腹部核磁共振扫描

定义

An abdominal magnetic resonance imaging scan is an imaging test that uses powerful magnets and radio waves. The waves create pictures of the inside of the belly area. 它不使用辐射(x射线).

Single magnetic resonance imaging (MRI) images are called slices. The images can be stored on a computer, viewed on a monitor, printed on film or scanned to a disk. One exam produces dozens or sometimes hundreds of images.

选择的名字

Nuclear magnetic resonance - abdomen; NMR - abdomen; Magnetic resonance imaging - abdomen; MRI of the abdomen; Liver MRI - abdomen; Pancreas MRI - abdomen; Kidney MRI - abdomen

如何执行测试

You may be asked to wear a hospital gown or clothing without metal zippers or snaps (such as sweatpants and a t-shirt). 某些类型的金属会导致图像模糊.

你将躺在一张狭窄的桌子上. The table slides into a large tunnel-shaped scanner.

有些检查需要特殊的染料(造影剂)。. Most of the time, the dye is given during the test through a vein (IV) in your hand or forearm. The dye helps the radiologist see certain areas more clearly.

During the MRI, the person who operates the machine will watch you from another room. The test lasts about 30 to 60 minutes, but it may take longer.

如何准备考试

You may be asked not to eat or drink anything for 4 to 6 hours before the scan.

Tell your health care provider if you are afraid of close spaces (have claustrophobia). You may be given a medicine to help you feel sleepy and less anxious. Your provider may also suggest an open MRI, in which the machine is not as close to your body.

在测试前，告诉你的十大赌博平台排行榜你是否有:

• 人工心脏瓣膜
• 脑动脉瘤夹
• 心脏除颤器或起搏器
• 内耳(耳蜗)植入物
• Kidney disease or dialysis (you may not be able to receive contrast)
• 最近放置的人工关节
• 某些类型的血管 支架
• Worked with sheet metal in the past (you may need tests to check for metal pieces in your eyes)

因为核磁共振成像含有强磁铁, metal objects are not allowed into the room with the MRI scanner. 避免携带下列物品:

考试的感觉如何

核磁共振检查不会引起疼痛. You may get medicine to relax you if you have a problem lying still or are very nervous. Moving too much can blur MRI images and cause errors.

The table may be hard or cold, but you can ask for a blanket or pillow. The machine makes loud thumping and humming noises when turned on. 你可以戴上耳塞来减少噪音.

An intercom in the room allows you to speak to someone at any time. Some MRI facilities have televisions and special headphones to help you pass time.

There is no recovery time, unless you were given a medicine to help you relax. After an MRI scan, you can go back to your normal diet, activity, and medicines.

为什么要进行测试

An abdominal MRI provides detailed pictures of the belly area from many views. It is often used to clarify findings from earlier ultrasound or CT 扫描检查.

这个测试可以用来看:

• 血液在腹部流动
• 腹部的血管
• 腹痛引起腹部疼痛或肿胀的原因
• The cause of abnormal blood test results, such as liver or kidney problems
• 腹部的淋巴结
• Masses in the liver, kidneys, adrenals, 胰腺, or spleen

MRI可以区分肿瘤和正常组织. This can help your provider know more about the tumor such as size, severity, and spread. 这叫做分期.

In some cases it can give better information about masses in the abdomen than CT.

异常结果意味着什么

出现异常结果可能是由于:

• 腹主动脉瘤
• 脓肿
• 癌症 or tumors that involves the adrenal glands, liver, gallbladder, 胰腺比如肾、输尿管、肠或膀胱
• 脾脏肿大 或肝脏
• 胆囊或 胆汁 管问题
• 肝血管瘤
• 肾盂积水 (尿液回流导致肾脏肿胀)
• 肾脏感染
• 肾脏损伤或疾病
• 肾结石
• 淋巴结肿大
• 下腔静脉阻塞
• 门静脉阻塞(肝脏)
• Blockage or narrowing of the arteries that supply the kidneys
• 肾静脉血栓形成
• 肾或肝 移植排斥反应
• 肝硬化
• 癌症从腹部外开始扩散

风险

核磁共振不使用电离辐射. No side effects from the magnetic fields and radio waves have been reported.

The most common type of contrast (dye) used is gadolinium. 它很安全. 过敏反应很少见，但也可能发生. If you have a history of severe allergic reactions to other medicines you should notify your doctor. In addition, gadolinium can be harmful to people with kidney problems who need dialysis. Tell your provider before the test if you have kidney problems.

The strong magnetic fields created during an MRI can cause heart pacemakers and other implants not to work as well. The magnets can also cause a piece of metal inside your body to move or shift.

参考文献

Al Sarraf AA, McLaughlin PD, Maher MM. Current status of imaging of the gastrointestinal tract. In: Adam A, Dixon AK, Gillard JH, Schaefer-Prokop CM, eds. 格兰杰 & Allison's Diagnostic Radiology: A Textbook of Medical Imaging. 7日艾德. Philadelphia, PA: Elsevier; 2021:chap 18.

莱文MS，戈尔RM. 胃肠病学诊断成像程序. 参见:Goldman L, Schafer AI主编. Goldman-Cecil医学. 26日艾德. Philadelphia, PA: Elsevier; 2020:chap 124.

milto A, Boll DT. Liver: normal anatomy, imaging techniques, and diffuse diseases. 见:Haaga JR, Boll DT编. 全身CT和MRI. 6日艾德. Philadelphia, PA: Elsevier; 2017:chap 43.