Objective To measure and evaluate slice sensitivity profile(SSP)and the full width at half-maximum(FWHM)for a 64-slice spiral CT system.Methods Using the same CT technique and body mode as those used for clinical CT,delta phantom was scanned with Somatom Sensation 64-slice spiral CT.SSPs and FWHM were measured both with reconstruction slice width of 0.6 mm at pitch = 0.50,0.75,1.00,1.25,1.50 and with reconstruction slice width of 0.6,1.0,1.5 mm at pitch = 1 respectively.Results For normal slice width of 0.6 mm,the measured FWHM,i.e.effective slice width,is 0.67,0.67,0.66,0.69,0.69 mm at different pitch.All the measured FWHM deviate less than 0.1mm from the nominal slice width.The measured SSPs are symmetrical,bell-shaped curves without far-reaching tails,and show only slight variations as a function of the spiral pitch.When reconstruction slice width increase,relative SSP become wider.Conclusions The variation of pitch hardly has effect all on SSP,effective slice width,and z-direction spatial resolution for Sensation 64-slice spiral CT system,which is helpful to optimize CT scanning protocol.

Objective To compare imaging quality and radiation dose on DR and dual-sided reading of CR system.Methods The TRG of ALVIM statistics phantom was exposed by DR and dual-sided reading of CR with the same radiation dose,then the exposure factor and the entrance surface dose (ESD) were recorded.After that,the phantom was exposed by dual-sided reading of CR with various mAs ( 3.2,4.0,4.3,4.8 and 5.2 mAs) and the same kV,and the ESD was recorded,too.The acquired images were read by three radiologists on the monitor of diagnosis work station with the same window width and window level,then the total points of the images were given with the method of a five-level confidence scale.ROC curves were drawn and probability Pdet was calculated.Then the data was analyzed statistically by analysis of variance (ANOVA).Results The ROC analysis of bone substitute with diameter from 0.5 to 1.0 mm and muscle substitute with diameter from 0.9 to 2.0 mm showed A (z) values of 0.742 to 0.923 and 0.635 to 0.900 for DR system when the radiation dose was 137.5 μGy.The ROC analysis of bone substitute and muscle substitute showed A(z) values of 0.526 to 0.586 and 0.473 to 0.560 for dual-sided reading of CR at the same radiation dose.The probability Pdet discrepancy of bone substitute in two systems was from 0.216 to 0.337,with the highest of 0.337 in the diameter of 1.0 mm.The probability Pdet discrepancy by muscle substitute in two systems was from 0.075 to 0.342,with the highest of 0.342 in the diameter of 2.0 mm.There was significant statistical difference between the two groups ( F =35.30,P ＜ 0.01 ).When the exposure factor of dual-sided reading of CR system was 75 kV,4.8 mAs,the ESD was 180.4 μ Gy,the ROC analysis in the bone substitute with diameter from 0.5 to 1.0 mm and muscle substitute with diameter from 0.9 to 2.0 mm showed A(z) values was the same.The probability Pdet discrepancy of bone substitute in two systems was from - 0.003 to 0.009.The probability Pdet discrepancy of muscle substitute in two systems was from -0.005 to 0.008,and there was no statistical difference between the two groups ( F =5.23,P ＞0.05).When the probability Pdet of two systems was the same,the ESD was 180.4 μGy by dual-sided reading of CR system,and the ESD was 137.5 μGy by DR system.Conclusion Detection with DR system was proved to be superior to dual-sided reading of CR system at the same radiation dose.When the image quality was similar,the radiation dose of DR system was less than the dual-sided reading of CR system.

Objective To explore the optimum voltage for digital chest radiography in adult. Methods PMMAs of Different thickness (7.2, 9.0, 10. 8 and 12. 6 cm) were used to simulate chest of different depth ( 17. 5, 22. 5, 27.0 and 32. 5 cm). The combinants of contrast-detail Cdrad 2.0 phantom and above PMMAs were exposed with automatic exposure control (AEC) and different tube voltages. The images of these combinants were obtained and the entrance surface dose (ESD) was recorded. The imaging quality factor (IQF) was calculated and the curves were drawn between the ESD,IQF and kV. The PMMAs of different thickness, on which a contrast object ( PMAA of 5 cm diameter and 1.8 cm thickness ) was placed, were exposed with the same condition used for above test. Their images were obtained and SNRs were calculated. Results The ESD, SNR and IQFinv of different chest depth decreased with increase of kV.When tube voltages of 70, 100 and 140 kV were used, for 17. 5 cm chest depth, the ESD was 0. 22, 0. 09 and 0. 06 mGy, the IQF was 43.3, 58. 8 and 72. 0, the SNR was 7.5, 6. 2 and 5.0; for 22. 5 cm chest depth, the ESD was 0.37, 0.12 and 0.06 mGy, the IQF was 56. 0, 61.4 and 65.3, the SNR was 6. 4, 5.2 and 3. 8; for 27. 0 cm chest depth, the ESD was 0. 52, 0. 20 and 0. 09 mGy, the IQF was 54. 2, 64. 3 and 91. 0, the SNR was 6. 0, 4. 8 and 3. 5; for 31.5 cm chest depth, the ESD was 0.53, 0.24 and 0. 10 mGy,the IQF was 53.2, 66. 8 and 95.3, the SNR was 5. 7, 4. 5 and 3. 0. Conclusion To balance ESD, SNR and IQF, proper tube voltage should be chosen for chest radiography according to thickness and constitution of patients.

Objective To investigate the small-world property of default mode network in relapsingremitting multiple sclerosis (RRMS) compared with the (matched) healthy control subjects,using a graph theory for resting-state functional network analysis.Methods Twenty four patients with RRMS and 24 age-,and sexmatched healthy controls were exanined with resting-state functional MRI (R-fMRI) and 3D-T1WI on Trio 3.0 Tesla.The R-fMRI data were preprocessed,then 20 regions of interest (ROIs) was defined and extracted from the default mode network.The functional connectivity between a pair of regions was defined as the Pearson's correlation coefficient in the time courses.Graph theoretical analysis was implemented and compared with the property of binary functional network.Further,the relationships were examined between the topological property of functional networks and the clinical parameters.Results In this study,functional network in the default mode network was conducted,and the small-world characteristics were observed in both RRMS and healthy control group.In the range of densities (Dmin:0.01∶0.48 ;Dmin =0.42),compared with healthy control group,RRMS groups had a slightly smaller normalized clustering coefficient (P＞0.05),a slightly larger normalized path length (P＞0.05),and a slightly decrease small-world index (P＞0.05).The left posterior cingulated cortex showed a significantly larger clustering coefficient in RRMS group (P=0.031) on the network threshold at Dmin.The area under a curve (AUC) for clustering coefficient measure curves of the left posterior cingulated cortex (density range of 0.42:0.01:0.48) between two groups were compared.The AUC result was similar to the Dmin result (P=0.031).Negative correlation was observed between the clustering coefficient of left posterior cingulated cortex and the Paced Auditory Serial Addition Test (PASAT) in both the Dmin(P=0.023) and the AUC (P=0.020).Conclusion The default mode network has small-world property in RRMS group.The significantly increased clustering coefficience is observed in the left posterior cingulated cortex,which may be a side effect.

ObjectiveTo study the role of Kukoamine B (KB) in inhibiting the inflammatory response of small intestine in septic mice and its molecular mechanisms.Methods Twenty-four male ICR mice were randomly divided into control group, model group, and KB intervention group (each,n= 8). Sepsis model was reproduced by intra-peritoneal injection of 20 mg/kg lipopolysaccharide (LPS), while equivalent normal saline was given in control group, and 20μg/kg KB was injected through caudal vein 4 hours after LPS challenge in KB intervention group. The blood/tissue samples (jejunum and ileum) were harvested 8 hours after LPS injection. The levels of plasma LPS, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were measured. The pathological changes in small intestine tissues were observed under light microscope, while the levels of inflammatory cytokines TNF-α and IL-1β in the tissue homogenates (jejunum and ileum) were assessed by enzyme linked immunosorbent assay (ELISA). The activity of myeloperoxidase (MPO) was measured by colorimetry. The expression of intercellular adhesion molecule-1 (ICAM-1) was determined by immunohistochemistry. The expressions of inducible nitric oxide synthase (iNOS) mRNA was assayed by reverse transcription-polymerase chain reaction (RT-PCR). The activation of nuclear factor-κΒ (NF-κΒ) was determined by Western Blot.Results The mice in model group were found to have an increase in microvascular permeability, interstitial edema, and infiltration of white blood cells, and the levels of LPS, TNF-α and IL-1β in their plasma, with an increase in concentrations of TNF-α and IL-1β, activity of MPO, positive expression of ICAM-1, expression of iNOS mRNA and NF-κB protein in small intestine (jejunum and ileum). Compared with model group, in mice with KB intervention, microvascular permeability, interstitial edema, and infiltration of white blood cells were reduced significantly, while the levels of LPS, TNF-α and IL-1β in plasma, the concentration of TNF-α and IL-1β, the activity of MPO, the positive expression of ICAM-1, the expression of iNOS mRNA and NF-κB protein in small intestine (jejunum and ileum) were significantly decreased [plasma LPS (kEU/L): 654.09±28.13 vs. 1 155.65±47.15, TNF-α (ng/L): 12.75±0.47 vs. 30.61±0.71, IL-1β (ng/L): 53.06±5.32 vs. 64.47±2.61; jejunum TNF-α(ng/L): 43.27±1.20 vs. 64.82±2.09, IL-1β (ng/L): 326.38±14.47 vs. 535.22±13.48, MPO (U/g): 0.14±0.01 vs. 0.32±0.02, iNOS mRNA (2-ΔΔCt): 2.39±0.13 vs. 10.80±0.22, NF-κB protein (gray value): 0.687±0.062 vs. 1.404±0.046; ileum TNF-α (ng/L): 62.75±3.92 vs. 104.24±2.82, IL-1β(ng/L): 408.06±1.70 vs. 521.97±1.16, MPO (U/g): 0.36±0.08 vs. 0.66±0.05, iNOS mRNA (2-ΔΔCt): 1.65±0.11 vs. 3.59±0.29, NF-κB protein (gray value):0.830±0.114 vs. 1.609±0.051, allP< 0.05].Conclusion KB can combine with LPS and inhibit LPS/Toll-like receptor 4 (TLR4) signaling pathway, thereby significantly inhibit the inflammatory response and protect the function of the small intestine in LPS-induced septic mice.

Objective To investigate the inhibitory effect of kukoamine B (KB) on lung inflammatory responses in mice with sepsis and its possible molecular mechanism.Methods Twenty-eight male mice were randomly divided into control group (n=8),lipopolysaccharide (LPS) group (n=10),and LPS + KB group (n=10).Sepsis model was reproduced by intra-peritoneal injection of 20 mg/kg LPS,while equivalent normal saline was given in control group,and 20 μg/kg KB was injected through caudal vein 4 hours after LPS challenge in LPS + KB group.After 8 hours of LPS challenge,the concentration of LPS in plasma and the activity of myeloperoxidase (MPO) in the lung tissue were determined.The contents of tumor necrosis factor-α (TNF-α) and interleukin-lβ (IL-1β) in plasma,alveolar lavage fluid and lung tissue homogenates were assessed by enzyme linked immunosorbent assay (ELISA).The activation of nuclear factor-κB (NF-κB) and the expression of inducible nitric oxide synthase (iNOS) in lung tissue were determined by Western Blot.The pathological changes in lung tissues were observed with hematoxylin-eosin (HE) staining.The expression of intercellular adhesion molecule-1 (ICAM-1) in lung tissue was determined by immunohistochemistry.Results Compared with control group,the concentration of LPS in plasma (kEU/L:1 155.650 ± 147.149 vs.31.390 ± 18.859),MPO activity (U/g:1.177 ±0.093 vs.0.775 ±0.166),NF-κB activity (gray value:1.557 ±0.105 vs.0.824 ±0.032) and the expression of iNOS (gray value:0.650 ±0.129 vs.0.392 ±0.097) were significantly increased in LPS group (all P＜0.05).After KB intervention,the concentration of LPS (624.461 ± 149.012),MPO activity (0.919 ±0.023),NF-κB activity (1.127 ±0.074) and the expression ofiNOS (0.425 ± 0.066) were significantly lowered (all P＜0.05).Compared with control group,the contents of TNF-α (ng/L:47.325 ± 13.864 vs.6.534 ± 0.544,13.382 ± 2.231 vs.3.748 ± 0.692,31.127 ± 7.399 vs.14.948 ± 4.673) and IL-1β (ng/L:74.329 ± 11.890 vs.29.921 ± 6.487,9.422 ± 2.674 vs.1.105 ± 0.364,528.509 ± 32.073 vs.109.945 ± 13.561) in plasma,alveolar lavage fluid and lung tissue homogenates were obviously enhanced in LPS group (all P＜0.05).With KB intervention,the contents of TNF-α (20.331 ± 7.789,7.145 ± 1.202,15.966 ± 2.946) and IL-1β (57.707 ±8.098,2.212 ± 0.878,426.154 ± 11.270) were markedly reduced (plasma TNF-α:F=16.052,P=0.002; IL-1β:F=20.649,P=0.000; lung tissue homogenates TNF-α:F=31.134,P=0.001; IL-1β:F=22.792,P=0.002;alveolar lavage fluid TNF-α:F=10.013,P=0.009; IL-1β:F=319.857,P=0.000).In addition,leukocyte infiltration to the lung tissue was attenuated,and the expression of ICAM-1 was reduced by KB in histological examination.Conclusion KB,as a neutralizer of LPS,can inhibit the release of inflammatory mediators,reduce the pulmonary inflammatory response and protect the function of lung in septic mice.

Objective To determine the inhibitory effect and mechanism of exogenous carbon monoxide against excessive neutrophil infiltration in liver and lung tissues during sepsis.Methods Thirty-two mice were subjected to sham operation (sham group),cecal ligation and perforation (CLP) group,CLP with 8 mg/kg of exogenous carbon monoxide releasing molecule Ⅱ (CORM-2) (CORM-2 group),and CLP with 8 mg/kg of inactive variants of CORM-2 (iCORM-2) (iCORM-2 group) according to the random number table,with 8 mice per group.Liver and lung tissues were collected at 24 hours after surgery to examine the pathologic changes,myeloperoxidase (MPO) activity and malonaldehyde (MDA) content.Another 60 mice were enrolled into the same 4 groups with 15 mice per group and were tested for 72-hour survival rate.Bone marrow neutrophils were isolated and divided into normal control group,1 μg/ml lipopolysaccharide (LPS) group,1 μg/ml LPS plus 10 μmol/L CORM-2 group (low dose group),1 μg/ml LPS plus 50 μmol/L CORM-2 group (high dose group),1 μg/ml LPS plus 50 μmol/L iCORM-2 group (iCORM-2 group).Under the agarose chemotaxis,qPCR and immunofluorescence detection of formyl peptide receptor 1 (FPR1) were performed.Results CLP group presented enhanced activity of MPO [liver:(9.1 ± 1.1) U/g,lung:(16.3 ± 2.8) U/g],increased MDA content [liver:(76.5 ±11.3) nmol/mg,lung:(32.4 ± 10.3) nmol/mg] and 72-hour survival rate of 20％ as compared with the sham group (all P ＜ 0.05).CORM-2 group showed inhibited activity of MPO [liver:(5.2 ± 0.8) U/g,lung:(7.5 ± 2.4) U/g],increased MDA content [liver:(46.7 ± 6.1) nmol/mg,lung:(23.8 ±7.3) nmol/mg] and 72-hour survival rate of 67％ as compared with the sham group (all P ＜ 0.05).LPS enhanced neutrophil migration (61.3 ± 7.1) (P ＜ 0.05) and expression of FPR1 which was enriched in the membrane.Meanwhile,neutrophil migration was significantly inhibited in a dose-dependent of CORM-2 (low dose group:43.3 ±6.1,high-dose group:23.3 ±5.9) (P＜0.05).Conclusions Exogenous carbon monoxide is effective to inhibit the excessive neutrophil infiltration,attenuate oxidative stress or pathological injury,and improve the survival from sepsis.The mechanism is associated with the down-regulation of FPR1,inhibition of FPR1 enrichment in the membrane,and decreased neutrophil migration.