To the Editor.
—I would like to respond to the letter from Snodgrass1 concerning our study of the magnetic resonance imaging (MRI) characteristics of tuberous sclerosis (TS).2 First of all, we did not say, as Dr Snodgrass implies, that MRI can be expected to identify all patients with TS. True, one patient with TS had a normal MRI, but this same patient was also the only patient whose computed tomographic (CT) scan was normal (the criteria for inclusion in our study were so strict that there can be no doubt of this patient's diagnosis of TS). In three additional recent studies involving a total of 19 patients with TS, MRI showed evidence of TS in every patient.3-5 Thus, while we made no claim for the infallibility of MRI, 43 of 44 patients with TS reported so far have had MRI abnormalities. These same studies also support our finding
Roach ES. Usefulness of Magnetic Resonance Imaging in Tuberous Sclerosis. Arch Neurol. 1988;45(8):830–831. doi:10.1001/archneur.1988.00520320016004