目的:研究基于光子计数探测器CT(photon-counting detector CT,PCD-CT)采集的能谱定位像(spectral localizer radiograph,SLR)定量检测股骨颈的面积骨密度(areal bone mineral density,aBMD)的效能。方法:于2024年7月至2025年4月前瞻性...目的:研究基于光子计数探测器CT(photon-counting detector CT,PCD-CT)采集的能谱定位像(spectral localizer radiograph,SLR)定量检测股骨颈的面积骨密度(areal bone mineral density,aBMD)的效能。方法:于2024年7月至2025年4月前瞻性纳入需接受双能量X射线吸收法(dual-energy X-ray absorptiometry,DXA)以及CT扫描这2种检查的受试者(≥18岁)。这些患者在PCD-CT上接受检查获取SLR,由2名观察者在SLR上独立、盲法测量患者左侧股骨颈的aBMD。以DXA的测量结果为标准,评估SLR对aBMD的定量准确性及针对异常骨量(T值<-1.0)的诊断效能。结果:本研究共纳入63名受试者(其中女性36人),平均年龄(64.30±13.20)岁,DXA测得的中位aBMD值为0.889[四分位间距(interquartile range,IQR)为0.749~1.031]g/cm^(2),其中23人(36.51%)表现出异常骨量。2名观察者测量的aBMD值[中位数(IQR)表示]分别为0.879(0.760~0.985)g/cm^(2)和0.891(0.784~0.977)g/cm^(2),基于SLR测量的aBMD值具有极好的观察者间一致性(组内相关系数为0.98)。以DXA结果为参考,SLR测量aBMD的中位百分比绝对误差为6.66%(IQR为3.64%~9.80%),基于SLR诊断异常骨量的准确率、灵敏度、特异度分别为95.24%(50/63)、95.65%(22/23)、95.00%(38/40)。结论:基于PCD-CT采集的能谱定位像可以准确定量股骨颈的骨密度,并表现出较高的异常骨量诊断效能。展开更多
CBCT scanners have been widely used in angiography,radiotherapy guidance,mammography and oral maxillofacial imaging.To cut detector size,reduce manufacturing costs and radiation dose while keeping a reasonable FOV,the...CBCT scanners have been widely used in angiography,radiotherapy guidance,mammography and oral maxillofacial imaging.To cut detector size,reduce manufacturing costs and radiation dose while keeping a reasonable FOV,the flat panel detector can be placed off-center horizontally.This scanning configuration extends the FOV effectively.However,each projection is transversely truncated,bringing errors and artifacts in reconstruction.In this paper,a simple but practical method is proposed for this scanning geometry based on truncation compensation and the modified FDK algorithm.Numerical simulations with jaw phantom were conducted to evaluate the accuracy and practicability of the proposed method.A novel CBCT system for maxillofacial imaging is used for clinical test,which is equipped with an off-center small size flat panel detector.Results show that reconstruction accuracy is acceptable for clinical use,and the image quality appears sufficient for specific diagnostic requirements.It provides a novel solution for clinical CBCT system,in order to reduce radiation dose and manufacturing cost.展开更多
基金Supported by National Key Technology R&D Program of the Ministry of Science and Technology(No.2012BAI07B05)
文摘CBCT scanners have been widely used in angiography,radiotherapy guidance,mammography and oral maxillofacial imaging.To cut detector size,reduce manufacturing costs and radiation dose while keeping a reasonable FOV,the flat panel detector can be placed off-center horizontally.This scanning configuration extends the FOV effectively.However,each projection is transversely truncated,bringing errors and artifacts in reconstruction.In this paper,a simple but practical method is proposed for this scanning geometry based on truncation compensation and the modified FDK algorithm.Numerical simulations with jaw phantom were conducted to evaluate the accuracy and practicability of the proposed method.A novel CBCT system for maxillofacial imaging is used for clinical test,which is equipped with an off-center small size flat panel detector.Results show that reconstruction accuracy is acceptable for clinical use,and the image quality appears sufficient for specific diagnostic requirements.It provides a novel solution for clinical CBCT system,in order to reduce radiation dose and manufacturing cost.
