完全植入式静脉输液港术后港体翻转临床分析

目的探讨完全植入式静脉输液港(TIVAP)术后港体翻转的发生原因、确诊方法、处理措施及预防策略。方法回顾性分析2015年12月至2018年10月428例接受TIVAP植入术患者临床资料。记录术后港体翻转率、发生时间、原因分析和处理措施。结果428例患者术中港体均未缝合固定,术后6例发生港体翻转,均经影像学检查证实,港体翻转率为1.4%(6/428)。其中男2例,女4例;年龄55~71岁,平均(65.0±6.3)岁。术后23~451 d出现港体翻转,2例考虑与皮下组织过剩/疏松相关,1例考虑为囊袋尺寸过大,其余3例原因不明。处理措施:单纯手法复位3例,囊袋内注射0.9%氯化钠溶液后手法复位1例,囊袋内注射0.9%氯化钠溶液手法复位失败后切开复位1例,直接切开复位1例。结论TIVAP植入术后港体翻转发生率低,易于确诊和复位,因此没有必要常规缝合固定港体。建议选择宽基底、凸缘设计港体。港体翻转原因尚需进一步研究探讨。     

半剂量增强三维容积液体衰减翻转恢复序列诊断脑转移瘤的价值

目的探讨在半剂量（0．05mmol／kg体质量）MR对比剂条件下,三维容积液体衰减翻转恢复（3D-T2FLAIR）序列诊断脑转移瘤的价值。方法对49例临床疑诊脑转移瘤患者行半剂量增强三维容积扰相梯度回波（3D-SPGR＋Chalf）序列、半剂量增强3D-T2FLAIR（3D-T2FLAIR＋Chalf）序列和常规剂量增强3D-SPGR（3D-SPGR＋C）序列图像采集。共14例（104个病灶）最终诊断为脑转移,比较3D-SPGR＋Chalf、3D-T2FLAIR＋Chalf、3D-SPGR＋C序列图像所显示的病灶对比度比（CR）值、最短径值及病灶数目。结果3D-T2FLAIR＋Chalf序列图像中,脑转移病灶的CR值、最短径值及所检出的最短径〈5mm的病灶数目均显著高于3D-SPGR＋C序列、3D-SPGR＋Chalf序例。对检出最短径≥5mm的病灶,3D-SPGR＋Chalf序列明显少于3D-T2FLAIR＋Chalf,而3D-T2FLAIR＋Chalf与3D-SPGR＋C序列无明显差异。结论半剂量增强3D-T2FLAIR序列对诊断脑转移瘤具有重要临床应用价值。     

预先吸入不同浓度富氧气体对急性低压缺氧暴露的生理影响

通过人体急性暴露到低氧性缺氧环境和动物高空迅速减压实验，观察了预先吸入模拟分子筛产氧系统不同富氧浓度的气体对应急减压瞬间的生理影响。模拟暴发性缺氧实验结果表明，当预先供氧浓度低于60％，在暴露到暴发性缺氧环境10s内出现缺氧反应，而高于70％供氧浓度时未出现缺或变化；动物高空迅速减压缩果进一步表明，减压前预先吸入氧浓度为70％～100％，在迅速减压瞬间的生理反应是等效的，吸入各种富氧浓度气体与纯氧之间的血氧饱和度及静脉氧分压光明显差别（P＞0.05），但与迅速减压前呼吸空气（21％氧）的结果之间有显著的差别（P＜0．05）。高空迅速减压时氧自体内向外界的反向弥散有两个过程，它与减压瞬间生理效应和有效意识时间有密切关系。此结果为机教分子筛氧气系统的研制与应用提供了生理依据。     

A haemophilia A and B molecular genetic diagnostic programme in Hungary: a highly informative and cost-effective strategy

Our aim was to set up a protocol in order to provide carrier and prenatal diagnosis to Hungarian haemophilia A (HA) and B (HB) patients and their relatives. For HA, a combination of direct mutation detection and some indirect marker analyses were used: the detection of the inversion mutation and analysis of three polymorphisms, BclI, IVS13 (CA)n and P39(CA)n. In severe cases, direct mutation detection was performed first. In inversion-negative severe cases and in moderate and mild cases, indirect methods were used. For carrier and prenatal diagnosis in HB, four polymorphisms, DdeI, TaqI, XmnI, and HhaI were examined. Our DNA bank contains samples from 50 HA families (34 severe, 15 moderate and one mild) and seven HB families from different parts of the country. In 100% of the HA cases either the gene inversion and/or at least one of the polymorphisms was found to be informative for carrier or prenatal diagnosis. In the HB cases, an informative marker was found in 95% of the cases (19 of 20). We conclude that these strategies are sufficient to make genetic diagnosis available to almost all HA and HB families in the region. This approach is highly informative and cost-effective, so it can be very useful in countries where direct sequencing of genes for factor VIII and IX is not available for routine diagnosis.     

FLAIR血管内高信号在急性后循环多发性脑梗死中的临床意义

目的探讨核磁共振液体衰减反转恢复(FLAIR)序列血管内高信号(FVH)在急性后循环多发性脑梗死中的临床意义。方法收集2013年1月~2015年10月在我科住院的后循环脑梗死患者62例,其中多发性脑梗死患者28例,单发脑梗死患者34例。均行头部MRI检查,包括磁共振弥散加权像(DWI)、T_1加权像和FLAIR序列。比较两组患者的一般资料、常见脑血管病危险因素、实验室检查及影像学资料。采用Logistic回归分析后循环多发性脑梗死相关的危险因素。进一步探讨FVH的产生机制。结果后循环多发性脑梗死组与单发脑梗死组在性别、年龄、高血压、糖尿病、胆固醇、甘油三酯、低密度脂蛋白、心律失常、吸烟等方面差异无统计学意义(P0.05)。与后循环单发脑梗死比较,多发性脑梗死组FVH更多见、严重程度更高(P0.001)。Logistic回归分析显示FVH为后循环多发性脑梗死的独立危险因素(OR值1)。结论 FLAIR序列血管内高信号可作为后循环多发性脑梗死的参考征象,预示后循环严重狭窄。     

Background suppression in arterial spin labeling MRI with a separate neck labeling coil

In arterial spin labeling (ASL) MRI to measure cerebral blood flow (CBF), pair-wise subtraction of temporally adjacent non-labeled and labeled images often can not completely cancel the background static tissue signal because of temporally fluctuating physiological noise. While background suppression (BS) by inversion nulling improves CBF temporal stability, imperfect pulses compromise CBF contrast. Conventional BS techniques may not be applicable in small animals because the arterial transit time is short. This study presents a novel approach of BS to overcome these drawbacks using a separate 'neck' radiofrequency coil for ASL and a 'brain' radiofrequency coil for BS with the inversion pulse placed before spin labeling. The use of a separate 'neck' coil for ASL should also improve ASL contrast. This approach is referred to as the inversion-recovery BS with the two-coil continuous ASL (IR-cASL) technique. The temporal and spatial contrast-to-noise characteristics of basal CBF and CBF-based fMRI of hypercapnia and forepaw stimulation in rats at 7 Tesla were analyzed. IR-cASL yielded two times better temporal stability and 2.0-2.3 times higher functional contrast-to-noise ratios for hypercapnia and forepaw stimulation compared with cASL without BS in the same animals. The Bloch equations were modified to provide accurate CBF quantification at different levels of BS and for multislice acquisition where different slices have different degree of BS and residual degree of labeling. Improved basal CBF and CBF-based fMRI sensitivity should lead to more accurate CBF quantification and should prove useful for imaging low CBF conditions such as in white matter and stroke.