Phase-contrast magnetic resonance imaging (PC-MRI) is a valuable and noninvasive method for evaluating hemodynamics and assessing the severity of disease processes involving the cardiovascular system. The basical principles, influential factors and the applications of PC-MRI in the assessment of cardiovascular diseases were reviewed in this paper.

Objective To review the neuron synaptic plasticity in hioppocampus in the pathogenesis of depression in present studies,and expected to provide reference and basis for study of depression in clinic and model.Methods The wordsdepression, antidepression, chronic unpredictable stimulate, hippocampus, synapse,plasticity were used as index words.Analysis the relationship of depression or antidepression and synaptic plasticity in hippocampus from the results of researches enrolled at home or abroad.Summarize the effect of neuron synaptic plasticity in hioppocampus in the pathogenesis of depression.Result Totally 37 articles enrolled.They show the onset of depression or antidepressant processes always combine with the damage or recover of neuron synaptic plasticity.Conclusion The reduction or damage in synaptic plasticity in hippocampus is likely to be the pathogenesis of depression,like the changes of function or expression of SYN-1,MAP-2,SYT-1,PSD-95 or any other synapse-associated proteins.Meanwhile,studies of using enrich environment to treat depression indicated that depression is likely related to the synaptic plasticity in hippocampus in another way.But who are the synapse-associated proteins related to synaptic plasticity in depression? How to design the enrich environment.? These still need further study.

Objective To evaluate the potential high risk factors of femoral head necrosis after femoral neck surgery in adult patients. Methods From January 2009 to October 2014,390 patients with femoral neck fractures in our hospital were treated with multiple hollow compression screws. All patients were followed up for 12 to 60 months. Then retrospectively analyzed the incidence rates of femoral head nec-rosis and the clinical data about age,gender,fracture side,Garden index,fracture shift condition,internal medicine complications,whether to do lower limb preoperative traction,restoration method,postoperative load time and whether take out hollow compression screw internal fixa-tion,so as to explore the higher risk factors for femoral head necrosis. Results Among the 390 cases,352 cases got followed up. There were 45 cases of them ended with nonunionand 49 cases ended with femoral head necrosis. The univariate regression analysis results showed that the age,fracture shift condition,internal medicine complications,postoperative load time and Garden index,whether take out internal fixation were risk factors for femoral head necrosis (P<0. 05). The multi-factor results showed that aged from 40 to 60 years old,transfered fracture, seriously complications,time of loading less than 3 mouths,Ⅲ and Ⅳ Garden index,take out internal fixation were the high risk factors for femoral head necrosis (P<0. 05). Conclusion Patients who aged from 40 to 60 years old and having transfered fracture,seriously complica-tion,early weight bearing,high Garden index and internal fixation take-out would increase the risk of femoral head necrosis.

Objective To evaluate the features and visualization of venous arcades of the pancreatic head (VAPH) using 16-slice CT with different techniques.Methods Portal-phase CT scanning with 16-slice CT was performed in 40 cases.The visualized rate of VAPH with axial images,thin slice maximum intensity projection(TSMIP) and volume rendering(VR) was assessed.Results With axial images,TSMIP and VR,the visualized rate of right gastro-epiploic vein and gastro-colic vein were all 100% and 80% respectively;while for right colic superior vein was 100%,87.5% and 80%;pancreaticoduodenal posterior-superior vein was 92.5%,65% and 40%;pancreaticoduodenal anterior-superior vein was 92.5%,62.5% and 45% respectively.Conclusion VAPH can be showed definitely using 16-slice CT in combination of axial images,TSMIP and VR images.

Objective:To analyzise the upper removable partial denture for Kennedy Ⅰdentition defect how to affects the consonants acoustic characteristics. Methods: Before and after restoration use the computer speech lab(CSL) to analyze 12 patients' acoustic characteristics. Then at 1, 2, 4 and 8 weeks, to compare each patient different time's area of energy concentration, the first area of energy concentration band width of consonants /s/,/sh/,/j/; the locus of /t/. Results:There was significant difference between the area of energy concentration and the first area of energy concentration band width in /s/ of the groups before restoration and at the beginning and after one week(P0.05) in other consonants groups.Conclusion: The main area which affects the acoustic characteristics is the anterior part of the anterior palate plate of the removable partial denture. From the acoustics point of view, to lay the major connector on the upper gingival, the median line area are not suitable, while the posterior part of the hard palate fitting to lay it.

PurposeTo prospectively investigate the effect of gadolinium contrast media on the quality of intravoxel incoherent motion (IVIM) MRI images and the quantification of corresponding parameters for abdominal solid organs, and to explore the appropriate time for abdominal IVIM scan.Materials and MethodsTwenty patients underwent the same abdominal IVIM scan before and after gadolinium contrast administration. The signal-to-noise ratio (SNR) of liver, spleen, pancreas and kidneys were measured on diffusion-weighted imaging (DWI) images at b=50 s/mm2, 300 s/mm2 and 800 s/mm2. SNR and contrast-to-noise ratio (CNR) of hepatocellular carcinoma (HCC) (n=16) were also calculated. Apparent diffusion coefficient (ADC) value and IVIM parameters including pure diffusion coefficient (D), pseudo-diffusion coefficient (D*) and perfusion fraction (f) of liver, spleen, kidneys parenchyma and HCC were measured and compared. ResultsSNR of liver on post-contrast DWI at b=50 s/mm2 were significantly lower than that of pre-contrast (t=2.397,P<0.05). CNR of HCC increased significantly on b=300 s/mm2 DWI images after contrast (t=-3.380,P<0.01). SNR of kidneys on DWI of any b value decreased after contrast administration (Z=-2.675--2.201,P<0.05). SNR of spleen, pancreas and HCC were not statistically different between pre-contrast and post-contrast images (t orZ=-1.324-1.104,P>0.05). As for IVIM parameters, only ADC and D values of kidneys demonstrated a significant reduction after contrast (ADC:t=3.569,P<0.01; D:Z=-3.053,P<0.01). No significant differences were detected for all parameters of liver, spleen and HCC between pre-contrast and post-contrast images (t=-1.102-1.689,P>0.05). ConclusionAdministration of gadolinium contrast media may result in decrease of SNR of liver on low b value DWI and SNR of kidneys at any b value, but it increases CNR of hepatic lesions on medium b value DWI. Administration of gadolinium contrast media does not make a significant effect on SNR of spleen, pancreas and hepatic lesions. Furthermore, ADC and D values of kidneys decrease after administration of gadolinium contrast media. There is no significant influence of contrast medium on DWI and IVIM parameters of liver, hepatic lesions and spleen.

OBJECTIVEThis study aims to evaluate the optical data of the different sites of the cobalt-chrome (Co-Cr) alloy abutments covered by four different all-ceramic crowns and the color difference between the crowns and target tab using a digital dental spectrophotometer.

METHODSTen Co-Cr alloy abutments were made and tried in four different groups of all-ceramic crowns, namely, Procera aluminia, Procera zirconia, Lava zirconia (Lava-Zir), and IPS E.max glass-ceramic lithium disilicate-reinforced monolithic. The color data of the cervical, body, and incisal sites of the samples were recorded and analyzed by dental spectrophotometer. The CIE L*, a*, b* values were again measured after veneering. The color difference between the abutments covered by all-ceramic crowns and A2 dentine shade tab was evaluated.

RESULTSThe L* and b* values of the abutments can be increased by all of the four groups of all-ceramic copings, but a* values were decreased in most groups. A statistical difference was observed among four groups. After being veneered, the L* values of all the copings declined slightly, and the values of a*, b* increased significantly. When compared with A2 dentine shade tab, the ΔE of the crowns was below 4.

CONCLUSIONFour ceramic copings were demonstrated to promote the lightness and hue of the alloy abutments effecttively. Though the colorimetric baseline of these copings was uneven, veneer porcelain can efficiently decrease the color difference between the samples and thee target.

Ceramics ; Chromium Alloys ; Cobalt ; Color ; Colorimetry ; Crowns ; Dental Materials ; Dental Porcelain ; Dental Prosthesis Design ; Humans ; Metal Ceramic Alloys ; Titanium ; Zirconium

Objective To investigate the CT and MRI features of intraductal papillary neoplasm of the bile duct (IPNB).Methods Thirty eight patients with IPNB finally diagnosed by puncture biopsy or surgery were enrolled in this study.All the CT or MRI data were investigated retrospectively.Twenty one patients underwent CT examinations,17 patients underwent MRI examinations.The features of IPNB including the distribution features of the nodules or masses,CT and MRI features of cholangiectasis,mucus were analyzed.The accuracy differences of CT and MRI for the preoperatively diagnosing mucus and tumor growing along mucous were compared by nonparametric test.Results The lesions (including 5 patients with solitary lesions and 19 patients with multiple lesions) were located in intrahepatic bile duct in 24 patients,3 patients occurred simultaneously in intrahepatic and portal bile duct,2 lesions occurred in portal bile duct,8 lesions occurred in common bile duct,the lesions of 1 patient occurred simultaneously in common bile duct,cystic duct and gallbladder.Seventeen and 11 patients appeared nodules locating in dilated bile duct on CT and MRI,respectively.Four and 5 patients appeared cystic lesions with multiple nodules of the liver on CT and MRI,respectively.Higher contrast enhancement on CT and MRI in arterial phase than that in portal vein and equilibrium phase were observed in 18 and 12 patients,respectively.Excluding the patients undergoing puncture,CT was better than MRI in evaluating whether the mucus was present,with the accuracies of 30.0％ (6/20) and 6.3％ (1/16) for CT and M RI,respectively (Z =2.58,P ＜ 0.05).CT was worse than MRI in preoperatively evaluating the features of tumor growing along mucous,with the accuracies of 77.8％ (14/18) and 92.6％ (13/14) for CT and MRI,respectively (Z =4.23,P ＜ 0.01).Conclusion IPNB had the features of growing along mucous of the bile duct,nodule or mass in dilated bile duct and other features,CT and MRI are important in diagnosing the IPNB.

Objective To evaluate blood oxygen level-dependent (BOLD) MRI on assessing renal damage after injection of iodine contrast medium with a 3.0 T system. Methods Routine MRI examination,including T1WI and T2WI, and BOLD MRI were performed in 29 SD rats with a 3.0 T system before the injection of iodine contrast agent and 20 min, 24 h, 48 h, 72 h after the injection, respectively. T2 * and R2 * ( = 1/T2 * ) measurements were obtained in the cortex, inner and outer medulla of kidney,respectively. The results obtained before contrast agent administration were considered as the self-controls.AVONA test were used for the comparison of R2 * values in different parts of both kidneys before contrast agent administration. Two-sample t test was used to compare R2 * values before and at each time point after contrast agent administration, and R2 * values in different parts of the kidneys. Results Before contrast agentadministration, R2 * values in outer medulla in both sides of kidney [R2 *left oM = (31.76 ± 2.73 ) / s,R2 * right OM = (32.77±3.07) /s] were higher than those in cortex [R2 * left c=(30.20±3.48) /s,R2 * right c = (28.84 ±3.11 )/s] and in inner medulla [ R2 * letf IM = (29.54 ± 2.42) /s, R2 * right IM =(28.37±2.80) /s ] ( F = 3.357 and 14.961, P＜ 0.05 ). There was no statistical significance in R2 *values in the three parts between left and right kidney, including cortex, outer and inner medulla (P＞0.05). After contrast agent administration, R2* values in outer medulla changed obviously, which reached to the peak values at 20 minutes after contrast agent administration [R2* left OM = ( 43.57 ± 3.84 )/s,R2*right OM= (44.58±3.13) /s] and dropped from 24 hours [R2*left OM = (42.07 ±4.82) /s,R2* right OM = (42.89±3.40) /s]. R2* values in inner medulla and cortex only presented slight changes.Conclusion R2* values reflected the changes of oxygen content in renal cortex and medulla quantitatively,which helped for detecting medullar ischemia and hypoxia. BOLD MR imaging could offer a feasible method for evaluating oxygen metabolism and renal injury in cortex and medulla.

Objective To investigate the feasibility of magnetic resonance diffusion-weighted intravoxel incoherent motion (DW-IVIM)imaging and its reproducibility in normal liver.Methods Thirty-five young healthy volunteers underwent liver DW-IVIM ex-amination twice on a 1 .5 Tesla Philips MR scanner.Parameter maps of D,D* and f were generated by using a manufacturer-sup-plied software.Six Region-of-interests (ROIs)(3 ROIs in left and right liver lobe,respectively)were drawn on three consecutive middle slices,respectively.The average values of D,D* and f were measured and compared between the left and right liver lobe. The reproducibility of D,D* and f measurement were assessed with Bland-Altman method.Results The values of D,D* and f of left liver lobe [D(×10-3 mm2/s):1.250±0.210,D*(×10-3 mm2/s):101.906±15.063 ,f(%):22.954±5.268]were statistically higher than those of right liver lobe[D(×10-3 mm2/s):1.039±0.124,D*(×10-3 mm2/s):100.127±20.757,f(%),18.317± 3.671](D,f,P<0.001,D*,P<0.232-0.605),however ,their reproducibility of left liver lobe [limit of agreement(LOA):22.55%,51.05%,39.3%,respectively]were lower than those of right liver lobe (LOA:20.3%,39.25%,33.9%).The D values had the best reproducibility in both the left and right liver lobe.Conclusion The liver DW-IVIM is feasible.The values of D,D*and f in left liver lobe were higher that those in right liver lobe but with worse reproducibility of measurement.The D value was most reproducible in both liver lobes.