Objective:To evaluate the sensitivity of the ArcCheck dosimetry system in detecting the leaf open time errors during the center and off-center helical tomotheray delivery quality assurance (DQA).Methods:Nine nasopharyngeal carcinoma (NPC) patients were selected in this study. Two DQA plans were created for each patient: the" center" plan was created by moving the image of the ArcCheck phantom to place the high dose region on the phantom center and the " off-center" plan was created by offsetting the phantom and putting several diodes through a higher does region. Leaf open time errors of 2, 4, 6, 8 and 10 ms were introduced to the Sinogram which was modified using Matlab. Each intentional error plan and original (no error) plan for each patient were measured using both " center" and " off-center" DQA methods, the γ analysis was performed to evaluate the DQA results. The different dose and distance error criteria of 3%/3 mm, 3%/2 mm and 2%/2 mm were selected, and different thresholds of 5%, 10% and 15% were selected for γ analysis. The gradient and the minimum detectable error approach were taken to quantitatively analyze the sensitivity. The correlation between different dose distance error criteria and different thresholds was also evaluated by Pearson correlation analysis. Results:The absolute value of γ gradient of the " center" DQA plans were larger than those of the " off-center" plans in all different γ criteria (all P<0.05). The stricter the γ criteria were adopted, the more sensitive DQA results of leaf open time error were obtained. The minimum detectable error was 2 ms in all different γ criteria for the " center" DQA plan. The minimum error detectability of the " off-center" DQA plan was weaker than that of the " center" DQA plan. The γ passing rates of three different dose distance error criteria were significantly strongly correlated for the " center" DQA plan ( R2>0.9). For the " off-center " DQA plan, only the 3%/3 mm and 3%/2 mm criteria were significantly strongly correlated ( R2>0.9). Significant strong correlation was observed in the γ passing rate at different thresholds between the " off-center" and " center" DQA plans. Conclusions:The " center" DQA plan method is more sensitive than the " off-center" DQA plan method in all γ criteria, and the γ passing rates in different γ criteria are strongly correlated for the " center" DQA plan. The " center" DQA plan method is recommended.

Objective To explore the effect of preventing adhesion after the orbital blowout fracture on orbit tissue by amniotic membrane. Design Experimental study. Participants Twenty-six New Zealand rabbits. Methods Establishing rabbit orbital blowout fracture model, the right orbit of twenty rabbits was repaired by hydroxyapatite (HA) parceled of amniotic membrane, and left orbit was only repaired by HA, the orbits of the other six rabbits weren't repaired. Then we got the tissue around bone after one week and one month, and compared the difference of three groups. Main Outcome Measures Inflammatory response of tissue around bone was ana- lyzed by HE, picric acid Sirius Scarlet dying, TGF-?immunohistoehemical observation. Results One week after operation, HE and im- munohistochemistry showed that the difference was not significant in inflammatory response between experimental group and control group (P=0.351, P=0.413), and difference is significant between blank group and experimental group (P=0.012, P=0.041). One month after operation, HE and immunohistoehemistry showed that the difference was significant in inflammatory response between experimental group and control group(P=0.037, P=0.048), and there is no significant difference between experimental group and blank group(P=0.285, P=0.472). Conclusion It has an important role of anti-inflammatory and anti-adhesion in the chronic stage of inflammatory after orbital blowout fracture repaired by man-made plates of amniotie membrane.

Actins ; metabolism ; Bone Neoplasms ; blood ; complications ; diagnostic imaging ; pathology ; surgery ; Diagnosis, Differential ; Female ; Humans ; Hypophosphatemia ; blood ; etiology ; Ilium ; Mesenchymoma ; blood ; complications ; diagnostic imaging ; pathology ; surgery ; Middle Aged ; Osteomalacia ; blood ; etiology ; Phosphates ; blood ; Platelet Endothelial Cell Adhesion Molecule-1 ; metabolism ; Tomography, X-Ray Computed

Objective To study the value of DSA for hepatic vascular anatomy,and to evaluate the efficacy of portal vein occlusion in rabbits with hepatic VX2 tumor.Methods Twenty New Zealand white rabbits were randomly divided into two groups with 10 in each group,including test group A and positive control group B of ham operation.For the test group A,portal branch ligation(PBL)was performed for the left external branch after 3 weeks of the tumor implantation to the left external lobe.Two weeks later,the DSA of hepatic artery and portal vein were performed in all of the rabbits.Results The total displaying effectiveness of the branches of hepatic artery by DSA was better than that by vascular perfusion.There was hypovascular blood supply to hepatic artery implantation of the tumor in the test group A,comparing with that of the group B.Conclusion DSA can clearly display spacial details of the hepatic vascular anatomy in rabbits,and play an important role in post-procedual evaluation of the portal vein occlusion in rabbits.

Objective To investigate the clinical features,treatment response and prognosis in children with Takayasu′s arteritis(TA) in order to improve the understanding of TA.Methods A retrospective study of 10 children with TA was performed.All of them were admitted and diagnosed in Peking University First Hospital from Jan.1998 to Oct.2008.The clinical features,laboratory tests,imaging modalities,treatment response and prognosis were all collected and evaluated.Results There were 3 boys and 7 girls in the 10 patients with TA,and the ratio of male to female was 12.3.The onset was from 4 months to 9 years old,with average age at 5.5 years old.The average duration of diagnosis was 7.6 months.The incidences of hypertension,vascular bruits,albuminuria,convulsion were present in 100%,100%,70% and 40%,respectively.The clinical types included typeⅡ(60%),type Ⅲ(10%) and type Ⅳ(30%).The acute phase inflammatory indices of activity such as erythrocyte sedimentation rate(ESR),C-reactive protein(CRP) and white blood cell(WBC) were not evidently increased.Tuberculosis infection was found in 6 out of 10 patients and anti-tuberculosis treatment was performed.Six patients were treated with steroids and 3 cases of them were also given immunosuppressives cyclophosphamide or methotrexate.Three of the 10 patients received anti-hypertensive and vasodilator.Two patients received percutaneous translurminal angioplasty and 1 patient received nephrectomy.One patient died of renal failure,heart failure and shock.Conclusions The patients with TA had high prevalence of tuberculosis infection,diagnosis as often late because of lack of specific clinical features at the acute inflammatory period.When organic ischaemia occurred,treatment response was usually unsatisfactory.Patients with multi-systemic and multi-viscera lesions should have comprehensive examination,especially for those with hypertension,pulseless and vascular bruits,in order to rule out TA.Early ultrasonography,computed tomography and magnetic resonnance image methods are valued in eariler diagnosis and they are the key factors to improve prognosis.

Objective To study the regulatory effect of interferons(IFNs) on retinoic acid-inducible gene-Ⅰ(RIG-Ⅰ) and the roles of RIG-Ⅰ in IFNs signaling pathway. Methods RIG-Ⅰ expression before and after IFNs treatment in mouse embryonic fibroblasts(MEFs) were analyzed with Northern blotting and semi-quantitative RT-PCR assay.MEFs isolated from wild-type and RIG-Ⅰ-/-mice were used to test growth inhibition and antiviral activity of IFNs with MTT assay and cytopathic effect inhibition assay. Results Both IFN-? and IFN-? could induce RIG-Ⅰ expression in MEFs.Treated with 100 U/mL IFN-?,growth inhibition and antiviral activity of MEFs from wild-type mice were more significant than those from RIG-Ⅰ-/-mice.With the absence of RIG-Ⅰ,the antiviral protective role IFN-? plays was significantly weaker than the wild type. Conclusion RIG-Ⅰ gene is a novel mediator of interferon effects on cells.It may participate in the inflammation responses mediated by IFNs through modulating cytokines production.

Objective:To determine the law of dose variation in nasopharyngeal carcinoma patients treated with helical tomotherapy by observing the difference between the actual and planned doses of targets and at-risk organs in these patients. Methods:Ten naso-pharyngeal carcinoma patients were treated with helical tomotherapy. Each single dose distribution and the corresponding computed tomography (CT) images were transmitted to the commercial software MIMvista 6.50, which was used to perform deformable image registration on the CT images. The sum of the actual dose was then obtained by accumulating the single doses. The image-guided actu-al dose was denoted as Plan 2, and the initial plan was called Plan 1. The dose-volume histogram of the dose distribution of targets and at-risk organs in Plans 1 and 2 were compared. Results:The D98 and D95 doses of the planning gross target volume (PGTV) in Plan 2 were significantly lower than those in Plan 1. Compared with Plan 1, the Dmean and D50 doses of double parotids in Plan 2 were higher by 42.23%and 63.82%(P<0.001, P=0.001) on average, respectively, for the left parotid, as well as by 38.64%and 66.76%(P=0.002, 0.004), respectively, for the right parotid. The D2 dose of spinal cord in Plan 2 was significantly higher than that in Plan 1. The doses were higher by 16.49%on average (P=0.026). Conclusion:To achieve precise and individually adaptive radiotherapy, correcting the error between anatomy and placement during tomotherapy for nasopharyngeal carcinoma patients is necessary.

Objective To investigate the impact of injection current (IC), injection voltage (IV), and pulse forming network (PFN) on energy (depth ratio D20/D10) and profiles of helical tomotherapy, and to improve the quality control for the stability of beam characteristics.Methods The energy and profiles were measured by ion chamber and TomoDose at different values of IC, IV, and PFN, the relationship between the energy and various parameters was evaluated by Pearson correlation analysis, and the changes in profiles were evaluated by comparative analysis.Results The energy had no correlation with IV and PFN values (P>0.05), but had a strong correlation with IC value (P=0.007), which showed a downward trend with the increase in IC.For the profiles in the x direction:(1) in the main beam region (-200 to 200 mm), the shoulder area of the profiles increased regularly with the increase in IC.There were no significant changes for the profiles when the IV values ranged from 6.42 V to 6.54 V, and the shoulder area of the profiles reached the highest point with IV=6.60 V, then decreased with further increase in IV.The shoulder area of the profiles decreased regularly with the increase in PFN.(2) In the penumbral region (±200 mm outside), all the three parameters had no effect on the profiles.For the profiles in the y direction:(1) in the main beam region (-20 to 20 mm), the profiles showed an upward trend in the area with an off-axis distance less than 16 mm when IC values were 5.40 V and 5.46 V, and showed an upward trend in the area with an off-axis distance less than 16 mm.But on the whole, the shoulder area of the profiles increased with the increase in IC, and was not affected by IV and PFN.(2) In the penumbral region (±20 mm outside), the profiles decreased regularly with the increase in IV, and was not affected by IC and PFN.IC had the highest influence on the profiles in the main beam region, followed by PFN and IV.Only IV had impact on the profiles in the penumbral region.Conclusions When the energy needs to be adjusted, the IC value should be given a priority, and PFN should be taken as a supplementary factor.When the profile needs to be adjusted, the IC value should be given a priority, and IV should be used as an auxiliary factor in the main beam region.But in the penumbral region, adjustment of parameters is only related to the profiles in y direction, so the IV value should be adjusted.This study has a guiding role in the quality control of energy and profiles, which can reduce the blindness of quality control, thus saving the time.

Objective To assess the effectiveness of extra-anatomic prosthesis bypass in the retroperitoneum as a treatment for infected abdominal aortic aneurysms (iAAAs).Methods We retrospectively reviewed the records of 10 consecutive patients diagnosed with iAAAs and treated by an extraanatomic prosthesis bypass in the retroperitoneum over the past 7 years.All 10 patients were regularly followed up by outpatient observation after their discharge.Results Ten patients with iAAAs underwent an extra-anatomic prosthesis bypass in the retroperitoneum and debridement of the infected aneurysm.An emergency operation was performed for one patient who underwent concomitant gastrointestinal procedures for aortoduodenal fistula,the other 9 cases underwent an elective operation after an intravenous antibiotic therapy for 2-4 weeks.All 10 patients were definitely diagnosed by one or more sequential CT scans combining with other methods.All patients had at least a positive preoperative blood culture or intraoperative tissue culture during the perioperative period,including Salmonella in 5 cases,Burkholderia pseudomallei in 3 cases,Escherichia coli in 1 case,Klebsiella pneumoniae in 1 case.All patients were discharged in 4-6 weeks after their operations.Except 1 case who died 16 months after surgery,all other patients were alive and were free from graft infection during the follow-up period.Conclusions The extra-anatomic prosthesis bypass in the retroperitoneum for treating iAAAs are safe and effective.

Objective To detect the change of cerebral perfusion in pediatric patients with Leigh's syndrome (LS)by using MR perfusion technique.Methods Twelve patients with Leigh's syndrome and thirteen normal children were scanned with the sequence of flow-sensitive alternating inversion recovery exempting separate T_1 measurement (FAIREST).Their relative cerebral blood flow(rCBF)values were obtained in regions of bilateral basilar nuclei and bilateral thalami.Student t-test was used to compare them between the two groups and receiver operating characteristic(ROC)curve analysis was carried out.Results Statistical analysis revealed significant difference between two groups in the regions of bilateral basilar nuclei and right thalamus(t =3.26,P =0.002;t =2.25 ,P =0.018 ;t =2.88 ,P =0.004,respectively).The rCBF values for LS group and control group were 0.432?0.158 and 0.619?0.125 for right basilar nuclear, 0.478?0.186 and 0.621?0.123 for left basilar nuclear,0.630?0.189 and 0.833?0.160 for right thalamus,respectively.The areas under the ROC curves were 0.833 and 0.756 for the rCBF of right and left basilar nuclear,respectively.Conclusion Relative CBF maps may reveal changes of cerebral blood flow in some specific brain regions in patients with Leigh's syndrome.It can provide additional information to the clinicians in the evaluation of the disease.