THE EFFECTIVE USE OF MAGNETIC-RESONANCE-IMAGING IN THE DIAGNOSIS OF ACOUSTIC NEUROMAS

The diagnostic approach to acoustic neuromas is complex but these tumo urs are infrequent in patients even with a suggestive clinical picture . Easy access to an efficient, reliable and cost effective investigati on is desirable. Magnetic resonance imaging is now the imaging modalit y of choice and this paper shows that it may be used effectively as th e sole investigation. T2-weighted (T2W) fast spin echo axial images ta king 1 min 37 s to acquire were compared with T1-weighted (T1W) gadoli nium-enhanced axial images, taking 5 min 11 s to acquire, in 157 patie nts. The T2W images were satisfactory alone in 43% of patients and all owed confident diagnosis of seven of the nine acoustic neuromas. Parti al volume artefact and CSF flow artefact resulted in equivocal examina tions in the remaining patients. Using both sequences in every patient , imaging time was 7 min 41 s and at least 40 patients could be examin ed in 1 day, thus ensuring efficient patient throughput. We suggest th at T2W fast spin echo axial images be routinely obtained and that only when they are equivocal should T1W gadolinium-enhanced axial sequence s be employed.