1. A method for retrieving a medical picture, comprising the steps of: applying an image processing algorithm to a first medical picture to obtain a first processing result; applying said image processing algorithm to each medical picture of a set of medical pictures stored in a data base to obtain a second processing result, said set not containing said first medical picture; comparing the first processing result with each second processing result; and retrieving from said data base a second medical picture, a picture in said set of medical pictures having a second processing result comparable to the first processing result.