Dynamic Alterations of Spontaneous Neural Activity in Parkinson's Disease: A Resting-State fMRI Study.

Objective: To investigate the dynamic amplitude of low-frequency fluctuations (dALFFs) in patients with Parkinson's disease (PD) and healthy controls (HCs) and further explore whether dALFF can be used to test the feasibility of differentiating PD from HCs. Methods: Twenty-eight patients with PD and 28 demographically matched HCs underwent resting-state functional magnetic resonance imaging (rs-fMRI) scans and neuropsychological tests. A dynamic method was used to calculate the dALFFs of rs-fMRI data obtained from all subjects. The dALFF alterations were compared between the PD and HC groups, and the correlations between dALFF variability and disease duration/neuropsychological tests were further calculated. Then, the statistical differences in dALFF between both groups were selected as classification features to help distinguish patients with PD from HCs through a linear support vector machine (SVM) classifier. The classifier performance was assessed using a permutation test (repeated 5,000 times). Results: Significantly increased dALFF was detected in the left precuneus in patients with PD compared to HCs, and dALFF variability in this region was positively correlated with disease duration. Our results show that 80.36% (p < 0.001) subjects were correctly classified based on the SVM classifier by using the leave-one-out cross-validation method. Conclusion: Patients with PD exhibited abnormal dynamic brain activity in the left precuneus, and the dALFF variability could distinguish PD from HCs with high accuracy. Our results showed novel insights into the pathophysiological mechanisms of PD.

Diagnostic accuracy of magnetic resonance angiography for Budd-Chiari syndrome: A meta-analysis.

In recent years, the role of magnetic resonance angiography (MRA) in the diagnosis of Budd-Chiari Syndrome (BCS) has been the focus of various clinical studies. The purpose of the present study was to perform a meta-analysis of the diagnostic performance of MRA in patients with BCS by using digital subtraction angiography as a reference method. The search strategy for relevant research articles was based on the Cochrane Handbook for Systematic Reviews, and literature databases (including PubMed, Medline and China National Knowledge Infrastructure) and reference lists of retrieved studies published from 2000 to 2016 were searched. The Quality Assessment of Diagnostic Accuracy Studies tool was used to assess the methodological quality of these research studies by two reviewers independently. Summary estimates of the sensitivity, specificity, positive/negative likelihood ratio (LR+/-), diagnostic odds ratio (DOR) and the summary receiver operating characteristic (SROC) curve of MRA in identifying BCS were obtained. The pooled MRA estimates had a sensitivity of 97.6% [95% confidence interval (CI), 95.1-99.0%], a specificity of 70.7% (95% CI, 54.5-83.9%), an LR+ of 3.163 (95% CI, 2.03-4.94) and an LR- of 0.045 (95% CI, 0.02-0.09). The overall DOR was 94.053 (95% CI, 32.71-270.41). The area under the SROC curve was 0.972. In conclusion, MRA is an accurate modality for evaluating BCS.

Three-dimensional arterial spin labeling imaging and dynamic susceptibility contrast perfusion-weighted imaging value in diagnosing glioma grade prior to surgery.

The current study aimed to investigate whole-brain three-dimensional arterial spin labeling imaging (3D ASL) and dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI), in regards to their diagnostic value of preoperative glioma grade. The parameter values obtained after correction will be correlated with the diagnostic value of 3D ASL and DSC-PWI perfusion. In the current study, 50 patients with gliomas confirmed by pathology were used, including 27 low-grade gliomas (LGGs) and 23 high-grade gliomas (HGGs). Prior to surgery all patients underwent 3 Tesla magnetic resonance imaging (MRI), 3D ASL, DSC-PWI and conventional enhanced MRI scans to obtain original 3D ASL and DSC-PWI images, and the tumor regions with the most obvious parenchyma perfusion and contralateral normal white matter were selected. In these areas, the ASL-relative cerebral blood flow (ASL-rCBF), DSC-relative cerebral blood flow (DSC-rCBF) and DSC-relative cerebral blood volume (DSC-rCBV) parameter values were then obtained after correction for individual differences. The results of the present study show that ASL-CBF, DSC-CBF, DSC-CBV values and ASL-rCBF, DSC-rCBF, DSC-rCBV values increased as the grade of the glioma being imaged increased, and there was a marked difference between the HGGs and the LGGs. ASL-rCBF was significantly positively correlated with DSC-rCBF (r=0.580, P<0.01). In addition, ASL-rCBF was significantly positively correlated with DSC-rCBV (r=0.431, P<0.01). Receiver operating characteristic (ROC) curves were applied to compare the two perfusion parameters of DSC-PWI and 3D ASL in the diagnosis of glioma grade. ASL-rCBF had the highest area value under the ROC curve (0.836). The areas under the ROC curve of DSC-rCBF and DSC-rCBV were analyzed using the Z test, but the difference was not statistically significant. When ASL-rCBF, DSC-rCBF and DSC-rCBV were cutoff at 2.24, 1.85 and 1.68, the sensitivity of HGG diagnosis was 83.2, 91.3 and 91.3%, and the specificity was 77.7, 63.9 and 66.7%, respectively.

Comparison of 3.0T MRI with 3D LAVA sequence and digital subtraction angiography for the assessment of accessory hepatic veins in Budd-Chiari syndrome.

PURPOSE: To compare 3D liver acceleration volume acquisition (LAVA) and digital subtraction angiography (DSA) for evaluating the presence of accessory hepatic veins (AHV) in Budd-Chiari syndrome (BCS). MATERIALS AND METHODS: This was a retrospective study in 228 patients with BCS who underwent 3.0T magnetic resonance imaging (MRI) with the 3D LAVA sequence. Two reviewers noted AHV: openings located in the inferior vena cava (IVC), caliber, and the angle of entering into the IVC. MRI results were compared to DSA. Kappa statistics were calculated to quantify intrareader variability in detecting AHVs. RESULTS: On MRI, 63 patients demonstrated no AHV on LAVA images, 70 had one AHV, 62 had two AHVs, 26 patients had three AHVs, six patients had four AHVs, and one patient had five AHVs (P < 0.05 vs. DSA). The mean caliber of the AHVs was 8.3 ± 4.0 mm compared to 9.9 ± 3.2 for DSA (P < 0.001). Among the 301 AHVs, there were 140 with acute angles (46.5%), 71 with right angles (23.6%), and 90 with obtuse angles (29.8%). The prevalence of AHVs on DSA was 54.8% (125/228), while MRI demonstrated 301 AHVs in 165 patients, for a prevalence of 72.4% (165/228) compared to 54.8% for DSA (P = 0.001). The two methods were concordant in only 116/228 (50.9%) patients. The kappa coefficient demonstrated good intrareader consistency for all documented MRI findings of AHVs (κ = 0.626 for caliber and κ = 0.65 for angles). CONCLUSION: More AHVs were visible on MRI LAVA sequences than on conventional DSA. LEVEL OF EVIDENCE: 4 J. Magn. Reson. Imaging 2017;45:401-409.

Use of high-resolution 3.0-T magnetic resonance imaging to characterize atherosclerotic plaques in patients with cerebral infarction.

The present study aimed to evaluate the utility of high-resolution magnetic resonance imaging (MRI) in the characterization of atherosclerotic plaques in patients with acute and non-acute cerebral infarction. High-resolution MRI of unilateral stenotic middle cerebral arteries was performed to evaluate the degree of stenosis, the wall and plaque areas, plaque enhancement patterns and lumen remodeling features in 15 and 17 patients with acute and non-acute cerebral infarction, respectively. No significant difference was identified in the vascular stenosis rate between acute and non-acute patients. Overall, plaque eccentricity was observed in 29 patients, including 13 acute and 16 non-acute cases, with no significant difference identified between these groups. The wall area of stenotic arteries and the number of cases with plaque enhancement were significantly greater in the acute patients, but no significant difference in plaque or lumen area was identified between the 2 patient groups. Lumen remodeling patterns of stenotic arteries significantly differed between the acute and non-acute patients; the former predominantly demonstrated positive remodeling, and the latter group demonstrated evidence of negative remodeling. In conclusion, patients with acute and non-acute cerebral infarction exhibit specific characteristics in stenotic arteries and plaques, which can be effectively evaluated by high-resolution MRI.

The effects of fludarabine on rat cerebral ischemia.

Cerebral ischemic injury involves a variety of cellular and molecular events. Signal transducers and activators of transcription-1 (STAT-1) activation is associated with neuronal cell death and contributes to ischemic injury. The effects of fludarabine, a specific inhibitor of STAT1 protein, on cerebral ischemic/reperfusion (I/R) injury were studied in a rat model. Rats subjected to I/R injury were either treated with intra-cerebroventricular injection of fludarabine (5,000 µM, 10 µl) or saline 20 min before middle cerebral artery occlusion (MCAO). MR examinations including T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and perfusion-weighted imaging (PWI) were performed after I/R period. Then rat brains were sectioned for triphenyltetrazolium chloride (TTC) stains, analyzed by Western blot and TUNEL staining of apoptosis. It was found that fludarabine treatment decreased the infarct volume of the cerebrum and the number of apoptotic neural cells in the ischemic brain. Compared to saline-treated group, the apparent diffusion coefficient (ADC) and cerebral blood volume (CBV) in the ischemic region were greater, and the mean transit time (MTT) was shortened in the fludarabine-treated group. Moreover, fludarabine inhibited the expression level of phosphorylated STAT1 (P-STAT1) in neural cells after I/R injury, whereas the expression of phosphorylated STAT3 (P-STAT3) was increased. Therefore, we concluded that fludarabine administrated in early stage of cerebral ischemia had neuroprotective effects, and the underlying mechanism could be mediated through inhibiting STAT1 phosphorylation and activating the cross regulation between STAT1 and STAT3 in neural cells.

[Reduced-dose mode with low-voltage and low contrast agent in coronary artery CT angiography-a preliminary study].

OBJECTIVE: To evaluate image quality of low-voltage coronary artery computed tomographic (CT) angiography with low contrast agent in comparison with image quality. METHODS: Forty-five patients underwent coronary artery computed tomographic (CT) angiography. They were randomly assigned to 3 groups, group A (n = 15) were scanned in 120 kVp with 350 mgI/ml iodinated contrast agent mode, group B (n = 15) were scanned in 100 kVp with 350 mgI/ml iodinated contrast agent mode, group C (n = 15) were scanned in 100 kVp with 270 mgI/ml iodinated contrast agent mode. Then measured CT attenuation value of three main branches (RCA, LAD and CX) of coronary artery, And compare the SNR, CNR, the effective radiation dose(ED) and iodine intake. The Kappa test were used to quantify inter- and intra-reader agreement in detecting quality of the images under different scanning solutions. RESULTS: Three groups of coronary artery CT image quality was no statistically significant differences (all P values >0.05), Good inter- and intra-reader agreement ( k = 0.754, P < 0.05) for the detection of noise in all the patients. There was significant difference in the CT attenuation of RCA, LAD and CX among the 3 groups (P < 0.05), the CT attenuation was the highest in group B, the CT value of RCA, LAD and CX were 537 ± 90, 505 ± 90, 484 ± 75 HU, respectively.the CT attenuation was the lowest in group C, the CT value of RCA, LAD and CX were 357 ± 126, 360 ± 95, 378 ± 121 HU, respectively. There was no significant difference in the SNR and CNR among the 3 groups (P > 0.05). There was significant difference in the ED among the 3 groups (P < 0.05). The ED value of the group A was bigger than the value of the group B and C. There was no significant difference between the group B and C. Compared the group A and B, the iodine intake of the group C had fallen by 23%. CONCLUSIONS: The coronary artery CT angiography using 100 kVp with 270 mgI/ml iodinated contrast agent provide similar objective or subjective image quality compared with the (350 mgI/ml) and the 100 kVp (350 mgI/ml), thus enabling effective dose and iodine intake reduction without loss of diagnostic information.

Hepatocellular carcinoma in Budd-Chiari syndrome: enhancement patterns at dynamic gadolinium-enhanced T1-weighted MR imaging.

The objective of this study was to analyze the enhancement patterns at dynamic gadolinium-enhanced T1-weighted MR imaging in patients of Hepatocellular Carcinoma (HCC) with associated Budd-Chiari syndrome (BCS). The MR imaging findings in 10 patients of HCC with associated BCS were compared to those of 32 other patients of HCC without BCS. During the arterial phase, significantly more lesions with BCS were hyperintense than lesions without BCS; during the equilibrium phase, significantly more lesions with BCS were slightly hyperintense or isointense than lesions without BCS (P < 0.05 for both). For HCC, contrast enhancement on MRI shows different enhancement patterns between patients of HCC with associated BCS and those without BCS.

Peripheral lymphadenopathy as the initial manifestation of malignant mesothelioma in a child.

Peripheral lymphadenopathy is a rare presentation in malignant mesothelioma. We describe a unique case of malignant mesothelioma arising in an 11-year-old boy, for whom peripheral lymphadenopathy was the initial manifestation of the disease. The final diagnosis was confirmed by a broad panel of immunohistochemical markers. Literature review disclosed only 2 cases in childhood that initially presented with peripheral lymphadenopathy. Pathologists should be aware of this rare biologic behavior of malignant mesothelioma to reach the correct and prompt diagnosis.

[Study on between magnetic resonance venography and digital subtraction angiography on the inferior vena cava obstructive interface morphology of Budd-Chiari syndrome].

OBJECTIVE: To evaluate magnetic resonance venography (MRV) in diagnosing obstructive interface morphology of Budd-Chiari syndrome(BCS). METHODS: MRV examination was performed on 44 cases of BCS, and the images of obstructive interface morphology of the inferior vena cava were reviewed by two radiologists. RESULTS: In all 44 cases, there were 37 cases with complete obstruction and 7 with incomplete obstruction. MRV showed 4 cases with membrane with hole of incomplete obstruction. The morphologies MRV demonstrated that the proximal part of the 37 cases with complete obstruction were mainly divided into the cone type (36 cases) and the planum type (1 case). Besides, the type of distal end of obstruction were the cone type (30 cases), the planum type (4 cases) and the irregular type (3 cases). The overall sensitivity, specificity, positive and negative predictive values for the diagnosis of MRV were respectively 100%%, 57.1%, 92.5% and 100% as compared to the DSA. CONCLUSION: The examination of MRV is capable of revealing the obstructive interface morphology of the inferior vena cava, especially for the distal end of obstruction. MRV can provide guidelines in interventional treatment of Budd-Chiari syndrome.