Abstract:
Cardiac MRI intra- and inter-observer errors are routinely calculated to quantify analysis variability. Scan-rescan variability is a more stringent test where subjects are scanned and analyzed on two separate occasions. This incorporates variability due to patient positioning, EKG lead placement, scout and cine image placement, and changes in scan parameters, in addition to the variability in the analysis. This represents the true variability associated with determining patient disease progression or treatment effect in a clinical trial. Due to the difficulty of controlling loading conditions and their effect on end-diastolic and end-systolic volumes, scan-rescan variability is best determined using left ventricular mass (LVM) which can reasonably be expected to be constant between scans. As this is a difference measurement between both the endocardial and epicardial surfaces it is also particularly sensitive to errors in the placement of these contours.
