ABSTRACT

Background The main task of imaging in oncology is the detection of the smallest lesion in the whole body of a patient. Hence lesion detectability is our goal. In the simplest imaging theory, where the influence of the observer is neglected, a lesion is detectable if the signal to noise ratio (some authors refer to this ratio more rigorously as the contrast to noise ratio, see reference1) exceeds the value of 4-5. Thus we have two parameters.