Impact of different conditions of breath-holding on the results of renal artery Doppler sonography: A pilot study

Purpose To investigate the impact of different breath-holding conditions on the results of renal artery Doppler ultrasonography (RADS). Methods In 45 healthy volunteers, we performed RADS examination during breath-holding while breathing naturally and after a deep inspiration. We measured and compared peak systolic flow velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) of the right (RRA) and left (LRA) renal artery, and PSV, EDV, RI, acceleration time and acceleration index (AI) of the right and left interlobar arteries. Results The RRA and LRA PSV were, respectively, 76 +/- 13 cm/s and 77 +/- 15 cm/s under natural breathing and 93 +/- 18 cm/s and 89 +/- 24 cm/s after deep inspiration (P <= .001). The RRA and LRA EDV were also greater at deep inspiration (P < .001 and P = .019, respectively). There was no significant difference in RRA or LRA RI. The PSV, RI, and AI of the right and left interlobar arteries were greater after deep inspiration (P <= .001), without difference in AI. Conclusion Breath-holding conditions may influence Doppler measurements of renal artery flow velocity and should be reported and taken into account.