Introduction
CT (computed tomography) scan is an imaging method used for the diagnosis. It is a combination of X-rays and computer technology. It is used to record pictures of the internal organs. The disease or injuries of the organs and structures inside the chest can be diagnosed using a CT scan. The use of computer technology gives a more detailed image of the chest cavity than X-rays. Though the images are two-dimensional, they can be modified into three-dimensional images using computer technology.
What Are the Uses of a Chest CT Scan Using Contrast?
Computed tomography is used to identify the abnormalities in the chest.
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Block: The contrast dye highlights the blood vessels in the chest. Any block produced by the embolus formation in the blood vessels is observed using computed tomography.
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Injuries: The trauma to the hard structures like ribs is observed on the monitor after scanning.
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Bleeding: The injuries to the components in the intrathoracic cavity, like aortic injury and damage to the cardiac tissue, cause profuse bleeding. This intrathoracic bleeding is visualized with the computed tomography scan.
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Infections: Respiratory infections cause an accumulation of unwanted fluid in the chest cavity. The presence of fluid is indicated in the CT scan.
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Tumor: The abnormal tissue proliferation over the internal organs causes a lung tumor or thoracic tumor. This is diagnosed with the scan images. The size and the spread of the cancer tissue can be diagnosed.
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Biopsy: A part of the cancer tissue is removed from the lungs for biopsy. A surgeon uses the scan pictures to guide the tool while removing the tissue. A sample is collected from the chest cavity to know about the cause of the fluid. One end of the needle is pierced inside the chest with a CT scan examination.
What Is the Role of Contrast in Computed Tomography?
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Before scanning, the contrast dye is given to the patient. This dye is used to enhance the quality of the image.
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Computed tomography with contrast is used by radiologists to interpret internal organs.
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The contrast is injected into the body through the intravenous route. Along with that, the patient is asked to drink the contrast. It is ingested into the body through the oral route. This method is called a double contrast study.
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The higher the contrast, the higher the quality of the scanned image. So the radiologist can easily visualize the abnormality using high contrast media.
What Are the Instructions to Follow While Scanning the Chest?
There are a few necessary measures to be taken before proceeding with the computed tomography scan. They are as follows;
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The patient should remove their dress and must wear the hospital gown. The body piercings and metallic or gold jewelry must be removed before scanning.
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A consent form explaining the uses and risks of the contrast in the chest computed tomography scan should be signed by the patient before the scan.
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Necessary medications are provided for patients who previously had anaphylactic reactions to the contrast.
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Do not consume food for three hours before the scan. The patient can drink water or clear fluids.
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The diabetic patient should avoid medication for up to 48 hours before the scan. The medication can be continued only if the contrast is eliminated from the body.
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After the procedure, the patient is kept under observation to monitor the rashes, skin reactions in the IV (intravenous) site, and breathing. If there is no trouble, the patient is discharged and sent home. Even a mild allergy in the past must be informed to the medical professional priorly.
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A device revolves around the body and produces X-ray beams. The images are developed as slices or sections of the lungs and chest. It is then processed in a computer, and the images are displayed on the monitor.
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Since the contrast dye is injected through an IV (intravenous route), it causes sensitivity and adverse side effects in some patients. Contact the physician if the IV site is tender and red. Swelling in the site indicates signs of infection.
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After the procedure, the patient can take the usual diet and carry on regular physical activities.
What Are the Risks of Computed Tomography Scan And Contrast?
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Radiation: Ask the operator about the amount of radiation exposure. Do not take risks if there have been multiple exposures in the past. It is better to have a time interval between two exposures. Maintain a record of radiation exposure during the treatment to avoid risks.
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Pregnancy: The physician must be informed if the patient is planning for pregnancy or is pregnant presently because there is a potential risk for the baby in organ formation due to the radiation. Breastfeeding mothers should consult the physician about feeding after the procedure.
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Allergic to Contrast: Some patients are allergic to the dye ingested during the computed tomography scan.
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Kidney Problems: If the patient has kidney problems, the waste products from the dye cannot be eliminated during excretion. So do not use contrast dye for patients with kidney problems. Also, there is a chance of kidney failure after the use of contrast. The risk rate is higher for patients with severe dehydration.
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Diabetes: The diabetic patient intakes Metformin medication during treatment. Ingestion of contrast interacts with the Metformin drug in the blood and causes metabolic acidosis. This change in the blood pH level is a life-threatening condition.
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Heart Disease: The presence of a pacemaker gives less accuracy to the CT scan. As they are more prone to cardiac infection, contrast dye should not be ingested.
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Stomach Problems: If the contrast is given through the oral route, the patient has diarrhea or constipation.
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Excretion: Iodine-based contrast cannot be ingested for patients with excretory problems. In that case, the physician must perform a computed tomography scan procedure without contrast.
Conclusion
Computed tomography is advised by the medical professional when the final diagnosis cannot be made using X-rays because the density of the organs observed in computed tomography is intense. Also, there is high radiation compared to X-rays. So computed tomography scans are advised only if there is a critical condition. Research says one in 2000 patients who are exposed to computed tomography are prone to malignancy. The radiation dosage produced during computed tomography is 10 to 20 mSv. Any exposure greater than 20 mSv causes potential effects and induces cancer. The U.S government has set an average limit of 3 mSv for CT scans.
