The purpose of this study is to compare contrast agents, Dotarem or MultiHance. The study will test to see how much of these two contrast agents are deposited in the bones or tissues of pediatric patients. The patients receiving contrast will then be compared against pediatric patients who have not received any contrast prior to cardiac surgeries.

When injected into the body, gadolinium contrast medium makes certain tissues, abnormalities or disease processes more clearly visible on a magnetic resonance imaging (MRI) scans and therefore gadolinium based contrast agents (GBCAs) are widely used in medical imaging. Recently, new evidence suggests that following GBCA administration, gadolinium can be deposited in body tissues even in the presence of normal renal function. Therefore, it is essential to ensure that significant accumulation of free Gd3+ is not occurring in the bones of children undergoing clinical contrasted MRI scans. This is particularly important for those pediatric patients who will undergo multiple repeated MRI exams throughout their lifetime and thereby be exposed to a large cumulative dose of gadolinium contrast. As the differences in stability between the various GBCAs may be a factor in gadolinium exposure, the primary objective of this study is to assess gadolinium deposition in the bones of pediatric patients in two patient groups: 1. patients who received IV administration of gadolinium contrast agent (Dotarem) and 2. patients who received IV administration of gadolinium contrast agent (MultiHance).

Once acquired the samples will be analyzed at an off-site facility, National Institute of Standards and Technology (NIST), using standardized equipment which has been certified for measuring gadolinium concentration in contrast agent samples. A signed agreement for the transfer of non-proprietary biological material between MUSC and NIST covers the transfer of the samples.

Inclusion Criteria:

• Female or male pediatric patient (patients aged newborn to 18 years old at the time of the MRI scan).

• Patients who require cardiac surgery for clinical purposes and meet one of the following three criteria:

  1. Patients who have undergone a routine contrast-enhanced MRI using MultiHance contrast agent only for clinical purposes.
  2. Patients who have undergone a routine contrast-enhanced MRI using Dotarem contrast agent only for clinical purposes.
  3. Patients who have not been exposed to gadolinium-based contrast agent administration

Exclusion Criteria:

• Patient with abnormal renal function (defined as eGFR MDRD<30 ml/min/1.73m2).
• Patient previously exposed to any other type of MRI gadolinium based contrast agent either at MUSC or at an outside facility
• Pregnant or breast feeding female patient
• Patient with a contraindication to MRI (e.g., pacemaker, aneurysm clip, severe claustrophobia, infusion pumps, cochlear implants metallic or others according to standard practice at MUSC).

All subjects, newborn to 18 years, scheduled for a prospective clinically indicated, contrast-enhanced, cardiac MRI will potentially be eligible for inclusion into the study. Potential subjects will be identified via pediatric cardiology, pediatric cardiothoracic surgery, or clinical schedules and consultation with attending physicians according to satisfaction of the inclusion and exclusion criteria listed above.