什么是CT扫描?

Computed tomography is commonly referred to as a CT scan. A CT scan is a diagnostic imaging procedure that uses a combination of x射线 和 computer technology to produce images of the inside of the body. It shows detailed images of any part of the body, 包括骨头, 肌肉, 脂肪, 器官和血管.

CT scans are more detailed than st和ard x射线. In st和ard x射线, a beam of energy is aimed at the body part being studied. A plate behind the body part captures the variations of the energy beam 后 it passes through skin, 骨, 肌肉和其他组织. While much information can be obtained from a regular X-ray, a lot of detail about internal organs 和 other structures is not available.

In CT, the X-ray beam moves in a circle around the body. This allows many different views of the same organ or structure 和 provides much greater detail. The X-ray information is sent to a computer that interprets the X-ray data 和 displays it in two-dimensional form on a monitor. Newer technology 和 computer software makes three-dimensional images possible.

CT scans may be performed to help diagnose tumors, 检查内出血, 或者检查是否有其他内伤或损伤. CT也可用于a 组织或液体活检.

Why are CT scans sometimes ordered 与 contrast?

CT扫描可以进行对比，也可以不进行对比. Contrast refers to a substance taken by mouth or injected into an IV line that causes the particular organ or tissue under study to be seen more clearly. Contrast examinations may require you to fast f或者一个 certain period of time before the procedure. Your doctor will notify you of this prior to the procedure.

You will need to let your doctor know if you have ever had a reaction to any contrast media 和/或者一个ny kidney problems. A reported seafood allergy is not considered to be a contraindication for iodinated contrast. If you have any medical conditions or recent illnesses, inform your doctor.

我该如何准备CT扫描?

如果你有 计算机断层血管造影(CTA) 或者一个 虚拟结肠镜检查, you will be given specific instructions when you make your appointment.

预防措施: If you are pregnant or think you may be pregnant, please check 与 your doctor before scheduling the exam.

服装: 你可能会被要求换上病号服. 如果是这样，我们会为你提供一件长袍. Please remove all piercings 和 leave all jewelry 和 valuables at home.

对比媒体你的检查可能需要做对比检查. The contrast media improves the radiologist’s ability to find structures that are abnormal 和 underst和 normal anatomy better.

• Some patients should not have an iodine-based contrast media. If you have problems 与 your kidney function, please inform your radiologist in advance. We may be able to perform the scan 没有 the contrast media or find an alternate imaging exam.
• The most common type of CT scan 与 contrast is the double-contrast study, which will require you to drink a contrast media before your exam begins in addition to the IV contrast. 你能喝的对比酒越多, the better the images are for the radiologist to visualize your digestive tract.

过敏: Please inform the access center representative when you schedule your scan if you have had an allergic reaction to any contrast media. IV contrast will not be administered if you have had a severe 或者一个naphylactic reaction to any contrast media in the past. Mild to moderate reactions warrant a plan that includes taking medication prior to CT检查. These plans will be discussed 与 you in detail when you schedule your exam. Any known reactions to a contrast media should be discussed 与 your personal physician.

吃/喝如果你的书房是有序的 没有 contrast, you can eat, drink 和 take your prescribed medications prior to your exam.

如果你的医生让你做CT扫描 与 contrast, do not eat anything three hours prior to your CT scan. 我们鼓励你喝清澈的液体. You may also take your prescribed medications prior to your exam.

糖尿病患者:有 糖尿病 should eat a light breakfast or lunch three hours prior to the scan time. 这取决于你的口服糖尿病药物, you may be asked to discontinue use of the medication for 48 hours 后 CT检查. Detailed instructions will be given following your examination.

药物治疗: All patients can take their prescribed medications as usual.

CT扫描的风险是什么?

If you are pregnant or think you may be pregnant, you should notify your health care provider.

The amount of radiation dose used in a CT scan is small. You may want to ask your doct或者一个bout the amount of radiation used during the CT procedure 和 the risks related to your particular situation.

If you are claustrophobic or tend to become anxious easily, tell your doct或者一个head of time. You may be prescribed a mild sedative to take before the procedure to make you more comfortable.

CT扫描时发生了什么?

CT scans may be performed on an outpatient basis 或者一个s part of your stay in a hospital. Procedures may vary depending on your condition 和 your physician’s practices. 一般来说，CT扫描遵循这个过程:

• 你可能会被要求换上病号服. 如果是这样，我们会为你提供一件长袍. A locker will be provided to secure all personal belongings. Please remove all piercings 和 leave all jewelry 和 valuables at home.
• If you are to have a procedure done 与 contrast, an IV line will be started in the h和 或者一个rm for injection of the contrast media. For oral contrast, you will be given a liquid contrast preparation to swallow. In some situations, the contrast may be given rectally.
• You will lie on a scan table that slides into a large, circular opening of the scanning machine.
• The technologist will be in another room where the scanner controls are located. However, you will be in constant sight of the technologist through a window. Speakers inside the scanner will enable the technologist to communicate 与 和 hear you. You may have a call button so that you can let the technologist know if you have any problems during the procedure. The technologist will be watching you at all times 和 will be in constant communication.
• 扫描仪开始在你周围旋转, x射线 will pass through the body for short amounts of time. You will hear clicking sounds, which are normal.
• The x射线 absorbed by the body’s tissues will be detected by the scanner 和 transmitted to the computer. The computer will transform the information into an image to be interpreted by the radiologist.
• It is important that you remain very still during the procedure. You may be asked to hold your breath at various times during the procedure.
• 如果您的手术使用造影剂, you may feel some effects when the contrast is injected into the IV line. 这些影响包括脸红的感觉, 咸味:口中的咸味或金属味, 短暂的头痛, 或者恶心和/或呕吐. 这些影响通常会持续几分钟.
• You should notify the technologist if you have any breathing difficulties, 出汗, 麻木或心悸.
• When the procedure has been completed, you will be removed from the scanner.
• If an IV line was inserted for contrast administration, the line will be removed.
• 而CT检查本身不会引起疼痛, having to lie still for the length of the procedure might cause some discomfort or pain, particularly in the case of a recent injury or invasive procedure, 比如手术. The technologist will use all possible comfort measures 和 complete the procedure as quickly as possible to minimize any discomfort or pain.

CT扫描后会发生什么?

• If contrast media was used during your procedure, you may be monitored f或者一个 period of time f或者一个ny side effects or reactions to the contrast, 比如瘙痒, 肿胀, 皮疹或呼吸困难.
• 如果你感到疼痛, redness 和/or 肿胀 at the IV site 后 you return home following your procedure, 你应该通知你的医生, as this could indicate an infection or other type of reaction.
• There is typically no special type of care required 后 a CT scan. You may resume your usual diet 和 activities unless your doct或者一个dvises you differently.
• Your doctor may give you additional 或者一个lternate instructions 后 the procedure, 这取决于你的具体情况.

What are some of the advances in CT technology?

CT技术的进步包括:

• High-resolution CT: This type of CT scan uses very thin slices (less than 0.1英寸), which are effective in providing greater detail in certain conditions, 比如肺病.
• Helical or spiral CT: During this type of CT scan, both the patient 和 the X-ray beam move continuously, x射线束环绕着推荐十大正规网赌平台. The images are obtained much more quickly than 与 st和ard CT scans. The resulting images have greater resolution 和 contrast, providing more detailed information. Multidetector-row helical CT scanners may be used to obtain information about calcium buildup inside 心脏的冠状动脉.
• 超快的CT (also called electron beam CT): This type of CT scan produces images very rapidly, thus creating a type of "movie" of moving parts of the body, 比如心脏的腔室和瓣膜. This scan may also be used to obtain information about calcium buildup inside 心脏的冠状动脉, 但螺旋扫描仪更为常见.
• 计算机断层血管造影(CTA): Angiography (或者一个rteriography) is an X-ray image of the blood vessels. A CT angiogram uses CT technology rather than st和ard x射线 or fluoroscopy to obtain images of blood vessels — for example, 心脏的冠状动脉.
• 结合 正电子发射断层扫描 和 CT (PET/CT): The combination of CT 和 正电子发射断层扫描 technologies into a single machine is referred to as PET/CT. PET/CT combines the ability of CT to provide detailed anatomy 与 that of PET to show cell function 和 metabolism in order to offer greater accuracy in the diagnosis 和 treatment of certain types of diseases, 尤其是癌症. PET/CT may also be used to evaluate conditions such as 癫痫, 阿尔茨海默病 和 冠状动脉疾病.