DETECTION OF SUBTLE CHANGES IN THE BRAINS OF INFANTS AND CHILDREN VIASUBVOXEL REGISTRATION AND SUBTRACTION OF SERIAL MR-IMAGES

PURPOSE: To compare conventional two-dimensional multisection images w ith registered three-dimensional Volume and subtraction images for det ecting subtle changes in the brains of infants and children. METHODS: Twenty-six patients (24 with hemorrhagic/ischemic lesions) and one eac h with perinatal infection and Sturge-Weber disease were examined on t wo or more occasions with conventional multisection T1- and T2-weighte d sequences as well as with 3-D T1-weighted volume sequences. A regist ration program was used to match the volume images to subvoxel dimensi ons, and subtracted images (second volume set minus the first) were ob tained. The multisection images were compared with the 3-D and subtrac ted images and graded for detection of changes in a variety of brain s tructures. RESULTS: In 16% to 33% of comparisons of different structur es, the multisection images and the 3-D registered and subtracted imag es showed changes equally well. The 3-D registered and subtracted imag es were better than the multisection images in 67% to 84% of compariso ns for detection of changes in the cerebral hemispheres, ventricles, b rain stem, cerebellum and in lesions. Statistically significant differ ences were found between the graded performance of the registered 3-D images and the conventional 2-D images in detecting cerebral infarctio n and hypoxic ischemic encephalopathy. In the late phase following neo natal cerebral infarction (1 to 11 months), the 3-D registered and sub tracted images revealed growth of the brain at the margins of the lesi ons. CONCLUSION: Subvoxel registration of serial MR images may be of v alue in detecting subtle changes in the brains of infants and children .