Recent consensus states that the risk of nephrogenic systemic fibrosis or nephrotoxicity following administration of a Group II gadolinium contrast agent is extremely low, and that the potential harm of delayed diagnosis or misdiagnosis from delaying or withholding Group II gadolinium contrast agent for a clinically indicated MRI in a patient with acute kidney injury or eGFR less than 30 mL/min/1.73 m 2 may outweigh the risk of nephrogenic systemic fibrosis, regardless of dialysis status 11. However, nearly all unconfounded cases of nephrogenic systemic fibrosis have been linked to one of the three linear Group I gadolinium contrast agents. There is an association between the use of gadolinium-based contrast agents in patients with renal failure and nephrogenic systemic fibrosis (NSF).
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See full article here: nephrogenic systemic fibrosis (NSF) Non-contrasted MR imaging such as arterial spin labeling (ASL), time of flight (TOF), phase contrast (PC), diffusion-weighted imaging (DWI), magnetic resonance spectroscopy (MRS), susceptibility-weighted imaging (SWI), and amide proton transfer (APT) imaging may provide an alternative imaging technique in answering specific diagnostic questions 13. The clinical significance of gadolinium deposition is thus far unknown 4. dentate nucleus of the cerebellum, globus pallidus) following administration of gadolinium contrast agents. Gadolinium deposits in trace amounts in various organs, especially the brain (e.g.
The risk of adverse reactions is higher in patients with bronchial asthma, a history of reactions to iodine-based contrast media, or others. There is a 30% possibility of recurrence of hypersensitivity in patients who have had a previous hypersensitivity episode to gadolinium contrast agents 9. These adverse reactions can be acute or chronic. Adverse reactionsĪdverse reactions to gadolinium contrast agents are relatively rare, occurring in 0.04-0.3% of administrations, of which 0.4-9% are severe 1-6. Most gadolinium contrast agents are excreted through the renal system and therefore have a prolonged half-life in renal failure. Gadolinium shortens T2 relaxation time and actually results in a hypointense signal. At very high concentrations of gadolinium contrast media, a signal void may appear to be present. Which one of these dominates depends on the characteristics of the tissue. Tissue that demonstrates enhancement following administration of gadolinium-containing IV contrast does so because of a combination of the following two mechanisms 3: Linear or macrocyclic: based on the molecular structure of the organic ligand (may be ionic or non-ionic) Ionic or non-ionic: based on their net charge in solution Gadolinium contrast agents are subcategorised into: Furthermore, some of the MRI contrast media employ other chemical elements than gadolinium, e.g. It should be noted that IV contrast is not required for all MR angiography, MR venography and MR perfusion sequences. Imaging of vessels in MR angiography or MR venographyĬalculating MR perfusion parameters (e.g. This can have a number of uses:ĭetection of focal lesions (e.g. As a result, on T1-weighted images they have a brighter signal. Gadolinium molecules shorten the spin-lattice relaxation time (T1) of voxels in which they are present. The gadolinium ion is useful as an MRI contrast agent because it has seven unpaired electrons, which is the greatest number of unpaired electron spins possible for an atom.
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