A SURVEY OF ROUTINE HEAD CT PROTOCOLS IN AUSTRALIA

The choice of scanning protocol in CT will affect the dose delivered t o the patient. A nationwide survey of CT operators was carried out in Australia in 1994 to determine the variation in routine head CT protoc ols. Only 29% of respondents used the supraorbitomeatal (SOM) baseline and thus avoided scanning the eyes. At 74% of sites, the routine prot ocol included scans both before and after injection of contrast. Howev er, the post-contrast protocol differed from that used in the pre-cont rast series in a number of cases. Where 5 mm thick slices were used, t he mAs was 16% higher than for 10 mm thick slices. Increased awareness of the influence of. baseline, slice thickness/spacing and accompanyi ng exposure factors on patient dose may lead to greater standardizatio n of head CT scanning protocols.