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Importance of Pulse Repetition Frequency Adjustment for 3‐ and 4‐Dimensional Power Doppler Quantification
Author(s) -
Miyague Andre H.,
Pavan Theo Z.,
Soares Carlos A.,
De Catte Luc,
Nastri Carolina O.,
Welsh Alec W.,
Martins Wellington P.
Publication year - 2015
Publication title -
journal of ultrasound in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 91
eISSN - 1550-9613
pISSN - 0278-4297
DOI - 10.7863/ultra.15.01021
Subject(s) - doppler effect , pulse repetition frequency , filter (signal processing) , medicine , flow velocity , acoustics , flow (mathematics) , biomedical engineering , nuclear medicine , physics , telecommunications , computer science , computer vision , radar , astronomy , mechanics
Objectives To determine the influence of the pulse repetition frequency (PRF) and wall motion filter on the 3‐dimensional (3D) power Doppler vascularization‐flow index (VFI) and volumetric pulsatility index (PI) obtained from spatiotemporal image correlation (STIC) data sets acquired from a common carotid artery of a healthy participant. Methods We acquired 11 STIC data sets, 1 for each PRF value ranging from 0.6 to 9.0 kHz. Vascularization‐flow index and volumetric PI values were determined from the 440 static 3D data sets contained in these STIC data sets. Additionally, 3 sets of radio‐frequency data were acquired for offline processing of different wall motion filter values for PRF values of 0.6, 3.3, and 10 kHz. Results We constructed VFI curves and observed 2 patterns: a flattened pattern with a low PRF and a triphasic pattern with a high PRF, correlating with the known pulsed wave Doppler profile of this vessel. Volumetric PI values were around 0 for low PRF settings and increased with increasing PRF. Analysis of the radiofrequency data showed that increasing wall motion filter values gradually filtered out the low‐velocity power Doppler signals while retaining the higher‐velocity ones, allowing the distinction of integrated power Doppler signal velocity throughout the cardiac cycle. Conclusions We conclude that the PRF and wall motion filter dramatically influence 3D power Doppler indices and the volumetric PI, and the use of PRF values in which minimum VFI values are measured during the diastolic phase in the spectral Doppler wave may validate the use of the volumetric PI.