Cardiac CT Imaging for Ischemic Stroke: Current and Evolving Clinical Applications

Abstract

While the etiology of ischemic stroke is heterogeneous, approximately 20%-40% of all stroke cases result from cardiac or aortic origin. Transesophageal echocardiography (TEE) has become the reference standard modality for the detection of potential sources of cerebral embolism. Because of the advances in computed tomographic (CT) technology, cardiac CT can be used in the evaluation of potential cardioembolic sources. During the past decade, cardiac CT has been tested and compared with TEE for the diagnosis of cardioembolic sources. Many studies showed that cardiac CT is a very useful and powerful modality for the detection of cardioembolic sources, as well as for risk assessment in patients with stroke. Cardiac CT is a reliable alternative imaging modality to TEE for the evaluation of cardioembolic sources in patients with ischemic stroke, avoiding the discomfort and risks associated with TEE. In addition, cardiac CT can be used to simultaneously diagnose coronary artery disease in stroke patients. However, based on current guidelines, cardiac CT is currently not recommended for use in the initial evaluation of intracardiac structures or risk assessment in stroke patients. The aim of this review is to discuss the potential clinical applications of cardiac CT in an ischemic stroke population, focusing on the diagnosis of cardioembolic sources and cardiovascular risk assessment using cardiac CT. RSNA, 2017.

Predictive Value of Cardiac CTA, Cardiac MRI, and Transthoracic Echocardiography for Cardioembolic Stroke Recurrence

“…aorta and aortic arch was identified as a plaque >4 mm thick with complex morphologic features, such as ulcerations or superimposed thrombi [22]. Valvular vegetation was defined as irregularly shaped, oscillating masses distinct from the endocardium of the mitral or aortic valve [23]. Cardiac tumors were defined as variably enhancing, heterogeneous intracardiac or myocardial masses [24].…”

Interpreting Change in Quantitative Imaging Biomarkers

“…In the literature we found evidence that QIBs commonly have a within-subject variance that varies proportionately with the magnitude of the biomarker [8, 9, 10, 11, 12]. There is also some evidence that for some biomarkers, there is a range where the within-subject variance is modest, but outside the range the variance is much higher [8].…”

Cardiac Magnetic Resonance Imaging in Patients with Acute Ischemic Stroke and Elevated Troponin: A TRoponin ELevation in Acute Ischemic Stroke (TRELAS) Sub-Study

“…While conventional coronary angiography is the gold standard to detect CAD, the required periprocedural application of heparin – increasing the risk of hemorrhagic transformation – exposure to radiation, procedure-related complications as well as the needed dual antiplatelet therapy after coronary intervention limit the feasibility in the acute phase of ischemic stroke. While noninvasive cardiac computed tomography could add information about underlying CAD [3], the disadvantage of exposure to radiation is also present. Subsequently, assessment of an underlying CAD is often incomplete in patients with acute ischemic stroke in clinical practice.…”