Head CT scan
Definition
A head
Alternative Names
Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain
How the Test is Performed
头部CT在十大赌博平台排行榜或放射中心进行.
你躺在一张狭窄的桌子上,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.
计算机生成身体区域的独立图像,称为切片. These images can be:
- Stored
- Viewed on a monitor
- Printed on film
- Saved to a disk
头部区域的三维模型可以通过将切片堆叠在一起来创建.
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.
一次完整的扫描通常只需要30秒到几分钟.
How to Prepare for the Test
某些CT检查需要一种特殊的染料,称为造影剂. 它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, 如果您正在服用糖尿病药物二甲双胍(Glucophage),请告知您的十大赌博平台排行榜. You may need to take extra precautions. 如果你有任何肾功能问题,也要让你的十大赌博平台排行榜知道,因为静脉造影剂会加重肾功能问题.
如果您的体重超过300磅(135公斤),请查看CT机是否有重量限制. Some machines do.
在研究过程中,您将被要求摘掉首饰,并可能需要穿病号服.
How the Test will Feel
CT扫描产生的x射线是无痛的. 有些人躺在坚硬的桌子上可能会感到不舒服.
通过静脉注射造影剂可能导致:
- Slight burning feeling
- Metallic taste in the mouth
- Warm flushing of the body
这是正常的,通常会在几秒钟内消失.
Why the Test is Performed
建议进行头部CT扫描,以帮助诊断或监测以下情况:
- 出生时(先天性)头部或脑部的缺陷
- Brain infection
- Brain tumor
- Buildup of fluid inside the skull (
hydrocephalus ) - 脑部、头部或面部的损伤(创伤
Stroke - Bleeding in or around the brain
它也可以用来寻找以下原因:
- Abnormal head size in children
- Changes in thinking or behavior
- Fainting
- 头痛,当你有某些其他体征或症状时
- Hearing loss (in some people)
- Symptoms of damage to part of the brain, such as vision problems, muscle weakness, numbness and tingling, hearing loss, speaking difficulties, or swallowing problems
What Abnormal Results Mean
Abnormal results may be due to:
- Abnormal blood vessels (
arteriovenous malformation ) - Bulging blood vessel in the brain
(aneurysm) - Bleeding (for example,
subdural hematoma or bleeding in the brain tissue) - Bone infection
Brain abscess or infection- Brain damage due to injury
- Brain tissue swelling or injury
- Brain tumor or other growth (mass)
- Loss of brain tissue
(cerebral atrophy) - Hydrocephalus
- Problems with the hearing nerve
- Stroke or
transient ischemic attack (TIA)
Risks
Risks of CT scans include:
- Being exposed to radiation
- Allergic reaction to contrast dye
- Kidney damage from the contrast dye
CT扫描比普通x射线使用更多的辐射. 长期进行多次x光或CT扫描可能会增加患癌症的风险. 然而,任何一次扫描的风险都很小. 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.
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. 如果一个对碘过敏的人接受这种对比, nausea or vomiting, sneezing, itching, or
hives may occur. - 如果你一定要给这样的对比, 你的十大赌博平台排行榜可能会在测试前给你抗组胺药(如苯海拉明)或类固醇,以防止过敏反应.
- 肾脏帮助排出体内的碘. 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.
在极少数情况下,这种染料可能会引起危及生命的过敏反应
Considerations
CT扫描可以减少或避免诊断颅骨问题的侵入性手术. 这是研究头部和颈部最安全的方法之一.
其他可以代替头部CT扫描的检查包括:
MRI of the head - Positron emission tomography (
PET ) scan of the head
References
Barras CD, Bhattacharya JJ. 脑成像的现状和解剖特征. 见:Adam A, Dixon AK, Gillard JH, Schaefer-Prokop CM,编. Grainger & Allison's Diagnostic Radiology. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 53.
Chernecky CC, Berger BJ. Cerebral computed tomography - diagnostic. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:310-312.
Review Date: 07/05/2022