No Signal Intensity Increase in the Dentate Nucleus on Unenhanced T1-weighted MR Images after more than 20 Serial Injections of Macrocyclic Gadolinium-Based Contrast Agents

Zielsetzung:

To determine the effect of more than twenty serial injections of macrocyclic gadolinium-based contrast agents (GBCAs) on the signal intensity (SI) of the dentate nucleus (DN) on unenhanced T1-weighted MR images.

Material und Methodik:

In this retrospective, institutional review board-approved study, 33 patients who underwent at least 20 consecutive MRI examinations (plus an additional MRI for reference) with the exclusive use of macrocyclic GBCAs (gadoterate meglumine and gadobutrol) were analyzed. SI ratio differences were calculated for DN-to-pons (DNP) and DN-to-middle cerebellar peduncle (DNMCP) ratios by subtracting the SI ratio at the first MRI from the SI ratio at the last MRI scan. One-sample t-tests were employed to examine if the SI ratio differences differed from 0 and Bayes factors were calculated to quantify the strength of evidence for each test.

Ergebnisse:

Patients underwent a mean of 23.03 ± 4.20 GBCA administrations (mean accumulated dose: 491.21 ± 87.04 ml of a 0.5 M GBCA solution) with an average of 12.09 ± 2.16 weeks between every administration. Both ratio differences did not differ significantly from 0 (DNP: -0.0032 ± 0.0154, p = 0.248; DNMCP: -0.0011 ± 0.0093, p = 0.521) and one-sided Bayes factors provided substantial to strong evidence against an SI ratio increase (Bayes factor for DNP = 0.09, for DNMCP = 0.12).

Schlussfolgerungen:

Our study indicates that 20 or more serial injections of macrocyclic GBCAs administered with on average three months between each injection are not associated with an SI increase in the DN.