What is a contrast medium?
The contrast medium used for computerized tomography examinations are iodine-based and are administered as fluid to be ingested and / or in the form of an intravenous injection.
Iodine administered intravenously
Sometimes intravenous injection is necessary, depending on the type of examination required. When your turn arrives, you will be invited into the doctor's room and a canula ("Venflon") will be placed in an arm vein by the injecting physician.
The injected iodine stains the entire blood and organs and improves the quality of the examination.
The dye accentuates the differences between sick and healthy tissues and makes blood vessels visible. Iodine injection is especially important if a malignant disease is suspected or followed-up. It is important to notify the doctor prior to receiving the injection if you have the following conditions: Cardiac diseases, diabetes, renal diseases, thyroid diseases as well as allergies, especially to iodine. A small proportion of patients may suffer from iodine allergy, but in the majority of cases no adverse effects are expected. Should you be interested in additional details, you may address the doctor who is giving the injection and he will be happy to answer all your questions before the injection is given.
Iodine administered as a fluid for swallowing
In abdominal and pelvic CT examinations iodine is given for drinking.This substance enables a better assessment of the stomach, the small intestine loops and the colon. You will be asked to drink 4 glasses of half a liter capacity slowly over a period of one and a half to two hours. It is necessary to drink one glass every half an hour in order to distribute the swallowed content as evenly as possible over the bowel for uniform staining. The contrast medium is stored in the waiting room and is served chilled, with or without sweetened raspberry flavoring.
Other drinkable contrast media– in the event of severe iodine allergy, an alternative contrast medium based on barium (a heavy metal) is also available.
A questionnaire MUST be filled in before the examination.
Please bring with you to the examination the results of your most recent renal function test (creatinine or BUN). This test is part of the routine chemical blood tests carried out frequently by your health fund.
The iodine injection may often be accompanied by a feeling of heat or by a bitter taste in the mouth. After the CT is completed you will remain under observation for about 30 minutes in order to ascertain that no side effects occur.
If you received an iodine injection, copious drinking is recommended after the examination for more rapid clearance of the contrast medium from the body.
If you are aware of severe hypersensitivity to iodine, intravenous injection of iodine is forbidden.
In the event of mild hypersensitivity, the radiologist should be consulted and performance of the examination should be considered only after prior medical preparation. We do not perform CT examinations with iodine on patients with an iodine allergy, even with medical preparation, and recommend that such examinations, if absolutely necessary, should be performed in a hospital.
Information for diabetic patients taking Metformin (Glucophage) who are about to undergo CT examinations with iodine injections: If you are taking Metformin (Glucophage) and are about to undergo an examination in our Institute requiring the administration of iodine containing contrast medium,
please follow these instructions to safeguard your health:
Following the examination, this medicine must not be taken for 48 hours. The reason for this is incidences of acidosis, even resulting in death, reported after patients being treated with Metformin received iodine containing the contrast medium. In such cases, patients developed acute renal failure following the iodine injection, causing an accumulation of Metformin in the body that resulted in severe secondary acidosis.
Please refer to your attending physician for instructions as to how to act in regard with taking your medicine and diet while not taking Metformin, in order to keep your blood glucose level under control.
It is also recommended that you refer to your attending physician in order to carry out blood tests (renal function) prior to the re-administration of Metformin.
For further details and clarifications please call: