Measurement of small inter-scan fluctuations in voxel dimensions in magnetic resonance images using registration

We present a method to estimate fluctuations in voxel dimensions in MR images. In the proposed method images of a standard test object are acquired serially and registered to an initial dataset. We present the results of experiments where changes in voxel dimensions between 0.1% and 2% were prescribed and measured with an accuracy of 0.02%. The method can be integrated as part of a standard MRI Quality Assurance program and may also be useful to correct for inter-scan variability introduced by fluctuations in gradient performance.