Interval between contrast administration and T1-weighted MRI for cerebral adrenoleukodystrophy: a single-case observation.

In adrenoleukodystrophy (ALD), contrast enhancement (CE) is a disease activity marker, but there is uncertainty about the optimal delay, if any, between contrast injection and magnetic resonance imaging (MRI) acquisition to avoid false-negative results. We acquired axial two-dimensional (2D) and three-dimensional (3D) T1-weighted gradient-echo every 6 min from 0 to 36 min after contrast administration (gadobutrol 0.1 mmol/kg) in an ALD patient with enlarging white matter lesions and progressive neuropsychological symptoms, using a 3-T magnet. The image signal over time was qualitatively assessed and measured in two regions of interest. On 3D sequences, no definite CE was appreciated, whereas on 2D sequences, CE was noticed after 6 min and definitely evident after 12 min, when 73% of the maximum signal intensity was measured. In ALD subjects, contrast-enhanced 2D T1-weighted gradient-echo sequences acquired at least 10 min after contrast injection may be considered to reduce false negative results.Relevance statementOur report is the first attempt to find an optimal delay between contrast administration and T1-weighted acquisition in cALD patients in order to correctly detect disease activity and avoid false negative results.Key points• The optimal time between contrast injection and image acquisition for MRI of adrenoleukodystrophy is unknown.• Contrast enhancement predicts adrenoleukodystrophy progression and could help patient's selection for the therapy.• We acquired two post-contrast T1-GRE-2D/3D sequences several times to find the best injection-time.• T1-weighted 2D GRE resulted more sensitive than T1-weighted 3D GRE even after long intervals from injection.• A delay of about 10 min may minimize false negatives.