低剂量CT血流灌注成像对阿尔茨海默病的诊断价值

目的 评价低剂量CT血流灌注成像对阿尔茨海默病(Alzheimer's disease,AD)的诊断价值.方法 根据临床诊断标准随机选择52例AD和30例健康对照组.对他们进行低剂量血流灌注扫描(CTPI),并在工作站上进行处理,生成伪彩图及进行灌注参数测量,灌注参数包括脑血容量(cerebral blood volume,CBV)、脑血流量(cerebral blood flow,CBF)、平均通过时间(mean transit time,MTT)和达峰时间(time to peak,TTP).选择双侧额叶皮质、双侧颞叶皮质、双侧海马、双侧基底节区域进行测量.结果 健康对照组的双侧额叶、颞叶、基底节和海马CBV、CBF值明显高于AD组,而AD组上述部位的MTT和TTP明显大于健康对照组,有统计学意义(P＜0.05).结论 AD患者伴有微循环障碍和缺血改变.低剂量CT灌注对AD的诊断有一定意义.     

CT灌注成像短期评估烟雾病行脑血管重建术的血运重建疗效

目的 探讨CT灌注成像(CTP)技术检验接受脑血管重建术的烟雾病患者手术疗效。方法 28例烟雾病患者接受脑血管重建术(颞浅动脉-大脑中动脉搭桥术联合脑-硬膜-颞肌贴敷术)等方法,手术前后分别行CTP检查。在手术前后分别测量并比较患者术侧灌注参数的绝对值、术侧与对侧镜像区灌注参数的相对值,对比分析脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)、达峰时间(TTP)。结果 28例烟雾病患者桥血管均显示通畅,CTP术侧灌注参数中比较后CBF(颞叶和顶叶)、CBV(额叶、颞叶、顶叶)、MTT(顶叶)、TTP(额叶、颞叶、顶叶)存在统计学意义(P<0.05)。术侧比镜像对照区的rCBF(颞叶)、rMTT(顶叶)、rTTP(顶叶)存在统计学意义(P<0.05)。结论 手术干预后,烟雾病患者的脑血流重建有所改善,特别是在严重的灌注受损患者中。因此,CTP不仅能反映脑微循环信息的功能成像,有助于判断烟雾病脑缺血的部位、严重程度、选择手术侧别和手术方式,更能快速了解术后缺血情况是否得到改善,可作为检验手术疗效的重要检测方法。     

成人原发性甲状腺功能减退症的脑血流灌注显像特征

目的 观察成人原发性甲状腺功能减退症(甲减)患者局部脑血流(rCBF)显像特点,以探索甲减致脑中枢神经系统损害的机制.方法 对15例正常对照组及45例甲减患者分别进行了脑SPECT显像.结果 45例成人甲减患者rCBF减低为91.11%(41/45例),正常为8.89%.20%的甲减患者脑血流灌注出现弥漫性减低,71.11%的患者出现局灶性减低.病变累及的部位主要是颞叶和额叶,其中额叶异常18例(56.25%);颞叶异常31例(96.88%);顶叶异常9例(28.13%);枕叶异常5例(15.63%),基底节异常11例(34.38%).临床甲减组双侧额叶、颞叶、顶叶、基底节及右侧枕叶rCBF明显低于对照组(P《0.01或0.05).亚临床甲减组双侧颞叶、左侧额叶及左侧基底节rCBF也明显低于对照组(P《0.01或0.05).甲减组的额叶、颞叶R/L比值与对照组比较有显著差异(P《0.01).结论 成人原发性甲减患者存在不同程度的脑血流灌注减低,这与其引起的神经精神方面症状可能密切相关,并对指导临床治疗有积极意义.     

低剂量脑CT灌注成像联合IMR的图像质量评价

目的 探讨低剂量脑CT灌注成像(CTPI)联合全模型迭代重组(IMR)技术临床应用的可行性.方法 收集因临床怀疑急性脑梗死行脑CTPI检查的患者80例.A组35例, B组45例.A、B组分别采用80 kV,150 mAs+传统滤波反投影(FBP)及80 kV,30 mAs+IMR重建.选取A、B 组脑灌注正常的一侧脑各30侧.比较2组图像主观评分、有效剂量(ED)和阿尔伯塔脑卒中计划早期CT评分层面2(ASPECTS2)水平大脑中动脉供血区灰白质的CT值、图像噪声(SD)、信噪比(SNR)、对比噪声比(CNR)以及灌注参数值.结果 A、B 2组ED分别为2.52、0.50 mSv;2组灰白质的灌注参数、CT值、SD,CNR,灰质SNR及主观评分之间无明显统计学差异(P>0.05);2组白质SNR存在明显统计学差异(P<0.05).结论 IMR联合30 mAs的CTPI在保证图像质量和灌注参数稳定的前提下明显降低辐射剂量.     

多系统萎缩弥散张量成像的基于体素分析

目的 利用基于体素的分析方法对震颤麻痹型多系统萎缩(MSA-P)患者的弥散张量成像(DTI)数据进行研究,探索其脑内微结构改变.资料与方法 入组24例MSA-P患者(病例组)及26例健康志愿者(对照组),分别行全脑结构成像及弥散张量成像.比较两组各向异性分数(FA)图和平均扩散率(MD)图,得出反映病例组与对照组差异的统计参数图.结果 与对照组相比,病例组FA值减低累及双侧脑干、小脑半球、岛叶、顶叶、额叶、颞叶及枕叶,差异有统计学意义(P＜0.005),其中白质受累较灰质显著;MD值在双侧脑干、小脑半球、基底节、岛叶、额叶、颞叶及枕叶处较对照组升高,差异有统计学意义(P＜ 0.005).结论 DTI技术可以敏感地通过显示MSA-P患者脑内微结构的改变反映其受累情况,基于体素的分析方法有助于客观展示全脑受累情况.     

急性兔脑微栓塞模型的CT灌注成像研究

目的:建立稳定的兔脑微栓塞模型,探讨CT灌注成像(CTPI)技术对早期脑缺血的诊断价值.方法:30只健康新西兰种大白兔,随机分成2组,其中A组5只,为假手术对照组;B组25只,为微栓塞组.分离右侧颈部血管,经颈外动脉向颈内动脉注入直径约0.5mm的SiO2颗粒10枚,栓塞后30min行CTPI,分别测量灌注异常侧与正常对侧的CBF、CBV及MTT值.24h处死动物取脑组织行HE染色.利用SPSS11.0统计学软件进行CBF、CBV及MTT ROC曲线分析,评价各灌注参数诊断早期脑缺血的准确性.结果:A组CTPI及病理均未见明显异常.B组3只因实验意外死亡,1只因下肢静脉穿刺失败导致CTPI失败,21只行CTPI检查,其中18只CTPI异常,HE染色10只脑梗死,7只脑缺血,1只未见明显异常;3只CTPI未见明显异常,HE染色1只轻度脑缺血,2只未见明显异常.灌注异常主要表现为局部CBF降低、MTT延长、CBV无明显变化或轻度上升、下降,包括5只右侧额、颞叶片状低灌注;4只右侧额叶、颞叶、基底节及小脑片状低灌注;7只右侧颞叶小片低灌注;2只双侧额颞叶小片低灌注.灌注异常侧与正常对侧CBF值、MTT值比较差异有统计学意义,CBV值差异无统计学意义.ROC曲线分析提示CBF＜ 67.06ml/(min·100g)、CBV＜ 3.08ml/100g、MTT＞ 4.58s,诊断早期脑缺血的灵敏度和特异度分别为84.6％、74.4％、87.2％.结论:CBF、MTT诊断早期脑缺血具有较高的准确性,CTPI技术可以准确、无创地反映兔脑微栓塞模型的血流动力学变化.     

多体素^1H MRS测定正常脑组织不同区域的代谢物分布

目的: 测定正常人脑组织不同部位代谢物浓度、计算其比值.材料和方法: 用多体素磁共振质子波谱PRESS序列测定100例正常脑组织的额叶、颞叶、顶叶、枕叶、基底节区和小脑代谢物浓度,观察NAA、Cho、Cr的波峰特点,计算和分析NAA/Cr、Cho/Cr、NAA/Cho的比值.结果: 正常脑实质的1H波谱Levene方差分析显示额叶、颞叶、顶叶、枕叶、基底节区和小脑的NAA/Cr(P<0.000)和NAA/Cho(P=0.001)有显著差异,Cho/Cr在上述各部位的浓度无显著差异(P=0.068).进一步用Bonferroni方差分析比较各组间显著差异性显示小脑NAA/Cr低于额叶、顶叶、枕叶的NAA/Cr(P值分别<0.05,<0.01,<0.05),小脑NAA/Cho低于顶叶、枕叶的NAA/Cho(P均<0.01),而额叶、颞叶、顶叶、枕叶、基底节区之间NAA/Cr、NAA/Cho无显著差异.结论: 多体素1H MRS可以测定NAA/Cr、Cho/Cr、NAA/Cho浓度比值,不同解剖部位代谢物浓度不尽相同,为颅脑代谢异常提供参考标准.     

不同管电流对正常颅脑CT灌注参数和辐射剂量的影响

目的分析管电流与正常颅脑各灌注参数及图像质量之间的关系,探讨低电流颅脑CT灌注扫描的可行性。资料与方法 2010年7月至2011年5月所有拟行颅脑CT灌注检查的受检者,按管电流随机分为A组(常规剂量组)(200 mA),B组(150 mA),C组(120 mA),D组(100 mA)不同管电流进行扫描,每组筛选10例无颅脑疾病者进行研究。在额叶、颞叶及小脑白质对称各选取3个感兴趣区,分别测量脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)和达峰时间(TTP),噪声(SD)及辐射剂量(E),计算对比度噪声比(CNR)、变异系数(CV)及信噪比(SNR),并对各参数进行统计学分析,记录各组辐射剂量。结果各兴趣区各项灌注参数在4组间比较差异无统计学意义。在4组间两两比较结果显示,A组与D组额叶、颞叶、小脑CBF及额叶、颞叶CBV组间两两比较差异有统计学意义,A组与C组颞叶CBF及额叶CBV组间两两比较差异有统计学意义,A组与B组各项灌注参数组间两两比较差异无统计学意义。各组客观图像质量指标在4组间比较差异显著,而在4组间两两比较结果显示A组与B组CNR差异无统计学意义。随着电流的降低,CV、SD有升高趋势,SNR有降低趋势。A～D组的吸收剂量分别为2.39 mSv、1.79 mSv、1.43 mSv、1.2 mSv。结论以150 mA的低管电流行颅脑CT灌注扫描对灌注参数和图像质量无明显影响,与常规剂量组对比辐射剂量降低25%,可用于低剂量颅脑CT灌注扫描。     

Influence of Tube Current on CT Perfusion and Radiation Dose of Normal Head

目的 分析管电流与正常颅脑各灌注参数及图像质量之间的关系,探讨低电流颅脑CT灌注扫描的可行性.资料与方法 2010年7月至2011年5月所有拟行颅脑CT灌注检查的受检者,按管电流随机分为A组(常规剂量组)(200 mA),B组(150 mA),C组(120 mA),D组(100 mA)不同管电流进行扫描,每组筛选10例无颅脑疾病者进行研究.在额叶、颞叶及小脑白质对称各选取3个感兴趣区,分别测量脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)和达峰时间(TTP),噪声(SD)及辐射剂量(E),计算对比度噪声比(CNR)、变异系数(CV)及信噪比(SNR),并对各参数进行统计学分析,记录各组辐射剂量.结果 各兴趣区各项灌注参数在4组间比较差异无统计学意义.在4组间两两比较结果显示,A组与D组额叶、颞叶、小脑CBF及额叶、颞叶CBV组间两两比较差异有统计学意义,A组与C组颞叶CBF及额叶CBV组间两两比较差异有统计学意义,A组与B组各项灌注参数组间两两比较差异无统计学意义.各组客观图像质量指标在4组间比较差异显著,而在4组间两两比较结果显示A组与B组CNR差异无统计学意义.随着电流的降低,CV、SD有升高趋势,SNR有降低趋势.A～D组的吸收剂量分别为2.39 mSv、1.79 mSv、1.43 mSv、1.2 mSv.结论 以150 mA的低管电流行颅脑CT灌注扫描对灌注参数和图像质量无明显影响,与常规剂量组对比辐射剂量降低25％,可用于低剂量颅脑CT灌注扫描.     

慢性脑缺血患者脑血流动力学与脑代谢改变的影像学研究

目的 探讨慢性脑缺血患者影像学特点,评价其脑血流动力学与脑代谢之间的相关性.方法 对55例临床拟诊为慢性脑缺血的患者行常规头颅CT平扫和CT灌注(CTP)检查.以CTP图为参考,对出现脑灌注异常患者共43例行单体素质子磁共振波谱(1H-MRS)检查.测量灌注异常区与对侧脑组织血流动力学和代谢参数,分析两者之间的相关性.结果 55例慢性脑缺血患者中有43例发现脑灌注异常,CTP及1H-MRS显示病变侧平均通过时间(MTT)、达峰时间(TTP)较对侧明显延长,氮-乙酰天门冬氨酸∕肌酸(NAA/Cr)、氮-乙酰天门冬氨酸∕胆碱(NAA/Cho)较对侧降低,差异均有统计学意义(P＜0.01);脑血容量(CBV)、胆碱∕肌酸(Cho/Cr)高于对侧镜像区,差异有统计学意义(P＜0.05);脑血流量(CBF)较对侧略低,差异无统计学意义(P＞0.05);另外12例未见灌注异常.灌注异常区NAA/Cho与MTT、TTP均呈负相关(P＜0.01).结论 慢性脑缺血患者存在脑血流动力学和脑代谢的异常,脑代谢异常可在一定程度上反映脑血流动力学损害情况.     

The role of interventional radiology in trauma

Introduction Interventional Radiology has evolved into a specialty having enormous input into the care of the traumatized patient.In all hospitals,regardless of size,the Interventional Radiologist must consider their relationships with the trauma service in order to     

Sexual homicide: Brief review of the literature and case report involving rape,genital mutilation and human arson

The objective of the current paper is to report a new case of sexual murder involving human arson and summarize the literature on the phenomenon of sexual homicide. The present case study is unprecedented in Greece and a rarity in international literature due to the fact that the victim suffered genital mutilation and incineration while still alive. The evaluation consisted of 176 articles; 53 were reviewed by the authors. The results revealed sparse, but significant, research findings. The authors discuss the limitations regarding research, incidence of the phenomenon, crime-scene patterns, offender characteristics (killing methods, motive inferences, sociodemographic data, classifications, psychopathology, modus operandi), and victim selection. The incidence of the phenomenon is unclear (1–4%) due to non-standardized criteria. It is an expression of displaced anger or sexual sadism and/or a way to elude detection (ancillary benefit). Most offenders (in their first kill) and victims were in their late 20s to early 30s and belong to Caucasian populations. Personal weapons were commonly used against women, strangulation is the prevalent killing method against children, and firearms against men. Most of the sexual homicide perpetrators are non-psychotic at the time of the attack, but experience personality pathology, primitive defenses, pathological object relations, and withdrawal into fantasy in order to deal with social isolation.     

Extension du modèle puissance–temps limite pour estimer la production d’énergie aérobie et anaérobie lors de l’exercice intense

Aim

Examine how the modelling of the relation between power and time to exhaustion can provide an estimation of the production of aerobic and anaerobic energy during intense exercise.

Current knowledge

The hyperbolic model made it possible to define the critical power corresponding to the maximal rate of energy renewed by aerobic metabolism. A new model distinguishing the critical power from the maximal aerobic power has been built to estimate more precisely the anaerobic contribution. Data from middle distance runners and subjects tested on cycle ergometer showed a relative contribution of anaerobic metabolism arising from critical power and increasing until around 10 % of total power when aerobic energy production reaches its maximum.

Prospects

Considering the slow component of oxygen uptake would provide a more precise analysis of energy production and transformation during exercise at high intensity.     

Beziehungen zwischen Aufprallgeschwindigkeit,Fahrzeugbeschädigungen,Frakturen und „Wurfweite” bei 50 tödlichen Fußgänger-PKW-Unfällen

Zusammenfassung Aus 160 Obduktionen von Fußgängern, die durch PKW getötet worden waren, sind 50 nach folgenden Gesichtspunkten ausgewählt worden:Auffahrunfälle Erwachsener mit gesicherten Angaben in den Gerichtsakten über Fahrzeugbeschädigungen, Zusammenstoßstellen, Endlage der Fußgänger und Bremsspuren. Aus diesen Daten wurden Ausgangs- und Aufprallgeschwindigkeiten berechnet sowie die Wurfweite der Fußgänger gemessen.Die Ausgangsgeschwindigkeiten, nach der Berechnung zwischen 32 und 95 km/h, lagen meistens etwas höher als die angegebenen Geschwindigkeiten. Zwischen Ausgangs- und Aufprallgeschwindigkeiten waren die Differenzen größer. Ab 12 km/h Aufprallgeschwindigkeit kam es bereits zu tödlichen Verletzungen. Auffallend ist die zweigipfelige Verteilung der Häufigkeit sowohl bei der Einteilung nach den Aufprallgeschwindigkeiten als auch nach den Deformationsarbeiten (Aufprallgeschwindigkeit: 26% bei 51–60 km/h und 22% bei 21 bis 30 km/h; Deformationsarbeit: 34% bei 39–200 kpm und 30% bei 701–1000 kpm).Bei Aufprallgeschwindigkeiten über 50 km/h wurden doppelt so viel Knochenbrüche an der Wirbelsäule und am Becken als bei Aufprallgeschwindigkeiten unter 50 km/h festgestellt.Bei 44 Fußgängerunfällen lag ein Drittel innerhalb der Erwartungsgrenze der Wurfweite nach Fiala, je ein Drittel aber darüber bzw, darunter.Das Beschädigungsbild und die Anstoßverletzungen geben Hinweise zur Ermittlung der Aufprallgeschwindigkeit, vor allem wenn weitere Berechnungsgrundlagen fehlen.

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Summary Fifty cases were selected from 160 autopsies performed on pedestrians who were accidentally killed by private motorcars; the cases were selected according to the following criteria:The cases were confined to impact accidents involving adults in which reliable evidence could be gathered from the Court records in relation to damage to the car, the place of collision, the final position of the injured pedestrian and the extent of skidmarks. The initial and collision speeds of the cars were calculated from these facts and the distance of projection of the pedestrians were measured.The initial speeds, calculated between 32 and 95 km/h, were, in most cases, higher than the declared speeds. The differences between initial and collision speeds were larger. Fatal injuries could arise from a collision velocity of only 12 km/h. A striking feature of the analysis was the distribution of two peaks of frequency whether these were classified according to the collision speeds or according to the deformation of the vehicle (collision speed: 26% at the speed of 51 to 60 km/h and 22% at the speed of 21 to 30 km/h; deformation work: 34% at the deformation work of 39 to 200 kpm and 30% at the deformation work of 701 to 1,000 kpm).Twice as many fractures of the vertebral column and pelvis were sustained at collision speeds over 50 km/h as were sustained under 50 km/h.In one third of 44 pedestrian accidents, the distance of projection was within the expected range described by Fiala; in one third the distance was above and in one third below the expected range.If additional data for calculation were lacking, the patterns in injury arising from the impacts gave indications from which it was possible to estimate the collision speed.

Stipendiat der Alexander v. Humboldt-Stiftung, Dozent Dr. med. S. Kamiyama, Dept. of Legal Medicine, School of Medicine, Chiba University, 313 Inohanacho, Chiba, Japan.     

Diagnóstico ecográfico del neumotórax

The ultrasonographic diagnosis of pneumothorax is based on the analysis of artifacts. It is possible to confirm or rule out pneumothorax by combining the following signs: lung sliding, the A and B lines, and the lung point. One fundamental advantage of lung ultrasonography is its easy access in any critical situation, especially in patients in the intensive care unit. For this reason, chest ultrasonography can be used as an alternative to plain-film X-rays and computed tomography in critical patients and in patients with normal plain films in whom pneumothorax is strongly suspected, as well as to evaluate the extent of the pneumothorax and monitor its evolution.     

Carbohydrate Supplementation during Exercise: Does It Help? How Much is Too Much?

KEY POINTS· Carbohydrate intake during exercise can delay the onset of fatigue and improve performance of prolonged exercise as well as exercise of shorter duration and greater intensity (e.g., continuous exercise lasting about 1h and intermittent high-intensity exercise), but the mechanisms by which performance is improved are different.     

磁共振DWI和动态增强鉴别颅底脊索瘤和侵袭性垂体瘤的应用

目的 探讨磁共振扩散加权成像(DWI)和动态增强在颅底脊索瘤和侵袭性垂体瘤(IPA)鉴别诊断中的应用价值.方法 搜集经手术病理证实且影像学有鞍区破坏的颅底脊索瘤患者15例、向鼻咽部侵犯的IPA患者20例.测量二者的表观扩散系数(ADC)值,绘制受试者工作特征曲线(ROC),分析动态增强曲线的类型,统计达峰时间(TTP)、增强峰值(EP)和最大对比增强率(MCER),分析各个参数在鉴别诊断中的价值.结果 颅底脊索瘤的ADC值为(1.274±0.07)×10-3mm2/s,高于IPA ADC值(0.672±0.03) ×10-3 mm2/s(P ＜0.001),ADC阈值为0.964×10-3mm2/s时,ROC曲线下面积为0.997,敏感度为93.3％,特异度为100％.颅底脊索瘤时间-信号强度曲线(TIC)Ⅰ型14例,TICⅢ型1例,此例TICⅢ型者TTP约40 s;IPA TIC Ⅰ型7例,TICⅢ型13例.颅底脊索瘤和IPA的EP、MCER差异均有统计学意义(P ＜0.001).结论 ADC值和TIC的类型及其相关参数(EP,MCER)有助于颅底脊索瘤和IPA之间的鉴别.     

Hip and pelvic injuries in the elderly

Fractures of the hip and pelvis are frequent and serious injuries in elderly patients. Due to the aging population, their incidence should double by 2050. Therefore, the social and economical implications of these fractures are significant. Delay in diagnosis increases the associated morbidity and mortality. The purpose is to review the imaging features of these fractures, the imaging techniques (projections, CT) to depict them and their classification based on severity.