title: MR imaging of the brain in large cohort studies: feasibility report of the population- and patient-based BiDirect study.
abstract: OBJECTIVE
  To describe the implementation and protocol of cerebral magnetic resonance imaging (MRI) in the longitudinal BiDirect study and to report rates of study participation as well as management of incidental findings.
  
  
  METHODS
  Data came from the BiDirect study that investigates the relationship between depression and arteriosclerosis and comprises 2258 participants in three cohorts: 999 patients with depression, 347 patients with manifest cardiovascular disease (CVD) and 912 population-based controls. The study program includes MRI of the brain. Reasons for non-participation were systematically collected. Incidental findings were categorized and disclosed according to clinical relevance.
  
  
  RESULTS
  At baseline 2176 participants were offered MRI, of whom 1453 (67 %) completed it. Reasons for non-participation differed according to cohort, age and gender with controls showing the highest participation rate of 79 %. Patient cohorts had higher refusal rates and CVD patients a high prevalence of contraindications. In the first follow-up examination 69 % of participating subjects completed MRI. Incidental findings were disclosed to 246 participants (17 %). The majority of incidental findings were extensive white matter hyperintensities requiring further diagnostic work-up.
  
  
  CONCLUSIONS
  Knowledge about subjects and sensible definition of incidental findings are crucial for large-scale imaging projects. Our data offer practical and concrete information for the design of future studies.
  
  
  CONCLUSIONS
  • Willingness to participate in MRI is generally high, also in follow-up examinations. • Rates of refusal and prevalence of contraindications differ according to subject characteristics. • Extensive white matter hyperintensities considerably increase the disclosure rates of incidental findings. • MRI workflow requires continuous case-by-case handling by an interdisciplinary team.
authors.affiliation: Institute of Epidemiology and Social Medicine, University of Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany. anja.teuber@uni-muenster.de.
authors.forename: Anja
authors.initials: A
authors.lastname: Teuber
authors.affiliation: Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Sundermann
authors.affiliation: Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Kugel
authors.affiliation: Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany.
authors.forename: Wolfram
authors.initials: W
authors.lastname: Schwindt
authors.affiliation: Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Heindel
authors.affiliation: Department of Neurology, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Minnerup
authors.affiliation: Department of Psychiatry, University of Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany.|Department of Psychiatry, University of Marburg, Rudolf-Bultmann-Straße 8, 35039, Marburg, Germany.
authors.forename: Udo
authors.initials: U
authors.lastname: Dannlowski
authors.affiliation: Institute of Epidemiology and Social Medicine, University of Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Berger
authors.affiliation: Institute of Epidemiology and Social Medicine, University of Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Wersching
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology; D016022:Case-Control Studies; D015331:Cohort Studies; D000075202:Contraindications; D003865:Major Depressive Disorder / Q000000981:diagnostic imaging* / Q000453:epidemiology; D005240:Feasibility Studies; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D033162:Incidental Findings; D002537:Intracranial Arteriosclerosis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D045808:Refusal to Participate; D012737:Sex Factors; D014342:Truth Disclosure
keywords: Cohort studies; Contraindications; Incidental findings; Magnetic resonance imaging; Refusal to participate