The Radiology Department, sometimes called the x-ray, is the facility in the hospital which carries out the radiological examinations of patients, using a range of equipment, including x ray, CT scanning, ultrasound and magnetic resonance imaging (MRI).
The radiologists are doctors specially trained to interpret the results and carry out some of the more complex examinations. They are supported by radiographers who are highly trained to carry out many of the x-ray and other imaging procedures.
Computed tomography (CT) of the chest uses special equipment to obtain multiple cross-sectional images of the organs and tissues of the chest. CT produces images that are far more detailed than a conventional chest x-ray. CT is especially useful because it can simultaneously show many different types of tissue, including the lungs, heart, bones, soft tissues, muscle and blood vessels. A computer, processes the images to create cross-sectional pictures or "slices" of the chest. CT scanning involves relatively low radiation exposure and is not invasive. No preparation is required prior to the exam.
CT of the chest is commonly used to take a closer look at findings detected on conventional chest x-rays. The CT examination may provide more specific information regarding the nature and extent of the findings or, in some cases, determine that the chest is normal.
CT may be used to detect and evaluate the extent of tumors that arise in the lung and mediastinum, or tumors that have spread there from other parts of the body. CT is routinely used to assess whether tumors are responding to treatment.
When someone has abnormal CT findings but the cause is uncertain, a percutaneous needle biopsy may be needed to directly examine the tissue. CT can be used to help guide the biopsy needle to the area in question.
CT Chest can demonstrate other lung disorders, such as old or new pneumonia, tuberculosis, emphysema, bronchiectasis, and diffuse interstitial lung disease. When the clinical findings and regular chest x-ray are inconclusive, CT may clarify the situation. Inflammation or other diseases of the pleura, the membrane covering the lungs, can be seen in CT images. High-resolution CT (HRCT) may be used for further evaluation. This uses thinner slices with possible expiration and prone views.
A CT angiogram (CTA) may be performed to evaluate the blood vessels (arteries and veins) in the chest. This is commonly used to look at the pulmonary arteries to diagnose a pulmonary embolism (PE).
You should dress comfortably but avoid any clothing in the chest area that has a zip or jewelry as metal objects may affect the CT images. Women should always inform their physician or the radiographer if there is any possibility that they are pregnant.
The CT scanner is a large unit with a hole running directly through its center, giving the appearance of a doughnut. You will lie on a table that can move up or down and can slide into and out of the center of the cavity. The computer is not in the examining room, but in an adjoining control room.
The radiographer will make certain that you are correctly positioned on the CT table. Pillows may be used to help maintain the correct position during the examination. For the initial scans, the table will move rapidly through the scanner to determine the correct starting position. The rest of the scans are made as the table moves more slowly through the cavity in the scanner. The best chest CT scans are obtained when you are able to hold your breath. If this is not possible, you will be asked to breathe quietly and regularly.
You will have a small canula inserted into an arm vein and contrast is injected into the vein before scanning begins. You must tell the radiographer if you have any allergies to medications or iodine (which is a part of many contrast materials) and whether you have a history of asthma, diabetes, a heart disorder or kidney disease. These conditions may indicate a greater risk of an adverse reaction to contrast material.
After the CT examination is completed, you may have to wait a short time while the radiologist checks the scans to make sure the quality is good enough to be correctly interpreted.
CT scanning is a pain-free procedure. The intravenous contrast injected into your vein may make you feel a flush of heat or a metallic taste in your mouth, usually lasting no more than a minute or two. You also may notice mild itching. If this persists or hives develop, effective medication is available. Very rarely a patient becomes short of breath or has swelling in the throat or another part of the body, indicating a more serious reaction to contrast material that must be promptly treated. If you experience any of these symptoms, inform the radiographer immediately.
The examination usually takes 30 minutes, including preparation time. The actual scan time is less than 30 seconds.
A radiologist experienced in CT scanning will examine and interpret the CT findings. After reaching a conclusion, the radiologist will send a detailed report to your consultant, who will give you the results.
If you have a query about having the CT, please ring the Radiology Department between 9am and 5pm, Monday to Friday & 9am and 12pm Saturday.