Increased signal intensity in the pulvinar on T1-weighted images: a pathognomonic MR imaging sign of Fabry disease

Abstract

Background and purpose: Fabry disease is a multisystem X-linked disorder characterized clinically by angiokeratoma, corneal and lenticular abnormalities, acroparesthesia, and renal and cardiac dysfunction and stroke. We sought to describe novel neuroimaging characteristics of Fabry disease.

Methods: Neuroradiologic records of 104 hemizygous patients with Fabry disease evaluated between 1994 and 2002 were reviewed. In total, 94 MR studies consisting of T1- and T2-weighted images were examined for the presence of hyperintensity on the T1-weighted images. Additional CT, gradient-echo (T2*-weighted), and fat-suppression MR studies were reviewed to characterize further the T1 abnormality in selected patients. In some patients, cerebral blood flow (CBF) was quantified by using arterial spin tagging (AST).

Results: Overall, 22 patients ( approximately 23%) demonstrated pulvinar hyperintensity on T1-weighted images; the frequency increased with age to over 30% by age 50 years. Susceptibility-weighted T2* studies demonstrated a low-signal-intensity abnormality in the pulvinar in the more severe cases, whereas CT demonstrated the pulvinar to be mineralized. CT attenuation corresponded with an increasing signal intensity on T1-weighted images. Posterior circulation CBF was found to be elevated on individual AST studies, especially in the thalamus.

Conclusion: Hyperintensity in the pulvinar on T1-weighted images is a common finding in Fabry disease, likely reflecting the presence of calcification. Although other minreralizing abnormalities may result in calcification of deep gray nuclei, exclusive involvement of the pulvinar may be distinctively characteristic to Fabry disease. Increased CBF in the posterior circulation, particularly the thalamus, suggests that the dystrophic calcification is secondary to cerebral hyperperfusion and selective vulnerability of the pulvinar and adjacent thalamic nuclei. The finding of isolated pulvinar hyperintensity on T1-weighted images should suggest Fabry disease, particularly when seen in conjunction with other nonspecific neuroradiologic manifestations of the disease.

Fig 1.

A, Age distribution of patients with (black bars) and those without (gray bars) hyperintensity on T1-weighted images. B, Percentage of patients with hyperintensity on T1-weighted images by decade of age (n = 94 patients)

Fig 2.

Serial, axial T1-weighted MR images (5-mm sections) demonstrate the range of pulvinar hyperintensities observed. A and B, Mild to moderate abnormality. C, Marked abnormality.

Fig 3.

Comparison of CT and MR findings in the posterior thalamus. A–C, T1-weighted images through the thalamus in three patients with mild (A), moderate (B), and marked (C) hyperintensity, respectively. D–F, Corresponding CT scans demonstrate increased attenuation indicating calcification is present only in the moderate and marked cases. G–I, Corresponding gradient-echo T2*-weighted images demonstrate that susceptibility-induced signal intensity loss is seen in the pulvinar in only the moderate and marked cases. Numbers in upper right are patient identifiers.

Fig 4.

A–C, Selected axial CT scans demonstrate dystrophic calcification of the subcortical arcuate fibers, globus pallidus, pulvinar, and cerebellar corticomedullary junction in a more severely affected patient with Fabry disease. Number in upper right is the patient identifier.

Fig 5.

Direct axial AST images demonstrate increased relative CBF in the thalamus and posterior circulation at the anterior and posterior commissure plane in a patient without (A) and one with (B) the T1-weighted MR imaging abnormality. The dark thalamic regions in the pulvinar in B correspond to the damaged mineralized areas in the midst of the still hyperperfused pulvinar region.