胸部CT血管造影

定义

CT angiography combines a CT scan with the injection of dye. This technique is able to create pictures of the blood vessels in the chest and upper abdomen. CT代表计算机断层扫描.

选择的名字

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

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 multiple 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 chest 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分钟. 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, to be delivered into the body before the test starts. Contrast helps certain areas show up better on x-rays.

• 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 medications before the test in order to safely receive it.
• 在接受对比之前, tell your provider if you take the diabetes medication 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. 如果你的体重超过300磅(135公斤), 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

CT扫描产生的x射线是无痛的. Some people may have discomfort from lying on the hard table.

If you have contrast through a vein, you may have a:

• 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

可以做胸部CT血管造影:

• 如果有肺部血栓的症状, 比如胸痛, 快速的呼吸, 或者呼吸短促
• 胸部受伤或外伤后的
• 在肺部或胸部手术前
• To look for a possible site to insert a catheter for hemodialysis
• For swelling of the face or upper arms that cannot be explained
• To look for a suspected birth defect of the aorta or other blood vessels in the chest
• 检查动脉(动脉瘤)是否扩大
• 在动脉中寻找裂口(解剖)
• 评估心脏周围的某些血管

正常的结果

Results are considered normal if no problems are seen.

异常结果意味着什么

A chest CT may show many disorders of the heart, lungs, or chest area, including:

• 怀疑 上腔静脉阻塞: This large vein moves blood from the upper half of the body to the heart.
• 肺部有血块.
• Abnormalities of the blood vessels in the lungs or chest, such as 主动脉弓综合征.
• 主动脉瘤(在胸部)也称为胸主动脉瘤.
• 的一部分变窄 引出心脏的大动脉(主动脉).
• 动脉壁撕裂(剥离).
• Inflammation of the blood vessel walls (vasculitis).
• 肺血管问题, including narrowing of pulmonary veins of abnormal connections between pulmonary arteries and veins (arteriovenous malformations).

风险

CT扫描的风险包括:

• 暴露在辐射中
• 对造影剂过敏
• 造影剂对肾脏的损害

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) and/or steroids before the test.
• 肾脏帮助将碘排出体外. Those 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. 如果你在考试中呼吸困难, 你应该立即通知扫描仪操作员. Scanners come with an intercom and speakers, so someone can hear you at all times.

参考文献

Carmichael SP, Mowery NT, Martin RS, Meredith JW. 急性创伤的处理. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, eds. 萨比斯顿外科教科书. 21艾德. Philadelphia, PA: Elsevier; 2022:chap 17.

吉尔曼米. Congenital and developmental diseases of the lungs and airways. In: Digumarthy SR, Abbara S, Chung JH，等. 解决胸部影像学问题. Philadelphia, PA: Elsevier; 2020:chap 15.

雾人是的. Angiography: principles, techniques and complications. 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 78.