Characterizing blood clots using acoustic radiation force optical coherence elastography and ultrasound shear wave elastography

Abstract

Thromboembolism in a cerebral blood vessel is associated with high morbidity and mortality. Mechanical thrombectomy (MT) is one of the emergenc proceduresperformed to remove emboli. However, the interventional approaches such as aspiration catheters or stent retriever are empirically selected. An inappropriate selection of surgical devices can influence the success rate during embolectomy, which can lead to an increase in brain damage. There has been growing interest in the study of clot composition and using a priori knowledge of clot composition to provide guidance for an appropriate treatment strategy for interventional physicians. Developing imaging tools which can allow interventionalists to understand clot composition could affect management and device strategy. In this study, we investigated how clots of different compositions can be characterized by using acoustic radiation force optical coherence elastography (ARF–OCE) and compared with ultrasound shear wave elastography (SWE). Five different clots compositions using human blood were fabricated into cylindrical forms from fibrin-rich (21% red blood cells, RBCs) to RBC-rich (95% RBCs). Using the ARF–OCE and SWE, we characterized the wave velocities measured in the time-domain. In addition, the semi-analytical finite element model was used to explore the relationship between the phase velocities with various frequency ranges and diameters of the clots. The study demonstrated that the wave group velocities generally decrease as RBC content increases in ARF–OCE and SWE. The correlation of the group velocities from the OCE and SWE methods represented a good agreement as RBC composition is larger than 39%. Using the phase velocity dispersion analysis applied to ARF–OCE data, we estimated the shear wave velocities decoupling the effects of the geometry and material properties of the clots. The study demonstrated that the composition of the clots can be characterized by elastographic methods using ARF–OCE and SWE, and OCE demonstrated better ability to discriminate between clots of different RBC compositions, compared to the ultrasound-based approach, especially in clots with low RBC compositions.

Novel Human Acute Ischemic Stroke Blood Clot Analogs for In Vitro Thrombectomy Testing

“…In addition to their use in in vitro thrombectomy testing, human clot analogs can also be used to investigate the ability of novel diagnostic imaging methods to identify the composition of the occlusive clot. 37,38 For the DA technique, the FPE is associated with successful clot ingestion and depends on the clot mechanical properties. Of the 15 clots tested, FPEs were achieved for 12 clots, and 7 (58%) of them were due to successful ingestion.…”

Intraoperative Ultrasound Shear-Wave Elastography in Focal Cortical Dysplasia Surgery

“…As stated above, SWE is not suitable for deep-seated epileptogenic lesions (e.g., mesial temporal-lobe epilepsy) because depth reduces shear-wave spread. In the near future, probe miniaturization and shear-wave field enhancement should allow for significant advances for the elastographic exploration of deep-seated lesions [ 41 , 42 , 43 ].…”

Viscoelasticity Imaging of Biological Tissues and Single Cells Using Shear Wave Propagation

“…Viscosity assessment in shear wave OCE is in its early phase of development. Proposed methods used shear wave frequency dispersion [343][344][345][346], storage and loss moduli using a rheological model [347], and the elastic wave attenuation [345].…”