核专业英语

1、Introduction

Radiology is the medical specialty concerned with the study and application of x-rays and other technologies (such as ultrasound and magnetic resonance) to produce and interpret images of the human body for the diagnosis of disease. X-rays are invisible waves of energy that are produced by an energy source (such as an x-ray machine or cathode ray tube) and are useful in the diagnosis and treatment of disease. Nuclear medicine is the medical specialty that uses radioactive substances in the diagnosis and treatment of disease. These radioactive substances (radionuclides) are materials that emit high-speed particles and energy-containing rays from the interior of their matter. The emitted particles and rays are called radioactivity and can be of three types: alpha particles, beta particles, and gamma rays. Gamma rays are used effectively as a diagnostic label to trace the path and uptake of chemical substances in the body.

放射学是研究和应用x射线和其他技术(如超声波和磁共振)来做出和解释人体图像，来诊断疾病的医学专业。x射线是由能量源(如x光机或阴极射线管)产生的不可见的能量波，对疾病的诊断和治疗有很大作用。核医学是利用放射性物质进行疾病诊断和治疗的医学专业。这些放射性物质(放射性核素)是从物质内部发射高速粒子和含能射线。发射出粒子和射线的能力称为放射性，放射性物质有三种类型：α粒子，β粒子和γ射线。γ射线被有效地用作一种诊断工具，以追踪化学物质在体内的路径和吸收。

Several characteristics of x-rays are useful to physicians in the diagnosis and treatment of disease.

Some of these characteristics are the following:

x射线的一些特征对医生诊断和治疗疾病是有用的。

其中一些特征如下：

①Ability to cause exposure of a photographic plate. If a photographic plate is placed in front of a beam of x-rays, the x-rays, traveling unimpeded through the air, will expose the silver coating of the plate and cause it to blacken.

使感光平面曝光的能力。如果把感光平面放在一束x射线前，x射线在空气中无阻地传播，就会使感光板的镀银层暴露出来，使其变黑。

②Ability to penetrate different substances to varying degrees. X-rays pass through the different types of substances in the human body (air in the lungs, water in blood vessels and lymph, fat around muscles, and metal such as calcium in bones) with varying ease. Air is the least dense substance and allows the greatest transmission. Fat is denser, water is next, followed by hard materials, such as calcium in bone, which is the densest and transmits least. If the x-rays are absorbed (stopped) by the denser body substance (e.g., calcium in bones), they do not reach the photographic plate held behind the patient, and white areas are left in the x-ray detector (plate).

能在不同程度上穿透不同物质。x光穿透人体不同类型的物质(肺部的空气，血管和淋巴液中的水，肌肉周围的脂肪，骨骼中的钙等金属)的能力各不相同。空气是密度最小的物质，传播力最大。脂肪密度较大，其次是水，其次是硬物质，如骨中的钙，它是密度最大，传递最少的。如果x光被较密集的身体物质(如骨骼中的钙)吸收(停止穿透)，它们就不能到达病人身后的感光板，在x光检测器(感光板)上呈现空白区域。

③Invisibility. X-rays cannot be detected by sight, hearing, or touch. Workers exposed to x-rays must wear a film badge to detect and record the amount of radiation to which they have been exposed.

不可见。视觉、听觉和触觉都无法感觉到x射线。暴露在x光下的工作人员必须佩戴一个胶片标记，以检测和记录他们所受到的辐射量。

④Travel in straight lines. This property allows the formation of precise shadow images on the x-ray plate and also permits x-ray beams to be directed accurately at a tissue site during radiotherapy.

走直线。这种特性允许x线形成精确的图像，也允许其在放射治疗期间精确地定向并到达组织部位。

⑤Scattering of x-rays. Scattering occurs when x-rays come into contact with any material. Greater scatter occurs with dense objects and less scatter with those substances that are radiolucent. In digital imaging, an image receptor replaces film.

x射线的散射作用。当x射线与任何物质接触时就会发生散射。密度大的物体会产生较大的散射，而那些有辐射的物质会产生较小的散射。在数字成像技术中，图像接收器代替胶片。

⑥Ionization. X-rays have the ability to ionize substances through which they pass. Ionization is a chemical process in which the energy of an x-ray beam causes rearrangement and disruption within a substance, so that previously neutral particles are changed to charged particles called ions. This strongly ionizing ability of x-rays is a double-edged sword. In x-ray or radiation therapy, the ionizing effect of high energy x-ray beams can help kill cancerous cells and stop tumor growth; however, ionizing x-rays in even small doses can affect normal body cells, leading to tissue damage and malignant changes. Thus, persons exposed to high doses of x-rays are at risk for the development of leukemia, thyroid tumors, breast cancer, or other malignancies. 

电离。x射线有使其通过的物质发生电离的能力。电离是一种化学过程，在这个过程中，x射线束的能量会导致物质内部的重排和破坏，使之前的中性粒子变成带电粒子，即离子。x射线的强电离能力是一把双刃剑。在x射线或放射治疗中，高能x射线束的电离效应可以帮助杀死癌细胞和阻止肿瘤生长；然而，即使是小剂量的电离x射线也会影响正常的身体细胞，导致组织损伤和恶性变化。因此，暴露于高剂量x射线下的人有发展为白血病、甲状腺肿瘤、乳腺癌或其他恶性肿瘤的风险。

①X-Ray Studies

X-ray imaging is used in a variety of ways to detect pathologic conditions. Digital radiography is a form of x-ray imaging in which digital x-ray sensors are used instead of traditional photographic film. Thus images can be enhanced and transferred easily, and less radiation can be used than in conventional radiography. The chest x-ray is the most commonly performed diagnostic x-ray examination. Mammography uses low-dose x-rays to visualize breast tissue.

①x射线

x射线成像用于多种方式来检测疾病。数字射线照相是x射线成像的一种形式，用数字x射线传感器代替传统的照相胶片。因此，图像可以容易地被加强或转换，并可以比传统的射线照相使用更少的辐射。胸部x光检查是最常见的诊断性x光检查。乳房x线照相术使用低剂量x射线来可视化乳房组织。

②Computed Tomography (CT)

The CT scan, sometimes called “CAT scan” (because the technique originally was known as “computerized axial tomography”), is made by beaming x-rays at multiple angles through a section of the patient's body. The absorption of all of these x-rays, after they pass through the body, is recorded and used by a computer to create multiple cross-sectional images. The ability of a CT scanner to detect abnormalities is increased with the use of iodine-containing contrast agents, which outline blood vessels and confer additional density to soft tissues.

②计算机断层扫描(CT)

CT扫描，有时也被称为“CAT扫描”(因为这项技术最初被称为“计算机轴向断层扫描”)，是将x射线从多个角度射向病人身体的一个部位。所有这些x射线经过人体吸收后的情况会被记录下来，并由计算机生成多个横截面图像。含碘造影剂的使用，增强了CT扫描仪检测异常的能力，这种造影剂能勾勒出血管轮廓，增加软组织的密度。

③Contrast Studies

A contrast material used in diagnostic radiologic studies: Barium Sulfate. Barium sulfate is a radiopaque substance that is mixed in water and used for examination of the upper and lower GI (gastrointestinal) tract. An upper GI series (UGI) involves oral ingestion of barium sulfate so that the esophagus, stomach, and duodenum can be visualized. A barium enema (BE) study is a lower GI series that opacifies the lumen (passageway) of the large intestine using an enema containing barium sulfate. This test has largely been replaced by endoscopy, which allows visualization of the inside of the bowel. A double-contrast study uses both a radiopaque and a radiolucent contrast medium.

用于诊断放射学研究的造影剂——硫酸钡，是一种不溶于水的不透明物质，用于检查上、下消化道。上消化道系列(UGI)包括口服硫酸钡，可以看到食道、胃和十二指肠。钡剂灌肠(BE)是利用含有硫酸钡的灌肠液观察不透明的下消化道——大肠腔。这种检查在很大程度上已经被内窥镜所取代，内窥镜可以让你看到肠道内部。双重对比研究使用了不透明和透明的对比介质。