超声扫描

An ultrasound scan, sometimes called a sonogram, is a procedure that uses high-frequency sound waves to create an image of part of the inside of the body.

An ultrasound scan can be used to monitor an unborn baby, diagnose a condition, or guide a surgeon during certain procedures.

How ultrasound scans work

使用一种称为超声探针的小型设备，它散发出高频声波。

You can't hear these sound waves, but when they bounce off different parts of the body, they create "echoes" that are picked up by the probe and turned into a moving image.

This image is displayed on a monitor while the scan is carried out.

Preparing for an ultrasound scan

Before having some types of ultrasound scan, you may be asked to follow certain instructions to help improve the quality of the images produced.

例如，可能建议您：

• drink water and not go to the toilet until after the scan- 在扫描未出生的婴儿或骨盆区域之前可能需要这一点
• 在扫描之前避免进食或喝几个小时– this may be needed before a scan of your digestive system, including the liver and gallbladder

Depending on the area of your body being examined, the hospital may ask you to remove some clothing and wear a hospital gown.

If you need a sedative to help you relax, this will be given through a small tube into the back of your hand or into your arm.

在某些情况下，您也可能会在扫描前注射一种称为对比剂的无害物质，因为这可以使图像更清晰。

What happens during an ultrasound scan

大多数超声扫描持续15至45分钟。它们通常在医院放射科，由医生，射线照相师或超声检查员进行。

They can also be carried out in community locations such as GP practices, and may be performed by other healthcare professionals, such as midwives or physiotherapists who have been specially trained in ultrasound.

有不同种类的超声扫描，具体取决于扫描身体的哪一部分以及原因。

这三种主要类型是：

• external ultrasound scan – the probe is moved over the skin
• internal ultrasound scan – the probe is inserted into the body
• endoscopic ultrasound scan – the probe is attached to a long, thin, flexible tube (anendoscope) and passed further into the body

这些技术如下所述。

External ultrasound scan

信用：

An external ultrasound scan is most often used to examine the heart or an unborn baby in the womb.

It can also be used to examine the liver, kidneys and other organs in the tummy and pelvis, as well as other organs or tissues that can be assessed through the skin, such as muscles and joints.

A small handheld probe is placed on your skin and moved over the part of your body being examined.

将润滑凝胶放在您的皮肤上，以使探针移动平稳。这也确保了探针和皮肤之间连续接触。

除了皮肤上的传感器和凝胶（通常很冷）外，您不应该有任何感觉。

If you're having a scan of your womb or pelvic area, you may have a full bladder that causes you a little discomfort.

扫描完成后，附近会有一个厕所，可以清空膀胱。

Internal or transvaginal ultrasound scan

信用：

An internal examination allows a doctor to look more closely inside the body at organs such as the prostate gland, ovaries or womb.

A "transvaginal" ultrasound means "through the vagina". During the procedure, you'll be asked to either lie on your back, or on your side with your knees drawn up towards your chest.

A small ultrasound probe with a sterile cover, not much wider than a finger, is then gently passed into the vagina or rectum and images are transmitted to a monitor.

内部检查可能会引起一些不适，但通常不会引起任何疼痛，不应该花很长时间。

内窥镜超声扫描

信用：

During an endoscopic ultrasound scan, an endoscope is inserted into your body, usually through your mouth, to examine areas such as your stomach or food pipe (oesophagus).

通常，您会被要求躺在您的身边，因为内窥镜被小心地向下推向胃。

The endoscope has a light and an ultrasound device on the end. Once it's been inserted into the body, sound waves are used to create images in the same way as an external ultrasound.

通常，您会得到一个镇静剂，使您保持镇定和局部麻醉spray to numb your throat, as an endoscopic ultrasound scan can be uncomfortable and may make you feel sick.

You may also be given a mouth guard to keep your mouth open and protect your teeth, in case you bite the endoscope.

超声扫描后

In most cases, there are no after-effects and you can go home soon after the scan is finished.

如果没有使用镇静剂，您可以直接开车，吃饭，喝酒并返回其他正常活动。

If you had an endoscopic ultrasound and were given a sedative to help you relax, you'll usually be advised to stay in hospital for a few hours until the medication starts to wear off.

您需要安排有人从医院接您，并在接下来的24小时内与您在一起。

在此期间，您不应该开车，喝酒或操作机械。

You may be told the results of your scan soon after it's been carried out, but in most cases the images will need to be analysed and a report will be sent to the doctor who referred you for the scan.

They'll discuss the results with you a few days later or at your next appointment, if one's been arranged.

Are there any risks or side effects?

There are no known risks from the sound waves used in an ultrasound scan. Unlike some other scans, such asCT扫描, ultrasound scans don't involve exposure to辐射.

外部和内部超声扫描没有任何副作用，通常没有痛苦，尽管您可能会感到不适，因为探针被压在皮肤上或插入体内。

如果您进行了内部扫描并且对乳胶过敏，那么让超声检查员或医生进行扫描就知道这一点很重要，以便他们可以使用无乳胶探针盖。

Endoscopic ultrasounds can be a bit more uncomfortable and can cause temporary side effects, such as a sore throat or bloating.

There's also a small risk of more serious complications, such as internal bleeding.