The artifacts in magnetic resonance imagines(MRI) seriously degrade the imagine quality and affect the exact diagnosis. The reasons that may cause artifacts in magnetic resonance imaging and the suppressing methods are presented in this paper. One of the intractability appeared in researches is how to restrain all kinds of artifacts quickly and efficiently. It is important to search for new methods to solve this problem. It may provide reliable basis for medical observation and clinical diagnosis.

[ Abstract]Objective To investigate the effect of two-tage skin grafting with artificial dermis for perianal hidradenitis suppurativa. Methods A total of 20 cases diagnosed as perianal hidradenitis suppu-rativa in our hospital were selected from 2011 to 2013. In the first-stage operation,all diseased skin inclu-ding the superficial subcutaneous fatty tissue was excised,and normal deep subcutaneous fatty tissue was preserved. Then,artificial dermis was grafted to the preserved fatty tissue. After two weeks,split-hickness skin grafts were used for the skin defects as the second-tage operation. Graft success,recurrence and post-operative appearance were evaluated in these patients who were followed up for 9 to 28 months. Results Skin grafts of all 19 patients were successfully survived. The recurrence of hidradenitis suppurativa oc-curred in only one patient. This patient was treated with reoperation and the postoperative appearance was welly recovered. Conclusion Two-tage skin grafting with artificial dermis appears to be a good treatment option for perianal hidradenitis suppurativa.

BACKGROUND:The whole-kidney acelular matrix scaffold in rats prepared by perfusion method is proved to have goodin vitro biocompatibility, butin vivo biocompatibility is stil unclear. OBJECTIVE:To produce a whole-kidney acelular matrix scaffold in rats by perfusion method and to evaluate the in vivo biocompatibility of the scaffold. METHODS:The whole-kidney acelular matrix scaffold in Wistar rats was prepared by perfusion method and evaluated with the folowing tests. (1) Acute toxicity test: mice were subject to intraperitoneal injection of whole-kidney acelular matrix scaffold extract liquid, normal saline and phenol. (2) Hemolytic test: Anticoagulant blood samples from New Zealand rabbits were mixed with whole-kidney acelular matrix scaffold extract liquid, normal saline and distiled water, respectively. (3) Pyrogen test: Whole-kidney acelular matrix scaffold extract liquid was injected into the ear vein of New Zealand rabbits. (4) Intracutaneous stimulation test: Whole-kidney acelular matrix scaffold extract liquid was injected subcutaneously into New Zealand rabbits for observing whether there was a skin stimulus response. (5) Subcutaneous implantation test: The whole-kidney acelular matrix scaffold was implanted subcutaneously into the back of New Zealand rabbits. RESULTS AND CONCLUSION:There was no cel residual in the whole-kidney acelular matrix scaffold preparedby perfusion method, and no acute systemic toxicity, hemolytic reaction, pyrogen response, and skin stimulus respons, indicating the scaffold has a good histocompatibility in the rabbits. These findings suggest that the whole-kidney acelular matrix scaffolds in Wistar rats prepared by perfusion method have goodin vivo biocompatibility.

Objective:To analyze the incidence trend, current status and survival period of young patients with lung cancer aged from 15 to 44 years in Shanghai between 2002 to 2005. Methods:All the data were collected from the database of registration and ma-nagement system of diagnosed cancer cases in Shanghai city organized by Shanghai Municipal Center for Disease Control & Prevention. The incidence trend was analyzed by using APC(annual percent change)model. The survival period and median survival time were calculated by using SPSS 12.0 software and life table method. The univariate and multivariate analyses were analyzed by using Kaplan-Meier and COX regression model, respectively.Results:A total of 972 young patients with lung cancer who aged from 15 to 44 years were diagnosed in Shanghai between 2002 and 2005, accounting for 3.09% of the whole percentage of adenocarcinoma in young patients was higher than that in whole lung cancer population at the same period, while the TNM stage was not significantly different between male and female young patients. Multivariate analysis demonstrated that gender, pathological classification and TNM stage were independent prognostic factors for young patients with lung cancer. Conclusion:The lung cancer had different characteristics in young patients compared with that in whole lung cancer population in Shanghai city. It was necessary to further investigate the biologic behavior of lung cancer in young patients.

BACKGROUND: At present, there is little related report about producing a whole-kidney acellular matrix (ACM) scaffold in rats using perfusion. The cellular biocompatibility of the ACM is poorly understood. OBJECTIVE: To produce a whole-kidney ACM scaffold in rats by perfusion, to evaluate the cytocompatibility of ACM with the L929 cells in vitro, and to assess the possibility of ACM as the cytoskeleton and tissue-engineered urinary organ construction. DESIGN, TIME AND SETTING: An in vitro observation was performed at the Central Laboratory of Zhujiang Hospital, Southern Medical University from February to May 2009. MATERIALS: Kidneys were obtained from 12-week-old Whista rats, while ureter, renal veins and renal artery were reserved. Intravenous catheters were inserted through renal arteries to establish channels for perfusion. Whole-kidney retrograde perfusion was performed with successively heparinized PBS, 1% SDS, deionized water, 1% TritonX-100 and antibiotic-containing PBS under a pressure of 9.81 kPa to prepare whole-kindney acellular matrix scaffolds. METHODS: ① Samples were randomly divided into blank group (without any cells), negative control group (culture media), experimental group (rat kidney ACM leaching liquor), and positive control group (culture media containing 0.64% phenol). L929 cells in the logarithmic phase were seeded in 96-well plates at the density of 4×10~3/well, with 5 wells in each group. At 24, 72, and 120 hours after incubation, cells were stained with MTT method to detect absorbance at 490 nm and calculate relative growth rate. ② Control group (culture medium), experimental group (rat kidney ACM leaching liquor), and positive control group (culture media containing 0.64% phenol) were set up to detect cell apoptosis at 48 hours after culture using flow cytometry. MAIN OUTCOME MEASURES: Microstructure of the scaffold, cytotoxicity and cell apoptotic rate. RESULTS: After SDS and TritonX-100 union processing, reticulate structures made of basilar membrane and collagen were shown under scanning electron microscope rather than normal structures of cells. At every time intervals (24, 72, and 120 hours), there was no significant difference in the absorbance between experimental group and negative control group (P > 0.05). The grade of the cytotoxicity of the ACM was .0-1. There was no significant difference in cell apoptotic rate between experimental group and negative control group (P > 0.05). CONCLUSION: The whole-kidney acellular matrix scaffolds in rat by perfusion have good biocompatibility.

OBJECTIVEAn optimal automatic selection method of permissible source region is proposed to reduce the ill-conditioned and ill-posed problems in the reconstruction of the light source in bioluminescence tomography.

METHODSThe 2D images captured by CCD are mapped into surface light irradiance distribution based on the light propagating model. The relation matrix between the source and light distribution is obtained by finite element method. Permissive source region is determined by using the automatic selection method proposed in this paper, and then Tikhonov regularization is applied to reconstruct the light source.

RESULTSThe center point distance between the optimal permissible source region and true source is 1.26 mm, and the center point error of the reconstructed light source and true source is 0.47 mm, the volume error is 9.13 mm3.

CONCLUSIONThe optimal permissive source region selection strategy is effective to locate the permissive source region close to the true source, and reduces the reconstructed error due to subjective orientation of permissible source region. This proposed method is the basis of high precision source reconstruction in bioluminescence tomography.

Objective To observe the risk factors for portal vein thrombosis (PVT) in cirrhotic patients prior to receiving endoscopic treatment to prevent gastroesophageal varices rebleeding.Methods A retrospective analysis was conducted on cirrhotic patients admitted to Zhongshan Hospital,Fudan University from 2008 to 2013 for secondary prevention of gastroesophageal varices bleeding via endoscopic treatment.Relevant information and data were collected,followed by an univariate analysis and multiple Logistic regression analysis in attempt to identify potential factors affecting the formation of PVT.Results Totally 591 patients were enrolled in the present study and were classified as present-PVT group (n =122,20.64 ％) and absent-PVT group (n =469,79.36 ％).Univariate analysis showed that MELD score,hemoglobin,platelet count,total bilirubin,alanine aminotransferase,blood urea nitrogen,splenectomy ratio all achieved statistical significance between the two groups (P＜0.05).The multiple Logistic regression showed that MELD score,lowered blood urea nitrogen,elevated D-dimer and history of splenectomy were independent factors associated with the formation of PVT (P values were separately 0.016,0.026,0.014 and ＜0.001).Conclusions Cirrhotic patients should receive regular surveillance for MELD score,liver function,D-dimer and portal vein ultrasonography,especially in patients received with a previous history of splenectomy.

Objective To investigate the self-regulation of the autonomic nervous system following the cognitive stress tests after heart rate variability (HRV) biofeedback therapy in patients with post-stroke depression (PSD). Methods From May, 2013 to December, 2015, 48 patients with PSD were randomly divided into feedback group (n=25) and control group (n=23). The feedback group received HRV biofeed-back therapy, while the control group only received relaxation therapy without feedback signal. HRV parameters were tracked during the cognitive stress test in quiet baseline state, cognitive stress state, and resting state before and after treatment. Results Under the stress condi-tion, the low frequency of both groups increased during the first cognitive test, and the rate was higher in the control group than in the feed-back group (P=0.02). The heart rates during the second cognitive test decreased in the feedback group, while increased in the control group (P=0.05). After rest, the heart rate of the feedback group decreased below the baseline (P=0.02). Conclusion During the cognitive stress test, HRV biofeedback therapy can achieve a dynamic balance between sympathetic and parasympathetic nerves by reducing sympathetic sensibility, which improved patients' adaptive capacity to cope with their internal physiological environment and external environmental pressures.

Objective To investigate the correlation between capsule endoscopy Crohn′s disease activity index (CECDAI ) , capsule endoscopy Lewis score , simplified Crohn′s disease activity index (sCDAI) ,C reactive protein (CRP) ,erythrocyte sedimentation rate (ESR) and Crohn′s disease (CD) activity .Methods From April 2009 to April 2014 , 120 patients having received capsule endoscopy examination and diagnosed as CD were collected . The data of CRP and ESR were analyzed . The CD severity was scored by CECDAI ,Lewis score and sCDAI .Spearman correlation was performed to analyze the correlation between CECDAI ,Lewis score ,sCDAI ,CRP and ESR .Results Among all the patients , CECDAI had a good correlation with Lewis score (r=0 .645 , P< 0 .01) and also was correlated with sCDAI (r=0 .190 , P< 0 .05) ,CRP and ESR (r= 0 .315 and 0 .393 ,both P< 0 .01) .However ,the Lewis score was not correlated with sCDAI ,CRP and ESR (r=0 .052 ,0 .041 and 0 .021 ,all P>0 .05) . sCDAI had a good correlation with CRP and ESR (r=0 .438 and 0 .429 ,both P<0 .01) .Among patients whose capsule endoscope failed to pass through the whole small intestinal ,the CECDAI had no significant correlation with sCDAI ,CRP and ESR (r=0 .126 ,0 .181 and 0 .269 ,all P>0 .05) .Conclusions Lewis score ,sCDAI ,CRP and ESR can reflect disease activity of CD patients in a certain degree .CECDAI is the most suitable index in evaluating the disease activity of CD patients .Therefore ,it is necessary to attach importance to capsule endoscopy examination .

Objective To construct Fisher discrminant functions with index of ultrasonography. Methods A total of 48 non-neoplastic ovarian cysts, 137 benign and 120 malignant ovarian tumors were enrolled in this study. Taking ultrasonographic parameters and Doppler blood flow signals as differential diagnosis variable, a diagnosis model was developed using stepwise discriminant analysis. Then a projection and territorial map were drew and the diagnostic ability of the model was verified with substitution method and jackknife. Results ①Univariate analysis indicated that ovarian cysts volume, end-diastolic blood flow velocity (V_(ED)), mean blood flow velocity (V_m), resistance index (RI), pulse index (PI), physical property, echo, shape, boundary, ascites and blood flow signal have statistical difference among the three kinds of ovarian cysts. ②Stepwise discriminant analysis showed that volume, resistance index, physical property, shape and boundary are the independent prognostic variables. The two Fisher discriminant functions were as following: Function 1=0.002volume-4.793 RI+0.468physical property+0.862shape+0.901boundary-4.076, Function 2=0.005volume-1.480 RI+0.851physical property-0.291shape+0.443boundary+0.524. ③The projective positions of three kinds of ovarian cysts at 2D coordinates were clear. ④The sensibility and specificity of mode for diagnosis non-neoplastic ovarian cysts, benign and malignant ovarian tumors was 91.67%, 88.32% and 93.33% with substitution method, and was 91.67%, 86.13% and 93.33% with jackknife method. Conclusion Cysts volume, RI, physical property, shape and boundary are the significant differential prognostic variables. Fisher discriminant analysis can provide a reliable prognostic model for ovarian cysts.