背景与目的:鼻咽癌颅底骨侵犯的常规评估依赖CT,但CT的电离辐射存在潜在危害。零回波时间磁共振成像(zero echo time magnetic resonance imaging,ZTE-MRI)可在无辐射条件下获得高分辨率骨结构信息。本研究旨在系统评价ZTE-MRI对鼻咽癌...背景与目的:鼻咽癌颅底骨侵犯的常规评估依赖CT,但CT的电离辐射存在潜在危害。零回波时间磁共振成像(zero echo time magnetic resonance imaging,ZTE-MRI)可在无辐射条件下获得高分辨率骨结构信息。本研究旨在系统评价ZTE-MRI对鼻咽癌颅底骨侵犯的诊断效能,并探讨其临床替代CT的可行性。方法:本前瞻性研究收集2020年4月—2022年12月在福建省肿瘤医院诊治的鼻咽癌患者95例为起始对象,并根据排除标准进行剔除。运用GE Discovery 750w 3.0T MR扫描仪,获取常规平扫、增强扫描,利用ZTE-MRI技术获取ZTEMRI和CT图像。影像检查结果由两位放射科医师分别独立阅片评估颅底骨侵犯情况。本研究经福建省肿瘤医院伦理委员会批准(K2025-314-01)并获得患者知情同意。结果:共计80例鼻咽癌患者纳入最终分析。CT诊断鼻咽癌颅底骨侵犯与参比标准有高度一致性,差异有统计学意义(κ=0.645,P<0.001)。ZTE-MRI诊断鼻咽癌颅底骨侵犯与参比标准亦有高度一致性,差异有统计学意义(κ=0.774,P<0.001)。ZTE-MRI联合常规MRI诊断鼻咽癌颅底骨侵犯与参比标准具有极强一致性,差异有统计学意义(κ=0.912,P<0.001)。结论:ZTE-MRI技术为鼻咽癌颅底骨侵犯提供“类CT”图像,在临床上ZTE-MRI技术可以替代CT检查。展开更多
Objective To observe the value of isotropic volumetric MRI for displaying perineural spread(PNS)of cranial nerve(CN)in nasopharyngeal carcinoma.Methods Eighty-seven patients with pathologically proven nasopharyngeal c...Objective To observe the value of isotropic volumetric MRI for displaying perineural spread(PNS)of cranial nerve(CN)in nasopharyngeal carcinoma.Methods Eighty-seven patients with pathologically proven nasopharyngeal carcinoma were prospectively enrolled.MR scanning,including three-dimensional liver acquisition with volume acceleration-flexible(3D LAVA_Flex)image,T2WI with fat suppression(T2WI-FS),T1WI,contrast enhancement(CE)T1WI-FS of nasopharynx and neck region were performed.The displaying rates of CN PNS were evaluated and compared between 3D LAVA_Flex and T2WI-FS,T1WI,CE-T1WI-FS at patient level,CN group level and neural level,respectively.Results The displaying rate of CN PNS in all 87 nasopharyngeal carcinoma patients by 3D LAVA_Flex sequence was 49.43%(43/87),higher than that of conventional MRI(30/87,34.48%,P=0.001).Among 59 patients with advanced nasopharyngeal carcinoma diagnosed with conventional sequences,the displaying rate of CN PNS was 71.19%(42/59)by 3D LAVA-Flex sequence,higher than that of conventional MRI(30/59,50.85%,P=0.001).At both patient level and posterior CN level,significant differences of the displaying rate of CN PNS were found between 3D LAVA-Flex sequence and T2WI-FS,T1WI,CE-T1WI-FS,while at CN level,the displaying rates of mandibular nerve PNS,CNⅨ—ⅪPNS in jugular foramen(P<0.05)and CNⅨ—ⅫPNS in carotid space of 3D LAVA_Flex sequence were all significantly higher than that of T2WI-FS,T1WI and CE-T1WI-FS(all P<0.05),of PNS of CNⅢ—Ⅴin cavernous sinus were higher than that of T2WI-FS(P<0.05),while of PNS of hypoglossal nerve were significantly higher than that of T2WI-FS and T1WI(both P<0.05).Conclusion 3D LAVA_Flex sequence could be used to effectively display CN PNS of nasopharyngeal carcinoma.展开更多
"Riding mining" is a form of mining where the working face is located above the roadway and advances parallel to it.Riding mining in deep soft rock creates a particular set of problems in the roadway that in..."Riding mining" is a form of mining where the working face is located above the roadway and advances parallel to it.Riding mining in deep soft rock creates a particular set of problems in the roadway that include high stresses,large deformations,and support difficulties.Herein we describe a study of the rock deformation mechanism of a roadway as observed during riding mining in deep soft rock.Theoretical analysis,numerical simulations,and on site monitoring were used to examine this problem.The stress in the rock and the visco-elastic behavior of the rock are considered.Real time data,recorded over a period of 240 days,were taken from a 750 transportation roadway.Stress distributions in the rock surrounding the roadway were studied by comparing simulations to observations from the mine.The rock stress shows dynamic behavior as the working face advances.The pressure increases and then drops after peaking as the face advances.Both elastic and plastic deformation of the surrounding rock occurs.Plastic deformation provides a mechanism by which stress in the rock relaxes due to material flow.A way to rehabilitate the roadway is suggested that will help ensure mine safety.展开更多
文摘背景与目的:鼻咽癌颅底骨侵犯的常规评估依赖CT,但CT的电离辐射存在潜在危害。零回波时间磁共振成像(zero echo time magnetic resonance imaging,ZTE-MRI)可在无辐射条件下获得高分辨率骨结构信息。本研究旨在系统评价ZTE-MRI对鼻咽癌颅底骨侵犯的诊断效能,并探讨其临床替代CT的可行性。方法:本前瞻性研究收集2020年4月—2022年12月在福建省肿瘤医院诊治的鼻咽癌患者95例为起始对象,并根据排除标准进行剔除。运用GE Discovery 750w 3.0T MR扫描仪,获取常规平扫、增强扫描,利用ZTE-MRI技术获取ZTEMRI和CT图像。影像检查结果由两位放射科医师分别独立阅片评估颅底骨侵犯情况。本研究经福建省肿瘤医院伦理委员会批准(K2025-314-01)并获得患者知情同意。结果:共计80例鼻咽癌患者纳入最终分析。CT诊断鼻咽癌颅底骨侵犯与参比标准有高度一致性,差异有统计学意义(κ=0.645,P<0.001)。ZTE-MRI诊断鼻咽癌颅底骨侵犯与参比标准亦有高度一致性,差异有统计学意义(κ=0.774,P<0.001)。ZTE-MRI联合常规MRI诊断鼻咽癌颅底骨侵犯与参比标准具有极强一致性,差异有统计学意义(κ=0.912,P<0.001)。结论:ZTE-MRI技术为鼻咽癌颅底骨侵犯提供“类CT”图像,在临床上ZTE-MRI技术可以替代CT检查。
文摘Objective To observe the value of isotropic volumetric MRI for displaying perineural spread(PNS)of cranial nerve(CN)in nasopharyngeal carcinoma.Methods Eighty-seven patients with pathologically proven nasopharyngeal carcinoma were prospectively enrolled.MR scanning,including three-dimensional liver acquisition with volume acceleration-flexible(3D LAVA_Flex)image,T2WI with fat suppression(T2WI-FS),T1WI,contrast enhancement(CE)T1WI-FS of nasopharynx and neck region were performed.The displaying rates of CN PNS were evaluated and compared between 3D LAVA_Flex and T2WI-FS,T1WI,CE-T1WI-FS at patient level,CN group level and neural level,respectively.Results The displaying rate of CN PNS in all 87 nasopharyngeal carcinoma patients by 3D LAVA_Flex sequence was 49.43%(43/87),higher than that of conventional MRI(30/87,34.48%,P=0.001).Among 59 patients with advanced nasopharyngeal carcinoma diagnosed with conventional sequences,the displaying rate of CN PNS was 71.19%(42/59)by 3D LAVA-Flex sequence,higher than that of conventional MRI(30/59,50.85%,P=0.001).At both patient level and posterior CN level,significant differences of the displaying rate of CN PNS were found between 3D LAVA-Flex sequence and T2WI-FS,T1WI,CE-T1WI-FS,while at CN level,the displaying rates of mandibular nerve PNS,CNⅨ—ⅪPNS in jugular foramen(P<0.05)and CNⅨ—ⅫPNS in carotid space of 3D LAVA_Flex sequence were all significantly higher than that of T2WI-FS,T1WI and CE-T1WI-FS(all P<0.05),of PNS of CNⅢ—Ⅴin cavernous sinus were higher than that of T2WI-FS(P<0.05),while of PNS of hypoglossal nerve were significantly higher than that of T2WI-FS and T1WI(both P<0.05).Conclusion 3D LAVA_Flex sequence could be used to effectively display CN PNS of nasopharyngeal carcinoma.
基金Supported by the National Natural Science Foundation of China (Nos. 50834005 and 51074163)the Ministry of Education Support Program for New Century Excellent of China(No. NCET-08-0837)+1 种基金the Fundamental Research Funds for the Central Universities of ChinaYouth Science and Technology Foundation of China University of Mining and Technology(No. 2010QNB25)
文摘"Riding mining" is a form of mining where the working face is located above the roadway and advances parallel to it.Riding mining in deep soft rock creates a particular set of problems in the roadway that include high stresses,large deformations,and support difficulties.Herein we describe a study of the rock deformation mechanism of a roadway as observed during riding mining in deep soft rock.Theoretical analysis,numerical simulations,and on site monitoring were used to examine this problem.The stress in the rock and the visco-elastic behavior of the rock are considered.Real time data,recorded over a period of 240 days,were taken from a 750 transportation roadway.Stress distributions in the rock surrounding the roadway were studied by comparing simulations to observations from the mine.The rock stress shows dynamic behavior as the working face advances.The pressure increases and then drops after peaking as the face advances.Both elastic and plastic deformation of the surrounding rock occurs.Plastic deformation provides a mechanism by which stress in the rock relaxes due to material flow.A way to rehabilitate the roadway is suggested that will help ensure mine safety.
