Perirolandic cortex in infants: signal intensity on MR images as a landmark of the sensorimotor cortex.

PURPOSE

To correlate the perirolandic low signal intensity seen on T2-weighted magnetic resonance (MR) images in neonates and infants with the anatomically located sensorimotor cortex.

MATERIALS AND METHODS

Axial T2-weighted MR images of 146 consecutive patients less than 6 months old were reviewed. The sensorimotor cortex was located by identifying the central sulcus. Two independent readers attempted to identify the central sulcus using two anatomic methods independently and in combination. The location of the central sulcus was compared with that of the perirolandic low signal intensity.

RESULTS

Seventy-two normal hemispheres in 36 patients and 91 abnormal hemispheres in 47 patients showed clear perirolandic low signal intensity. The central sulcus was located anatomically in 70 and 72 normal hemispheres (97% and 100%, respectively) and 90 and 91 abnormal hemispheres (99% and 100%, respectively). In all normal hemispheres, the identified central sulcus correlated with the perirolandic low signal intensity. In contrast, an apparent mismatch was found in two hemispheres in a patient with Dandy-Walker syndrome.

CONCLUSION

The perirolandic low signal intensity seen on T2-weighted MR images is located exactly in the anatomic sensorimotor cortex in normal brains, whereas a mismatch can occur in abnormal brains.