Whole-body MRI as a screening tool?

Abstract

Screening (early detection of disease in asymptomatic groups of persons) with whole-body MR (wb-MR) has only recently become possible. Technical requirements include extended scanner table range and extended coverage with surface coils. This allows for examining the whole body without repositioning the patient. wb-MR angiography can be combined with cerebral and cardiac MR to form a comprehensive screening protocol for atherosclerosis; and many malignancies can technically be screened for, such as colonic, bronchial, or renal carcinoma. The prerequisites for suited target diseases include enhanced therapeutic options if the disease is detected in an early stage, they should be harmful if detected late, and they should be sufficiently prevalent. The first studies on wb-MR screening reported low prevalences of a variety of assessable pathologies in non-selected groups; prevalences, however, increase with the presence of risk factors. More recent results are suggestive of a potential prognostic impact of MR screening, but studies on the outcome have not yet been published. This article also discusses potential problems and limitations of wb-MR. Some tumour entities cannot sufficiently be assessed, although the structures are included in the field of view. Incidental findings have to be anticipated; they might have an unforeseeable impact on the subject's well being. wb-MR seems technically 'ready' for screening. The cost-benefit relation of wb-MR screening, however, especially the impact on the health of the screened subjects, still remains to be investigated.