Whole body magnetic resonance imaging - Incidental findings in a general population cohort: A threat to valid prospective assessments of health related outcomes? What is the significance of the progression of incident MR findings?

• Applicants: Dr. Robin Bülow; Professor Dr. Jean-François Chenot; Professorin Dr. Marie-Luise Kromrey; Professor Dr. Carsten Oliver Schmidt
• Subject Area: Public Health, Healthcare Research, Social and Occupational Medicine
• Term: since 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 191163974

Magnetic resonance imaging (MRI) is an established imaging approach in population-based research. The internationally best-published implementation of a whole-body MRI (wb-MRI) protocol to date was realized in the Study of Health in Pomerania (SHIP, N=3371 MRI examinations). Dealing with the numerous incidental findings (IFs) presented a major challenge, largely because information from a routine clinical diagnostic context was entirely missing. Against this background, two previous DFG projects have laid the foundation for a much better understanding of IFs in population-based research by integrating data from clinical SHIP examinations, postal surveys, claims data, and hospital data. Moderate to severe distress was very common in the short term and there was strong evidence of prolonged cascades of care following the SHIP MRI examination, leading to a 10% increase of outpatient costs over two years. The number of biopsies increased significantly after the MRI examination, which usually led to no or clinically irrelevant findings. Few additional malignancies were diagnosed. This indicates potential overtesting and overdiagnosis. The minor reduction of mortality among MRI participants after adjusting for potential confounders was inconclusive. Taken together, our findings indicate that communicated MRI findings entailed a considerable burden to individual participants and the health care system, while providing limited benefits. SHIP research objectives were partially corrupted due to the introduction of bias. However, another important area related to IFs has received less attention. This concerns the progression of incidental wb-MRI findings. There is a lack of evidence from population-based studies that target the course of a wider range of IFs across anatomic regions. SHIP offers the unique opportunity to address this because there exist wb-MRI follow-up (N=2234) examinations with a largely comparable protocol approximately 6-8 years after baseline. We address the following main research questions: How do baseline MRI findings progress morphologically? Does this alter the initial evaluation of MR findings? Which factors predict morphological changes of MR findings? How does progression of findings relate to the long-term well-being of SHIP participants? To assess these questions, MR images in persons with a disclosed IF will be reassessed to quantify and classify morphological changes. Established linkages from the previous project phases with our hospital and claims data will be used to assess the impact and potential selection bias due to drop-outs. Follow-up results from the clinical SHIP assessments will complement this to embrace the participants’ long-term perspective. The results will not only be relevant from a scientific point of view for population-based epidemiology but also for the further development of guidance to better deal with IFs in diagnostic screening.

• DFG Programme: Research Grants
• Co-Investigator: Dr. Elizabeth Sierocinski