Direct Thrombus Imaging in Stroke

Abstract

There is an emergent need for imaging methods to better triage patients with acute stroke for tissue-plasminogen activator (tPA)-mediated thrombolysis or endovascular clot retrieval by directly visualizing the size and distribution of cerebral thromboemboli. Currently, magnetic resonance (MR) or computed tomography (CT) angiography visualizes the obstruction of blood flow within the vessel lumen rather than the thrombus itself. The present visualization method, which relies on observation of the dense artery sign (the appearance of cerebral thrombi on a non-enhanced CT), suffers from low sensitivity. When translated into the clinical setting, direct thrombus imaging is likely to enable individualized acute stroke therapy by allowing clinicians to detect the thrombus with high sensitivity, assess the size and nature of the thrombus more precisely, serially monitor the therapeutic effects of thrombolysis, and detect post-treatment recurrence. This review is intended to provide recent updates on stroke-related direct thrombus imaging using MR imaging, positron emission tomography, or CT.

Susceptibility Vessel Sign in the ASTER Trial: Higher Recanalization Rate and More Favourable Clinical Outcome after First Line Stent Retriever Compared to Contact Aspiration

“…In addition, we have not been able to analyse thrombi retrieved after MT and therefore did not compare SVS and histology. However, published articles failed to find a reliable and reproducible association between the thrombi histology and recanalization results [ 10 , 36 ]. Indeed, there are inherent biases in assessing histologic characteristics of thrombi retrieved in vivo .…”

“…Thrombus composition could therefore be studied using the susceptibility vessel sign (SVS) on gradient recalled echo (GRE) sequences [ 9 ]. Intracranial clots are SVS-positive when red blood cells (RBCs) are predominantly present within the thrombus [ 8 , 10 - 12 ]. Retrospective and monocentric studies have shown that the qualitative evaluation of SVS could help predict recanalization and functional outcome after EVT [ 6 , 13 - 16 ].…”

In vivo monitoring of thrombosis in mice by optical coherence tomography

“…Recent development in imaging technologies offers in vivo detection and observation of thrombus, such as magnetic resonance and computed tomography and ultrasound . However, these methods are insufficient for thrombus evaluation in small animals such as mice due to the relatively low resolution and the small vessel sizes .…”

Thermoresponsive Behavior of Magnetic Nanoparticle Complexed pNIPAm-co-AAc Microgels

“…Nanoparticles including gold nanoparticles (AuNPs) and magnetic nanoparticles (MNPs) have been widely applied in the development of functional nanosystems for optical modulators [5,22], biosensors [23,24], imaging agents [25], and biological interfacing technology [26]. This suggests that complexation of the nanoparticles with responsive hydrogels allows the development of multipotent materials in a wide range of applications [27][28][29][30][31][32].…”