The value of brain scanning in the diagnosis of recurrences of brain tumours.

The Authors consider critically the possibilities of brain scanning in the diagnosis of recurrences of brain tumours. They examine a series of 143 cases subjected in 180 brain scans exams. The accuracy of the diagnosis is demonstrated by operative controls and verified by the results of the Common neuroradiologic investigations (angiography and air study). The analysis of patients according to the different types of tumours, enabled us to make the following conclusions: 1) Percentages of positivity of recurrences with astrocytomas and localisations in the posterior fossa are highest than that obtainable with the primitive tumour. 2) Flap activity is not considered as a limitative factor of the diagnostic possibilities of recurrence, except in meningiomas of small dimensions, near the longitudinal sinus. 3) In our series, there is only a false negative, surgically verified, and diagnosis of negativity is confirmed by the percentages of accordance with neuroradiogical methods. 4) Pneumoencephalography is more valuable than arteriography in the diagnosis of recurrence, but only the association of the two methods provides percentages of exact diagnosis comparable to the results of brain scanning. 5) Brain scanning gave false positive results only in cases of radionecrosis.