Standardization of power Doppler quantification of blood flow in the human fetus using the aorta and inferior vena cava
Autor: | Jonathan M. Rubin, Nicholas M. Fisk, Alec W. Welsh, J. B. Fowlkes |
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Rok vydání: | 2005 |
Předmět: |
medicine.medical_specialty
Aorta Radiological and Ultrasound Technology Cardiac cycle business.industry Obstetrics and Gynecology Hemodynamics Blood volume General Medicine Blood flow Anatomy Inferior vena cava medicine.anatomical_structure Reproductive Medicine medicine.vein Internal medicine medicine.artery Circulatory system cardiovascular system Cardiology Medicine Radiology Nuclear Medicine and imaging business Artery |
Zdroj: | Ultrasound in Obstetrics and Gynecology. 26:33-43 |
ISSN: | 0960-7692 |
Popis: | Objective This study aimed to test the applicability to the fetus of mathematical techniques developed to standardize power Doppler indices of adult regional perfusion. Method Fetal power Doppler imaging was performed on 14 fetuses (25–37 weeks’ gestation) using a standardized parasagittal plane, examining renal and aortic blood flow, and additionally inferior vena caval (IVC) flow in one fetus. Images were stored and transferred for off-line computer analysis using purpose-designed software. We first tested the need for techniques to remove the effects of red blood cell clumping on power Doppler amplitude, then performed further analyses to: (1) investigate cardiac cycle effects on aortic amplitude; (2) determine the spatial consistency of, and influence of angle of insonation on, maximal pixel value; (3) quantify temporal consistency; and (4) compare peak pixel values in the fetal aorta and IVC. Results No rouleaux effect on the vascular profile was detectable, in contrast to that identified in the adult. Within each fetus a consistent value was seen in the center of the aorta corresponding to 100% vascular amplitude, which was unaltered by the phase of the cardiac cycle, with a coefficient of variation of 28.9% at 89 ◦ and 6.5% at 73 ◦ . This value was constant in the aorta and IVC. Conclusion Fetal blood does not appear to form rouleaux to any significant degree, so there is no artificially elevated maximal value for power Doppler amplitude as seen in the adult. We propose that the value representing 100% amplitude may be consistently measured in the center of large fetal vessels such as the aorta, allowing the direct measurement of fractional moving blood volumes in the human fetus. Copyright 2005 ISUOG. Published by John Wiley & Sons, Ltd. |
Databáze: | OpenAIRE |
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