CT angiography - chest

Definition

CT血管造影结合了CT扫描和注射染料. 这项技术能够绘制出胸部和上腹部血管的图像. CT stands for computed tomography.

Alternative Names

Computed tomography angiography - thorax; CTA - lungs; Pulmonary embolism - CTA chest; Thoracic aortic aneurysm - CTA chest; Venous thromboembolism - CTA lung; Blood clot - CTA lung; Embolus - CTA lung; CT pulmonary angiogram

How the Test is Performed

你将被要求躺在一张狭窄的桌子上，这张桌子滑进了CT扫描仪的中心.

在扫描仪内，机器的x射线束围绕着你旋转.

计算机生成人体区域的多个独立图像，称为切片. 这些图像可以存储，在显示器上观看，或打印在胶片上. 通过将切片堆叠在一起，可以创建胸部区域的三维模型.

考试时你必须保持不动，因为移动会使图像模糊. 你可能会被告知短时间屏住呼吸.

Complete scans usually take only a few minutes. 最新的扫描仪可以在30秒内对你的全身进行从头到脚的扫描.

How to Prepare for the Test

Certain exams require a special dye, called contrast, 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.

• 造影剂可以通过手或前臂的静脉注射. If contrast is used, 您也可能被要求在测试前4到6小时内不要吃或喝任何东西.
• 让你的医疗保健提供者知道你是否曾经对对比有过反应. 您可能需要在测试前服用药物，以便安全地接受测试.
• Before receiving the contrast, 如果你服用糖尿病药物二甲双胍(Glucophage)，请告知十大赌博平台排行榜. You may need to take extra precautions.

对于肾功能不佳的人来说，这种对比会加重肾功能问题.  如果你有肾脏问题的历史，和你的十大赌博平台排行榜谈谈.

Too much weight can damage the scanner. If you weigh more than 300 pounds (135 kilograms), 在测试前和你的十大赌博平台排行榜谈谈体重限制.

在研究过程中，您将被要求摘掉首饰并穿上病号服.

How the Test will Feel

The x-rays produced by the CT scan are painless. 有些人躺在坚硬的桌子上可能会感到不舒服.

如果你通过静脉造影，你可能有:

• Slight burning feeling
• Metallic taste in your mouth
• Warm flushing of your body

这是正常的，通常会在几秒钟内消失.

Why the Test is Performed

A chest CT angiogram may be done:

• For symptoms that suggest blood clots in the lungs, such as chest pain, rapid breathing, or shortness of breath
• After a chest injury or trauma
• Before surgery in the lung or chest
• 寻找一个可能的位置插入血液透析导管
• 面部或上臂肿胀，无法解释
• 检查是否有主动脉或其他胸腔血管的先天缺陷
• To look for a widening of an artery (aneurysm)
• To look for a tear in an artery (dissection)
• To assess certain blood vessels around the heart

Normal Results

如果没有发现任何问题，则认为结果正常.

What Abnormal Results Mean

胸部CT可显示心脏、肺或胸部的许多疾病，包括:

• Suspected blockage of the superior vena cava这条大静脉将血液从身体的上半部分输送到心脏.
• Blood clot(s) in the lungs.
• 肺或胸腔血管的异常，如 aortic arch syndrome.
• Aortic aneurysm (in the chest area), also called thoracic aortic aneurysm.
• Narrowing of part of the major artery leading out of the heart (aorta).
• Tear in the wall of an artery (dissection).
• 血管壁炎症(血管炎).
• Problems with pulmonary vessels, 包括肺静脉狭窄或肺动脉与肺静脉连接异常(动静脉畸形).

Risks

Risks of CT scans include:

• Being exposed to radiation
• Allergic reaction to contrast dye
• Damage to kidneys from contrast dye

CT scans use more radiation than regular x-rays. 长期进行多次x光或CT扫描可能会增加患癌症的风险. However, the risk from any one scan is small. 你和你的十大赌博平台排行榜应该权衡这种风险和对医疗问题做出正确诊断的好处. 大多数现代扫描仪都采用了减少辐射的技术.

Some people have allergies to contrast dye. 如果你曾经对注射造影剂有过敏反应，让你的十大赌博平台排行榜知道.

• 最常见的静脉造影剂含有碘. If you have an iodine allergy, you may have nausea or vomiting, sneezing, itching, or hives if you get this type of contrast.
• If you absolutely must be given such contrast, 十大赌博平台排行榜可能会在检查前给你开抗组胺药(如苯海拉明)和/或类固醇.
• The kidneys help remove iodine out of the body. 那些患有肾脏疾病或糖尿病的人可能需要在测试后接受额外的液体来帮助将碘排出体外.

这种染料很少会引起危及生命的过敏反应 anaphylaxis. If you have any trouble breathing during the test, you should notify the scanner operator immediately. 扫描仪配有对讲机和扬声器，因此有人可以随时听到您的声音.

References

Carmichael SP, Mowery NT, Martin RS, Meredith JW. Management of acute trauma. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL，编辑. Sabiston Textbook of Surgery. 21st ed. Philadelphia, PA: Elsevier; 2022:chap 17.

Gilman M. 肺和气道的先天性和发育性疾病. In: Digumarthy SR, Abbara S, Chung JH, eds. Problem Solving in Chest Imaging. Philadelphia, PA: Elsevier; 2020:chap 15.

Reekers JA. 血管造影术:原理、技术和并发症. 见:Adam A, Dixon AK, Gillard JH, Schaefer-Prokop CM，编. Grainger & 艾利森诊断放射学:医学影像教科书. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 78.