肛管和肛周尖锐湿疣中人乳头状瘤病毒的检测及意义

将３２例肛管和肛周尖锐湿疣进行Ａｐｇａｒ评分和凹空细胞分型，应用聚合酶链反应和免疫组化技术检测ＨＰＶ抗原和ＤＮＡ，并观察ＨＰＶ在尖锐湿疣组织中的分布状况。结果发现Ａ型１４例，Ｂ型１８例，Ａ型与高积分尖锐湿疣的关系较Ｂ型密切。ＰＣＲ和免疫组化检测阳性率分别为２５％（８／３２）和２２％（７／３２）。我们发现在尖锐湿疣组织中，不论是否是凹空细胞或凹空细胞分型如何及Ａｐｇａｒ积分高低，均有ＨＰＶ分布，但阳性率不同。这表明在正确诊断尖锐湿疣时，凹空细胞核形态、组织学改变和特殊检测三者各起作用并彼此相关。本文还探讨了浆膜型抗原发生机制。     

Prostate cancer: added value of subtraction dynamic imaging in 3T magnetic resonance imaging with a phased-array body coil

Purpose

To determine the added value of dynamic subtraction magnetic resonance (MR) imaging for the localization of prostate cancer.

Materials and Methods

We examined 21 consecutive patients who underwent MR imaging in 3T unit with a phased-array body coil and then had radical prostatectomy. After T2-weighted fast spin-echo imaging, we performed a contrast-enhanced dynamic 3D gradient-echo imaging consisting of pre-contrast, 2 successive early-phased (first imaging was started just after the appearance of contrast material in the aortic bifurcation followed by second imaging 35 seconds after the initiation of first imaging) and one 5-minute delayed post-contrast series. Subtraction of pre-contrast images from corresponding post-contrast images of each phase was performed on the console.

Results

On ROC analysis, the overall accuracy (A_z value) of dynamic imaging combined with subtraction imaging was higher than T2-weighted imaging (p = 0.001) or conventional dynamic imaging alone (p = 0.074) for localization of cancer foci regardless of their zonal locations. Among pathologically verified 81 lesions, the mean volume of detected lesions with the subtraction images (n = 49, 0.69 cm³) was smaller than with T2-weighted images (n = 14, 1.05 cm³) or conventional dynamic images (n = 43, 0.71 cm³).

Conclusion

For localization of small prostate cancer, additional subtraction for the dynamic imaging could be superior to both T2-weighted imaging and un-subtracted dynamic imaging.     

Comparison of pelvic phased-array versus endorectal coil magnetic resonance imaging at 3 Tesla for local staging of prostate cancer

Purpose

Several studies have demonstrated the superiority of endorectal coil magnetic resonance imaging (MRI) over pelvic phased-array coil MRI at 1.5 Tesla for local staging of prostate cancer. However, few have studied which evaluation is more accurate at 3 Tesla MRI. In this study, we compared the accuracy of local staging of prostate cancer using pelvic phased-array coil or endorectal coil MRI at 3 Tesla.

Materials and Methods

Between January 2005 and May 2010, 151 patients underwent radical prostatectomy. All patients were evaluated with either pelvic phased-array coil or endorectal coil prostate MRI prior to surgery (63 endorectal coils and 88 pelvic phased-array coils). Tumor stage based on MRI was compared with pathologic stage. We calculated the specificity, sensitivity and accuracy of each group in the evaluation of extracapsular extension and seminal vesicle invasion.

Results

Both endorectal coil and pelvic phased-array coil MRI achieved high specificity, low sensitivity and moderate accuracy for the detection of extracapsular extension and seminal vesicle invasion. There were statistically no differences in specificity, sensitivity and accuracy between the two groups.

Conclusion

Overall staging accuracy, sensitivity and specificity were not significantly different between endorectal coil and pelvic phased-array coil MRI.     

基于目标场法和CST仿真的低场磁共振射频线圈设计

根据临床对人体肺部磁共振成像的需要,设计一种用于肺部0.06 T低场磁共振成像的3He射频线圈。通过预先设定感兴趣区域（ROI）及其内部的目标磁场,运用目标场法逆向求解ROI内产生目标磁场所需的源电流密度分布,流函数获取射频线圈理想绕组。然后利用CST软件建模简化线圈绕组,场路协同仿真研究负载射频线圈在不同品质因数（Q值）下的射频场B1和特定吸收率（SAR）分布等性能指标。仿真实验结果表明,通过改变射频电路的电容值可调整线圈的Q值,线圈Q值越大,单位功率信号激励下产生的B1场强越高,SAR值越高,传输效率越低,而B1场均匀性不受影响,一直保持在近90%。通过射频线圈仿真,验证了目标场法联合CST仿真设计方法的可行性,可推广至高频射频线圈设计。     

A review on brain structures segmentation in magnetic resonance imaging

Background and objectivesAutomatic brain structures segmentation in magnetic resonance images has been widely investigated in recent years with the goal of helping diagnosis and patient follow-up in different brain diseases. Here, we present a review of the state-of-the-art of automatic methods available in the literature ranging from structure specific segmentation methods to whole brain parcellation approaches.MethodsWe divide first the algorithms according to their target structures and then we propose a general classification based on their segmentation strategy, which includes atlas-based, learning-based, deformable, region-based and hybrid methods. We further discuss each category's strengths and weaknesses and analyze its performance in segmenting different brain structures providing a qualitative and quantitative comparison.ResultsWe compare the results of the analyzed works for the following brain structures: hippocampus, thalamus, caudate nucleus, putamen, pallidum, amygdala, accumbens, lateral ventricles, and brainstem. The structures on which more works have focused on are the hippocampus and the caudate nucleus. In general, the accumbens (0.69 mean DSC) is the most difficult structure to segment whereas the structures that seem to get the best results are the brainstem, closely followed by the thalamus and the putamen with 0.88, 0.87 and 0.86 mean DSC, respectively. Atlas-based approaches achieve good results when segmenting the hippocampus (DSC between 0.75 and 0.90), thalamus (0.88–0.92) and lateral ventricles (0.83–0.93), while deformable methods perform good for caudate nucleus (0.84–0.91) and putamen segmentation (0.86–0.89).ConclusionsThere is not yet a single automatic segmentation approach that can emerge as a standard for the clinical practice, providing accurate brain structures segmentation. Future trends need to focus on combining multi-atlas methods with learning-based or deformable approaches. Employing atlases to provide spatial robustness and modeling the structures appearance with supervised classifiers or Active Appearance Models could lead to improved segmentation results.     

Examination of joint space by magnetic resonance imaging in anatomically normal knees

The medial and lateral knee joint spaces of 184 patients who had anatomically normal knees were measured by using magnetic resonance imaging (MRI) method. The findings were compared according to age, sex, height, and body mass index changes of the individuals and the mean values of medial and lateral knee joint spaces were calculated in every group. The results show that in an anatomically normal population, all the individuals have larger lateral knee joint spaces than medial knee joint spaces. The patients lose knee joint space regularly with increasing age. Children have larger knee joint spaces than adults. Men have larger knee joint spaces than women. The knee joint space size of the patients increase regularly with increasing height up to 180 cm. The patients, who are taller than 180 cm do not show any marked difference in joint space size, when compared with the patients whose heights differ in between 171–180 cm. Knee joint space size is not related to the body mass index of the individual. © 1996 Wiley-Liss, Inc.     

正常人与青少年特发性脊柱侧凸患者椎弓根磁共振对比

目的:应用MRI成像技术对正常人与青少年特发性脊柱侧凸(AIS)患者椎弓根的不对称性进行对比分析,评价AIS患者是否表现出一致的形态学特点。方法:分析8位正常人的76个椎弓根和10例AIS早期患者的80个椎弓根的MRI成像。测定并比较正常人和AIS早期患者椎弓根不对称的程度和方向。结果:正常人表现出椎弓长度的不对称,左侧椎弓根和椎板长度较长,差异无统计学意义。AIS患者也表现出不对称,两者相比后者的不对称性更明显并有统计学意义。AIS患者的这种椎弓根不对称在侧凸凸侧和凹侧之间没有一致的分布。结论:研究AIS椎骨形态学的标准应该重新考虑,AIS椎骨形态不对称的类型依赖于特定的病因。     

Utility of gradient recalled echo magnetic resonance imaging for the study of myelination in cuprizone mice treated with fingolimod

The availability of high‐field‐strength magnetic resonance imaging (MRI) systems has brought about the development of techniques that aim to map myelination via the exploitation of various contrast mechanisms. Myelin mapping techniques have the potential to provide tools for the diagnosis and treatment of diseases, such as multiple sclerosis. In this study, we evaluated the sensitivity of T₂*, frequency shift and susceptibility measures to myelin levels in a cuprizone mouse model of demyelination. The model was supplemented with two different dosages of fingolimod, a drug known to positively affect demyelination. A decrease in grey–white matter contrast with the cuprizone diet was observed for T₂*, frequency shift and susceptibility measures, together with myelin basic protein antibody findings. These results indicate that T₂*, frequency shift and susceptibility measures have the potential to act as biomarkers for myelination. Susceptibility was found to be the most sensitive measure to changes in grey–white matter contrast. In addition, fingolimod treatment was found to reduce the level of demyelination, with a larger dosage exhibiting a greater reduction in demyelination for the in vivo MRI results. Overall, susceptibility mapping appears to be a more promising tool than T₂* or frequency shift mapping for the early diagnosis and treatment of diseases in which myelination is implicated.     

Predictors of panic symptoms during magnetic resonance imaging scans

This study examined the usefulness of a score derived from nine items of Wolpe and Lang’s (1964) Fear Survey Schedule (FSS) in predicting the number of symptoms consistent with panic reported by a large outpatient sample undertaking magnetic resonance imaging (MRI) scans. The items were those identified by Lukins, Davan, and Drummond (1997) as likely to reflect fears associated with the aversive characteristics of the MRI procedure (i.e., noise, confinement, and isolation) and were taken 1 week before the scan. The MRI-related FSS score was a better predictorof symptoms consistent with panic attack during the scan than (a) Rachman and Taylor’s (1993) Claustrophobia Questionnaire, (b) a score derived from nine FSS items reflecting common community fears, or (c) a measure of state anxiety. It is suggested that the brief MRI-related FSS scale can provide information important for planning patient management during MRI scans at a time when the information can be most useful.     

基于双模态磁共振成像和决策层融合的抑郁症辅助诊断

本研究提出一种基于结构和功能双模态磁共振成像数据融合的抑郁症分类算法,首先利用功能脑网络和深度学习网络分别提取功能和结构磁共振成像数据特征,并计算类概率,然后使用软投票法和加权投票法在决策层对两种类概率数据进行融合,充分提取功能与结构磁共振成像的数据信息,得到更加准确的分类效果。试验结果表明,数据融合方法可以显著提高抑郁症分类效果,获得91.34%的准确率和96.62%的召回率,更好地实现了抑郁症的辅助诊断与预后。