1. Retrospective analysis to determine the safety of gadobenate dimeglumine (Gd-BOPTA) in pediatric subjects referred for routine diagnostic cardiovascular MRI G. Schneider, H. Schürholz, P. Fries, A. Bücker Saarland University Hospital, Clinic of Diagnostic and Interventional Radiology, Homburg / Saar, Germany

2. Introduction MRI is widely considered the imaging modality of choice for pediatric patients who may require multiple follow-up examinations over an extended period of time. Unfortunately, the advent of nephrogenic systemic fibrosis (NSF) among patients with severe renal insufficiency has brought the issue of gadolinium safety into question. This is potentially a major concern for pediatric patients whose kidneys are relatively underdeveloped compared with those of adults.

3. Introduction Gadobenate dimeglumine is a Gd-based contrast agent which has proven extremely safe among adult subjects for a variety of indications.

4. Introduction It is an acyclic, ionic molecule with a lipophilic group (arrow) and possesses high relaxivity compared to other Gd-based contrast agents. Due to its increased relaxivity relative to other agents reduced doses can be used to achieve comparable signal enhancement.

5. Introduction Although gadobenate dimeglumine is not yet approved in Germany for MR imaging of pediatric subjects, it is routinely used off-label at our center. The present retrospective analysis was performed to determine the safety of gadobenate dimeglumine in pediatric patients referred for routine diagnostic imaging.

6. Material and Methods A total of 88 pediatric subjects (age range: 0 years – 15 years) underwent CE-MRI as part of clinical routine. All evaluated subjects were in-patients at our hospital. Very young patients underwent MR imaging either in sedation or general anesthesia. A total of 134 injections were made. The injected dose in each case was 0.1 mmol/kg BW.

7. Material and Methods Monitoring for adverse events was performed from the moment of injection of gadobenate dimeglumine to at least 24 hours post- injection. Depending on the clinical necessity, laboratory measurements, and in some cases vital sign and ECG determinations, were made before and after the contrast-enhanced examination.

8. Results Gadobenate dimeglumine was well-tolerated by all patients No serious adverse events occurred in any of the 88 subjects (134 studies). No significant changes of creatinine or bilirubin levels were noted among subjects with laboratory tests performed before and after gadobenate dimeglumine injection.

9. Results CE-MRA of a 4 year old child with arterial tortuosity syndrome.

10. Results Partial anomalous pulmonary venous return in a 5 year old boy.

11. Results Pseudocoarctation in an 8 year old boy.

12. Results Coarctation in a one month old boy

13. Results PAVM´s due to Osler´s disease in an 11 year old girl.

14. Results A total of 21 subjects underwent 2 or more contrast-enhanced examinations while 10 subjects underwent 3 or more examinations. Despite the relatively large cumulative dose of gadobenate dimeglumine in some patients and the reduced renal function in the youngest patients, no detrimental effects of gadobenate dimeglumine were noticed. No patients exhibited symptoms of NSF.

15. Conclusions Based on the results of our retrospective analysis, gadobenate dimeglumine is a safe and efficient contrast agent for routine diagnostic cardiovascular MRI of pediatric patients. As in adults, gadobenate dimeglumine allows for high resolution MRA with very good depiction of especially small vessels at a dose of 0.1mmol/kg BW. The excellent safety profile and image quality achieved with relatively low doses of gadobenate dimeglumine is highly beneficial and should be borne in mind in any discussions of contrast agent safety in pediatric subjects.