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Investigating the limitations of single breath‐hold renal artery blood flow measurements using spiral phase contrast MR with R‐R interval averaging
Author(s) -
Steeden Jennifer A.,
Muthurangu Vivek
Publication year - 2015
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.24638
Subject(s) - phase contrast microscopy , spiral (railway) , interval (graph theory) , medicine , blood flow , contrast (vision) , cardiology , radiology , mathematics , physics , mathematical analysis , combinatorics , optics
Purpose 1) To validate an R‐R interval averaged golden angle spiral phase contrast magnetic resonance (RAGS PCMR) sequence against conventional cine PCMR for assessment of renal blood flow (RBF) in normal volunteers; and 2) To investigate the effects of motion and heart rate on the accuracy of flow measurements using an in silico simulation. Materials and Methods In 20 healthy volunteers RAGS (∼6 sec breath‐hold) and respiratory‐navigated cine (∼5 min) PCMR were performed in both renal arteries to assess RBF. A simulation of RAGS PCMR was used to assess the effect of heart rate (30–105 bpm), vessel expandability (0–150%) and translational motion (x1.0–4.0) on the accuracy of RBF measurements. Results There was good agreement between RAGS and cine PCMR in the volunteer study (bias: 0.01 L/min, limits of agreement: −0.04 to +0.06 L/min, P = 0.0001). The simulation demonstrated a positive linear relationship between heart rate and error ( r = 0.9894, P < 0.0001), a negative linear relationship between vessel expansion and error ( r = −0.9484, P < 0.0001), and a nonlinear, heart rate‐dependent relationship between vessel translation and error. Conclusion We have demonstrated that RAGS PCMR accurately measures RBF in vivo. However, the simulation reveals limitations in this technique at extreme heart rates (<40 bpm, >100 bpm), or when there is significant motion (vessel expandability: >80%, vessel translation: >x2.2). J. Magn. Reson. Imaging 2015;41:1143–1149 . © 2014 Wiley Periodicals, Inc .