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

Abstract

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 (K̄p) and uncertainty (σ·Kκ p1) values for GFR. Results: In transplanted kidneys, average absolute variation, of K̄p was 6.4% = 4.8% (max = 16.6%). In native kidneys average absolute variation of K̄D 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. σ·K p1 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. © 2008 Wiley-Liss, Inc.