Turboprop+: Enhanced turboprop diffusion‐weighted imaging with a new phase correction

Faster periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion‐weighted imaging acquisitions, such as Turboprop and X‐prop, remain subject to phase errors inherent to a gradient echo readout, which ultimately limits the applied turbo factor (number of gradient echoes between each pair of radiofrequency refocusing pulses) and, thus, scan time reductions. This study introduces a new phase correction to Turboprop, called Turboprop+. This technique employs calibration blades, which generate 2‐D phase error maps and are rotated in accordance with the data blades, to correct phase errors arising from off‐resonance and system imperfections. The results demonstrate that with a small increase in scan time for collecting calibration blades, Turboprop+ had a superior immunity to the off‐resonance‐related artifacts when compared to standard Turboprop and recently proposed X‐prop with the high turbo factor (turbo factor = 7). Thus, low specific absorption rate and short scan time can be achieved in Turboprop+ using a high turbo factor, whereas off‐resonance related artifacts are minimized. Magn Reson Med 70:497–503, 2013. © 2012 Wiley Periodicals, Inc.