CT contrast dye allergies

[Rich66]

Anyone have a sense how much difference the contrast makes in a scan? Due to some allergic reactions despite premeds, they are doing mom's next CT without contrast.
Anyone ever look into which dye they reacted to? I'm gathering that the more expensive kind is less prone to allergy:

1: Allergy Asthma Proc. 2005 May-Jun;26(3):199-203. Links
Anaphylactoid reactions to radiocontrast media.

Canter LM.
Harvard Medical School, Tosteson Medical Education Center, MA 02115, USA.
As the role for diagnostic and therapeutic contrast-enhanced imaging increases, review of the epidemiology, mechanisms, risk factors, and pretreatment for radiocontrast-mediated anaphylactoid reactions becomes more and more pertinent. Ongoing research has failed to elucidate the precise mechanisms of both early and late reactions, though the current data point to a multifactorial pathogenesis. The risk of reactions has decreased over time as contrast media have evolved from ionic, high-osmolality to nonionic, low-osmolality formulations; however, the expense of the low-osmolality agents limit their universal use. Today, 1-12% of patients exhibit adverse responses ranging from mild to severe, with individual risk depending on the type of contrast administered and certain baseline patient characteristics. For those high-risk patients who must receive contrast, effective pret

[ElaineM]

There are various types of cat scan dye, but I don't remember all the names. The drug most widely used can cause skin issues and breathing problems during the scan. However, your Mother might want to ask her doctor to provide benedryl and predisone to conteract the allergies from the cat scan dye. She could also ask the doctor and/or the technicians to slow down the dye infusion during the scan if she does not want to have the scan without the contrast dye.

[ElaineM]

P. S. The cat scan pictures are not as clear without the dye. The contrast dye makes the pictures easier to see.

[Henny]

Hi Rich,
The contrast used in CT's is an iodine based one. Anyone with iodine allergies can have trouble with it. Usually patients are premedicated with Benedryl but sometimes that doesn't work
They take the pictures while the contrast is going through the veins. It's just a way to more clearly differentiate veins from the surrounding areas.
I would think a reaction to the contrast is far worse than not having it onboard for the scan. Your mom should get a good scan even without contrast

Henny