CT Examination (Simple & Contrast) Information
What is CT Examination (CT Scan)?
CT examination uses X-rays to produce cross-sectional images of the body to help diagnose disease. There are two types of CT examinations.
- A simple CT examination (no contrast agent) takes approximately 5 to 10 minutes.
- A Contrast CT examination (using a contrast agent) takes approximately 15 to 30 minutes.
Contrast CT Examination
During a contrast CT scan, a non-ionic iodine contrast agent is injected intravenously to accurately determine the presence and diagnosis of disease. During the intravenous injection, the patient will experience a sensation of heat along the blood vessels and throughout the body.
In rare cases, the following side effects to the contrast agent may occur.
Contrast Agent Side Effects
- Mild side effects (incidence, 0.1% to 5% or less): urticaria (hives), sneezing, nausea, vomiting, dizziness, itching, etc.
- Severe side effects (incidence, approx. 0.2%): hypotension (low blood pressure), dyspnea (difficulty breathing), disorientation, etc.
Most side effects occur shortly after injection, but we take every precaution to provide appropriate treatment for side effects during the examination. In rare cases, side effects may appear hours or days after the test.
In such cases, please contact the Tokyo Metropolitan Cancer Detection Center, Gastroenterology Outpatient Department TEL 042-327-0201.
（[During evening hours (from 5:00 p.m. to 8:00 a.m.), Saturdays, Sundays, and holidays, please contact the ER (Emergency Room) at Tokyo Metropolitan Tama Medical Center at 042-323-5111.]
Examination Precautions
- Please inform us if you are pregnant or presumably pregnant.
- Please inform us if you have a cardiac pacemaker or an implantable defibrillator.
- There are no dietary restrictions for those undergoing simple CT examinations.
- Do not eat breakfast if you have a contrast CT exam in the morning.
- If you have a contrast CT exam in the afternoon, have breakfast by 9:00 a.m. and do not have lunch.
- In either case, you may drink water, tea, and your regular medications. However, diabetic medications should be taken as directed by the physician.
- You may be asked to change into an examination gown, so please dress appropriately.
- Remove all necklaces, magnetic acupressure patches, compresses, disposable body warmers, and undergarments with metal fittings.
After the Examination
- The test results will be available at a later date.
- After a Contrast CT exam, the iodine contrast agent is expelled from the body through urine, so please drink more fluids than usual.