Patient Exposure and Image Quality in Medical X-ray Imaging

医学 X 射线成像中的患者曝光和图像质量

• 批准号: 60580182
• 负责人: KANAMORI Hitoshi
• 金额: $ 0.7万
• 依托单位: Kyoto Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1986
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-60580182/
• 关键词: Medical x-ray imaging; Patient exposure; 画質; X線スペクトル

In diagnostic radiography, a large x-ray tube current value of hundreds mA is required. Therefore, in measuring x-ray spectra with the factors used in diagnostic radiography, a germanium detector receives too large photon fluence rate which causes great error due to the pile up phenomenon. We have developed low capacity cables, and reduced the photon fluence rate by decreasing the tube current to less than a few mA without changing the high voltage waveforms. Then the measurement of the x-ray spectra with diagnostic radiographic factors was readily performed.Photon spectra were measured for various tube-voltage ripple rates, and various object thickness of aluminum and acrylic resin at 70 kV. The photon spectra were converted to energy spectra and exposure spectra, and then attenuation curves were obtained.Dependence of relative exposures at surface position of objects and mAs values on high-voltage ripple-rate was estimated using X-ray spectra, spectral speeds of the six screen-film systems, exposure attenuation curves, and speed attenuation curves. It has been verified quantitatively that 3-phase X-ray units are better than single-phase X-ray units from the view points of patient exposure and image quality in diagnostic radiology.

在诊断射线照相中，需要数百mA的大X射线管电流值。因此，在用诊断射线照相中使用的因素测量X射线能谱时，由于堆积现象，锗探测器接收的光子注量率太大，造成很大的误差。我们开发了小容量电缆，在不改变高压波形的情况下，将管电流降低到几毫安以下，从而降低了光子注量率。测量了不同管电压波纹率、不同厚度的铝和丙烯酸树脂在70千伏时的光子光谱。将光子谱转换为能谱和曝光谱，得到衰减曲线，利用X射线光谱、6种屏膜系统的光谱速度、曝光衰减曲线和速度衰减曲线估算了物体表面位置的相对曝光量和mAs值对高压波纹率的依赖关系。从诊断放射学患者曝光和图像质量的角度，定量地验证了三相X线机优于单相X线机。

项目成果

H. Kanamori: "Measurement of diagnostic x-ray spectra with small-capacity high-voltage cables" Medical and Biological Engineering and Computing. 23, S2. 1334-1335 (1985)

H. Kanamori：“用小容量高压电缆测量诊断 X 射线光谱”医学和生物工程与计算。

M. Matsumoto: "Measurement of Diagnostic X-ray Spectra for Various High-Voltage Waveforms - 70 kVp" Japanese Journal of Medical Imaging and Information Sciences. 3. 39-50 (1986)

M. Matsumoto：“各种高压波形的诊断 X 射线光谱的测量 - 70 kVp”日本医学影像和信息科学杂志。

M. Matsumoto: "Dependence of Relative Exposure at Surface Position and mAs Values on High-Voltage Ripple-Rates,Estimated from X-ray Spectra" Japanese Journal of Medical Imaging and Information Sciences. 3. 81-88 (1986)

M. Matsumoto：“表面位置相对曝光和 mAs 值对高压纹波率的依赖性，根据 X 射线光谱估算”《日本医学影像与信息科学杂志》。

松本政雄: 医用画像情報学会雑誌. 3. 81-88 (1986)

Masao Matsumoto：医学影像与信息科学学会杂志，3. 81-88 (1986)。

松本政雄: 医用画像情報学会雑誌. 4. (1987)

松本正男：医学影像与信息科学学会杂志 4。（1987）。