CT appearance of experimental thalamic radiofrequency lesion in dog

The location and extent of thalamic lesions following thalamotomy can be identified as a large low density area in the acute stage to a small spot in the chronic stage. Stereotactic experimental radiofrequency lesions were placed in the thalamus of 35 mongrel dogs. CT images and whole brain specimens were obtained on days 0, 3, 7, 10, 14, 21 and 60. The appropriate time to map the lesions in the thalamus was thought to be about day 14, because of the thalamic size ratio and the correction of the ventricular deformity. The histological area of the lesion at day 14 corresponded better to the contrast-enhanced area than to that of the plain CT. These results suggest that the lesion demonstrated by contrast-enhanced CT scans at day 14 gives the best anatomical mapping of the actual histological defect.