乳腺肿块^99mTc—MIBI显像规律与其组织病理学关系的初步探讨

为探讨９９ｍＴｃ甲氧基异丁基异腈（ＭＩＢＩ）乳腺显像诊断乳腺癌的临床价值及不同组织病理学特点的显像规律，对８４例乳腺肿块患者行９９ｍＴｃＭＩＢＩ显像检查。肘静脉“弹丸”式注射９９ｍＴｃＭＩＢＩ７４０～９２５ＭＢｑ，动态采集血流相、血池相、５分钟早期摄取相及６０、１２０分钟延迟相图像，并计算病变的早、晚期摄取比值。结果表明：乳腺病变显像特点随组织病理学类型不同而有明显差别。４３例乳腺癌中３７例诊断为阳性，６例假阴性；４１例良性病变中３例有放射性浓集。此法检出乳腺癌的灵敏度、特异性分别为８６０５％和９２６８％。因此，９９ｍＴｃＭＩＢＩ显像对鉴别乳腺良、恶性病变具有重要临床应用价值，但对癌细胞密度低的恶性肿瘤，如硬癌及有多发性坏死而血供不良的恶性肿瘤诊断效果不佳。     

^99mTc—DTPA雾化吸入检测肺泡清除功能及初步分析

为探讨检测肺泡清除功能的方法以及肺泡清除功能变化的可能机理，应用９９ｍＴｃＤＴＰＡ雾化吸入２～３分钟后，启动γ相机连续动态采集３０分钟，以前５分钟的曲线斜率为Ｋ１，５分钟后的曲线斜率为Ｋ２。结果：正常对照组的时间放射性曲线为单室模型曲线，Ｙ＝Ａｅ－ｋｔ，在半对数坐标上为近似斜线，Ｋ１＝（９０８±４７９）×１０－３，Ｋ２＝（７３５±３２５）×１０－３（ｘ±ｓ）；吸烟、甲亢和哮喘组的Ｋ１、Ｋ２均高于正常（ｔ值３１６４～１０２３０，Ｐ＜００１），为双室或三室以上的多室模型曲线。结果表明：上肺与中肺的Ｋ１有显著差异，Ｋ１是一个灵敏指标。各病变组呼吸膜改变的主要原因是肺泡上皮或毛细血管内皮受损所致。     

Vessel enhancement filtering in three-dimensional MR angiograms using long-range signal correlation

Small vessels in three-dimensional MR angiograms have low visibility in maximum-intensity projection images because of their low contrast. In a previous study, we had two nonlinear filters that appeared to give significant improvement in small vessel detail. In this paper, we report on a generalization of this filter that allows a more general modeling of the vessels and a more complete suppression of background. One implementation of the general filter gave a vessel mean contrast-to-noise ratio that is 2.52 and 3.51 times higher than the vessel mean contrast-to-noise ratio obtained using our previously reported maximum-minimum (max-min) filter and cross- section filter, respectively.     

Ultrashort TE spectroscopic imaging (UTESI): Application to the imaging of short T2 relaxation tissues in the musculoskeletal system

Purpose

To investigate ultrashort TE spectroscopic imaging (UTESI) of short T2 tissues in the musculoskeletal (MSK) system.

Materials and Methods

Ultrashort TE pulse sequence is able to detect rapidly decaying signals from tissues with a short T2 relaxation time. Here a time efficient spectroscopic imaging technique based on a multiecho interleaved variable TE UTE acquisition is proposed for high‐resolution spectroscopic imaging of the short T2 tissues in the MSK system. The projections were interleaved into multiple groups with the data for each group being collected with progressively increasing TEs. The small number of projections in each group sparsely but uniformly sampled k‐space. Spectroscopic images were generated through Fourier transformation of the time domain images at variable TEs. T2* was quantified through exponential fitting of the time domain images or line shape fitting of the magnitude spectrum. The feasibility of this technique was demonstrated in volunteer and cadaveric specimen studies on a clinical 3T scanner.

Results

UTESI was applied to six cadaveric specimens and four human volunteers. High spatial resolution and contrast images were generated for the deep radial and calcified layers of articular cartilage, menisci, ligaments, tendons, and entheses, respectively. Line shape fitting of the UTESI magnitude spectroscopic images show a short T2* of 1.34 ± 0.56 msec, 4.19 ± 0.68 msec, 3.26 ± 0.34 msec, 1.96 ± 0.47 msec, and 4.21 ± 0.38 msec, respectively.

Conclusion

UTESI is a time‐efficient method to image and characterize the short T2 tissues in the MSK system with high spatial resolution and high contrast. J. Magn. Reson. Imaging 2009;29:412–421. © 2009 Wiley‐Liss, Inc.

     

128层CT灌注成像在脑胶质瘤分级的应用价值

目的探讨128层CT全脑灌注成像在脑胶质瘤术前分级的应用价值。方法回顾性分析32例脑胶质瘤病例资料,低级别组(WHOⅠ~Ⅱ级,21例)和高级别组(WHOⅢ~Ⅳ级,11例),均行CT灌注扫描,测量肿瘤实质部分和对侧正常脑组织的CBF、CBV及r CBF、r CBV。结果与低级别组比较,高级别组胶质瘤病灶区CBF、CBV及r CBF、r CBV均明显升高,两组间差异具有统计学意义(P0.05)。结论 128层CT灌注成像在胶质瘤术前分级具有较高的临床应用价值。     

Optimal concentration and time window for proliferation and differentiation of neural stem cells from embryonic cerebral cortex: 5% oxygen preconditioning for 72 hours

Hypoxia promotes proliferation and differentiation of neural stem cells from embryonic day 12 rat brain tissue, but the concentration and time of hypoxic preconditioning are controversial. To address this, we cultured neural stem cells isolated from embryonic day 14 rat cerebral cortex in 5% and 10% oxygen in vitro. MTT assay, neurosphere number, and immunofluorescent staining found that 5% or 10% oxygen preconditioning for 72 hours improved neural stem cell viability and proliferation. With prolonged hypoxic duration(120 hours), the proportion of apoptotic cells increased. Thus, 5% oxygen preconditioning for 72 hours promotes neural stem cell proliferation and neuronal differentiation. Our findings indicate that the optimal concentration and duration of hypoxic preconditioning for promoting proliferation and differentiation of neural stem cells from the cerebral cortex are 5% oxygen for 72 hours.     

Intercellular mitochondrial transfer in the brain,a new perspective for targeted treatment of central nervous system diseases

Aim

Mitochondria is one of the important organelles involved in cell energy metabolism and regulation and also play a key regulatory role in abnormal cell processes such as cell stress, cell damage, and cell canceration. Recent studies have shown that mitochondria can be transferred between cells in different ways and participate in the occurrence and development of many central nervous system diseases. We aim to review the mechanism of mitochondrial transfer in the progress of central nervous system diseases and the possibility of targeted therapy.

Methods

The PubMed databank, the China National Knowledge Infrastructure databank, and Wanfang Data were searched to identify the experiments of intracellular mitochondrial transferrin central nervous system. The focus is on the donors, receptors, transfer pathways, and targeted drugs of mitochondrial transfer.

Results

In the central nervous system, neurons, glial cells, immune cells, and tumor cells can transfer mitochondria to each other. Meanwhile, there are many types of mitochondrial transfer, including tunneling nanotubes, extracellular vesicles, receptor cell endocytosis, gap junction channels, and intercellular contact. A variety of stress signals, such as the release of damaged mitochondria, mitochondrial DNA, or other mitochondrial products and the elevation of reactive oxygen species, can trigger the transfer of mitochondria from donor cells to recipient cells. Concurrently, a variety of molecular pathways and related inhibitors can affect mitochondrial intercellular transfer.

Conclusion

This study reviews the phenomenon of intercellular mitochondrial transfer in the central nervous system and summarizes the corresponding transfer pathways. Finally, we propose targeted pathways and treatment methods that may be used to regulate mitochondrial transfer for the treatment of related diseases.