屏蔽或不屏蔽:屏蔽可能会对CT患者剂量产生意想不到的影响
Heli Riitta Sinikka Larjava1, Chibuzor T M Eneh2, Hannele M Niiniviita3
1Department of Medical Physics, Turku University Hospital and University of Turku, Turku, Finland. heli.larjava@varha.fi.
European radiology
|September 14, 2023
概括
患者的外平面屏蔽,旨在减少CT扫描中的辐射剂量,可以悖论地增加它. 这发生在扫描仪使用基于局部化的管电流调制时,导致显著的过度扫描和更高的患者辐射暴露.
科学领域:
- 医疗成像医学成像
- 辐射物理学 辐射物理学
背景情况:
- 在CT中患者屏蔽的目的是尽量减少辐射剂量.
- 外平面屏蔽用于阻止扫描体积之外的散射辐射.
- 管电流调制 (TCM) 是一种在CT中优化辐射剂量的技术.
研究的目的:
- 评估患者外平面屏蔽对胸部CT中管道电流调制 (TCM) 的影响.
- 评估可在定位器图像中看到但在扫描范围之外的外平面屏蔽是否会影响患者的辐射剂量.
- 为了在不同的CT扫描仪型号和供应商中研究这种效应.
主要方法:
- 在三个供应商的六种不同的CT扫描仪上扫描了一个人形幻影.
- 扫描是在扫描范围之外,但在定位器视野内放置的外平面盾牌的情况下和没有进行的.
- 在各种调度设置下记录管道电流值,以分析TCM和超扫描效应.
主要成果:
- 在定位器图像中可见的外平面屏幕显著增加了管道累积电流 (mA),最高记录的增加为217%.
- 在扫描结束之前,管道电流大幅上升,与未扫描数据相比,最终切片的差异为976%.
- 观察到的辐射剂量增加取决于CT扫描仪的TCM算法,特别是那些仅依赖局部化图像的图像.
结论:
- 在扫描体积之外,但在定位器内使用外平面屏蔽可以显著增加患者的辐射剂量.
- 这种剂量增加在使用基于局部化的TCM的CT扫描仪中是明显的.
- 过度扫描,一个潜在的后果,可能是微妙的,在扫描规划期间被忽视,但显著影响患者的辐射剂量.
相关概念视频
Radiological Investigation I: X-ray and CT
278
Radiological investigations, including X-rays and computed tomography (CT) scans, are critical for diagnosing and evaluating various medical conditions. These imaging techniques provide valuable insights into the body's internal structures, aiding in the detection of abnormalities, assessment of disease progression, and development of treatment strategies. This article delves into two primary radiological investigations, chest X-rays and CT scans, outlining their purpose, procedures, and...
278
Diamagnetic Shielding of Nuclei: Local Diamagnetic Current
894
An applied magnetic field causes the electrons present in the molecule to circulate, setting up a local diamagnetic current within the molecule. The local diamagnetic current arising from circulating sigma-bonding electrons induces a magnetic field, Blocal that opposes the applied magnetic field, B0. The effective magnetic field experienced by these nuclei is given by the difference between the applied and local magnetic fields in a phenomenon called local diamagnetic shielding. Essentially,...
894
Imaging Studies for Cardiovascular System V: CT
41
Cardiac computed tomography (CT) scanning is an advanced cardiac imaging technique that utilizes CT technology, with or without intravenous (IV) contrast, to produce accurate cross-sectional virtual slices of specific areas of the heart, coronary circulation, and major blood vessels such as the aorta, pulmonary veins, and arteries. The computer processes these slices to generate three-dimensional images. Multidetector CT (MDCT) is a rapid form of CT scanning that captures multiple slices...
41
Biological Effects of Radiation
15.5K
All radioactive nuclides emit high-energy particles or electromagnetic waves. When this radiation encounters living cells, it can cause heating, break chemical bonds, or ionize molecules. The most serious biological damage results when these radioactive emissions fragment or ionize molecules. For example, α and β particles emitted from nuclear decay reactions possess much higher energies than ordinary chemical bond energies. When these particles strike and penetrate matter, they...
15.5K
Nuclear Power
7.8K
Controlled nuclear fission reactions are used to generate electricity. Any nuclear reactor that produces power via the fission of uranium or plutonium by bombardment with neutrons has six components: nuclear fuel consisting of fissionable material, a nuclear moderator, a neutron source, control rods, reactor coolant, and a shield and containment system.
Nuclear Fuels
Nuclear fuel consists of a fissile isotope, such as uranium-235, which must be present in sufficient quantity to provide a...
Nuclear Fuels
Nuclear fuel consists of a fissile isotope, such as uranium-235, which must be present in sufficient quantity to provide a...
7.8K
Imaging Studies III: Computed Tomography
26
DefinitionComputed Tomography (CT) of the genitourinary (GU) tract is a non-invasive imaging modality that utilizes X-rays and computer processing to generate detailed cross-sectional images of the urinary system, encompassing the kidneys, ureters, bladder, and adjacent structures such as the adrenal glands.PurposeCT scans of the GU tract serve several diagnostic and therapeutic purposes, including:Diagnosis of Urinary Tract Diseases: Detects kidney stones, tumors, cysts, and congenital...
26


