Correlation between Magnetocaloric Properties and Magnetic Exchange Interaction in Gd54Fe36B10-xSix Amorphous Alloys.

Gd54Fe36B10-xSix (x = 0, 2, 5, 8, 10) amorphous ribbons were fabricated by melt-spinning technique. Based on the molecular field theory, the magnetic exchange interaction was analyzed by constructing the two-sublattice model and deriving the exchange constants JGdGd, JGdFe and JFeFe. It was revealed that appropriate substitution content of Si for B can improve the thermal stability, maximum magnetic entropy change and widened table-like magnetocaloric effect of the alloys, while excessive Si will lead to the split of the crystallization exothermal peak, inflection-like magnetic transition and deterioration of magnetocaloric properties. These phenomena are probably correlated to the stronger atomic interaction of Fe-Si than that of Fe-B, which induced the compositional fluctuation or localized heterogeneity and then caused the different way of electron transfer and nonlinear variation in magnetic exchange constants, magnetic transition behavior and magnetocaloric performance. This work analyzes the effect of exchange interaction on magnetocaloric properties of Gd-TM amorphous alloys in detail.

Lumican as a novel potential clinical indicator for acute aortic dissection: A comparative study, based on multi-slice computed tomography angiography.

The aim of the present study was to investigate the association between serum lumican levels and acute aortic dissection (AAD) severity. A total of 82 patients with chest or back pain and 30 healthy volunteers were recruited. Among the patients, there were 70 cases of AAD and 12 cases of intramural hematoma (IMH). AAD severity was determined using multi-slice computed tomography angiography (MSCTA). Serum was collected from the patients upon admission, and lumican levels were detected using an enzyme-linked immunosorbent assay. In addition, correlation analyses were conducted between lumican levels and AAD severity by designing a 'SCORE X, RANGE Y' system to measure the number of affected vital arteries and vertical range of false lumen, based on the MSCTA. Lumican levels differed significantly among the AAD patients (2.32±4.29 ng/ml), IMH patients (0.72±0.32 ng/ml) and healthy volunteers (0.85±0.53 ng/ml; P=0.003). In the AAD patients presenting within 12-72 h of symptom onset, the Spearman's rho correlation coefficient between lumican and SCORE or RANGE was 0.373 (P=0.046) and 0.468 (P=0.010), respectively. The present results suggest that lumican may be a potential marker for aiding the diagnosis and screening for AAD, and may be used to predict the severity of AAD.

Comparison of diffusion-weighted MRI acquisition techniques for normal pancreas at 3.0 Tesla.

PURPOSE: We aimed to optimize diffusion-weighted imaging (DWI) acquisitions for normal pancreas at 3.0 Tesla. MATERIALS AND METHODS: Thirty healthy volunteers were examined using four DWI acquisition techniques with b values of 0 and 600 s/mm2 at 3.0 Tesla, including breath-hold DWI, respiratory-triggered DWI, respiratory-triggered DWI with inversion recovery (IR), and free-breathing DWI with IR. Artifacts, signal-to-noise ratio (SNR) and apparent diffusion coefficient (ADC) of normal pancreas were statistically evaluated among different DWI acquisitions. RESULTS: Statistical differences were noticed in artifacts, SNR, and ADC values of normal pancreas among different DWI acquisitions by ANOVA (P <0.001). Normal pancreas imaging had the lowest artifact in respiratory-triggered DWI with IR, the highest SNR in respiratory-triggered DWI, and the highest ADC value in free-breathing DWI with IR. The head, body, and tail of normal pancreas had statistically different ADC values on each DWI acquisition by ANOVA (P < 0.05). CONCLUSION: The highest image quality for normal pancreas was obtained using respiratory-triggered DWI with IR. Normal pancreas displayed inhomogeneous ADC values along the head, body, and tail structures.

Optimization of MR diffusion-weighted imaging acquisitions for pancreatic cancer at 3.0T.

OBJECTIVES: To investigate and optimize diffusion-weighted imaging (DWI) acquisitions for pancreatic cancer at 3.0T. METHODS: Forty-five patients with pancreatic cancer were examined by four DWI acquisitions with b values=0 and 600s/mm(2) at 3.0T, including breath-holding DWI (BH-DWI), respiratory-triggered DWI (TRIG-DWI), respiratory-triggered DWI with inversion-recovery technique (TRIGIR-DWI), and free-breathing DWI with inversion-recovery technique (FBIR-DWI). Artifacts, contrast ratio (CR), contrast-to-noise ratio (CNR) and apparent diffusion coefficient (ADC) of pancreatic cancer were statistically compared among DWI acquisitions. RESULTS: TRIGIR-DWI displayed the lowest artifacts and highest CR compared to other DWI acquisitions. CNRs of pancreatic cancer in TRIG-DWI and TRIGIR-DWI were statistically higher than that in FBIR-DWI and BH-DWI. Different ADCs between pancreatic cancer and noncancerous pancreatic tissues were noticed by a paired-samples T test in TRIG-DWI (p=0.017), TRIGIR-DWI (p=0.00001) and FBIR-DWI (p=0.000041). CONCLUSIONS: TRIGIR-DWI may be the optimal acquisition of DWI for pancreatic cancer at 3.0T.

Correlation of coronary atherosclerosis and subclinical plaque phenotype of carotid artery: a 320-row multidetector computed tomographic angiography study.

OBJECTIVE: This study aimed to evaluate the correlation between coronary atherosclerosis and the phenotype of subclinical carotid artery plaque using 320-row computed tomography via an original single-injection protocol. METHODS: A total of 122 patients with suspected coronary artery disease but free of transient ischemic attack and stroke underwent computed tomographic angiography of carotid and coronary artery simultaneously. The mean attenuation was measured at each artery. The plaques in either carotid or coronary were classified into noncalcified, calcified, and mixed. Coronary plaque was evaluated with plaque score. Logistic regression analysis was used to determine the predictive value of coronary plaque score to the phenotype of carotid plaque. The prevalence of each phenotype of carotid plaque in different coronary stenosis groups was also analyzed. RESULTS: The mean (SD) attenuation of carotid and coronary artery was 456.3 (81.7) Hounsfield units (HU), 466.0 (85.5) HU, 446.5 (84.1) HU, and 476.4 (90.0) HU, respectively. There was a significant correlation between the noncalcified coronary plaque score and noncalcified plaque in carotid artery (odds ratio [OR], 2.9; P < 0.05). The coronary calcified plaque scores were significantly correlated with carotid mixed (OR, 1.8; P < 0.05) and calcified plaque (OR, 2.0; P < 0.05). The noncalcified plaque of carotid artery was more frequent (72.5% vs 67%) in the nonsignificant coronary stenosis group. CONCLUSIONS: The subclinical carotid plaque phenotypes are significantly associated with coronary plaque score and defined grade of stenosis in patients with suspected coronary artery disease. Our tailored computed tomographic angiography protocol may have a positive impact on secondary prevention.

Increased ratio of glutamate/glutamine to creatine in the right hippocampus contributes to depressive symptoms in patients with epilepsy.

PURPOSE: Our study aimed to investigate whether the glutamatergic system in the hippocampus is correlated with depressive symptoms in patients with epilepsy. METHODS: Fifty patients with epilepsy were recruited and divided into three groups on the basis of their Hamilton Depression Rating Scale (HAMD) scores. Single-voxel proton magnetic resonance spectroscopy ((1)H-MRS) was carried out. Pearson correlation analysis and multiple linear regression analysis were performed to investigate any correlation between the variables of hippocampal metabolites and HAMD scores. RESULTS: Proton magnetic resonance spectroscopy analysis showed that the ratio of glutamate/glutamine to creatine (Glx/Cr) in the right hippocampus was significantly increased in patients with moderate depression and correlated positively with HAMD scores. Multiple linear regression analysis showed that the ratio of Glx/Cr in the right hippocampus was an independent risk factor relating to depressive symptoms in patients with epilepsy. CONCLUSION: A disturbance of the hippocampal glutamatergic system may be involved in the pathogenesis of depression in epilepsy.

Decreased serum hepcidin concentration correlates with brain iron deposition in patients with HBV-related cirrhosis.

PURPOSE: Excessive brain iron accumulation contributes to cognitive impairments in hepatitis B virus (HBV)-related cirrhotic patients. The underlying mechanism remains unclear. Hepcidin, a liver-produced, 25-aminoacid peptide, is the major regulator of systemic iron metabolism. Abnormal hepcidin level is a key factor in some body iron accumulation or deficiency disorders, especially in those associated with liver diseases. Our study was aimed to explore the relationship between brain iron content in patients with HBV-related cirrhosis and serum hepcidin level. METHODS: Seventy HBV-related cirrhotic patients and forty age- sex-matched healthy controls were enrolled. Brain iron content was quantified by susceptibility weighted phase imaging technique. Serum hepcidin as well as serum iron, serum transferrin, ferritin, soluble transferrin receptor, total iron binding capacity, and transferrin saturation were tested in thirty cirrhotic patients and nineteen healthy controls. Pearson correlation analysis was performed to investigate correlation between brain iron concentrations and serum hepcidin, or other iron parameters. RESULTS: Cirrhotic patients had increased brain iron accumulation compared to controls in the left red nuclear, the bilateral substantia nigra, the bilateral thalamus, the right caudate, and the right putamen. Cirrhotic patients had significantly decreased serum hepcidin concentration, as well as lower serum transferring level, lower total iron binding capacity and higher transferrin saturation, compared to controls. Serum hepcidin level negatively correlated with the iron content in the right caudate, while serum ferritin level positively correlated with the iron content in the bilateral putamen in cirrhotic patients. CONCLUSIONS: Decreased serum hepcidin level correlated with excessive iron accumulation in the basal ganglia in HBV-related cirrhotic patients. Our results indicated that systemic iron overload underlined regional brain iron repletion. Serum hepcidin may be a clinical biomarker for brain iron deposition in cirrhotic patients, which may have therapeutic potential.

Reevaluation of glypican-3 as a serological marker for hepatocellular carcinoma.

BACKGROUND: Glypican-3 (GPC3) is a novel histochemical marker of hepatocellular carcinoma (HCC). However, its utility as a serologic marker for HCC is not conclusive. METHODS: A total of 1037 subjects, including 155 patients with HCC, 180 with chronic hepatitis, 124 with liver cirrhosis, 442 with non-HCC cancer and 136 healthy controls, were analyzed for serum GPC3 (sGPC3) by an ELISA constructed with 2 monoclonal antibodies. RESULTS: The average level of sGPC3 in HCC patients was 99.94±267.2ng/ml, which was significantly higher than in patients with chronic hepatitis (10.45±46.02ng/ml, P<0.0001), liver cirrhosis (19.44±50.88ng/ml, P=0.0013), non-HCC cancer (20.50±98.33ng/ml, P<0.0001) and healthy controls (4.14±31.65ng/ml, P<0.0001). The sensitivity of sGPC3 in HCC diagnosis was 40.0%, whereas the specificity was 98.5%, 94.4% and 87.1% in healthy controls, chronic hepatitis patients and liver cirrhosis patients, respectively. In addition, 13.5% (28/207) of lung cancer patients and 13.2% (9/68) of thyroid cancer patients had positive results with sGPC3. CONCLUSION: Serum GPC3 is a potential marker for HCC. However, the presence of sGPC3 in patients with lung cancer and thyroid cancer might limit its application as a single marker in the diagnosis of HCC.

T2* MRI of minimal hepatic encephalopathy and cognitive correlates in vivo.

PURPOSE: To evaluate regional brain iron deposition in minimal hepatic encephalopathy (MHE) patients using T2*-weighted gradient-echo imaging and to explore the relationship between T2* MR changes and cognitive performance. MATERIALS AND METHODS: Forty hepatitis-B virus (HBV)-related cirrhotic patients and 22 age-, sex-, and education-matched healthy controls were included in this study. Of the patients, twenty eight patients were diagnosed with MHE. All subjects were administered Number Connection Test-A (NCT-A), Letter Digit Substitution Test (LDST), Rey-Osterrieth Complex Figure Test (RCFT), and the Mini-Mental State Examination (MMSE). T2*-weighted gradient-echo images were acquired using 3 Tesla MRI. Phase values (putative iron levels) in the frontal-basal ganglia-thalamocortical circuits were measured. Spearman correlation and multiple linear regression analysis were performed. RESULTS: MHE patients exhibited significantly prolonged NCT-A time and decreased LDST, RCFT immediate and delayed recall scores. Significant decreases of phase values in the bilateral putamen were detected in MHE patients compared to without MHE patients and controls. Multiple linear regression analysis confirmed significant correlations between the phase values in the putamen and right frontal white matter and cognitive performances by MHE patients. CONCLUSION: Decreased phase values in the frontal cortical-basal ganglial circuits independently contribute to cognitive impairments in MHE patients.

Small solid tumors (< or = 2 cm) of the pancreas: relative accuracy and differentiation of CT and MR imaging.

BACKGROUND/AIMS: To determine the relative accuracy of CT and MRI in characterization of solid pancreatic masses (< or = 2cm) and useful imaging appearance for differentiating small pancreatic duct adenocarcinoma (PDAC) from other small solid pancreatic neoplasms. METHODOLOGY: CT and MRI scans of 46 patients with evidence of small pancreatic solid tumor were retrospectively evaluated, who underwent CT (n=30), MRI (n=4), or both (n=12). Two gastrointestinal radiologists independently recorded specific morphological features of tumors and the most likely diagnosis. RESULTS: With respect to specific histopathological characterization, CT and MRI were equally accurate. The mean number of correct diagnoses made by the two reviewers was 37.5 (88.4%) of 42 cases for CT compared to 12 (75%) of 16 cases for MRI (p=0.388). Location in the pancreatic head (p=0.000), presence of dilatation of MPD (p=0.000), presence of dilatation of CBD (p=0.001) and enhancement pattern (p=0.000) were statistically significant for differentiating PDAC from the other small solid pancreatic tumors, while pancreatic atrophy (p=0.069) was statistically inadequate for differentiation, although it gave a 96.4% specificity for the diagnosis of PDAC. CONCLUSIONS: CT and MRI are similarly accurate in the characterization of small solid pancreatic tumors. Small PDAC has characteristic CT and MRI findings that differentiate it from other small solid tumors.

Disease duration and arcuate fasciculus abnormalities correlate with psychoticism in patients with epilepsy.

PURPOSE: We sought to investigate the relationship between interictal personality changes and white matter abnormalities in epilepsy patients. METHODS: A total of 65 individuals with epilepsy and 40 demographically matched controls were evaluated by Eysenck Personality Questionnaire (EPQ) and diffusion tensor imaging (DTI) on 3T. Fractional anisotropy (FA) values of fibers were acquired. The relationship between EPQ scores, clinical variables and FA values was confirmed by Pearson correlation analysis and multiple linear regression analysis. RESULTS: Epilepsy patients had higher psychoticism scores (P score) and lower extraversion scores (E score) compared with controls. P scores were higher in patients with long duration (>10 years) and taking multiple antiepileptic drugs. No difference was found in E score according to all the clinical variables. Epilepsy patients showed significantly lower mean FA value compared with healthy controls in the bilateral uncinate fasciculus, cingulum bundle, arcuate fasciculus and forceps minor of the corpus callosum. Multivariate linear regression analysis revealed that duration of epilepsy and FA value of the right arcuate fasciculus was independent risk factors of psychoticism in epilepsy patients. CONCLUSIONS: Long disease duration and impairment of arcuate fasciculus integrity may predispose the development of psychoticism in patients with epilepsy. Our results provide important insights into the pathophysiological mechanisms underlying personality change in epilepsy.

Quantitative proteomics analysis by isobaric tags for relative and absolute quantitation identified Lumican as a potential marker for acute aortic dissection.

Acute aortic dissection (AAD) is a serious vascular disease. Currently the diagnosis relies on clinical and radiological means whereas serum biomarkers are lacking. The purpose of this study was to identify potential serum biomarkers for AAD using isobaric tags for relative and absolute quantitation (iTRAQ) approach. A total of 120 serum samples were collected from three groups: AAD patients (n = 60), patients with acute myocardial infarction (AMI, n = 30), and healthy volunteers (n = 30), whereas the first 10 samples from each group were used for iTRAQ analysis. Using iTRAQ approach, a total of 174 proteins were identified as significantly different between AAD patients and healthy subjects. Among them, forty-six proteins increased more than twofold, full-scale analysis using serum sample for the entire 120 subjects demonstrated that Lumican level was significantly increased relative to control and AMI samples. Further, Lumican level correlated with time from onset to admission in AAD but not AMI samples. Using iTRAQ approach, our study showed that Lumican may be a potential AAD-related serum marker that may assist the diagnosis of AAD.

Ferucarbotran versus Gd-DTPA-enhanced MR imaging in the detection of focal hepatic lesions.

AIM: To evaluate the efficacy of ferucarbotran-enhanced MR imaging in the detection of focal hepatic lesions compared to plain and Gd-DTPA-enhanced MR imaging. METHODS: Fifty-nine patients with suspected focal hepatic lesions were admitted to the study. Plain MR imaging (FSE T(2)WI with fat suppression and GRE T(1)WI sequences) and Gd-DTPA dynamic enhanced MR of the liver were initially performed followed by ferucarbotran-enhanced MR imaging 48 h later (including GRE T(1)WI, FSE T(2)WI with fat suppression, and GRE T(2)WI sequences). Images were reviewed independently by three observers. Results were correlated with surgery and pathologic examination or reference examination, and sensitivity was statistically calculated for the different MR imaging sequences. RESULTS: Among all confirmed lesions (n = 133), ferucarbotran-enhanced MR imaging revealed 130 lesions on FSE T(2)WI with fat suppression, 115 lesions on dynamic T(1)WI GRE, and 127 lesions on GRE T(2)WI. Pre-contrast MR imaging revealed only 84 lesions on GRE T(1)WI and 106 lesions on FSE T(2)WI with fat suppression, while Gd-DTPA dynamic enhanced GRE T(1)WI revealed 123 lesions. For 44 micro-lesions (< 1.0 cm) in all patients the detection rates were as follows: ferucarbotran-enhanced FSE T(2)WI with fat suppression, 93.2% (41/44); ferucarbotran-enhanced GRE T(2)WI, 88.6% (39/44); Gd-DTPA dynamic-enhanced GRE T(1)WI, 79.5% (35/44); pre-contrast FSE T(2)WI with fat suppression, 54.5% (24/44); and pre-contrast GRE T(1)WI, 34.1% (15/44). In detecting micro-lesions, statistically significant difference was found for Ferucarbotran-enhanced FSE T(2)WI with fat suppression and GRE T(2)WI sequences compared to the other sequences (P < 0.05). CONCLUSION: Ferucarbotran-enhanced FSE T(2)WI with fat suppression and GRE T(2)WI sequences are superior in detecting micro-lesions (< 1 cm) in comparison with plain and Gd-DTPA dynamic-enhanced MR imaging.

[Value of multidetector computed tomography in differentiating ovarian tumors from non-ovarian masses].

OBJECTIVE: To evaluate the ability of multidetector computed tomography (MDCT) in differentiating ovarian tumors from non-ovarian masses. METHODS: Forty-two cases with pelvic masses were examined with 16-row MDCT. All source image of each case was put into workstation for multi-planar reconstruction (MPR) and curved planar reconstruction(CPR). Axial image combined with 2D image was used for determining the relationship of the mass to ovarian vascular pedicle and identifying the normal ovary, which was compared with postoperative pathologic result and the finding during operation. All the data was compared using Fisher's exact test. RESULTS: There were 28 ovarian tumors and 14 non-ovarian tumors in this series. If the ovarian vascular pedicle sign was used for determining whether the tumor was from the ovary or not, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy was 89.3%, 85.7%, 92.6%, 80.0% and 88.1%, respectively, with a significant difference in differentiating the tumor from the ovary or non-ovarian organs (P <0.05). If the identification of full normal ovary was used to determine non-ovarian origin of the tumor, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy was 50.0%, 100.0%, 100.0%, 80.0% and 83.3%, respectively, also with a significant difference in differentiating the tumors from the ovary or non-ovarian organs (P <0.05). CONCLUSION: MDCT can clearly show the relationship of the tumor to the normal ovary and its vascular pedicle, which is very helpful in differentiating the ovarian tumors from a non-ovarian masses.