Cloud-Processed 4D CMR Flow Imaging for Pulmonary Flow Quantification

European Journal of Radiology Manuscript
Authors Raluca G. Chelu, MD Kevin W. Wanambiro, MD Albert Hsiao, MD PhD Laurens E. Swart, MD Teun Voogd, RT Allard T. van den Hoven, BSC Matthijs van Kranenburg, MD Adriaan Coenen, MD Sara Boccalini, MD Piotr A. Wielopolski, PhD Mika W. Vogel, PhD Gabriel P. Krestin, MD Shreyas S. Vasanawala, MD PhD Ricardo P.J. Budde, MD PhD Jolien W. Roos-Hesselink, MD PhD Koen Nieman, MD PhD


In this study, we evaluated a cloud-based platform for cardiac magnetic resonance (CMR) four-dimensional (4D) flow imaging, with fully integrated correction for eddy currents, Maxwell phase effects, and gradient field non-linearity, to quantify forward flow, regurgitation, and peak systolic velocity over the pulmonary artery.


We prospectively recruited 52 adult patients during one-year period from July 2014. The 4D flow and planar (2D) phase-contrast (PC) were acquired during same scanning session, but 4D flow was scanned after injection of a gadolinium-based contrast agent. Eddy-currents were semi-automatically corrected using the web-based software. Flow over pulmonary valve was measured and the 4D flow values were compared against the 2D PC ones.


The mean forward flow was 92 (±30) ml/cycle measured with 4D flow and 86 (±29) ml/cycle measured with 2D PC, with a correlation of 0.82 and a mean difference of −6 ml/cycle (−41–29). For the regurgitant fraction the correlation was 0.85 with a mean difference of −0.95% (−17–15). Mean peak systolic velocity measured with 4D flow was 92 (±49) cm/s and 108 (±56) cm/s with 2D PC, having a correlation of 0.93 and a mean difference of 16 cm/s (−24–55).


4D flow imaging post-processed with an integrated cloud-based application accurately quantifies pulmonary flow. However, it may underestimate the peak systolic velocity.