2022年6月13日 · CT值的是测定人体某一局部组织或器官密度大小的一种 [计量单位]，通常称亨氏单位 (hounsfield unit ，HU）。 CT值又叫HU值，HU（Hounsfiled Unit）值，反映了组织对X射线吸收程度. 以水的吸收程度作为参考，即水的HU=0，衰减系数大于水的为正直，小于水的为负值。 并以骨皮质和空气的HU值为上限和下限，空气为-1000，致密骨为+1000。 为了计算与论述方便，Hounsfield 将线性衰减系数划分为2000 个单位，称为CT 值。 以水吸收程度作为参考，即水 …

In CT scan, Hounsfield Unit (HU) is proportional to the degree of x-ray attenuation by the tissue. In CBCT, the degree of x-ray attenuation is shown by gray scale (voxel value). The aim of the present study was to investigate the relationship between gray scale in CBCT) and Hounsfield Unit (HU) in CT scan. Materials and methods.

2022年8月3日 · Assessing bone density in prospective dental implant sites is crucial both for choosing the implant type and for planning a drilling procedure that will ensure the implant’s primary stability and osseointegration. This study aimed to investigate possible differences between the bone densities of various edentulous sites in the maxilla and mandible.

乳腺CBCT性能检测模体 用于乳腺CBCT（乳腺颌面锥形束计算机断层扫描） 设备质量控制性能检测 。 符合 WS 818-2023《锥形束 X 射线计算机体层成像（ CBCT）设备质量控制检测标准》 。 模体模拟女性乳腺的大小和形状， 模体里面包含了不同的乳腺组织替代品来模拟真实的乳腺组织。 模体包含了 3 个模块， 分别是均匀性模块 、高对比分辨力测试模块 、低对比分辨力测试模块 ，水的CT值模块等。 A.2. 检测项目. 可检测的性能指标有： 图像均匀性 、高对比分辨力 、低对比 …

2020年10月19日 · Routine quality assurance (QA) of cone-beam computed tomography (CBCT) scans used for image-guided radiotherapy is prescribed by the American Association of Physicists in Medicine Task Group (TG)-142 report. For CBCT image quality, TG-142 recommends using clinically established baseline values as QA tolerances.

2022年11月8日 · HU（Hounsfiled Unit）值，反映了组织对X射线吸收程度。 以水的吸收程度作为参考，即水的HU=0，衰减系数大于水的为正直，小于水的为负值。 并以骨皮质和空气的HU值为上限和下限。

2012年8月1日 · The aim of this work was (1) to assess the accuracy of CBCT-based dose calculation for two HU adjustment approaches based on density assignments, which do not require knowledge about CBCT gray values and (2) to benchmark them against population-based HU-ED CBCT dose calculation and the original CT treatment plan.

2010年9月1日 · Precise calibration of Hounsfield units (HU) to electron density (HU-density) is essential to dose calculation. On-board kV cone beam computed tomography (CBCT) imaging is used predominantly for patients' positioning, but will potentially be used for dose calculation.

HU numbers from CBCT scans have been corrected for scatter and image artefacts (Depuydt et al 2006). Recent work (Richter et al 2008) found that HU numbers depended highly on acquisition parameters for the Elekta XVI system and showed differences from FBCT values and in dose calculations when CBCT data are used.

CBCT有潜力成为一种非常有用的在线ART工具 [1] ，通过每天计划的再优化能对正常组织起到更好地保护作用 [2] ；而对于治疗位置和剂量验证、治疗计划和计划再调整而言，日常治疗时所获取CBCT影像的有效性很大程度上依赖于其图像质量及其CT (hounsfi eld units, HU)值 ...