CT Scan During the scan, you are placed on a movable table, which slides into the centre of a large donut-shaped machine that takes the X-ray images around the body. The actual procedure usually takes about half an hour or less, but sometimes it may take two hours or more. What is CT Scan? CT Scan is a special examination using a combination of X-rays and computer technology to produce cross-sectional images of the body. It gives detailed information of your body, helping your doctor to diagnose and plan treatment for your medical condition.
What are the signs?
In preparation for a CT scan, you may need to fast, especially when X-ray dye is to be used. X-ray dye may be injected intravenously, taken by mouth or by an enema in order to increase the distinction between various organs or areas of the body.
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CT scan is a painless, noninvasive and accurate examination.
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It can be used to study various internal structures in your body, including the brain, chest, abdomen, pelvis, bones, bowel and vessels in the heart.
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In emergency cases, it can reveal internal injuries and bleeding quickly.
Risks X-ray radiation A CT scan involves exposure to a small amount of X-ray radiation and there are risks related to radiation exposure. However, the benefits often outweigh the risk. Contraindications • Pregnancy • Previous severe allergic reaction What is X-ray dye? X-ray dye is a special liquid, known as contrast medium. It is injected intravenously through a small tube placed in a vein, often in your forearm during a CT scan to better define and enhance blood vessels and to outline abnormal tissue and organs. Risks of X-ray dye i) Allergy Some patients may develop allergic reactions to X-ray dye. These are usually mild and will spontaneously disappear. Allergic reactions may include headache, sneezing, vomiting, confusion, weakness, warmth,
sweating, nervousness, difficulty in breathing, sickness in stomach, metallic taste, watery eyes, itchy eyes, itchy bumps on skin, red-colored skin, pale skin or uncontrollable shaking. If you experience any of these symptoms during CT scan, immediately tell your doctor or our staff. Your risk to contrast medium allergies is usually higher if you have history of asthma or multiple drug allergies. Please inform your doctor if you have history of asthma or drug allergies. You will need pre-medication prescribed by your doctor before the date of the CT examination to help prevent and minimise the risk to contrast medium allergy.
ii) Extravasation There is also a very small risk of extravasation, whereby the x-ray dye leaks out into the surrounding tissues in your arm causing swelling. iii) Kidney damage There may be a small chance of kidney damage if you have any of the following conditions: Pre-existing renal insufficiency, Diabetes mellitus, on nephrotoxic drug, hypertension, hyperuricemia or gout. Please inform your doctor if you have any of above conditions. You will need a blood test to check your creatinine level, prior to the CT scan with intravascular x-ray dye. Depending on the degree of preexisting kidney damage, the IV contrast enhanced CT scan may or may not proceed. This is to protect your kidneys from further damage.
To note 1. Stop taking Metformin on the day of scan and to resume 48 hours after the scan. 2. If you have history of asthma or drug allergies, you will need premedication, prescribed by your doctor before the date of the CT scan, to help minimise the risk to contrast medium allergy. 3. You are encouraged to drink plenty of fluid after the scan to help the body to wash-out the x-ray dye. Preparing for your scan ☐ CT Scan Preparation •
Pain that spreads down to your legs.
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You may take your medicines with small sips of plain water.
☐ CT Coronary Angiogram Please observe the following on the day of your scan: • No caffeine fluids (coffee, tea, milo, coke, etc). • No smoking. •
Fast 3 hours before CT scan (plain water is allowed).
• Do not drive or operate machinery after scan.
☐ CT Colonoscopy 3 days before examination date: ___________________________ •
No high fibre diet (eg. No vegetables, No fruits.)
Affix patient’s sticker.
1 day before examination date: ___________________________ •
Stay close to a rest room in view of bowel preparation for the day.
• 9am: Take 2 tablets of Bisacodyl (5mg each) with 1 cup (approx. 500ml) of plain water and 1 bottle of Tagitol V. Proceed with normal activities. • 3pm: Pour 40ml of the Lemon Sweet Purgative into a full glass (approx. 500ml) of plain water. Drink this mixture and take 1 bottle of Tagitol V. • 6pm: Pour 40ml of the Lemon Sweet Purgative into a full glass (approx. 500ml) of plain water. Drink this mixture and take 1 bottle of Tagitol V.
Venue:
Tower B, Level 2 (B25), Diagnostic Radiology
Appointment Date : ____________ Appointment Time : ____________ Examination Fee : ____________ (Medisave claimable, capped at $300 per year) * Please be punctual for your appointment. If you are unable to keep to the appointment, kindly call us to arrange a new appointment date. Tel: 6602 2701 (Office hours)
☐ Reminder Patient must be prescribed with Prednisolone if asthmatic or has multiple allergies.
Yishun Health is a network of medical institutions and health facilities of the National Healthcare Group. Admiralty Medical Centre • (65) 6807 8000 • www.admiraltymedicalcentre.com.sg Khoo Teck Puat Hospital • (65) 6555 8000 • www.ktph.com.sg Yishun Community Hospital • (65) 6807 8800 • www.yishuncommunityhospital.com.sg The information is correct at the time of printing and subject to revision without further notice.
DDR.PE.01.0517