important.

Radiation dose reduction using two orthogonal topograms associated with automatic tube voltage selection for lung CT scanning as compared with a single anteroposterior topogram.

OBJECTIVE: To evaluate the effectiveness of two orthogonal topograms on radiation dose and image quality (IQ) associated with topogram-based automatic tube voltage selection (ATVS) for lung CT scanning. METHODS: Thirty-seven patients were enrolled in this study. At baseline, only an anteroposterior topogram was obtained and at follow-up, both anteroposterior and lateral topograms were performed. ATVS was turned on during all scans. Objective and subjective IQ evaluations were performed and compared; tube voltage and radiation dose of each scan were noted and analyzed. RESULTS: A significant difference was observed regarding the objective parameters between baseline and follow-up only in image noise and signal-noise ratio (SNR) in the upper one-third of the image (image noise: 7.49 ± 1.08 vs. 9.10 ± 1.13, p < 0.001; SNR: 4.08 ± 0.87 vs. 3.37 ± 0.63, p < 0.001). No differences were found between baseline and follow-up in the subjective assessment of IQ. The radiation dose was significantly lower at follow-up than that at baseline (2.73 ± 0.83 mSv vs. 3.55 ± 1.24 mSv, respectively; p < 0.001). CONCLUSIONS: Using two orthogonal topograms associated with ATVS could significantly reduce the total radiation dose for lung CT scanning, while subjective IQ was maintained.

Effect of Repeated Injection of Iodixanol on Renal Function in Healthy Wistar Rats Using Functional MRI.

PURPOSE: To determine the optimal time interval of repeated intravenous injections of iodixanol in rat model and to identify the injury location and causes of renal damage in vivo. MATERIALS AND METHODS: Rats were randomly divided into Control group, Group 1 with one iodixanol injection, and Group 2 with two iodixanol injections. Group 2 was subdivided into 3 cohorts according to the interval between the first and second iodixanol injections as 1, 3, and 5 days, respectively. Blood oxygen level-dependent (BOLD) imaging and diffusion weighted imaging (DWI) were performed at 1 hour, 1 day, 3 days, 5 days, and 10 days after the application of solutions. RESULTS: Compared with Group 1 (7.2%), Group 2 produced a remarkable R2⁎ increment at the inner stripe of the renal outer medulla by 15.37% (P = 0.012), 14.83% (P = 0.046), and 13.53% (P > 0.05), respectively, at 1 hour after repeated injection of iodixanol. The severity of BOLD MRI to detect renal hypoxia was consistent with the expression of HIF-1α and R2⁎ was well correlated with HIF-1α expression (r = 0.704). The acute tubular injury was associated with urinary NGAL and increased significantly at 1 day. CONCLUSIONS: Repetitive injection of iodixanol within a short time window can induce acute kidney injury, the impact of which on renal damage in rats disappears gradually 3-5 days after the injections.

Two patterns of anterior insular cortex functional connectivity in bipolar disorder and schizophrenia.

OBJECTIVES: Bipolar disorder (BD) and schizophrenia (SZ) share structural abnormalities in the anterior insula cortex (AIC). The AIC appears to have a crucial role in emotional processing and regulation and cognitive control in BD and SZ. METHODS: Forty-six participants with BD, 68 with SZ and 66 healthy controls (HC) underwent functional magnetic resonance imaging scanning. Resting-state functional connectivity (rsFC) from AIC subregions (ventral and dorsal) was compared among the three groups. RESULTS: Compared to HC group, both BD and SZ groups exhibited increased rsFC from the ventral AIC (vAIC) and dorsal AIC (dAIC) to bilateral frontal pole and thalamus, the left middle frontal gyrus and the hippocampus. Meanwhile, the BD group demonstrated increased rsFC from the vAIC to the perigenual anterior cingulate cortex, the SZ group presented increased rsFC from the vAIC and dAIC to the right caudate. Compared with the BD group, the SZ group showed significantly increased rsFC from the vAIC and dAIC to the left middle frontal gyrus. CONCLUSIONS: The shared AIC rsFC abnormalities in both BD and SZ support the importance of the AIC in the common pathophysiology of BD and SZ. There were also disorder-specific features of AIC rsFC, which might implicate potential avenues for differentiating during the early stages.

Functional and structural changes in gray matter of parkinson's disease patients with mild cognitive impairment.

BACKGROUND AND PURPOSE: Cognitive impairment is a common non-motor complication of Parkinson's disease (PD). To investigate cognitive-related changes of gray matter (GM) structure and function in PD using voxel-based morphometry (VBM) and resting state functional connectivity (RSFC). MATERIALS AND METHODS: Resting state functional magnetic resonance imaging (rs-fMRI) and 3D-T1-weighted MRI scans were obtained from 21 PD patients with mild cognitive impairment (PD-MCI), 11 PD patients with normal cognitive function (PD-NC), and 21 healthy controls (HC). Functional connectivity (FC) was analyzed by defining the posterior cingulated cortex (PCC) as the seed region. VBM was performed to assess patterns of GM atrophy. RESULTS: In PD-NC versus HC, results indicated decreased PCC-FC in the right temporal gyrus(TG) and increased PCC-FC in the left medial temporal lobe(MTL), bilateral precuneus(Pcu), and parieto-occipital junction(POJ), as well as GM atrophy in the bilateral prefrontal-striatal circuit(pFTSC), TG and Pcu. In PD-MCI versus PD-NC, decreased PCC-FC was found in the bilateral prefrontal cortex(PFC), left POJ, and right TG. In addition, PCC-FC of the bilateral Pcu and GM volume of the left MTL, bilateral TG, and PFC were positively associated with cognitive score. CONCLUSIONS: Structural and functional damage of the PFC and temporal lobe are associated with subtle cognitive decline in PD, while functional enhancement of the MTL and POJ is involved in normal cognitive function of PD. In addition, the combined application of rs-fMRI and VBM analysis might become an effective means to investigate cognitive impairment-related GM abnormalities in PD-MCI patients prior to development of dementia.

Application of BOLD MRI and DTI for the evaluation of renal effect related to viscosity of iodinated contrast agent in a rat model.

PURPOSE: To evaluate the effects of viscosity of contrast agent (CA) on intrarenal oxygenation and diffusion as measured by blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) in a rat model. MATERIALS AND METHODS: Radiocontrast iodixanol formulated in three viscosities were designated 270, 320, and 350 (mg iodine/mL). Sixty-three male Wistar rats were divided into four groups. Saline and iodixanol (4 g iodine/kg) were administered. MR images were acquired on a 3.0T scanner at baseline and at 1 hour, 24 hours, 48 hours, and 72 hours postinjection of solutions. BOLD-MRI was performed with a multiple gradient-recalled-echo sequence. The changes in R2*, apparent diffusion coefficient (ADC), fractional anisotropy (FA), histology, and hypoxia-inducible factor-1α (HIF-1α) immunoexpression were evaluated. The R2*, ADC, and FA values were normalized to baseline to calculate ΔR2*, ΔADC, and ΔFA. RESULTS: Compared with baseline levels, distinct elevation of ΔR2* (P < 0.05) and obvious decrease in ΔADC (P < 0.01) and ΔFA (P < 0.05) were observed in all the anatomical compartments at 1 hour after administration of CA. The absolute values in ΔR2*, ΔADC, and ΔFA increased with increases in CA viscosity, and differed significantly between the CA groups in renal cortex (CO), outer stripe of outer medulla (OSOM), and inner stripe of outer medulla (ISOM) (all P < 0.05). A significant positive correlation was observed between ΔR2* and HIF-1α expression (P < 0.001, r = 0.75). Significant negative correlations were observed between ΔADC, ΔFA, and pathologies in CO, OSOM, ISOM (all P < 0.001, r = -0.68-0.87; all P < 0.001, r = -0.60-0.66). CONCLUSION: The effect of CA viscosity on intrarenal oxygenation and diffusion was viscosity-dependent, and was identified using BOLD-MRI and DTI. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1320-1331.

The papez circuit in first-episode, treatment-naive adults with major depressive disorder: combined atlas-based tract-specific quantification analysis and voxel-based analysis.

Previous findings suggest that the Papez Circuit may have a role in major depressive disorders. We used atlas-based tract-specific quantification analysis and voxel-based analysis to examine the integrity of white matter tracts involved in mood regulation (including tracts in the Papez Circuit). Diffusion tensor imaging acquired from 35 first-episode, treatment-naive adults with major depressive disorders and 34 healthy adult controls were compared. Our statistical approach compared structural integrity of 11 major white matter tracts between the major depressive disorder and adult controls, as well as illness duration influence in patients. Fractional anisotropy was decreased in the hippocampal cingulum and in the anterior thalamic radiation according to both analytical approaches, all of which were important tracts included in the Papez Circuit. Our results support the role of the Papez Circuit in major depressive disorders with the minimal probability of false positive due to similar findings in both analyses that have complementary advantages. Dysfunction of the Papez Circuit may be a potential marker for studying the pathogenesis of major depressive disorders.

Effects of iodinated contrast agents on renal oxygenation level determined by blood oxygenation level dependent magnetic resonance imaging in rabbit models of type 1 and type 2 diabetic nephropathy.

BACKGROUND: To evaluate the effects of contrast agents containing increasing concentrations of iodine on the renal oxygenation level determined by blood oxygenation level dependent (BOLD) magnetic resonance imaging (MRI) in a rabbit model of diabetic nephropathy. METHODS: BOLD-MRI was performed using saline or iodinated (I) contrast agents (200, 240, 300, 350 and 400 mg I/mL) at 1, 24, 48, and 72 h after experimentally inducing type 2 diabetic nephropathy in rabbits. Differences in renal oxygenation levels between type 1 and type 2 diabetic nephropathy were also assessed by BOLD-MRI after injecting 400 mg I/mL of contrast agent. RESULTS: Contrast agents increased the R2* values of the renal cortex, outer medulla, and inner medulla to the maximum levels at 24 h. The R2* values then decreased to their lowest levels at 72 h. The R2* was highest following injection of 400 mg I/mL, especially in the outer medulla. The R2* values were not significantly different between types 1 and 2 diabetic nephropathy. CONCLUSIONS: Iodinated contrast agents had the greatest influence on renal outer medulla oxygenation level at 24 h in type 2 diabetic nephropathy, with the greatest effects observed at the 400 mg I/mL dose level. There were no differences in BOLD-MRI values between type 1 and type 2 diabetic nephropathy after administering the contrast agent at 400 mg I/mL.

Clinical application and diagnostic value of noninvasive spinal angiography in spinal vascular malformations.

OBJECTIVE: The purpose of this study was to explore the value of computed tomographic (CT) spinal angiography with 256-slice CT and fast dynamic contrast-enhanced 3-dimensional magnetic resonance angiography (MRA) at 3.0 T in the diagnosis of spinal vascular malformations. METHODS: Seventeen patients who presented with suspected spinal vascular diseases by initial magnetic resonance and clinical findings all underwent CT spinal angiography. Among these, 10 patients underwent MRA, 15 patients underwent digital subtraction angiography (DSA) within 3 to 5 days, and 8 patients finally underwent surgical treatment. RESULTS: Computed tomographic angiography examination clearly showed the abnormal vascular lesions in 16 of the 17 patients, including 7 patients with the diagnosis of spinal dural arteriovenous fistula, 7 patients with perimedullary arteriovenous fistula, and 2 patients with spinal arteriovenous malformations. The results were consistent with the diagnosis of DSA or surgery. One patient was poorly diagnosed. The fistulas could be seen in 12 patients; feeding arteries were correctly displayed in 12 patients. The fistulas and feeding arteries were accurately shown in 7 of 10 patients by MRA; DSA results were also negative in the other 3 patients. CONCLUSIONS: Spinal angiography with 256-slice CT and contrast-enhanced MRA at 3.0 T can clearly show the extent of spinal vascular malformations, feeding arteries, and fistulas. They are safe, noninvasive, as well as rapid and can shorten the time of DSA diagnosis and treatment.

Mouse lymphatic endothelial cell targeted probes: anti-LYVE-1 antibody-based magnetic nanoparticles.

PURPOSE: To investigate the specific targeting property of lymphatic vessel endothelial hyaluronan receptor-1 binding polyethylene glycol-coated ultrasmall superparamagnetic iron oxide (LYVE-1-PEG-USPIO) nanoparticles to mouse lymphatic endothelial cells (MLECs). METHODS: A ligand specific target to lymphatic vessels was selected by immunohistochemical staining on the sections of a Lewis subcutaneous transplanted tumor. The z-average hydrodynamic diameter (HD), zeta potential, and the relaxivity of PEG-USPIO and LYVE-1-PEG-USPIO nanoparticles were determined with a laser particle analyzer and magnetic resonance T2 spin echo sequence, respectively. Prussian blue staining and transmission electron microscopy (TEM) of nanoparticle labeled cells were performed to determine the nanoparticles' binding form. Magnetic resonance imaging (MRI) was performed in vitro to evaluate the signal enhancement on the T2 spin echo sequence of the nanoparticle labeled cells. The iron content of the labeled cells after the Prussian blue staining and MRI scanning was determined by atomic absorption spectroscopy (AAS). RESULTS: The anti-LYVE-1 antibody was used as the specific ligand to synthesize the target probe to the MLECs. The mean z-average HDs of the LYVE-1-PEG-USPIO and PEG-USPIO nanoparticles were 57.42 ± 0.31 nm and 47.91 ± 0.73 nm, respectively, and the mean zeta potentials of the LYVE-1-PEG-USPIO and PEG-USPIO nanoparticles were 12.38 ± 4.87 mV and 2.57 ± 0.83 m V, respectively. The relaxivities of the LYVE-1-PEG-USPIO and PEG-USPIO nanoparticles were 185.48 mM(-1)s(-1) and 608.32 mM(-1)s(-1). Cells binding nanoparticles were visualized as blue granules in the Prussian blue staining. The TEM results of the labeled cells showed the specific localization of nanoparticles. The AAS results of labeled cells after the Prussian blue staining and MRI scanning showed that the LYVE-1-PEG-USPIO nanoparticles had good binding selectivity for MLECs. MRI results indicated that the PEG-USPIO and LYVE-1-PEG-USPIO nanoparticles could generate contrast on T2-weighted imaging, and the correlation between R2 and the iron content of the labeled cells was significantly positive. CONCLUSION: This study demonstrated that LYVE-1-PEG-USPIO nanoparticles might potentially be used as an MRI contrast agent for targeting MLECs, and the magnetic properties of LYVE-1-PEG-USPIO nanoparticles were suitable for MRI.

Whiter matter abnormalities in medication-naive subjects with a single short-duration episode of major depressive disorder.

Convergent studies have implicated white matter abnormalities in the pathophysiology of major depressive disorder (MDD). In this study, diffusion tensor imaging (DTI) was used to examine white matter abnormalities in 23 single-episode, medication-naive MDD participants versus 21 healthy control participants. Voxel-based analysis was used to investigate whole brain white matter abnormalities in the MDD group. Fractional anisotropy was significantly lower and apparent diffusion coefficient was significantly higher in the right superior longitudinal fasciculus (SLF) within the frontal lobe, right middle frontal and left parietal white matter in the MDD group compared with the healthy group.

Calcium signal-initiated early activation of NF-kappaB in neurons is a neuroprotective event in response to kainic acid-induced excitotoxicity.

We demonstrate that activation of nuclear factor kappaB (NF-kappaB) in neurons is neuroprotective in response to kainic acid (KA)-induced excitotoxicity. Combination of Western blotting, immunocytochemistry, and electrophoresis mobility shift assay showed that KA exposure induced a fast but transient nuclear translocation of the NF-kappaB p65 subunit and increased DNA-binding activity of NF-kappaB in primary cultured cortical neurons. The transient NF-kappaB activity was associated with upregulation of antiapoptotic Bcl-xL and XIAP gene products revealed by real-time PCR. Knockdown of p65 decreased neuronal viability and antiapoptotic gene expression. In addition, we showed that KA-stimulated DNA-binding activity of NF-kappaB was associated with reactive oxygen species and calcium signals, using AMPA/KA receptor antagonist, calcium chelator, and antioxidant. These results suggest that the fast and transient activation of NF-kappaB initiated by calcium signals is one of the important proximal events in response to KA-induced excitotoxicity, which has neuroprotective effect against KA-induced apoptosis.

Stabilization of mitochondrial function by tetramethylpyrazine protects against kainate-induced oxidative lesions in the rat hippocampus.

Mitochondria are critical regulators of cell death, a key feature of neurodegeneration. Reactive oxygen species (ROS) are crucial to Ca(2+)-mediated effects of glutamate receptor activation leading to neuronal degeneration. Tetramethylpyrazine (TMP) is a principal ingredient of Ligusticum wallichi Franchat (a Chinese herb), used for treatment of cardiovascular and cerebrovascular ischemic diseases. However, its protection against oxidative brain injury associated with excessive activation of glutamate receptors is unknown. In this study, we demonstrate TMP neuroprotection against kainate-induced excitotoxicity in vitro and in vivo. We found that TMP could partly alleviate kainate-induced status epilepticus in rats and prevented and rescued neuronal loss in the hippocampal CA3 but not the CA1 region. The partial prevention and rescue of neuronal loss by TMP were attributable to the preservation of the structural and functional integrity of mitochondria, evidenced by maintaining the mitochondrial membrane potential, ATP production, and complex I and III activities. Stabilization of mitochondrial function was linked to the observation that TMP could function as a reductant/antioxidant to quench ROS, block lipid peroxidation, and protect enzymatic antioxidants such as glutathione peroxidase and glutathione reductase. These results suggest that TMP may protect against oxidative brain injury by stabilization of mitochondrial function through quenching of ROS.

Preliminary evaluation of magnetic resonance fresh blood imaging for diagnosis of Budd-Chiari syndrome.

BACKGROUND: Budd-Chiari syndrome (BCS) is a rare disease with portal hypertension caused by the blockage of the hepatic vein and/or the inferior vena cava (IVC). Angiography is the "golden standard" for diagnosis, but it is an invasive examination. To assess the diagnostic value of a fresh blood imaging (FBI) relative to BCS, we used a magnetic resonance angiography (MRA) with an FBI sequence for a preoperative evaluation of the BCS patients in this study. METHODS: Fifty patients who were suspected of having BCS after they had been checked by a B-ultrasound were studied. 2D and 3D FBI were performed on a 1.5T superconductive MR scanner. Original images were rebuilt using a maximal intensity projection (MIP) method on the console. Two doctors reviewed all images before they learned of the angiography results. We then compared the diagnoses obtained from the FBI and angiography results to evaluate the diagnostic value of the FBI. RESULTS: Forty-one patients were diagnosed as BCS and 9 as non-BCS based on an angiography. The FBI correctly diagnosed 38 patients, incorrectly diagnosed 1 patient, and missed diagnosis in 3 patients. Thus, the diagnostic sensitivity of the FBI is 93% (38/41), the specificity is 89% (8/9) and the accuracy is 92% (46/50). The FBI images of the 13 membranous stenoses of the IVC showed a sudden stenosis of the post-liver segment of the IVC. The Images of the 5 patients with a membranous obstruction of the IVC showed IVC thickening and an absence of blood signals in the post-hepatic segment of the IVC. The images of the 4 patients with the segmental thrombosis of the IVC showed abnormal and intermittent signals in the IVC. The images of the 6 patients with a simple hepatic vein obstruction showed obstructive hepatic veins. The images of the 6 patients with the stenosis of both the IVC and the hepatic veins showed the stenosis of the IVC, the thickening of the hepatic veins and the formation of a compensatory circulation within the liver. Lastly, the images of the 7 patients showed a combination of the IVC thrombosis with stenosis or with the obstruction of one or two hepatic veins. CONCLUSIONS: An FBI can show a membranous stenosis, and an obstruction and thrombosis of the IVC. In addition, it can also demonstrate the thickening of the flexural hepatic vein and the development of intra-hepatic compensatory branches with slow blood flow. Thus, it can guide the puncturing and opening of the hepatic vein involved in an interventional therapy for BCS patients.