『微课堂』CT、PET、MR有何区别？

本期内容我们将讲解医用领域通过计算机控制的X射线断层扫描系统（CT）与磁共振成像诊断系统（MRI）及正电子放射断层扫描系统（PET）的技术区别。未来我们还会整理更多酷酷的医疗视频给广大临床工作者，这也是一个系列节目

CT stands for Computerized Tomography, a device takes many X-rays from different angles, and uses as a computer to create a three dimensional pictures of the inside of the body.

CT表示的是电子计算机断层扫描，它是一种可以从不同的角度吸收X射线的设备，而且它像计算机一样，可以用来创建人体内部的三维立体影像。

The CT scanner consists of a moving couch, not particularly narrow,that slowly moves a person through a hoop that has a shape of a very large donut.

CT扫描器包括一个不是特别窄的移动检测床，它可以将人慢慢地拖行至一个环形通道，其形状就像是一个巨大的甜甜圈。

The vast majority of people will not experience any sense of claustrophobia. You’ll be held onto the scanner couch by the radiographer.

绝大多数的人们都不会有幽闭恐惧症的感觉，做CT 时，将会有放射科医师帮着把你扶上检查床。

These days, most people go on to the scanner couch first. Before the scan starts, a small needle will usually be inserted into your arm for the injection of a contrast medium, this is a liquid that enhances the definition of scan.

如今，大多数人会先上扫描检查床，在扫描开始之前，会先在你的臂膀上用小针注射造影剂，这是一种可以增强扫描清晰度的液体。

You'll go through the scanner twice. First time is to get a general picture of the whole body, and the second time is to obtain the details of the scan.The actual scan only lasts about 20 seconds, during which time you’ll be asked to hold your breath.

你将进入扫描仪两次。第一次先获得整个身体的大致扫描影像，第二次将获取扫描的细节。实际的扫描仅仅持续大学20秒的时间，在这个过程中将可能会要求你屏住呼吸（最新）。

A more recent innovation is the MRI scan. An MRI scan uses magnetism to build up a three dimensional image of the inside of the body.

最近的一项创新扫描是MRI扫描，一台MRI扫描仪运用磁学原理可以实时构建人体内部的三维图像。

Like the CT scanner, the MRI scan also consists of a moving couch. This slowly moves a person through a cylinder that can be quite narrow, and some people find that this gives them a feeling of claustrophobia. There are a few open MRI scanners available for patients who suffer from claustrophobia which reduces this tunnel effect.

和CT扫描仪一样，MRI扫描仪的构造也包括可移动的检查床，它可以将人慢慢地移动至一个中间相当窄的中空圆筒状设备，有些人们会有一种幽闭恐惧症的感觉。当然也有少部分的开放MRI扫描仪可供那些在接受扫描过程中有幽闭恐惧症感觉的人们使用，这样可以减轻这种隧道反应。

You'll usually go on the scanner seat first, the radiographer give you a button on the end of a wire, so if you have any concerns you can immediately alert the staff. You can also talk to the nurses or radiographer while you are in the scanner.

通常情况下，你可能首先要坐上扫描检查床，放射科医生会给你一个安装在线缆一端的按钮，所以如果你有任何忧虑你可以及时地向工作人员发出警报。即便你在扫描仪里面也可以告诉护士或放射科医师。

As the scan uses magnetism, you need to make sure you’ve removed all metallic objects. You’ll also need to tell the radiologist if you have any internal metallic objects, such as a pacemaker, or if you have any surgical clips.

因为扫描运用磁学原理，所以你需要确保你身上已经去除了所以金属物件。你还需要告诉放射科医生你体内是否有金属物品，比如说心脏起搏器，或者手术芯片之类的东西。

Before the scan starts, a small needle is inserted into your arm for the injection of the contrast medium. While the scan taking place, it can be noisy. As the scan are producing repeated knocking sound，you’ll be offered headphones through which music will be played. It’s okay, you can choose the music you prefer to help reduce the noise and to relax you. The scan lasts for 30 minutes to an hour.

在扫描开始前，可能需要在你的臂膀上扎下小针头来注射造影剂。在扫描过程中会有噪音产生。由于扫描时会不断有敲击的声音产生，所以你将会被提供给一副耳机，在这个过程中可以用来播放音乐，当然这是可以的，你可以选择你喜欢的音乐，这可以帮助减少噪音，而且可以使你得到放松。整个扫描过程会持续30分钟到一个小时的时间。

The latest development in scan is the PET scan. PET stands for Positron Emission Tomography. In this scan, you’ll be given an injection of a rapidly acting radioactive substance that is used in a radioactive form of glucals.

最新的发展是PET扫描。PET表示正电子放射断层造影术。使用这种扫描，你讲会被注射一种极度活跃的(同时快速衰变的)放射性物质，这种物质是具有放射性的乙烯糖。

A PET scan is not as good as a CT or MRI scanning giving a good three dimensional picture of the body, and is therefore usually together with a (lodo?) CT scan to produce better pictures. Sometimes a PET scan may be combined with a full CT scan. The advantage of a PET scan is that the radio activity helps to tell what inside a shadow shown on a CT scan. In particular, whether it is cancer or not. For example, a cancer may have in large lympho glands near to it, and it may be uncertain as to whether they are in large because of cancer or for another reason. The PET will often help sort out this dilemma.

PET 扫描并没有像CT和MRI扫描那样好，因为CT和MRI扫描可以给出清晰的人体三维扫描图像。所以，PET扫描通常和CT扫描组合使用，从而形成更好的影像。有时候PET扫描需要和完整的CT扫描组合工作。PET扫描的优点在于放射波可以帮助我们看出CT扫描影像所显示的阴影部分里面是什么，尤其对于我们区分是否是癌症有很大帮助。例如，恶性肿瘤周围会有大量的淋巴结，但它是否是由于恶性肿瘤造成的还是其他原因造成的很难确定。但是PET就可以帮助区分解决这种困境。

PET scans can also be helpful after treatment for a cancer, to sort out whether the remaining lump is active cancer or is just dead or scar tissue. PET scanner also consists of a moving couch that slowly moves a person through a short tunnel.This is a bit narrower than a CT scan but much wider than an MRI scan, and most people don’t find that it causes claustrophobia.

PET扫描对于癌症治疗后也有帮助，用它可以区分出留下的肿块是阳性肿瘤还是仅仅是死掉的组织或者是伤疤组织。PET扫描诊断设备也包括可以移动的检测床，它可以慢慢地将人移入一段短短的隧道。这个短通道要比CT扫描通道稍微窄一些但是要比MRI扫描宽好多，而且大多数人都不会经历幽闭恐惧症的感觉。

About an hour before the scan starts, a small needle is inserted into your arm for the injection of radio active substance. The time is necessary for the radio active substance to be taken up by the tissues. Unlike the CT and MRI scans, you usually go into the scan on head first. You go into the scanner twice. The First time is to get the CT scan, and the second time to get the PET scan. The CT scan takes just a few seconds, but the PET scan takes around an hour.

大约在扫描开始前的一个小时，需要用小针头在臂膀上注射放射性物质,这一小时的时间是必要的，在此时间内可以让组织吸收注射过的放射性物质。与单纯CT和MRI扫描不同的是，用PET-CT扫描需要先让头部进入扫描仪，而且需要两次进入扫描仪。第一次做CT扫描，第二次做PET扫描。CT扫描只需几秒的时间,但是PET扫描却要花费大约一个小时的时间。

In diagnosing and assessing cancers, ultrasound scans, CT scans, PET scans and MRI scans are often complementary and may give different information. For example, for some cancers, CT scans will give more accurate information, whereas for others, MRI scan is better. For others a PET-CT scan gives the best information. So the choice of which sort of scan is used depends on which type of cancer is suspected or being investigated. Often, the combination of some, or occasionally, all of these scans may be used in an individual.

在诊断和评估癌症时，超声波扫描、CT扫描、PET扫描和MRI扫描通常是互补运用的，而且不同的使用方式可能会给予不同的信息。例如，对于某些癌症，CT扫描会给予更加准确的信息；然而对于其它一些癌症，运用MRI扫描效果会更好；还有一些癌症，运用PET-CT扫描可以提供最佳信息。所以，具体选择哪种方式扫描取决于怀疑是哪种癌症或研究哪种癌症。通常情况下，几种扫描方式组合使用，或者在某些场合下，对于同一个人甚至会运用以上提到的所有扫描方式。

微课堂是我们的最新专业服务板块，主要给临床医生和医疗器械相关从业人员（让你迅速从小白变大神的有力武器）提供全球最新的医疗科技、新产品视频。这些专业医疗器械产品相关技术的最新视频，未来也会扩展到其它学科领域，按照不同学科细分子频道。

如果你的英文足够好，愿意帮助大家（翻译成中文）共同提高，也愿意加入我们成为志愿者，可以后台和我们联系。

如需要转载 请后台联系我们，或者发邮件至[e-mail]