User:Shawnahmed

Contrast Media
Anything that is used in Radiology to increase the conspicuity of a particular tissue. First contrast media to be developed was in 1924 by bob.

Types of Contrast Media Commonly Used in Radiology
Heavy metal chelates Gadolineum Air

Indications for Contrast
Infection Tumor Inflammatory condition

Iodinated Contrast:
Renal damage, hypersensitivity reaction,

Renal Effects
Excreted by the kidneys. Risk of deposition within the tubules and subsequent tubular necrosis. Risks increased with dehydration and poor renal function.

Hypersensitivity Reaction
Most common type of reaction to Iodinated contrast. Type I hypersensitivity reaction involving stimulation of mast cells. Range in severity from n/v and uticaria to anaphylaxis

Gadolineum
Felt to be safer than Iodinated contrast materials. Risk of NSF. Increased with poor renal function.

Iodinated Contrast
The safe use of iodinated contrast material is dictated by the patient's history of previous hypersensitivity reaction, renal function, and hydration status.

Previous History of Hypersensitivity
Severity of the previous reaction as well as the urgency of the study should dictate the use. Previous mild reactions can be mitigated by premedication with benadryl. Previous history of anaphylaxis should, in most cases preclude the subsequent use of iodinated contrast. In such a case, consider MRI with gadolineum

Renal Failure
Renal toxicity is increased with poor renal function due to decreased clearance of the iodinated compound and increased tubular deposition. Risks increase with decreased GFR. Ways to mitigate these risks include hydration and acetylcysteine which have been shown to decrease the risk of renal damage with IV contrasts. Guidelines for the use of these methods vary by institution. Author published the following guidelines:

Gadolineum
Risk of hypersensitivity and NSF.

Hypersensitivity Reactions
Type I reaction as with iodinated compounds. Felt to be less likely due to bulky nature of the gadolineum compound. Range from mild reactions characterized by n/v, itchiness to anaphylaxis. Use should be dictated by prior history of reaction and importance of the study. Premedication possible.

Nephrogenic Systemic Schlerosis (NSF)
Rare systemic condition characterized by fibrosis of multiple tissues. Risk increased with poor renal function. No premedication to protect. Use of gadolineum in patient with renal disease should be dictated by need for study and GFR. GFR <30, absolute contraindication?