University of Twente Student Theses
In vivo validation of ultrafast ultrasound-based velocity vector imaging.
Schoonbrood, Maxime J. P. (2023) In vivo validation of ultrafast ultrasound-based velocity vector imaging.
|
PDF
2MB |
| Abstract: | Background: A stroke is a serious life-threatening medical condition. Of all strokes, 10-15% follow thromboembolism after the rupture of an atherosclerotic plaque in the internal carotid artery. Yet, the current criteria for the selection of patients for carotid endarterectomy based on conventional ultrasound are highly inadequate and lead to both over- and undertreatment. With the advent of ultrafast ultrasound, a new velocity vector imaging technique based on blood speckle tracking has been developed at the Radboud University Medical Center in Nijmegen, for the visualization of complex blood flow patterns that are associated with onset, progression, and rupture of atherosclerotic plaques. The visualization and quantification of complex blood flow patterns may enable better patient-specific risk assessment. Objective: The aim of this research is to evaluate the performance of ultrafast ultrasound-based velocity vector imaging using blood speckle tracking in the carotid artery of healthy volunteers in comparison to 4D flow MRI. Methods: This validation study included 20 healthy volunteers that underwent both ultrafast ultrasound-based velocity vector imaging and 4D flow MRI of the carotid artery. A semi-automatic algorithm was designed to perform registration of MRI to ultrasound based on segmentations of the carotid artery. The similarity of the registered planes was calculated based on the structural similarity index metric. Both techniques were compared qualitatively using temporal and spatial velocity profiles and quantitatively with a cosine similarity index of the velocity vector fields and a root-mean-square error of the correlation for axial and lateral velocity magnitudes. Results: The semi-automatic registration algorithm resulted in a registration for 7 volunteers, with a median structural similarity index of 0.94 [0.71 – 0.97]. The temporal and spatial velocity profiles showed fairly good correspondence. The median [min – max] cosine similarity for reliable velocity vector estimates was 0.77 [0.68 – 0.87] and the percentual RMSE for axial and lateral velocity magnitudes were 36% and 22%, respectively. Discussion: The registration of MRI to ultrasound is uncertain due to the low resolution of the MRI scan, which affects the reliability of the outcomes. Also, the lower temporal and spatial resolution of 4D flow MRI relative to ultrasound velocity vector imaging hinder the validation of short-lived events that underlie complex blood flow. Nevertheless, this study is a first step towards the in vivo validation of ultrafast ultrasound-based velocity vector imaging and underwrites its potential for implementation in future clinical practice. |
| Item Type: | Essay (Master) |
| Faculty: | TNW: Science and Technology |
| Subject: | 44 medicine, 50 technical science in general |
| Programme: | Technical Medicine MSc (60033) |
| Link to this item: | https://purl.utwente.nl/essays/97896 |
| Export this item as: | BibTeX EndNote HTML Citation Reference Manager |
Show download statistics for this publication
Show download statistics for this publicationRepository Staff Only: item control page