Compressed image quality assessment: Application to an interactive upper limb radiology atlas

Abstract

It is admitted that lossy compression can be used in the field of medical images under the control of experts. Lossy compression can offer substantial reduction of the volumes of medical images, being thus an efficient solution for both storage and transmission problem in the medical context. Furthermore, the use of touchpads in medicine has grown and many medical applications on this kind of support is now available. The storage capacity of this kind of terminal is limited, lossy compression represents a good alternative to allow greedy medical applications on such terminals. In this work, we address the problem of quality assessment of MRI scans from an interactive upper limb radiology atlas (Monster Anatomy Upper Limb). The quality assessment protocol is adapted from the International Telecommunication Union recommendations (ITU-R BT-500-11). In this paper, we propose to determine compression thresholds which are acceptable according to the quality required for the proper use of this radiology atlas. We show that this application (using a simple JPEG encoder) has a lossy compression threshold ranging from 13: 1 for the majority of the atlas images up to 27: 1 for the hand images. Finally, several objective image quality assessment algorithms (IQA) are also linked to subjective ratings of the panel of health professionals.