T2 shortening in the motor cortex: effect of aging and cerebrovascular diseases

To evaluate the effect of aging and cerebrovascular diseases on T2 shortening in the motor cortex at magnetic resonance (MR) imaging.

High-field-strength (1.5-T) MR images of 298 neurologically normal patients (157 male patients, 141 female patients; age range, 2-86 years) and 107 patients with cerebrovascular diseases (66 men, 41 women; age range, 41-86 years) were evaluated retrospectively. On T2-weighted spin-echo images, the signal intensities of the motor, sensory, parietal, temporal, and prefrontal cortices were divided into three grades compared with the signal intensity of the frontal subcortical white matter.

Decreased signal intensity (grade III) was not seen in any region in the neurologically normal patients younger than 60 years. After the age of 60 years, however, the signal intensity of the motor cortex decreased, and 43 (66%) of 65 neurologically normal patients reached grade III by age 80 years. In patients with cerebrovascular disease, grade III was seen in 12 (34%) of the 35 patients younger than 60 years (5th and 6th decades).

T2 shortening of the motor cortex was seen frequently in the older neurologically normal individuals and in patients with cerebrovascular diseases. These findings are compatible with those of a previously reported histochemical study of normal iron deposition in the motor cortex.