Nuclear medicine and ultrasound in the evaluation of neurologic diseases

The role of echoencephalography in neurologic diagnosis depends to some extent upon the availability of computerized transmission tomography. Where CTT is available, its superior ability to objectively evaluate the midline and ventricular size has largely eliminated the use of A-mode echoencephalography. CTT is capable of detecting acute subdural hematomas, and the relative absorption coefficients provide reliable characterization of the nature of a mass lesion. The combination of radionuclide brain scanning and CTT provides complementary information with remarkable sensitivity, to which A-mode echoencephalography has little to add. When CTT is not available and in situations where the appropriate information can be obtained utilizing ultrasound, A-mode echoencephalography employed by an experienced ultrasonographer may be of clinical value in detecting midline shifts, evaluating hydrocephalus in children, and following patients with CSF shunts. Finally, echoencephalography may provide reassuring information to the clinician dealing with patients with acute head trauma. (auth)