<title>Motion analysis of artery pulsation in neonatal cranial ultrasonogram</title>

Abstract

Using an optical-flow technique, we have quantitatively analyzed tissue motion due to artery pulsation accompanied with blood flow in a neonatal cranial ultrasonogram. The tissue motion vector was successfully calculated at each pixel in a series of echo images (32 frames, 640x480 pixels/frame, 8 bits/pixel, 33 ms/frame) taken in the brightness mode by using an ultrasound probe of 5.0MHz. The optical-flow technique used was a gradient method combined with local optimization for 3 x 3 neighbors. From two-dimensional mappings of tissue motion vectors and their timesequence variations, it was found that the tissue motion due to artery pulsation revealed periodic to-and-fro motion synchronized with heartbeat (300-500 ms), clearly distinguishing from unwanted non-periodic motion due to the sway of neonatal head during diagnosis.

A combined local-global optical flow approach for cranial ultrasonogram image sequence analysis

“…The cranial ultrasound image sequence of a newborn baby is taken as noisy, speckle-like gray scale image including non-rigid tissues such as cerebrums and arteries with local motion due to artery pulsation of blood flow [2]. Therefore, the tissue-motion may vary with time and place.…”

“…The scan ultrasound image sequences are not only use for real-time diagnosis but also recorded for future diagnosis. Pediatricians use an ultrasonogram to find the cranial abnormalities in a newborn baby, since they can observe the brain tissue through the anterior fontanel [2,5]. A key point of diagnosis is whether there is the artery pulsation accompanied with blood flow or not [5,6].…”

Analysis and visualization of pulsation in B-mode cranial ultrasound images

“…The B-mode cranial ultrasound images were taken as movie and recorded with a video tape at neonatal intensive care unit by a conventional ultrasonograph apparatus with the ultrasound probe of 5~7MHz. It was reported that the sway of the ultrasound probe and/or the movement of newborn baby head may cause artefacts of strong pulsation and that the poor optimization of brightness and contrast may decrease the sensitivity of tissue motion [4]. The visualization procedure is shown Fig.…”

“…Instead of using pixel value, optical flow with local optimization is used in [4]. The strength of artery pulsation of asphyxiated neonates such as hypoxic ischemic encephalopathy (HIE) babies were discuss in [5] by using optical flow method.…”