Doses are customized for men and women, for certain age brackets and weights, and for other variables for which minimal radiation doses are unclear. So far, protocols cover abdominal, cardiac, chest, musculoskeletal, neurological and pediatric exams. More types of imaging screens will come.
Thrall says that imaging technology is not a one-dose fits all, although that may have been how it was formerly applied.
Five or so years ago when the first 64-slice CT scans came out, he acknowledges, there was a rush to scan and a somewhat cavalier attitude on the part of providers over the impacts accumulated doses might have evolved.
Now that is being dramatically reversed, he says.
So far, he and other researchers have used dose threshold techniques on about 40 cadavers in what Thrall calls "a virtual autopsy."
"As cadavers become available, we image them in the CT suite, starting at very, very low doses, and then at increasingly higher doses until we get up to a dose above what we would use clinically. And from this data, we can further optimize the amount of radiation we give to patients."
He adds that technology is evolving so rapidly, there isn't the opportunity to perform dose-ranging studies in living patients.
"Rather than do the scan and realize you didn't use enough, the tendency has been to use more than enough to make sure you get a good image. But by having cadavers with different sizes we can really focus on the absolutely lowest dose that will be diagnostically acceptable."