Role of scintigraphy and computer-assisted tomography in brain examination

To assess the role of computer-assisted tomography (CAT) and scintigraphy in brain exploration, the authors analysed: (1) the diagnostic effectiveness of the two methods in 300 patients examined over a period of seven months; (2) the role assigned to each investigation in 169 patients operated on for intracranial lesion during the same period. The isotopic brain examination always included an initial angiographic study after the intravenous injection of a technetium compound. Study of the circulation of the cerebrospinal fluid was made with 111In-DTPA. The detection efficiency of CAT is higher than for scintigraphy in expansive processes, whereas, conversely, in cerebrovascular accidents of ischaemic origin, isotope angiography coupled with static imaging enables one to gain more information on cerebral perfusion than CAT. Similarly, when studying the cerebrospinal fluid, scintigraphy provides a greater amount of specific data on the mechanisms governing hydrocephalus, the mode of operation of a shunt, or the site of a cerebrospinal fluid fistula. Within a neurosurgical context, CAT by and large takes precedence in brain examination, but the investigation is usually accompanied by scintigraphy or a conventional neuroradiological examination. Scintigraphy was performed on 66% of the patients, whereas for neuroradiological examination the figure was 44%. Most of the scintigraphy came after CAT so as to obtain additional diagnostic information on the vascularization, the nature and, on occasion, the exact location of the lesion revealed by CAT. In more than one case out of two, scintigraphy provides enough additional information for one to avoid neuroradiological examination, which is more 'aggressive' and more dangerous. Hence scintigraphy represents an effective complement to CAT and can compete with the conventional neuroradiological technique. (author)