DE T E CT I ON of space-occupying lesions has been the goal of echoencephalography from its early inception. The growing interest in these techniques resides mainly on its being particularly well suited for longitudinal examinations, rapid, harmless, and free of discomfort. Several authors1-7 have published data regarding "mass echoes" in series of supratentorial space-occupying lesions. All these authors, with some exceptions6,8 have utilized, with minor modifications, the unidimensional (A-mode) echoencephalography. In general, most workers have reached the conclusion that while in a varying proportion of cases mass echoes can be obtained, the detection of a displacement of midline structures appears to be a more reliable and constant result.However, some authors have expressed the opinion that unidimensional (A-mode) echoencephalography can be misleading in a small but significant group of cases, particularly when the midline structures are dis-torted or closely related to the lesion itself.9-11 An intensity-modulated, linear, two-dimensional (B-mode) ultrasonic scanning provides a sonotomogram of many intra¬ cranial landmarks for each plane scanned. The advantages of this method have been discussed in previous papers.11·13We report here the results obtained with this technique in a series of supratentorial intracranial mass lesions. We shall consider the incidence of direct sonar "visualization" of the mass and that of its indirect demon¬ stration by virtue of a shift of midline struc¬ tures. The results of this test are compared with those obtained by other procedures such as EEG and radioactive scans, and all are correlated with the type of mass lesion, its histology, and its location. All these tests (electroencephalogram, sonar, and technetium Tc 99m scans) were obtained and inter¬ preted before radiological contrast studies were done.
Materials and MethodsThis series consists of 97 cases of the follow¬ ing supratentorial intracranial space-occupying lesions,