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

A.5
A.5 Methods for quality assurance and quality control
by a technical support team from the vendor of the equipment twice a year in each study
center to minimize errors. The resulting technical report will be checked by the competence
unit on biomaterials on a regular basis. Quality reports will be prepared to determine intra-
und interreliability between examiners/technicians as well as among study centers.
A.5.7 measures to assure high and consistent image quality in the mrI
substudy
Quality assurance of the imaging procedures represents a challenge, given the multicenter
design of the National Cohort. Standardization procedures established for imaging examinations
in the Study of Health in Pomerania (SHIP) will serve as a basic template for the
National Cohort.
For all examinations, SOPs are available for obligatory perusal by the examiners. The examination
procedure is tested in pilot studies. All examiners are trained over several months
and certified following the training period. Potential observer bias or trends are continuously
monitored. These efforts to ensure high quality standards result in low method and observer
variability and are particularly important given the long duration of the data acquisition
phase.
Technologist training: The MRI technologists on-site will already have adequate experience
in performing MRI examinations. In general, a minimum of 3 years of MRI experience
is required. All technologists will undergo centralized training, consisting of lectures and
practical lessons covering scanning and data transfer. Furthermore, they will be trained to
perform a first-line quality check (see below) after each study participant has been examined.
All technologists will be recertified on an annual basis. The same application engineer
from the vendor will also provide on-site training for the technologists of all imaging sites.
Automated operation and user guidance (DOT engine) are provided by the vendor to assure
highly standardized acquisitions.
Phantom measurements: It is anticipated that regular measurements on standard and
organ-specific MRI phantoms will be performed (phantoms will be specified after final decisions
have been made concerning the examination program). This ensures external validity
and also addresses the challenge of a long-lasting field phase.
Imaging devices: To minimize device-related bias, new high-end imaging devices with
identical hardware and software equipment from the same company are required for the
National Cohort, for which no updates (e.g., software updates) will be applied as long as
data are collected at baseline and during follow-up. Comprehensive imaging examinations
including MRI will be conducted only at centers where radiological expertise in large-scale
clinical and epidemiologic studies with high-quality standards is available.
Pilot studies: Before the start of the main study, pilot studies will be conducted to test the
feasibility of methods and procedures. During each pilot study, volunteers will be examined.
Information gained in these pilot studies will be used to optimize the procedures at each
study center, to detect real or potential leaks or blocks in the information flow, and to further
ensure the quality of the study.
First-line quality check: The first-line quality check will be performed at the imaging site by
the technologists for each examination. In general, this will include completion of a checklist
(preferably in electronic form, with paper as back-up) to ensure that all required sequences
were acquired, no major artifacts are present, and that adequate measures were taken to
store the acquired images. The criteria for the first-line check will be specified in advance
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