双源CT小肠造影双能量虚拟平扫的临床评估

目的：探讨64排双源 CT 小肠造影双能量虚拟平扫技术应用于临床的可行性。方法：采用双源 CT 机对39例患者进行小肠造影检查,常规行 CT 平扫以及动、静脉期对比增强双能量扫描（100 kVp／230 mAs 和 l40 kVp／178 mAs）。利用 Liver VNC 软件进行后处理,获得动、静脉期的虚拟平扫 CT 图像。以常规 CT 平扫图像作为标准,对虚拟平扫图像的质量进行评估,采用4级评分法：最高为4分（图像解剖细节清晰,完全能满足诊断）,最低为1分（图像模糊,不能满足诊断）。并对常规 CT 平扫、动、静脉期双能量 CT 扫描的辐射剂量进行比较。结果：39例中有腹部病变者25例,无明显异常者14例。与常规平扫图像比较,虚拟平扫图像上所有病灶均能显示,且病灶的范围、大小亦无明显差异;两位医师对虚拟平扫图像质量的评分均＞2分,两者的评分差异无统计学意义（P ＞0．05）。所有虚拟平扫图像完全能满足诊断要求。常规平扫、双能量动脉期、双能量静脉期扫描的剂量长度乘积（DLP）分别为（283．8750±57．1195）、（289．3750±53．1543）和（301．2917±55．3346）mGy·cm,三次扫描的 DLP 的差异无统计学意义（F ＝0．615,P ＝0．544）。结论：双源 CT 小肠造影检查时可仅进行双能量增强扫描,经后处理获得的虚拟平扫图像基本可取代常规 CT 平扫,从而可减少检查的辐射剂量。     

胰腺双能量CT虚拟平扫与真实平扫的初步对比研究

目的：比较双源CT胰腺双能量扫描虚拟平扫与真实平扫的图像质量差异。方法：67例患者行双源CT上腹部真实平扫（TNE）、动脉期和门脉期双能量扫描,通过双能量liver—VNC软件后处理分别得到动脉期和门脉期虚拟平扫图像,比较真实平扫、动脉期虚拟平扫和门脉期虚拟平扫三组图像中的胰腺CT值、竖脊肌CT值、图像噪声、胰腺信噪比、胰腺-竖脊肌对比噪声比、图像主观质量评分以及辐射剂量。结果：TNE、动脉期VNE和门脉期VNE三组图像中的胰腺CT值、竖脊肌CT值的差异无统计学意义（P〉0．05）;三组中图像噪声、胰腺信噪比和胰腺-竖脊肌对比噪声比的差异有统计学意义（P〈0．05）,且动脉期VNE图像噪声最低,信噪比最高;三组图像主观质量评分均满足临床诊断,且评分TNE〉动脉期VNE〉门脉期VNE（P〈0．001）;采用动脉期VNE的总有效剂量（ED）和采用门脉期VNE的总ED均低于采用TNE的总ED（P=0．001）。结论：双源CT双能量扫描胰腺虚拟平扫的图像质量接近于真实平扫,并且动脉期虚拟平扫图像质量优于门脉期,在临床胰腺三期增强扫描中可能替代真实平扫并且减少辐射剂量。     

双源CT双能量虚拟平扫技术在颈部淋巴结病变中的应用价值

目的 探讨双源CT双能量虚拟平扫技术在颈部肿大淋巴结中的临床应用价值.方法 回顾分析48例经病理证实并行颈部CT常规平扫及双能量模式增强扫描的颈部淋巴结肿大患者的影像资料,利用"Liver VNC"软件处理得到虚拟平扫图像.对颈部肿大淋巴结虚拟平扫(virtual noncontrast,VNC)图像和常规平扫(conventional noncontrast,CNC)图像在平均CT值、噪声,信号噪声比(signal to noise ratio,SNR),图像质量,对病灶的显示情况,辐射剂量(用CTDIvol和DLP表示)等方面进行比较研究.结果 常规平扫和虚拟平扫所测颈部肿大淋巴结的平均CT值差异无统计学意义(P>0.05);虚拟平扫图像噪声明显低于常规平扫,而信号噪声比明显高于常规平扫(P<0.05);虚拟平扫图像质量低于常规平扫但差异无统计学意义(P>0.05);虚拟平扫及常规平扫对颈部肿大淋巴结内坏死均可见显示;双能量扫描模式较常规扫描模式的总辐射剂量小(P<0.05).结论 在颈部肿大淋巴结检查中,1次双能量增强扫描可获得增强图像和VNC图像,而VNC图像基本不影响病灶的观察同时显著降低了辐射剂量,具有潜在的临床应用价值.     

双源CT虚拟平扫技术在阻塞性黄疸中的应用研究

目的探讨双源CT双能量虚拟平扫技术(VNC)在阻塞性黄疸病因诊断中的价值。方法对30例临床诊断为阻塞性黄疸患者(未口服对比剂)先行常规腹部平扫(CNC),然后口服阳性对比剂500ml,再行双能量强化扫描动脉期、常规强化门静脉期,之后采用肝脏虚拟平扫后处理软件Liver VNC,经参数调整,对双能量强化图像进行处理,得到VNC图像,以常规平扫图像为金标准比较VNC图像在病灶检出中的准确性,并利用t检验对比分析图像SNR,用轶和检验分析患者不同扫描方式接受的总辐射剂量容积CT剂量指数(CTDIvol)值和剂量长度乘积(DLP)值有无统计学差异。结果 VNC较CNC在图像质量上有所下降,但能满足诊断要求,在结石和肿瘤等病变检出中无明显差异,在剂量统计分析中虚拟组较常规组低,具有明显统计学差异(P=0.002<0.05)。结论虚拟平扫技术在病灶检出中可满足诊断要求,使其取代常规平扫成为可能,从而降低辐射剂量。     

双源双能量CT胰腺虚拟平扫的临床应用价值研究

目的 :探讨双源双能量CT胰腺虚拟平扫的临床应用价值。方法 :50例患者行上腹部双源CT常规平扫及动脉期、门脉期、延迟期双能量CT增强扫描,通过双能量"Liver VNC"软件后处理分别得到动脉期、门脉期及延迟期的虚拟平扫图像,比较常规平扫与3组虚拟平扫图像的胰腺平均CT值、竖脊肌平均CT值、SNR、对比噪声比(CNR)、图像主观质量、病灶显示情况及辐射剂量。结果:常规平扫与虚拟平扫图像的胰腺平均CT值、竖脊肌平均CT值差异均无统计学意义(均P0.05);虚拟平扫图像的SNR、CNR均高于常规平扫图像(均P0.05);常规平扫与虚拟平扫所有图像评分均在3分以上,差异有统计学意义(P0.05),均满足临床诊断需要;常规平扫与虚拟平扫图像对病灶有相似的检出功能;双能量扫描虚拟平扫的总有效剂量低于常规扫描(P0.05)。结论:双源双能量CT胰腺虚拟平扫图像质量较常规平扫图像有一定程度下降,但可满足临床诊断需求,同时又减少一次平扫的辐射剂量,且SNR更高,因此具有潜在的临床应用价值。     

双源CT双能量虚拟平扫在肺癌诊断中的初步研究

目的 探讨双源CT双能量虚拟平扫(VNC)技术在肺癌诊断中的价值.方法 对50例疑似肺癌患者行常规CT平扫和双能量CT增强扫描.观察50例患者常规CT平扫图像与VNC图像,测量降主动脉、左心房及胸椎椎体后方肌肉的平均CT值,计算信噪比(SNR),评价图像质量.使用Liver VNC软件程序获得肿块的VNC CT值及增强净增值.以CT值净增值≥20 HU为诊断肺癌的标准,对本组50例患者进行评价,计算诊断准确率.比较常规扫描与双能量扫描患者辐射剂量.结果 50例患者降主动脉的常规CT平扫与VNC平均CT值差异有统计学意义(P＜0.05);左心房及胸椎椎体后方肌肉平均CT值差异无统计学意义(P＞0.05).常规平扫与VNC降主动脉、左心房及胸椎椎体后方肌肉的SNR差异有统计学意义(P值＜0.05).常规平扫图像与VNC图像的质量评分平均得分无统计学意义.以净增值≥20 HU诊断肺癌为标准,34例经过最终病理证实为肺癌的病灶CT值的净增值为(38.69±18.3)HU,准确率为94.1％ (32/34);其余16例病灶CT值的净增值为(11.38±9.52) HU,假阳性率为6.25％ (1/16).比较常规扫描与双能量扫描辐射剂量,虽然VNC的CTDIvol、DLP、ED均稍高于常规平扫,差异具有统计学意义(P＜0.05),但运用VNC技术节省一次常规平扫剂量,平均每例患者可减少2.29 mSv有效剂量.结论 双源CT双能量VNC技术应用于胸部扫描,可有效降低辐射剂量,并能确保图像质量满足临床诊断要求,在肺癌的诊断中具有较高的应用价值.     

双源能谱CT虚拟平扫替代常规平扫评估食管癌的可行性研究

目的探讨双源能谱CT虚拟平扫(VNC)替代常规平扫(TNC)评估食管癌的可行性。方法回顾性收集经胃镜或手术病理证实的食管癌病人46例,所有病人均行TNC及双能量动、静脉双期增强扫描,经双能后处理软件获得动脉期VNC影像。由2名观察者分析TNC和VNC影像上病灶形态学特征(管壁是否增厚、肿瘤与周围组织关系、淋巴结肿大等),并对影像质量进行评分;2组间比较采用卡方检验或Wilcoxon秩和检验,观察者间一致性采用Kappa检验分析。采用配对t检验比较TNC与VNC影像的辐射剂量及其他定量评价参数。结果TNC和VNC影像上显示病灶形态学特征差异均无统计学意义(均P>0.05)。2名观察者对TNC和VNC影像质量主观评分的一致性均较好(均κ>0.75),且对2种影像的主观评分的差异无统计学意义(P>0.05)。2种影像上测得的食管癌病灶处管壁厚度的差异无统计学意义(P>0.05),VNC影像上降主动脉、皮下脂肪CT值高于TNC(P<0.05),但食管癌病灶、椎体后肌肉和空气的CT值差异无统计学意义(P>0.05)。与TNC相比,VNC影像具有较高的SNR和较低的噪声(均P<0.05)。双能量动、静脉期扫描有效辐射剂量小于常规三期扫描(P<0.05),其有效辐射剂量降低了(3.46±0.87)mSv。结论双源能谱CT可为食管癌病人提供与TNC影像质量相似的VNC影像,并降低了辐射剂量。     

双源 CT 双能量虚拟平扫在胸部疾病的临床应用研究

目的：探讨双源 CT(DSCT)双能量虚拟平扫(VNC)技术在胸部疾病的应用价值。方法对60例患者行胸部常规 CT平扫和双能量 CT 增强扫描。对比分析常规 CT 平扫图像与 VNC 图像,测量降主动脉、左心房及胸椎椎体后方肌肉的平均 CT 值、计算信噪比(SNR)、评价二者图像质量、比较辐射剂量。结果60例患者降主动脉的常规平扫与 VNC 平均 CT 值差异有统计学意义(P <0.05);左心房及胸椎椎体后方肌肉平均 CT 值无差异(P >0.05)。VNC 降主动脉、左心房及胸椎椎体后方肌肉的 SNR 均高于常规平扫(P <0.05)。运用增强序列卷积核重建得到的肺窗图像与常规平扫肺窗图像基本一致,对肺实变47例,空洞4例,结节26例,肿块24例,纤维化病变31例,胸膜病变29例二者均能清楚显示(P >0.05)。VNC 图像仅对4(4/49)例肺门区微小钙化灶显示较常规平扫图像模糊。常规平扫与 VNC 图像的质量评分差异无统计学意义。VNC 的容积 CT 剂量指数(CTDIvol)、剂量长度乘积(DLP)、有效剂量(ED)均稍高于常规平扫(P <0.05),但节省1次常规平扫剂量,平均每人可减少2.22 mSv ED。结论DSCT双能量 VNC 技术应用于胸部扫描,其图像质量能达到诊断要求,可有效降低辐射剂量,具有较好的临床应用价值。     

双源CT双能量上腹部虚拟平扫临床应用价值的初步探讨

目的 探讨双源CT(dual source computed tomography,DSCT)上腹部双能量虚拟平扫临床应用的可行性.资料与方法 对46例临床拟诊上腹部病变患者行DSCT上腹部常规平扫(CNCT)及动脉期、门静脉期双能量扫描(80 kV/404 mA和140 kV/96 mA).利用Liver VNC软件处理分别得到动脉期、门静脉期2组虚拟平扫数据,并与CNCT对照,比较三者在图像质量、辐射剂量、平均CT值、信噪比(SNR)及病灶检出上差异的统计学意义.结果 3次扫描患者接受的辐射剂量、所测肝、脾平均CT值的差异无统计学意义(P>0.05);虚拟平扫图像SNR明显高于CNCT组(P=0.00),2组虚拟平扫之间差异无统计学意义(P>0.05);虚拟平扫的图像质量较CNCT有所下降(F=241.80,P=0.00),但可满足临床诊断需求,动脉期虚拟平扫图像质量优于门静脉期(P=0.004);虚拟平扫和CNCT病灶检出性能相似.结论 相对门静脉期而言,肝动脉期的双能量虚拟平扫能提供更好的图像质量,可满足诊断需要,并可减少一次平扫的辐射剂量,具有更高的SNR、相似的病灶检出性能,具有潜在的临床应用价值.     

双源CT双能量虚拟平扫对脂肪肝的诊断价值

_目的：探讨双源 CT 双能量腹部虚拟平扫对脂肪肝的诊断价值。方法：回顾性分析采用双源 CT 行腹部双能量增强扫描诊断为脂肪肝的77例患者的平扫期（120 kV）及虚拟平扫（VNC）图像。虚拟平扫图像运用门脉期双能量（100及140 kV）图像重建而来。选择肝门层面测量真实平扫（TNC）与 VNC 图像上肝右叶、肝左叶、脾脏、下腔静脉的 CT 值及噪声,并在肝门层面测量上腹部前后径及左右径。记录整个扫描和平扫期对应的剂量长度乘积（DLP）。评价 TNC 与VNC 图像间各 CT 值及噪声的差异,分析两组图像上肝右叶噪声与前后径、左右径及平均径的关系。分别用肝/脾 CT 值比＜0．8、肝/下腔静脉 CT 值比＜1．0,做为诊断中重度脂肪肝的标准,比较 TNC 和 VNC 图像诊断中重度脂肪肝的一致性。结果：VNC 图像上肝左叶、右叶及脾脏的 CT 值均高于 TNC（P＜0．01）,差异小于10 HU。VNC 图像上各部位噪声均低于 TNC。TNC 图像上,肝右叶噪声与前后径、左右径、平均径均有中等相关性（r＝0．562,0．608,P＜0．01）;在 VNC图像上,肝右叶噪声与上述径线值相关性弱。用肝/脾 CT 值比＜0．8作为诊断重度脂肪肝的标准,VNC 与 TNC 图像诊断重度脂肪肝一致性的 kappa 值为0．591;用肝/静脉 CT 值比＜1．0作为诊断标准,两种图像一致性的 kappa 值为0．458。用 VNC 代替 TNC 图像,可降低24．2％的总扫描剂量。结论：VNC 图像与 TNC 图像在诊断中重度脂肪肝上具有中等的一致性,推荐运用肝/脾 CT 值比＜0．8这一诊断标准。     

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.