成像过程

骨头用

骨密度, also called dual-energy x-ray absorptiometry, DEXA或DXA, uses a very small dose of ionizing radiation to produce pictures of the inside of the body (usually the lower (or lumbar) spine and hips) to measure bone loss. It is commonly used to diagnose osteoporosis, 评估个体发生骨质疏松性骨折的风险. DXA is simple, quick and noninvasive. 这也是诊断骨质疏松症最常用和最标准的方法.

On the day of the exam, you may eat normally. 在考试前至少24小时内不要服用钙补充剂.

你应该穿宽松的衣服, 舒适的衣服, avoiding garments that have zippers, belts or buttons made of metal. 诸如钥匙或钱包之类的物品应该在被扫描的区域被移除.

考试时，你可能会被要求脱掉部分或全部的衣服，穿上长袍. You may also be asked to remove jewelry, removable dental appliances, 眼镜和任何可能干扰x射线图像的金属物品或衣服.

Inform your physician if you recently had a barium examination or have been injected with a contrast material for acomputed tomography (CT) scan or radioisotope scan. You may have to wait 10 to 14 days before undergoing a DXA test.

Women should always inform their physician and x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to radiation. If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby.

心脏CT血管造影

This important diagnostic imaging test uses an iodine-rich contrast material usually injected into your vein of your arm. A CT scan is performed while the contrast material flows through the 血管 to the various organs of the body. 考试后, 放射科医生使用专用计算机和专用计算机软件处理图像.

心脏CT检查前不需要特别准备. You should continue to take your usual medications but should avoid caffeine and smoking for four hours prior to the exam.

You should wear comfortable, loose-fitting clothing to your exam. You may be given a gown to wear during the procedure.

金属物体, 包括珠宝, 眼镜, 假牙, 和发夹, 会影响CT图像，应该放在家里或在检查前取出吗. 你也可能被要求摘掉助听器和可拆卸的牙齿. Women will be asked to remove bras containing metal underwire. You may be asked to remove any piercings, if possible.
Women should always inform their physician and the CT technologist if there is any possibility that they may be pregnant.

CT

Computed tomography (CT) is a diagnostic imaging test used to create detailed images of internal organs, 骨头, 软组织, 还有血管. The cross-sectional images generated during a CT scan can be reformatted in multiple planes and can even generate three-dimensional images which can be viewed on a computer monitor, printed on film or transferred to electronic media. CT scanning is often the best method for detecting many different cancers since the images allow your doctor to confirm the presence of a tumor and determine its size and location. CT is fast, painless, noninvasive, and accurate. In emergency cases, it can reveal internal injuries and bleeding quickly enough to help save lives.

You should wear comfortable, loose-fitting clothing to your exam. You may be given a gown to wear during the procedure.

你将被要求在几个小时前不要吃或喝任何东西, as contrast material will be used in your exam. You should inform your physician of all medications you are taking and if you have any allergies. If you have a known allergy to contrast material, 或“染料," your doctor may prescribe medications (usually a steroid) to reduce the risk of an allergic reaction. These medications generally need to be taken 12 hours prior to administration of contrast material. 为了避免不必要的延误，请在检查的确切时间之前联系你的医生.

Also inform your doctor of any recent illnesses or other medical conditions and whether you have a history of 心 disease, 哮喘, 糖尿病, kidney disease or thyroid problems. 这些情况中的任何一种都可能增加异常不良反应的风险.

Women should always inform their physician and the CT technologist if there is any possibility that they may be pregnant.

数字乳房x光检查

Mammography is specialized medical imaging that uses a low-dose x-ray system to see inside the breasts. 乳房x光检查, 叫做乳房x光检查, 艾滋病在妇女乳腺疾病的早期发现和诊断.

数字乳房x光检查, also called full-field digital mammography (FFDM), is a mammography system in which the x-ray film is replaced by electronics that convert x-rays into mammographic pictures of the breast. These systems are like those found in digital cameras and their efficiency enables better pictures with a lower radiation dose. These images of the breast are transferred to a computer for review by the radiologist and for long term storage. The patient's experience during a digital mammogram is like having a conventional film mammogram.

Before scheduling a mammogram, the American Cancer Society (ACS) and other specialty organizations recommend that you discuss any new findings or problems in your breasts with your doctor. 除了, inform your doctor of any prior surgeries, 激素使用, and family or personal history of breast cancer.

Do not schedule your mammogram for the week before your menstrual period if your breasts are usually tender during this time. The best time for a mammogram is one week following your period. Always inform your doctor or x-ray technologist if there is any possibility that you are pregnant.

The ACS also recommends you:

不用除臭剂, 考试当天在腋下或乳房上涂抹爽身粉或乳液. These can appear on the mammogram as calcium spots.
向进行检查的技术人员描述任何乳房症状或问题.
Obtain your prior mammograms and make them available to the radiologist if they were done at a different location. 这是与你目前的考试进行比较所需要的，通常可以在CD上获得.
Ask when your results will be available; do not assume the results are normal if you do not hear from your doctor or the mammography facility.

硬膜外注射

An epidural injection provides temporary or lasting relief from pain or inflammation in the spine or extremities (arms and legs). 成像引导可用于将针头放置在正确的位置，以获得最大的益处. The injection may also help confirm the exact site of the pain.

硬膜外注射是将药物注射到脊髓周围的空间, also known as the epidural space, to provide temporary or prolonged relief from pain or inflammation. The epidural space is the outermost part of the spinal canal. 类固醇, 麻醉剂, 抗炎药物通常是通过硬膜外注射来传递的. 注射可减轻脊神经根内及周围的疼痛和肿胀, as well as around damaged nerves which in time may heal.

You will receive specific instructions on how to prepare, 包括任何需要对你的常规用药计划做出的改变.
You may be instructed not to eat or drink anything for several hours before your procedure to prevent you from having an upset stomach following the injection.
You may be asked to wear a gown during the procedure.
You will probably be asked to use the restroom before the procedure.
You will then be positioned on your stomach or side on a special fluoroscopic or CT table that will give the doctor easy access to the injection site(s). 技术专家会帮助你尽可能舒适，无论是在 & 手术后.
你应该安排一个亲戚或朋友在手术后开车送你回家.

核磁共振成像

Magnetic resonance imaging (核磁共振成像) uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of the body's internal structures that are clearer, 更详细的, and more likely in some instances to identify and accurately characterize disease than other imaging methods. It is used to evaluate the body for a variety of conditions, including tumors and diseases of the liver, 心, 和肠道. It may also be used to monitor an unborn child in the womb. 核磁共振成像 is noninvasive and does not use ionizing radiation.

You may be asked to wear a gown during the exam, or you may be allowed to wear your own clothing if it is loose-fitting and has no metal fasteners.

Guidelines about eating and drinking before an 核磁共振成像 exam vary with the specific exam and also with the imaging facility. Unless you are told otherwise, 你可以遵循你的日常生活，照常进食和服药.

Some 核磁共振成像 examinations may require you to receive an injection of contrast material into the bloodstream. 放射科医生, technologist or a nurse may ask if you have allergies of any kind, such as an allergy to iodine or x-ray contrast material, 药物, 食物, 或者环境, 或者如果你有哮喘. 核磁共振成像检查中最常用的造影剂含有一种叫做钆的金属. Gadolinium can be used in patients with iodine contrast allergy but may require pre-medication. It is far less common for a patient to have an allergy to a gadolinium-based contrast agent used for 核磁共振成像 than the iodine-containing contrast for CT. 然而, 即使知道病人对钆造影剂过敏, it may still be possible to use it after appropriate pre-medication. Patient consent will be requested in this instance.

如果你有任何严重的健康问题，你也应该让放射科医生知道, or if you have had any recent surgeries. 一些条件, such as severe kidney disease, may prevent you from being given gadolinium contrast for an 核磁共振成像. If you have a history of kidney disease or liver transplant, it will be necessary to perform a blood test to determine whether the kidneys are functioning adequately.

Women should always inform their physician or technologist if there is any possibility that they are pregnant. 核磁共振成像 has been used for scanning patients since the 1980s with no reports of any ill effects on pregnant women or their unborn babies. 然而, because the unborn baby will be in a strong magnetic field, pregnant women should not have this exam in the first trimester of pregnancy unless the potential benefit from the 核磁共振成像 exam is assumed to outweigh the potential risks. Pregnant women should not receive injections of gadolinium contrast material except when absolutely necessary for medical treatment.

If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want to ask your physician for a prescription for a mild sedative prior to your scheduled examination.

Jewelry and other accessories should be left at home if possible or removed prior to the 核磁共振成像 scan. Because they can interfere with the magnetic field of the 核磁共振成像 unit, metal and electronic items are not allowed in the exam room. 这些项目包括:

珠宝、手表、信用卡和助听器，这些都有可能被损坏
别针、发夹、金属拉链和类似的金属物品，它们会扭曲核磁共振成像图像
可移动牙科手术
pens, pocket knives and 眼镜
身体穿孔

在大多数情况下，核磁共振检查对金属植入物患者是安全的，除了少数类型. People with the following implants cannot be scanned and should not enter the 核磁共振成像 scanning area:

cochlear (ear) implant
some types of clips used for brain aneurysms
some types of metal coils placed within 血管
nearly all cardiac defibrillators and pacemakers

如果你的身体里有医疗或电子设备，你应该告诉技术人员. 这些物品可能会干扰考试或构成潜在风险, depending on their nature and the strength of the 核磁共振成像 magnet. Many implanted devices will have a pamphlet explaining the 核磁共振成像 risks for that particular device. If you have the pamphlet, 在考试前将这一点告知技术专家或调度员是很有用的. Some implanted devices require a short period of time after placement (usually six weeks) before being safe for 核磁共振成像 examinations. Examples include but are not limited to:

artificial 心 valves
implanted drug infusion ports
artificial limbs or metallic joint prostheses
implanted nerve stimulators
metal pins, screws, plates, stents or surgical staples

一般来说，骨科手术中使用的金属物体在核磁共振成像检查中没有风险. 然而, a recently placed artificial joint may require the use of another imaging procedure. If there is any question of their presence, an x-ray may be taken to detect and identify any metal objects.

病人 who might have metal objects in certain parts of their bodies may also require an x-ray prior to an 核磁共振成像. You should notify the technologist or radiologist of any shrapnel, 子弹, 或者其他由于先前的事故而可能存在于你体内的金属碎片. 靠近眼睛的异物尤其是卡在眼睛里的异物尤为重要. Dyes used in tattoos may contain iron and could heat up during 核磁共振成像, but this is rarely a problem. 牙齿填充物和牙套通常不受磁场影响, but they may distort images of the facial area or brain, so the radiologist should be aware of them.

Infants and young children usually require sedation or anesthesia to complete an 核磁共振成像 exam without moving. Whether a child requires sedation will depend on the child’s age and the type of exam being performed. Moderate and conscious sedation can be provided at most facilities. A physician or nurse specializing in the administration of sedation or anesthesia to children should be available during the exam to ensure your child's safety. You will be given special instructions for how to prepare your child for the sedation or anesthesia.

核医学

Nuclear medicine is an imaging modality that is unique, because it provides doctors with information about both structure and functional assessment of most organs. 这是一种收集医疗信息的方法，否则这些信息将无法获得, 需要手术, or necessitate more expensive diagnostic tests. Nuclear medicine imaging procedures often identify abnormalities very early in the progress of a disease long before many medical problems are apparent with other diagnostic tests.

You may be asked to wear a gown during the exam, or you may be allowed to wear your own clothing.

Women should always inform their physician or technologist if there is any possibility that they are pregnant or if they are breastfeeding.

You should inform your physician and the technologist performing your exam of any medications you are taking, including vitamins and herbal supplements. You should also inform them if you have any allergies and about recent illnesses or other medical conditions.

Jewelry and other metallic accessories should be left at home if possible or removed prior to the exam because they may interfere with the procedure.

您将收到基于您正在进行的扫描类型的具体说明.
In some instances, certain medications or procedures may interfere with the examination ordered.

立体定向活检

Stereotactic breast biopsy uses mammography – a specific type of breast imaging that uses low-dose x-rays – to help locate a breast lump or abnormality and remove a tissue sample for examination under a microscope. It’s less invasive than surgical biopsy, leaves little to no scarring and can be an excellent way to evaluate calcium deposits or tiny masses that are not visible on ultrasound.

Women should always inform their physician if there is any possibility that they are pregnant. Some procedures using image-guidance are typically not performed during pregnancy because radiation can be harmful to the fetus.

You should not wear deodorant, 粉, 乳液, 或者在考试当天在你的腋下或乳房上喷香水.

Prior to a needle biopsy, 你应该向你的医生报告你正在服用的所有药物, including herbal supplements, and if you have any allergies, especially to anesthesia. Your physician may advise you to stop taking aspirin or a blood thinner three days before your procedure.

此外，告诉你的医生你最近的疾病或其他健康状况.
你可能想让一个亲戚或朋友陪你，然后开车送你回家. This is recommended if you have been sedated.

超声波

超声波 imaging uses a transducer or probe to generate sound waves and produce pictures of the body's internal structures. It does not use ionizing radiation, has no known harmful effects, 并提供了软组织的清晰图像，而这些软组织在x射线图像上表现不佳. 超声波通常用于帮助诊断无法解释的疼痛、肿胀和感染. It may also be used to provide imaging guidance to needle biopsies or to see and evaluate conditions related to blood flow. 这也是监测孕妇和胎儿的首选成像方法.

你应该穿舒适、宽松的衣服去做超声波检查. 你可能需要把检查区域的所有衣服和珠宝都拿掉.

You may be asked to wear a gown during the procedure.

检查前的准备工作将取决于你的检查类型. For some scans your doctor may instruct you not to eat or drink for as many as 12 hours before your appointment. For others you may be asked to drink up to six glasses of water two hours prior to your exam and avoid urinating so that your bladder is full when the scan begins.

x射线

x射线 or radiography uses a very small dose of ionizing radiation to produce pictures of the body's internal structures. x射线是最古老和最常用的医学成像形式. They are often used to help diagnosed fractured 骨头, 寻找损伤或感染，并确定软组织异物的位置. Some x-ray exams may use an iodine-based contrast material or barium to help improve the visibility of specific organs, 血管, 组织或骨骼.

Women should inform their physician and x-ray technologist, an individual specially trained to perform radiology examinations, 如果她们植入了宫内节育器(IUD)来预防怀孕.

Women should always inform their physician and x-ray technologist if there is any possibility that they are pregnant.