Some results of isotopic cranial section scanning are presented from a busy neurosurgical practice. Isotopes have been used for parenchymal lesions and also CSF pathway imaging. Comparisons with information yielded by other neuroradiological techniques have indicated that tomographic sections are a worthwhile addition to rectilinear isotope scans. In particular comparison with X-ray transmission (EMI) scans has confirmed the anatomical accuracy of the method and the two techniques have proved complementary in patient management.