Fahr disease: use of susceptibility-weighted imaging for diagnostic dilemma with magnetic resonance imaging

Fahr disease (FD), idiopathic bilateral striopallidodentate calcinosis, is a rare neurodegenerative disease that is characterized by symmetric extensive intracranial calcifications, predominantly in the basal ganglia (1). Magnetic resonance imaging (MRI) is exquisitely sensitive in detecting brain abnormalities and thus the best diagnostic method in the central nervous system. However, it is difficult to reliably identify calcifications by routine MRI because calcifications appear with various signal intensities on conventional MRI sequences (2,3). Therefore, computed tomography (CT), in general, is the preferable modality for detecting and localizing the extent of intracranial calcifications. Also, in cases of FD with the presence of calcifications that are suspicious on MRI, CT is considered to be critical for accurate diagnosis (2)