Depending on the study your physician has ordered, it may be necessary for you to receive an intravenous contrast injection. For CT, the contrast material is iodine based while a gadolinium based chelate is used as the contrast agent in MRI scans. While generally safe and effective, the iodinated contrast agents rarely can cause reactions in certain individuals with a history of allergies, asthma, renal disease, heart disease, diabetes and other medical conditions.

Intravenous contrast material is often, but not always, used in today's CT and MRI studies to help with diagnosis. An iodine based material is used for CT and gadolinium is used for MRI. The purpose is to “enhance” the tissues and organs of the body in such a way as to make them better stand out from each other, and to allow better visualization of abnormal areas within normal areas. This ability to differentiate normal from abnormal is important to make the correct diagnosis. See similar questions...

No, MRI dye uses gadolinium. The risk of reaction to this dye is much lower than to x-ray dye. It is not iodine-based; if you have had a serious reaction to x-ray dye, it is still safe for you to have MRI dye. See similar questions...

CT and MRI differ in two basic ways.CT uses x-rays to detect and record the radiation absorbed by different tissues, and sends the data to a computer to transform into images. MRI does not use x-rays. Instead, MRI employs a powerful magnetic field to monitor the nuclei of hydrogen atoms in water, the most abundant element in the body. See similar questions...

Yes, your doctor must provide a referral (prescription) in order for you to receive a examination. In addition, some insurance carriers or HMO’s require a precertification. Please discuss this with your doctor and your insurance company or HMO prior to your test. See similar questions...

The "dye" injection is a clear liquid contrast agent containing iodine. It enhances the soft tissues and helps to define abnormalities. It is essential in visualizing the blood supply to internal organs. The contrast is excreted by the kidneys within several hours. We use only nonionic contrast, a safe agent with very few side effects. See similar questions...

MRI scan is excellent at showing soft tissue such as spinal cord, nerve roots and herniated discs. A CT scan shows bone detail and some soft tissue. When looking for herniated discs or tumors, an MRI image will usually reveal much more detail. See similar questions...

MRI is an acronym: M (Magnetic) R (Resonance) I (Imaging). This technology is obtained by using a high magnetic field and radio waves. Instead of relying on x-rays, like other imaging technologies do, MRI uses a powerful magnet. Some are approximately 30,000 times stronger than the magnetic force of the earth. During an exam, the patient lies inside the opening (the bore) of the magnet. See similar questions...

Not everyone needs an injection for MR imaging. When an injection is needed, a pharmaceutical contrast agent called Gadolinium is administered to the patient. This is only done when the radiologist and/or the referring physician have determined that it is necessary for diagnostic purposes. Gadolinium contrast is used to make specific organs, blood vessels or tissue types "stand out" with more image contrast in the resulting picture. See similar questions...

Our preferred provider for mammograms, CTs, and MRIs is Bexar Imaging Centers. There are two locations one is located across from North Star Mall and other is off 7622 Louis Pasteur across from the Methodist Children's Emergency Room. See similar questions...

Sometimes MRIs require a contrast injection placed through an IV in your arm. MRI systems do not use ionizing radiation, and the contrast material enhances the MRI images and has a very low incidence of side effects. See similar questions...

If your examination is of the abdomen or pelvis, you will be asked to arrive 1 hour prior to your examination to drink oral contrast, which will allow for a better evaluation of the bowel. Although many examinations do not require intravenous injection of contrast, in some cases it may be required to optimize your study. This will be discussed with you in detail by one of our staff members at the time of your visit. See similar questions...

The CT scan itself is 10-15 minutes. However, to ensure optimum results and patient safety, you will be asked to fill out a medical questionnaire and you will be interviewed by one of our staff before your examination. If applicable, contrast administration will be discussed and administered. A Radiologist will review the image quality of your study before you leave. Your visit should be less than 45 minutes (longer if you need to arrive early to drink oral contrast for a abdomen or pelvic CT). See similar questions...

Our state of the art Spiral CT equipment produces a very low dose of x-ray exposure with negligible adverse effects. It is not much different than the exposure from "background environmental radiation" from the sun, air travel, television or computer screens. See similar questions...

The contrast is injected into a vein using a small needle during a specific period in the CT exam. The contrast circulates the blood stream, through the heart and arteries, capillaries and veins, to essentially “enhance” the tissue structure of your organs so they appear highlighted on the CT images for a more precise diagnosis. See similar questions...

Not everyone needs an injection for CT imaging. When an contrast injection is needed, a pharmaceutical contrast agent made of iodine is used. This is only done when the radiologist and/or the referring physician have determined that it is necessary for diagnostic purposes. Iodine contrast is used to make specific organs, blood vessels or tissue types "stand out" with more image contrast in the resulting picture. See similar questions...

The more information that our radiologist has when reviewing your exam, the more specific the interpretation will be. Correlations with other studies are often helpful. See similar questions...

CT and MRI provide different kinds of information. Your doctor determines which is the most appropriate test for you, and sometimes both are necessary. While both scanners are similar in appearance, CT scanners make images is by using x-rays to plot the difference in electron density of adjacent tissues, and MR scanners, as described above, make images based on differences in the density and behaviour of hydrogen protons. See similar questions...

Absolutely. We use “non-ionic” contrast, which has a much lower incidence of allergic reaction than the older “ionic” contrast. See similar questions...