腰椎CT扫描

定义

A computed tomography (CT) scan of the lumbar spine makes cross-sectional pictures of the lower back (lumbar spine). 它使用x射线来产生图像.

选择的名字

CAT scan - lumbar spine; Computed axial tomography scan - lumbar spine; Computed tomography scan - lumbar spine; CT - lower back

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.

Once you are inside the scanner, the machine's x-ray beam rotates around you. Modern "spiral" scanners can perform the exam without stopping.

A computer creates separate images of the spine area, called slices. These images can be stored, viewed on a monitor, or printed on film. Three-dimensional models of the spine area can be created by adding the slices together.

考试时你必须保持安静. 移动会导致图像模糊. You may be told to hold your breath for short periods of time.

扫描只需要10到15分钟.

如何准备考试

Some exams use a special dye, called contrast that is put into your body before the test starts. Contrast helps certain areas show up better on the x-rays.

对比可以用不同的方式来表达.

• It may be given through a vein (IV) in your hand or forearm.
• It may be given as an injection into the space around the spinal cord.

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 medicines before the test in order to avoid this problem.

在做对比之前, tell your provider if you take the diabetes medicine metformin (Glucophage). You may need to take extra steps before the test if you take this drug.

If you weigh more than 300 pounds (135 kilograms), find out if the CT machine has a weight limit. Too much weight can cause damage to the scanner's working parts.

You will be asked to remove jewelry and wear a hospital gown during the study as metal can affect the CT images.

考试的感觉如何

Some people may have discomfort from lying on the hard table.

Contrast given through an IV may cause a slight burning feeling, 嘴里有金属的味道, 还有温暖的身体潮红. These feelings are normal and go away in a few seconds.

为什么要进行测试

CT scans rapidly makes detailed pictures of the lower back. 该测试可用于寻找:

• 儿童颈椎的先天缺陷
• 脊柱问题，当脊柱MRI不能使用时
• 脊椎上部受伤
• 骨肿瘤或癌症
• 脊椎骨的骨折
• Disk herniations and compression of the spinal cord
• 手术后的愈合问题或疤痕组织

This test can also be used during or after an x-ray of the spinal cord and spinal nerve roots (myelography) or an x-ray of the disk (discography).

正常的结果

Results are considered normal if no problems are seen in the lumbar region in the images.

异常结果意味着什么

异常结果可能是由于:

• 由于年龄的增长而发生的退行性变化
• 脊柱先天缺陷
• 骨的问题
• 脊椎骨的骨折
• 腰椎间盘突出症
• 腰椎 脊髓狭窄
• 脊椎前移
• 愈合手术后疤痕组织的愈合或生长

风险

CT扫描的风险包括:

• 暴露在辐射中
• 对造影剂过敏
• 如果在怀孕期间造成先天缺陷

CT scans expose you to more radiation than regular x-rays. 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. Talk to your provider about this risk and how it weighs against the benefits of the test for your medical problem.

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. If a person with an iodine allergy is given this type of contrast, 恶心或呕吐, 打喷嚏, 瘙痒, or 荨麻疹 可能发生.
• 如果你一定要有这种对比, you may get antihistamines (such as Benadryl) or steroids before the test.
• 肾脏帮助将碘排出体外. People 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 anaphylaxis. If you have any trouble breathing during the test, you should tell the scanner operator right away. Scanners come with an intercom and speakers, so the operator can hear you at all times.

注意事项

The lumbar CT scan is good for evaluating large herniated disks, but it can miss smaller ones. This test can be combined with a myelogram to get a better image of the nerve roots and pick up smaller injuries.

参考文献

Grawboski T, Gilbert TM, Larson EP, Cornett CA. Degenerative conditions of the cervical and thoracolumbar spine. 见:米勒博士，汤普森博士，编辑. 口腔、Drez & 米勒的骨科运动医学. 5日艾德. Philadelphia, PA: Elsevier; 2020:chap 130.

Kapoor G, tom AP. Current status of imaging of the musculoskeletal system. In: Adam A, Dixon AK, Gillard JH, Schaefer-Prokop CM, eds. 格兰杰 & 艾利森诊断放射学. 7日艾德. Philadelphia, PA: Elsevier; 2021:chap 38.

威廉姆斯KD. Fractures, dislocations, and fracture-dislocations of the spine. In: Azar FM, Beaty JH，编辑. 坎贝尔整形外科. 14日艾德. Philadelphia, PA: Elsevier; 2021:chap 41.