Imaging Techniques in the Investigation of Cerebral Tumours

Supratentorial Tumours Part I: General Role of Imaging

“…Despite their traditional role, plain skull radiographs should not be performed when other non-invasive tests are available. Several studies have demonstrated that they are unreliable and only in a small number of cases are abnormalities demonstrated (Moseley 1986 andDu Boulay structural abnormality. andRadue 1978).…”

“…Amputation of the dorsum sellae may result from ballooning of the anterior end of the third ventricle due to obstructive hydrocephalus (Figure 1) but the other feature of raised intracranial pressure in adults, namely erosion of the lamina dura of the sella turcica (Sutton 1980) is often very subtle and may be mimicked by the aging process. Splaying of sutures in children indicating raised intracranial pressure, pathological intracranial calcification, focal bone erosion or hyperostosis ( Figure 2) and increased vascular markings are now of historical importance only (Moseley 1986). In the early ~O'S, radionuclide studies were by far the most reliable non-invasive means of detecting intracranial lesions (Moseley 1986).…”

“…Splaying of sutures in children indicating raised intracranial pressure, pathological intracranial calcification, focal bone erosion or hyperostosis ( Figure 2) and increased vascular markings are now of historical importance only (Moseley 1986). In the early ~O'S, radionuclide studies were by far the most reliable non-invasive means of detecting intracranial lesions (Moseley 1986). However, the limited resolution of the gamma camera and the limited altered vascularity and disturbance of the blood-brain barrier in certain tumours such as low grade gliomas resulted in a significant number of false-negative studies.…”

“…False-negative rates are particularly high in the case of brain stem and cerebellar tumours (Burrows 1976 andFelgin et a1 1975). Because of this and the nonspecific nature of any abnormality shown, there is little justification for continued conventional radionuclide scanning of the head either for diagnosis or for post-operative follow-up (Moseley 1986).…”

“…If there is a clinical suspicion of a brain tumour, imaging investigations are directed towards certain questions including (Moseley 1986): 1. Confirmation of the presence of an intracranial 2.…”