Streak Artefact Quantification for Abdominal CT

Streaking artefacts in computed tomography (CT) can be caused by photon starvation caused by highly attenuating regions. Patient positioning can influence the attenuation e.g. by arms raised or down in an abdominal CT scan. Positioning the arms alongside the body increases attenuation, therefore higher dose can be expected. Additionally the artefacts can cause a decrease in image quality. Measuring this quality decrease is the purpose of this article. We implemented different methods to quantise streaking artefacts and correlated them to the judgement of two radiologists in a study of 80 patients. High significance was found for a correlation coefficient of 0.57. This correlation from measurements and clinical usability (represented by the radiologists' ratings) enables to predict the usability by means of image processing alone. This can be included in the patient image as a correlate to the diagnostic usability, resp. a new volume can be made depending on the number.