Small acoustic neuromas: detection by high resolution gas CT cisternography

CT air meatography: review of side effects in 60 patients

Sixty patients investigated for a suspected acoustic neuroma were questioned on the side effects of CT air meatography, a minimum of three months following the procedure. Twelve per cent of patients found the procedure itself so painful that a repeat examination would only be contemplated under general anaesthesia. Only 20 per cent of patients were asymptomatic after the procedure while 28 per cent of patients required bed rest for 24 hours or more (average 4.4 +/- 2.8 days). Sixty-two per cent of patients took three days or longer to return to normal health. The duration and frequency of side effects is greater than previously reported, and emphasizes the need for full investigation of these patients prior to CT air meatography.

The morbidity of CT air meatography: a follow-up of 84 patients

At present CT air meatography is the examination of choice for all patients suspected of having a small acoustic neuroma not demonstrated by high resolution contrast enhanced computed tomography. Several publications have indicated that the examination is innocuous and can be carried out on an outpatient basis. An analysis of the side effects of this procedure in 84 patients suggests that it carries a significant morbidity and patients undergoing this examination should be admitted to hospital for at least 24 hours.

Postoperative CT findings in acoustic neurinomas operated upon by a translabyrinthine approach

The findings at CT examinations, performed on 46 patients with acoustic neurinomas about 6 months after translabyrinthine surgery, were analyzed and compared with preoperative findings. Direct as well as indirect signs of expansion had disappeared postoperatively. Bulging of cerebellar tissue towards the operative defect in the petrous bone, a finding not connected with local adhesions, was notable. Hypodensity in the vicinity of the removed tumor occurred either due to local widening of the subarachnoid space or due to changes within the cerebellar parenchyma. Local and general widening of the fourth ventricle as a sign of atrophy was a frequent finding.

The technique of direct multiplanar high resolution CT of the temporal bone

The technique of direct multiplanar high resolution CT opens new possibilities for detecting even the smallest lesions of the central nervous system and its coverings. The prerequisites are: Submillimetre spatial resolution. Thin slice thickness collimation. Sufficient radiation dose to keep the noise in the image around about 1%. No waiting time between scans other than short reconstruction times, or use of rapid sequence scan procedures. Possibility to position patients and immobilize them for direct scanning of coronal and sagittal planes without significantly reducing the patient's comfort. Possibility of using optional algorithms which improve spatial resolution further (MacroView) in order to bring out very fine details. This article describes the technique we have used in order to fulfil these prerequisites and also gives a few results relating to the imaging of the facial nerve canal.