鼻窦CT扫描

定义

A computed tomography (CT) scan of the sinus is an imaging test that uses x-rays to make detailed pictures of the air-filled spaces inside the face (sinuses).

选择的名字

CAT scan - sinus; Computed axial tomography scan - sinus; Computed tomography scan - sinus; CT scan - sinus

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. You may lie on your back, or you may lie face-down with your chin raised.

Once you are inside the scanner, the machine's x-ray beam rotates around you. 你不会看到旋转的x射线束. Modern "spiral" scanners can perform the exam without stopping.

A computer creates separate images of the body area. 这些被称为切片. The images can be stored, viewed on a monitor, or printed on film. Three-dimensional models of the body area can be created by stacking the slices together.

You need to stay still during the exam because movement causes blurred images. You may be told to hold your breath for short periods of time. Straps and pillows may be used to keep you still during the procedure. You may be asked to remove jewelry and earrings.

The actual scan should take about 30 seconds. 整个过程需要15分钟.

如何准备考试

对于一些测试, 你需要一种特殊的染料, 叫对比, delivered into the body before the test starts. Contrast helps certain areas show up better on the 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 medicines before the test in order to safely receive this substance.
• Let your provider know if you have kidney problems. Contrast may not be used if this is the case.
• 在接受对比之前, tell your provider if you take the diabetes medicine metformin (Glucophage). You may need to take extra steps to prepare.

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 scan.

考试的感觉如何

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

静脉注射造影剂可能导致:

• 轻微的灼烧感
• 口中有金属味
• 身体温热潮红

这些感觉是正常的. 它们会在几秒钟内消失.

为什么要进行测试

CT rapidly creates detailed pictures of the sinuses. 该测试可以诊断或检测:

• 鼻引流异常
• An abnormal finding on an x-ray or nasal endoscopy
• 鼻窦先天缺陷
• 鼻窦骨感染(骨髓炎)
• Injury to the face over the sinuses from trauma
• 嗅觉丧失
• 肿块和肿瘤，包括癌症
• Nasal airway blockage that does not get better with treatment
• 鼻息肉
• 反复流鼻血的原因(鼻出血)
• 鼻窦感染(鼻窦炎)

The results from this test may also help your provider plan for sinus surgery.

正常的结果

Results are considered normal if no problems are seen 在鼻窦里.

异常结果意味着什么

异常结果可能是由于:

• 出生缺陷
• 骨折
• 癌症
• 息肉 在鼻窦里
• 鼻窦感染(鼻窦炎)

风险

CT扫描的风险包括:

• 暴露在辐射中
• 对造影剂过敏

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. However, the risk from any one scan is very small. You and your provider should weigh this risk against the benefits of getting a correct diagnosis for a 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. A person with an iodine allergy may have nausea or vomiting, 打喷嚏, 瘙痒, 或者荨麻疹，如果给予这种对比.
• 如果需要对比, you may be given antihistamines (such as Benadryl) or steroids before the test.
• The kidneys help remove iodine out of the body. Those with kidney disease or diabetes may need to get 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, let the scanner operator know right away. Scanners have an intercom and speakers, so the operator can hear you at all times.

参考文献

DeMuri GP, Wald ER. 鼻窦炎. In: Bennett JE, Dolin R, Blaser MJ，编辑. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9日艾德. Philadelphia, PA: Elsevier; 2020:chap 62.

可汗M, Zinreich SJ, Aygun N. 鼻窦成像. In: Flint PW, Francis HW, Haughey BH, et al, eds. Cummings Otolaryngology: Head and Neck Surgery. 7日艾德. Philadelphia, PA: Elsevier; 2021:chap 38.