Deep Brain Nuclei T1 Shortening after Gadobenate Dimeglumine in Children: Influence of Radiation and Chemotherapy

Fellows’ Journal Club

The authors reviewed clinical charts and images of patients 18 years of age or younger with ≥4 gadobenatedimeglumine–enhanced MRIs for 6 years. Seventy-six children (60 unconfounded by treatment, 16 with radiochemotherapy) met the selection criteria. T1 signal intensity ratios for the dentate to pons and globus pallidus to thalamus were calculated and correlated with number of injections, time interval, and therapy. Among the 60 children without radiochemotherapy, only 2 had elevated T1 signal intensity ratios. Twelve of the 16 children with radiochemotherapy showed elevated signal intensity ratios. Statistical analysis demonstrated a significant signal intensity ratio change for the number of injections. Compared with published adult series, children show a similar pattern of T1 hyperintense signal changes of the dentate and globus pallidus after multiple gadobenatedimeglumine injections. The T1 signal changes in children are accelerated by radiochemotherapy.

Abstract

Figure 3 from paper
T1-weighted images acquired before (A and C) and after 10 gadobenate injections (B and D) in a patient being followed for a mass at the craniocervical junction with only surgical therapy (A and B) and a patient with medulloblastoma after an operation and radiochemotherapy (C and D). No signal change can be seen in the dentate for the patient without RCTX, while the patient with RCTX already shows signal changes after 10 injections.

BACKGROUND AND PURPOSE

Intrinsic T1-hyperintense signal has recently been reported in the deep gray nuclei on brain MR imaging after multiple doses of gadolinium-based contrast agents. Most reports have included adult patients and excluded those undergoing radiation or chemotherapy. We investigated whether T1 shortening is also observed in children and tried to determine whether radiochemotherapy is a risk factor for this phenomenon.

MATERIALS AND METHODS

In this single-center retrospective study, we reviewed clinical charts and images of all patients 18 years of age or younger with ≥4 gadobenate dimeglumine–enhanced MRIs for 6 years. Seventy-six children (mean age, 9.3 years; 60 unconfounded by treatment, 16 with radiochemotherapy) met the selection criteria (>4 MR imaging examinations; mean, 8). T1 signal intensity ratios for the dentate to pons and globus pallidus to thalamus were calculated and correlated with number of injections, time interval, and therapy.

RESULTS

Among the 60 children without radiochemotherapy, only 2 had elevated T1 signal intensity ratios (n = 20 and 16 injections). Twelve of the 16 children with radiochemotherapy showed elevated signal intensity ratios. Statistical analysis demonstrated a significant signal intensity ratio change for the number of injections (P < .001) and amount of gadolinium (P = .008), but not for the interscan time interval (P = .35). There was a significant difference in the average signal intensity ratio change between those with and without radiochemotherapy (P < .001). Chart review revealed no new neurologic deficits in any patients, related to their underlying conditions and prior surgeries.

CONCLUSIONS

Compared with published adult series, children show a similar pattern of T1 hyperintense signal changes of the dentate and globus pallidus after multiple gadobenate dimeglumine injections. The T1 signal changes in children may have a later onset but are accelerated by radiochemotherapy.

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Deep Brain Nuclei T1 Shortening after Gadobenate Dimeglumine in Children: Influence of Radiation and Chemotherapy
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jross
Jeffrey Ross • Mayo Clinic, Phoenix

Dr. Jeffrey S. Ross is a Professor of Radiology at the Mayo Clinic College of Medicine, and practices neuroradiology at the Mayo Clinic in Phoenix, Arizona. His publications include over 100 peer-reviewed articles, nearly 60 non-refereed articles, 33 book chapters, and 10 books. He was an AJNR Senior Editor from 2006-2015, is a member of the editorial board for 3 other journals, and a manuscript reviewer for 10 journals. He became Editor-in-Chief of the AJNR in July 2015. He received the Gold Medal Award from the ASSR in 2013.