Understanding the Influence of Flow Velocity, Wall Motion Filter, Pulse Repetition Frequency, and Aliasing on Power Doppler Image Quantification

Autor(es)

Martins, Maricy R. ^[1] ; Martins, Wellington P. ^[2] ; Soares, Carlos A. M. ^[2] ; Miyague, Andre H. ^{[3, 4]} ; Kudla, Marek J. ^[5] ; Pavan, Theo Z. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Philosophy Sci & Letters Ribeirao Preto, Dept Phys, Ave Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Ribeirao Preto Med Sch, Dept Obstet & Gynecol, Ribeirao Preto - Brazil

^[3] Univ Hosp Evangelico Curitiba, Dept Obstet & Gynecol, Curitiba, Parana - Brazil

^[4] Woman & Fetal Med Inst, Curitiba, Parana - Brazil

^[5] Med Univ Silesia, Clin Dept Oncol Gynecol, Katowice - Poland

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF ULTRASOUND IN MEDICINE; v. 37, n. 1, p. 255-261, JAN 2018.
• Citações Web of Science: 3

Resumo

ObjectivesAlthough power Doppler imaging has been used to quantify tissue and organ vascularity, many studies showed that limitations in defining adequate ultrasound machine settings and attenuation make such measurements complex to be achieved. However, most of these studies were conducted by using the output of proprietary software, such as Virtual Organ computer-aided analysis (GE Healthcare, Kretz, Zipf, Austria); therefore, many conclusions may not be generalizable because of unknown settings and parameters used by the software. To overcome this limitation, our goal was to evaluate the impact of the flow velocity, pulse repetition frequency (PRF), and wall motion filter (WMF) on power Doppler image quantification using beam-formed ultrasonic radiofrequency data. MethodsThe setup consisted of a blood-mimicking fluid flowing through a phantom. Radiofrequency signals were collected using PRFs ranging from 0.6 to 10 kHz for 6 different flow velocities (5-40cm/s). Wall motion filter cutoff frequencies were varied between 50 and 250Hz. ResultsThe power Doppler magnitude was deeply influenced by the WMF cutoff frequency. The effect of using different WMF values varied with the PRF; therefore, the power Doppler signal intensity was dependent on the PRF. Finally, we verified that power Doppler quantification can be affected by the aliasing effect, especially when using a PRF lower than 1.3 kHz. ConclusionsThe WMF and PRF greatly influenced power Doppler quantification, mainly when flow velocities lower than 20cm/s were used. Although the experiments were conducted in a nonclinical environment, the evaluated parameters are equivalent to those used in clinical practice, which makes them valuable for aiding the interpretation of related data in future research. (AU)

• Processo FAPESP: 14/21340-7 - Verificação da dependência do Power Doppler com a velocidade para avaliação da vascularização tecidual
• Beneficiário: Maricy Ramos Martins
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 13/18854-6 - Imagens fotoacústicas e ultrassônicas para caracterização de tecidos viscoelásticos
• Beneficiário: Theo Zeferino Pavan
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores