The Moon,as the closest celestial body to the Earth,plays a pivotal role in the progression of deep space exploration,and the establishment of research outposts on its surface represents a crucial step in this mission...The Moon,as the closest celestial body to the Earth,plays a pivotal role in the progression of deep space exploration,and the establishment of research outposts on its surface represents a crucial step in this mission.Lunar lava tubes are special underground caves formed by volcanic eruptions and are considered as ideal natural shelters and scientific laboratories for lunar base construction.This paper begins with an in-depth overview of the geological origins,exploration history,and distribution locations of lunar lava tubes.Subsequently,it delves into the presentation of four distinctive advantages and typical concepts for constructing bases within lava tubes,summarizing the ground-based attempts made thus far in lunar lava tube base construction.Field studies conducted on a lava tube in Hainan revealed rock compositions similar to those found during the Apollo missions and clear lava tube structures,making it a promising analog site.Lastly,the challenges and opportunities encountered in the field of geotechnical engineering regarding the establishment of lunar lava tube bases are discussed,encompassing cave exploration technologies,in-situ testing methods,geomechanical properties under lunar extreme environments,base design and structural stability assessment,excavation and reinforcement techniques,and simulated Earth-based lava tube base.展开更多
目的探讨透视触发3DLAVA技术对肝实质病变及血管的显示情况。方法21例经手术病理或治疗后确诊的肝实质内病变的患者选入本次研究。应用1.5T扫描仪（GE Excite HD Twinspeed1.5T）。动脉期应用透视触发技术,以确保肝脏动脉早期的成功显...目的探讨透视触发3DLAVA技术对肝实质病变及血管的显示情况。方法21例经手术病理或治疗后确诊的肝实质内病变的患者选入本次研究。应用1.5T扫描仪（GE Excite HD Twinspeed1.5T）。动脉期应用透视触发技术,以确保肝脏动脉早期的成功显示。对所有时相的主动脉、门脉、肝实质及病灶绘制信号强度-时间曲线,同时对动脉相及门脉相采用最大密度投影（MIP）,观察肝动脉及门脉的显示情况。结果21例病人均获得高质量6~8个时相的全肝图像。信号强度-时间曲线显示所有病例的门脉及肝实质均在第三个时相达到峰值,而不同病灶的信号强度-时间曲线各有特点,对诊断能够提供更多的帮助。MIP结合原图能清楚显示肝固有动脉的3~4级分支,对门脉系统的显示率达到100%。结论透视触发3DLAVA技术能够清楚显示肝实质病变的动态增强特点,能够清楚显示肝动脉、门脉的分支及其与病灶的关系。展开更多
目的探讨MR 3D LAVA(LAVA)动态强化扫描对于Budd-Chiari综合征的诊断价值。方法 21例Budd-Chiari综合征患者均行MR LAVA动态强化扫描,对各时相扫描分别进行MIP、MPR处理,并对图像质量和血管显示情况进行分析。结果动脉时相的3D MIP对肝...目的探讨MR 3D LAVA(LAVA)动态强化扫描对于Budd-Chiari综合征的诊断价值。方法 21例Budd-Chiari综合征患者均行MR LAVA动态强化扫描,对各时相扫描分别进行MIP、MPR处理,并对图像质量和血管显示情况进行分析。结果动脉时相的3D MIP对肝动脉观察的满意率达90.4﹪,第三时相冠状位MIP与多层面重组结合对门静脉、下腔静脉和肝静脉的显示满意率达100%。结论对于Budd-Chiari综合征,MR 3D LAVA动态强化扫描技术不仅能准确地显示肝动、静脉的解剖形态及病变,同时还能全面地观察肝脏及周围其他脏器的情况。展开更多
目的:探讨磁共振冠状面快速三维容积动态增强(liver acquisition with volume acceleration,LAVA)在低位胆道梗阻中的应用价值。方法:50例低位胆道梗阻患者(排除较明显胆道结石者),进行MR平扫(包括MRCP)及冠状面LAVA检查,对检查结果进...目的:探讨磁共振冠状面快速三维容积动态增强(liver acquisition with volume acceleration,LAVA)在低位胆道梗阻中的应用价值。方法:50例低位胆道梗阻患者(排除较明显胆道结石者),进行MR平扫(包括MRCP)及冠状面LAVA检查,对检查结果进行判读与分析,包括病变的定位诊断、定性诊断及恶性梗阻的手术可切除性预测,并与手术病理、经内镜逆行性胰胆管造影术(ERCP)或经皮肝穿胆道造影术(PTC)结果对照。结果:MR平扫(包括MRCP)及冠状面LAVA技术对低位胆道梗阻的定位诊断准确率分别为86%(43/50)、88%(44/50),两组间无统计学差异(P=1.000);定性诊断准确率分别为78%(39/50)、92%(46/50),两组间差异具有统计学意义(P=0.039);MR平扫(包括MRCP)结合冠状面LAVA的手术可切除性预测准确率为90.3%(37/41)。结论:MR冠状面LAVA动态增强可以直观地显示病变的位置、特征及与周围组织的关系,在低位胆道梗阻的定性诊断中具有重要作用,MR平扫结合冠状面LAVA增强扫描对于低位恶性胆道梗阻术前可切除性预测准确率较高。展开更多
基金supported by the National Natural Science Foundation of China(Nos.52125903 and 52339001).
文摘The Moon,as the closest celestial body to the Earth,plays a pivotal role in the progression of deep space exploration,and the establishment of research outposts on its surface represents a crucial step in this mission.Lunar lava tubes are special underground caves formed by volcanic eruptions and are considered as ideal natural shelters and scientific laboratories for lunar base construction.This paper begins with an in-depth overview of the geological origins,exploration history,and distribution locations of lunar lava tubes.Subsequently,it delves into the presentation of four distinctive advantages and typical concepts for constructing bases within lava tubes,summarizing the ground-based attempts made thus far in lunar lava tube base construction.Field studies conducted on a lava tube in Hainan revealed rock compositions similar to those found during the Apollo missions and clear lava tube structures,making it a promising analog site.Lastly,the challenges and opportunities encountered in the field of geotechnical engineering regarding the establishment of lunar lava tube bases are discussed,encompassing cave exploration technologies,in-situ testing methods,geomechanical properties under lunar extreme environments,base design and structural stability assessment,excavation and reinforcement techniques,and simulated Earth-based lava tube base.
文摘目的探讨透视触发3DLAVA技术对肝实质病变及血管的显示情况。方法21例经手术病理或治疗后确诊的肝实质内病变的患者选入本次研究。应用1.5T扫描仪（GE Excite HD Twinspeed1.5T）。动脉期应用透视触发技术,以确保肝脏动脉早期的成功显示。对所有时相的主动脉、门脉、肝实质及病灶绘制信号强度-时间曲线,同时对动脉相及门脉相采用最大密度投影（MIP）,观察肝动脉及门脉的显示情况。结果21例病人均获得高质量6~8个时相的全肝图像。信号强度-时间曲线显示所有病例的门脉及肝实质均在第三个时相达到峰值,而不同病灶的信号强度-时间曲线各有特点,对诊断能够提供更多的帮助。MIP结合原图能清楚显示肝固有动脉的3~4级分支,对门脉系统的显示率达到100%。结论透视触发3DLAVA技术能够清楚显示肝实质病变的动态增强特点,能够清楚显示肝动脉、门脉的分支及其与病灶的关系。
文摘目的探讨MR 3D LAVA(LAVA)动态强化扫描对于Budd-Chiari综合征的诊断价值。方法 21例Budd-Chiari综合征患者均行MR LAVA动态强化扫描,对各时相扫描分别进行MIP、MPR处理,并对图像质量和血管显示情况进行分析。结果动脉时相的3D MIP对肝动脉观察的满意率达90.4﹪,第三时相冠状位MIP与多层面重组结合对门静脉、下腔静脉和肝静脉的显示满意率达100%。结论对于Budd-Chiari综合征,MR 3D LAVA动态强化扫描技术不仅能准确地显示肝动、静脉的解剖形态及病变,同时还能全面地观察肝脏及周围其他脏器的情况。
文摘目的:探讨磁共振冠状面快速三维容积动态增强(liver acquisition with volume acceleration,LAVA)在低位胆道梗阻中的应用价值。方法:50例低位胆道梗阻患者(排除较明显胆道结石者),进行MR平扫(包括MRCP)及冠状面LAVA检查,对检查结果进行判读与分析,包括病变的定位诊断、定性诊断及恶性梗阻的手术可切除性预测,并与手术病理、经内镜逆行性胰胆管造影术(ERCP)或经皮肝穿胆道造影术(PTC)结果对照。结果:MR平扫(包括MRCP)及冠状面LAVA技术对低位胆道梗阻的定位诊断准确率分别为86%(43/50)、88%(44/50),两组间无统计学差异(P=1.000);定性诊断准确率分别为78%(39/50)、92%(46/50),两组间差异具有统计学意义(P=0.039);MR平扫(包括MRCP)结合冠状面LAVA的手术可切除性预测准确率为90.3%(37/41)。结论:MR冠状面LAVA动态增强可以直观地显示病变的位置、特征及与周围组织的关系,在低位胆道梗阻的定性诊断中具有重要作用,MR平扫结合冠状面LAVA增强扫描对于低位恶性胆道梗阻术前可切除性预测准确率较高。
