3D-CISS序列与3D-TSE序列对Ⅶ～Ⅸ对颅神经成像质量的比较

目的：通过3D-CISS序列与3D-TSE序列对Ⅶ-Ⅸ对颅神经成像质量的比较，确定3D-CISS序列对脑脊液包绕的Ⅶ-Ⅸ对颅神经和淋巴液充盈的内耳迷路成像显示的优势。方法：应用3D-CISS序列与3D-TSE序列分别对第Ⅶ-Ⅸ对颅神经及内耳迷路进行MR成像，在MPR图像及MIP重建图像上最大程度的显示颅神经及内耳迷路，并对两种序列的成像质量进行统计比较。结果：面神经的脑池段、内听道近段及远段、前庭蜗神经的脑池段及内听道近段、耳蜗、前庭及半规管在两个序列中全部以100％的几率显示；蜗神经、前庭上神经、前庭下神经及舌咽神经在3D-CISS序列、3D-TSE序列的显示几率依次分别为：100％、81．2％；100％、51．4％；100％、42．0％；100％、57．1％；面神经、前庭蜗神经的内听道段、内耳迷路、舌咽神经的3D-CISS序列成像质量明显优于3D-TSE序列成像；面神经、前庭蜗神经的脑池段3D-CISS序列成像质量略优于3D-TSE序列。结论：对于被脑脊液包绕的颅神经和淋巴液充盈的内耳迷路的成像，3D-CISS序列是最佳的选择。

Value of section plane,MPR,and 3D-CTVR techniques in the fine differential diagnosis of ossicular chain in the case of conductive hearing loss with intact tympanic membrane

Aim: To assess the quality of high-resolution CT section planes(HRCT), multi-planar reformation(MPR) and 3-dimensional volume rendered computer tomography(3D-CTVR) were here used in the fine differential diagnosis of ossicular chain in the case of conductive hearing loss with intact tympanic membrane.Methods: Here, 17 cases of otosclerosis and 22 cases of ossicular chain deformity were selected. All patients had normal external ear canals,intact tympanic membranes, conductive hearing loss, type A tympanograms, and negative Gelle's tests. The respective radiological reports of the status of the ossicles via 3 protocols were compared to surgical findings. The quantitative assessments of the representation of different segments of the ossicular chain were based on a 3-point scoring system.Results: MPR and CTVR imaging both showed the integrity of whole ossicular chain well. MPR and CTVR imaging were found to be superior to section planes with respect to showing the superstructure of the stapes and malformations(P > 0.05).Conclusion: CTVR and MPR imaging were found to be better able to show the whole ossicular chain in the conductive hearing loss with normal tympanic membranes. Furthermore, the use of these techniques can have profound contributive value in the differential diagnosis of otosclerosis and ossicular chain absence or malformation.

Stress Concentration Factors at Saddle and Crown Positions on the Central Brace of Two-Planar Welded CHS DKT-connections

A set of parametric stress analyses was carried out for two-planar tubular DKT-joints under different axial loading conditions. The analysis results were used to present general remarks on the effects of the geometrical parameters on stress concentration factors （SCFs） at the inner saddle, outer saddle, and crown positions on the central brace. Based on results of finite element （FE） analysis and through nonlinear regression analysis, a new set of SCF parametric equations was established for fatigue design purposes. An assessment study of equations was conducted against the experimental data and original SCF database. The satisfaction of acceptance criteria proposed by the UK Department of Energy （UK DoE） was also checked. Results of parametric study showed that highly remarkable differences exist between the SCF values in a multi-planar DKT-joint and the corresponding SCFs in an equivalent uni-planar KT-joint having the same geometrical properties. It can be clearly concluded from this observation that using the equations proposed for uni-planar KT-connections to compute the SCFs in multi-planar DKT-joints will lead to either considerably under-predicting or over-predicting results. Hence, it is necessary to develop SCF formulae specially designed for multi-planar DKT-joints. Good results of equation assessment according to UK DoE acceptance criteria, high values of correlation coefficients, and the satisfactory agreement between the predictions of the proposed equations and the experimental data guarantee the accuracy of the equations. Therefore, the developed equations can be reliably used for fatigue design of offshore structures.

Application of the multi-planar reconstruction in endovascular treatment of type B aortic dissection

Background Although Multi-planar reconstruction （MPR） has been considered a diagnostic imaging technique that observes more perspectives for diseases,few people have applied it surgically.In fact,MPR is also very useful to clinical operation,especially for patients with type B aortic dissection.It helps the surgeon to locate accurately with more information about aortic dissection,so that the safety and effectiveness of operation can be improved.This study examined the application of the MPR in intraoperative DSA imaging for precise positioning by accurately obtaining a crosssection,a spin angle of the coronal plane,and a tilt angle of the sagittal plane in treatment of type B aortic dissection.Methods The conventional and the MPR approaches were compared on positioning the aortic arch for surgery.A group of 40 patients （group A） and another group of 42 patients （group B） was sampled.About the comparison of baseline characteristics,a fourfold table X2 test was conducted on gender,and two independent samples t-test was applied to age between group A and group B.Spin as well as tilt angles for group A were obtained from the patients using both approaches,and their effectiveness was compared with pair t-tests; The MPR data guided stent-grafting in this group.Stent graft placement of group B was based on the conventional approach.Percentages of proximal distributed markers as well as incidences of complications were collected from both groups after stent graft placement.They were also compared with a fourfold table X2 test.Results Gender difference was not found between group A and group B （X2=0.80,P ＞0.05）,and age difference was not statistically significant （F=2.55,homogeneity of variance,t=-1.46,P ＞0.05）.A significant difference was found between the conventional and the MPR approaches for spin angle （t=9.17） as well as tilt angle （t=-2.07）,P ＜0.05.Percentage of proximal distributed markers （5.0％） of group A was significantly lower than that of group B （42.9％）,X2=15.92,P ＜0.05;and incidence of complications （5.0％） of group A was also significant lower than that of group B （21.4％）,X2=4.76,P ＜0.05.Conclusions Application of the MPR facilitated intraoperative angle adaption and led to satisfactory DSA.It is feasible in endovascular treatment of type B aortic dissection,and can effectively and safely guide surgical operations.