Computerised axial tomography.

Abstract

Computerised axial tomography has made an impressive impact on surgical neurology, and when the body scanner becomes available it will no doubt have similar advantages for the other specialities. It is a safe non-invasive method of investigating pathological processes of the brain. The amount of information so obtained is accurate to within 1% and at least a hundred times more inforation is obtained than from ordinary X-ray investigations. A review of 1 000 patients scanned is presented. Computerised axial tomography, if artefacts are eliminated completely, is most unlikely to yield a false positive scan. Its greatest value, however, is in the diagnosis of lesions in patients with head injuries and abscesses because these patients are very often moribund, and angiography, even when done expertly, may aggravate the clinical condition. Orbital and retro-orbital tumours have proved to be difficult to display other than by the EMI scanner methods. Acoustic neurinomata and meningiomata are also displayed with clarity, but owing to 'overshoot' artefact, other lesions, which do not enhance to the same extent on injection of Conray or Urografin, still offer a diagnostic problem. The investigation of epileptic patients has proved disappointing for the same reason that artefact obscures the low temporal lobe cut.