Gadolinium Retention in Pediatric Bone: Linear versus Macrocyclic MRI Contrast Agents

Background Gadolinium retention in bone after gadolinium-based contrast agent (GBCA) exposure is documented in adults but unquantified in children, who may have higher cumulative doses from early imaging. Purpose To quantify and compare residual gadolinium in pediatric bone tissue after macrocyclic and linear GBCA exposure. Materials and Methods In this prospective pilot study, individuals under 18 years of age scheduled for median sternotomy who had undergone clinically indicated GBCA-enhanced or unenhanced MRI were included between January 2018 and August 2024 at a single academic medical center and categorized into three groups: linear GBCA exposed (gadobenate), macrocyclic GBCA exposed (gadoterate), and control (no GBCA exposure). Bone samples were obtained during surgery and analyzed for gadolinium concentration (micrograms of gadolinium per gram of bone tissue). Linear regression modeling was used to analyze the impact of GBCA exposure on bone gadolinium concentration. Results A total of 29 individuals were included: nine exposed to linear GBCA (median age, 12.0 years [IQR, 4.0-14.0 years]; five male individuals), 11 exposed to macrocyclic GBCA (median age, 13.0 years [IQR, 3.3-14.8 years]; eight male individuals), and nine control individuals (median age, 1.8 years [IQR, 0.5-6.3 years]; seven male individuals). Gadolinium was detected in bone tissue in all groups. Median bone gadolinium concentrations were 0.001 μg/g (IQR, 0.0007-0.0015 μg/g) with no GBCA exposure, 0.007 μg/g (IQR, 0.004-0.011 μg/g) with gadoterate exposure, and 0.141 μg/g (IQR, 0.079-0.374 μg/g) with gadobenate exposure. GBCA exposure was associated with gadolinium concentration (adjusted R² = 0.77; P < .001). Gadobenate exposure was associated with higher gadolinium concentrations than no GBCA exposure (lnβ [log-transformed regression coefficient] = 4.9 [95% CI: 3.7, 5.9]; fold change, 129.8; P < .001) and gadoterate exposure (lnβ = 2.8 [95% CI: 1.6, 3.8]; fold change, 16.0; P < .001). Gadoterate exposure was also associated with higher gadolinium concentrations than no GBCA exposure (lnβ = 2.1 [95% CI: 1.5, 2.7]; fold change, 8.1; P < .001). Conclusion Exposure to the linear agent gadobenate at MRI was associated with higher gadolinium concentrations in bone tissue than no GBCA exposure or exposure to the macrocyclic agent gadoterate; trace gadolinium in the bone tissue of controls may reflect environmental exposure. Clinical trial registration no. NCT03337594 © RSNA, 2026 Supplemental material is available for this article.