Bistatic/multistatic radar has great potential advantages over its monostatic counterpart. However, the separation of a transmitter and a receiver leads to difficulties in locating the target position accurately and g...Bistatic/multistatic radar has great potential advantages over its monostatic counterpart. However, the separation of a transmitter and a receiver leads to difficulties in locating the target position accurately and guaranteeing space-timefrequency synchronization of the transmitter and the receiver.The error model of space-time-frequency synchronization in a motion platform of bistatic/multistatic radar is studied. The relationship between the space synchronization error and the transmitter platform position, receiver platform position, moving state, and beam pointing error, is analyzed. The effect of space synchronization error on target echo power is studied. The target scattering characteristics are restructured by many separate scattering centers of the target in high frequency regions. Based on the scattering centers model of the radar target, this radar target echo model and the simulation method are discussed. The algorithm of bistatic/multistatic radar target echo accurately reflects the scattering characteristics of the radar target, pulse modulation speciality of radar transmitting signals, and spacetime-frequency synchronization error characteristics between the transmitter station and the receiver station. The simulation of bistatic radar is completed in computer, and the results of the simulation validate the feasibility of the method.展开更多
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
基金supported by the National Natural Science Foundation of China(61271327)
文摘Bistatic/multistatic radar has great potential advantages over its monostatic counterpart. However, the separation of a transmitter and a receiver leads to difficulties in locating the target position accurately and guaranteeing space-timefrequency synchronization of the transmitter and the receiver.The error model of space-time-frequency synchronization in a motion platform of bistatic/multistatic radar is studied. The relationship between the space synchronization error and the transmitter platform position, receiver platform position, moving state, and beam pointing error, is analyzed. The effect of space synchronization error on target echo power is studied. The target scattering characteristics are restructured by many separate scattering centers of the target in high frequency regions. Based on the scattering centers model of the radar target, this radar target echo model and the simulation method are discussed. The algorithm of bistatic/multistatic radar target echo accurately reflects the scattering characteristics of the radar target, pulse modulation speciality of radar transmitting signals, and spacetime-frequency synchronization error characteristics between the transmitter station and the receiver station. The simulation of bistatic radar is completed in computer, and the results of the simulation validate the feasibility of the method.
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。
