CT血管造影-头颈部

定义

CT angiography (CTA) combines a CT scan with the injection of dye. CT代表计算机断层扫描. This technique is able to create pictures of the blood vessels in the head and neck.

选择的名字

Computed tomography angiography - brain; CTA - skull; CTA - cranial; TIA-CTA head; 中风-CTA head; Computed tomography angiography - neck; CTA - neck; Vertebral artery - CTA; Carotid artery stenosis - CTA; Vertebrobasilar - CTA; Posterior circulation ischemia - CTA; TIA - CTA neck; 中风 - CTA neck

如何执行测试

You will be asked to lie on a narrow table that slides into the center of the CT scanner.

While inside the scanner, the machine's x-ray beam rotates around you.

A computer creates many separate images of the body area, called slices. These images can be stored, viewed on a monitor, or printed on film. Three-dimensional models of the head and neck area can be created by stacking the slices together.

You must be still during the exam, because movement causes blurred images. You may be told to hold your breath for short periods of time.

完整的扫描通常只需要几秒钟. The newest scanners can image your entire body, head to toe, in less than 30 seconds.

如何准备考试

某些检查需要一种特殊的染料, 叫对比, 在测试开始前被输送到体内. 对比有助于某些区域在x射线上表现得更好.

• Contrast can be given through a vein (IV) in your hand or forearm. 如果使用对比, you may also be asked not to eat or drink anything for 4 to 6 hours before the test.
• Let your health care provider know if you have ever had a reaction to contrast. You may need to take medicines before the test in order to safely receive it.
• 在接受对比之前, tell your provider if you take the diabetes medicine metformin (Glucophage). 你可能需要采取额外的预防措施.

The contrast can worsen kidney function problems in people with poorly functioning kidneys. Talk to your provider if you have a history of kidney problems.

重量太大会损坏扫描仪. If you weigh more than 300 pounds (about 135 kilograms), talk to your provider about the weight limit before the test.

You will be asked to remove jewelry and wear a hospital gown during the study.

考试的感觉如何

Some people may have discomfort from lying on the hard table.

如果你通过静脉造影，你可能有:

• 轻微的灼烧感
• 嘴里有金属的味道
• 你的身体温暖地潮红

This is normal and usually goes away within a few seconds.

为什么要进行测试

CTA of the head may be done to look for the cause of:

• 思想或行为的变化
• 发音困难
• 头晕或眩晕
• 重影或视力丧失
• 晕倒
• Headache, when you have certain other signs or symptoms
• 听力损失(部分人)
• 麻木或刺痛，多见于脸部或头皮
• 吞咽问题
• 中风
• 短暂性脑缺血发作
• 你身体某个部位的弱点

颈部CTA也可以做:

• After trauma to the neck to look for damage to blood vessels
• 之前的计划 颈动脉手术
• 为脑肿瘤手术做计划
• 因涉嫌 vasculitis (inflammation of the blood vessel walls)
• 因涉嫌 脑内血管异常

正常的结果

如果没有发现任何问题，则认为结果正常.

异常结果意味着什么

异常结果可能是由于:

• 血管异常(动静脉畸形).
• 脑部出血(例如， 硬脑膜下血肿 或出血部位).
• 脑瘤或其他生长(肿块).
• 中风.
• 颈动脉狭窄或阻塞. (The carotid arteries provide the main blood supply to your brain. 它们位于你脖子的两侧.)
• 颈部椎动脉狭窄或阻塞. (The vertebral arteries provide blood flow to the back of the brain.)
• 动脉壁上的裂口(夹层).
• A weak area in the wall of a blood vessel that causes the blood vessel to bulge or balloon out (动脉瘤).

风险

CT扫描的风险包括:

• 暴露在辐射中
• 对造影剂过敏
• 染料会损害肾脏

CT扫描比普通x射线使用更多的辐射. Having many x-rays or CT scans over time may increase your risk for cancer. 然而，任何一次扫描的风险都很小. You and your provider should weigh this risk against the benefits of getting a correct diagnosis for a medical problem. Most modern scanners use techniques to use less radiation.

有些人对造影剂过敏. Let your provider know if you have ever had an allergic reaction to injected contrast dye.

• The most common type of contrast given into a vein contains iodine. 如果你对碘过敏，你可能有 恶心或呕吐, 打喷嚏, 瘙痒, or 荨麻疹 如果你得到这种对比.
• 如果你一定要给这样的对比, your provider may give you antihistamines (such as Benadryl) or steroids before the test.
• 肾脏帮助将碘排出体外. People with kidney disease or diabetes may need to receive extra fluids after the test to help flush the iodine out of the body.

Rarely, the dye may cause a life-threatening allergic response called 速发型过敏反应. Tell the scanner operator right away if you have any trouble breathing during the test. Scanners come with an intercom and speakers, so the operator can hear you at all times.

注意事项

A CT scan can reduce or avoid the need for invasive procedures to diagnose problems in the skull. This is one of the safest ways to study the head and neck.

Other tests that may be done instead of CT scan of the head include:

• 头部MRI
• 头部正电子发射断层扫描(PET)扫描

参考文献

Barras CD, Bhattacharya JJ. Current status of imaging of the brain and anatomical features. 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 53.

维波德FJ，奥洛斯基HLP. Neuroradiology: the surrogate of gross neuropathology. 见:Perry A, Brat DJ，编辑. Practical Surgical Neuropathology: A Diagnostic Approach. 第二版. Philadelphia, PA: Elsevier; 2018:chap 4.