Scientific Concept of the National Cohort (status ... - Nationale Kohorte

A.3
A.3 Study design
Informed Consent: Informed consent for the MRI examination will be obtained at the study
center by a physician. A flyer containing all relevant information in written form will be available
to the potential participants. In addition, the flyer will contain 2–3 figures showing the
MRI scanner and the imaging set-up. A video screen will be installed to show a brief movie
detailing the scanning procedure and the coil positioning as well as highlighting the duration
of the examination.
Set-up of imaging sites
Four imaging sites will be established to perform the whole-body MRI examinations in order
to safeguard highest image quality, internal validity, and cost-effectiveness. Scientific
evidence strongly suggests that standardization of MRI is not feasible over different MRI
devices 712-716 . Thus, to ensure that acquisitions are highly standardized and comparable,
new MRI devices from the same vendor and identical equipment are provided to selected
imaging sites. Association with further MRI sites will be allowed only in the case that these
sites provide evidence of sufficient comparability of key findings with the four National Cohort
sites. Trained and certified MRI technologists will be available at each site; they will
receive centralized training and certification.
Selection process of appropriate imaging sites: Upon evaluation of the current proposal,
the process for selecting appropriate imaging sites will be initiated. This will include an official
and publicly available request to apply as a potential MRI imaging site for the National
Cohort. The proposed selection criteria are:
� Proximity to study center.
� Maximum of one MRI device per cluster; the final distribution should take regional aspects
into account (North–South, West–East, rural–urban) to assure generalizability.
� Strong expertise of local radiologists in performing large-scale clinical whole-body
MRI or epidemiologic studies with high-quality standards.
� To assure optimal resource utilization, a minimum number of 5,000–10,000 subjects
per site will be examined for optimal facility utilization. Consequently, not only subjects
of Level 2 examinations, but also those with Level 1 examinations will be offered to
participate in the MRI substudy (see MRI follow-up examination).
Interaction between study center and imaging site: Interaction between the study center
and the imaging site will be of critical importance. Given the close relationship between the
study center and all study participants, the study center staff will have responsibility for all
information pertaining to the MRI examination and for obtaining consent and scheduling the
MRI appointments. This will assure highest participation rates as relevant information can
be conveyed personally.
The imaging site staff is required to inform participants about the long- and short-term availability
of imaging slots using a dedicated scheduling system. In addition, the imaging site
staff will need to welcome each participant, provide additional information if necessary,
and detail the specific procedures. Upon completion of the scan, the imaging site should
perform a quality assurance algorithm (as detailed in Sect. A.5.7) and transfer the data.
Should an important and urgent incidental finding be detected at the first-line reading in the
centralized reading core, this will be reported within 30 min to the imaging site to initiate
the feedback mechanism as detailed in Sect. A.7.2.5. For low-priority incidental findings,
this information will be transferred to the study center, which will contact the subject via a
general practitioner.
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