Improvement of MRI-functional measurement with automatic movement correction in native and transplanted kidneys

Purpose: To improve 2D software for motion correction of renal dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and to evaluate its effect using the Patlak-Rutland model. Materials and Methods: A subpixel-accurate method to correct for kidney motion during DCE-MRI was evaluated on native and transplanted kidneys using data from two different institutions with different magnets and protocols. The Patlak-Rutland model was used to calculate glomerular filtration rate (GFR) on a voxel-by-voxel basis providing mean ((K) over bar (p)) and uncertainty ((sigma) over bar (K-p))values for GFR. Results: In transplanted kidneys, average absolute variation of (K) over bar (p), was 6.4% +/- 4.8% (max = 16.6%). In native kidneys average absolute variation of (K) over bar (p), was 12.11% +/- 6.88% (max = 25.6%) for the right and 11.6% +/- 6% (max = 20.8%) for the left. Movement correction showed an average reduction of (sigma) over bar (K-p) of 6.9% +/- 6.6% (max = 21.4%) in transplanted kidneys, 30.9% +/- 17.6% (max = 60.8%) for the right native kidney, and 31.8% +/- 14% (max = 55.3%) for the left kidney. Conclusion: The movement correction algorithm showed improved uncertainty on GFR computation for both native and transplanted kidneys despite different spatial resolution from the different MRI systems and different levels of signal-to-noise ratios on DCE-MRI.