Walsh & Hoyt: Neuroimaging

Calcifications are rarely present in the neonate with SWS, but they can eventually be identified in the skull films or CT scans in 90% of patients, particularly in the posterior hemispheres. The characteristic gyriform or tram-track pattern of calcification usually forms after 2 years of age. This well-known sign, however, sometimes occurs in other neurologic disorders. In early life, CT scanning is more sensitive in detecting small amounts of calcium on the cortical surface and also in revealing underlying cortical atrophy than other forms of neuroimaging; however, CT scanning is unlikely to show the curvilinear pattern of calcification seen on skull radiographs.