Abstract #0112

Elimination of DWI Signal Dropouts Using Blipped Gradients for Dynamic Restoration of Gradient Moment

Kazim Gumus¹, Benedikt Poser¹, Brian Keating¹, Brian Armstrong², Julian Maclaren³, Thomas Prieto⁴, Oliver Speck⁵, Maxim Zaitsev⁶, Thomas Ernst¹

¹John A. Burns School of Medicine, U. of Hawaii, Honolulu, HI, United States; ²Dept. of Electrical Engineering and Computer, U. of Wisconsin-Milwaukee, Milwaukee, WI, United States; ³Dept. of Radiology, University Medical Center Freiburg, Freiburg, Germany; ⁴Neurology, Medical College of Wisconsin, Wauwatosa, WI, United States; ⁵Dept. Biomedical Magnetic Resonance, Otto-von-Guericke-University, Magdeburg, Germany; ⁶Dept. of Diagnostic Radiology, University Hospital Freiburg, Freiburg, Germany

Intra-scan head motion causes signal dropouts in DWI. A new method is presented to eliminate such artifacts. We used a Moir-Phase-Target based tracking system to measure head motion between excitation and acquisition. Knowing also the timing and amplitudes of gradients, we determined the motion-induced residual gradient moment (M) and restored the gradient balance prior to readout by applying a blip gradient of moment -M. The method was tested on two volunteers who performed intentional head movements. Gradient moment correction successfully eliminated signal dropouts compared to scans without correction. This method should be feasible on most modern scanner platforms.