Meta-analyses have found sensitivities of 96% to 99% and specificities of 92% to 94% for detection of left atrial or left atrial appendage thrombus with cardiac CT compared to a TEE reference standard [28-30]. When compared with intraoperative findings, cardiac CT was 100% sensitive and 85% specific for finding left atrial thrombus [31]. Complex left atrial appendage morphologies which predispose to thrombus formation can also be characterized by cardiac CT [32-34]. Additionally, cardiac CT can differentiate left ventricular thrombus from the myocardial wall with 1 study demonstrating a sensitivity, specificity, and positive and negative predictive values of 94%, 97%, 94%, and 97%, respectively [35]. Studies have also demonstrated cardiac CT to have comparable accuracy to TEE for identification of vegetations in the setting of infective endocarditis, another potential source of arterial embolism [36-38]. Cardiac CT can identify cardiac neoplasms, both benign and malignant, which have the potential to shed and embolize to distal arterial beds [39,40]. CTA Chest With IV Contrast Multidetector chest CTA with intravenous (IV) contrast can be used to evaluate for at-risk atherosclerotic plaque or the presence of thrombus in the thoracic aorta. CTA is useful in the assessment of the size, extent, and location of an embolic source in the aorta, which can aid in management decisions [13,41]. A number of small studies have used chest CTA to detect aortic mural thrombus that was suspected of embolization [1,12-14,42]. Specific data on the sensitivity and specificity of this imaging modality are lacking. MRA Chest Without IV Contrast Chest MRA without IV contrast is an imaging study, which can detect the presence of thrombus in the thoracic aorta. One small study found this examination to have a higher detection rate for aortic thrombus when compared with contrast-enhanced MRA, although the difference was not statistically significant [44].
Workup of Noncerebral Systemic Arterial Embolic Source. Meta-analyses have found sensitivities of 96% to 99% and specificities of 92% to 94% for detection of left atrial or left atrial appendage thrombus with cardiac CT compared to a TEE reference standard [28-30]. When compared with intraoperative findings, cardiac CT was 100% sensitive and 85% specific for finding left atrial thrombus [31]. Complex left atrial appendage morphologies which predispose to thrombus formation can also be characterized by cardiac CT [32-34]. Additionally, cardiac CT can differentiate left ventricular thrombus from the myocardial wall with 1 study demonstrating a sensitivity, specificity, and positive and negative predictive values of 94%, 97%, 94%, and 97%, respectively [35]. Studies have also demonstrated cardiac CT to have comparable accuracy to TEE for identification of vegetations in the setting of infective endocarditis, another potential source of arterial embolism [36-38]. Cardiac CT can identify cardiac neoplasms, both benign and malignant, which have the potential to shed and embolize to distal arterial beds [39,40]. CTA Chest With IV Contrast Multidetector chest CTA with intravenous (IV) contrast can be used to evaluate for at-risk atherosclerotic plaque or the presence of thrombus in the thoracic aorta. CTA is useful in the assessment of the size, extent, and location of an embolic source in the aorta, which can aid in management decisions [13,41]. A number of small studies have used chest CTA to detect aortic mural thrombus that was suspected of embolization [1,12-14,42]. Specific data on the sensitivity and specificity of this imaging modality are lacking. MRA Chest Without IV Contrast Chest MRA without IV contrast is an imaging study, which can detect the presence of thrombus in the thoracic aorta. One small study found this examination to have a higher detection rate for aortic thrombus when compared with contrast-enhanced MRA, although the difference was not statistically significant [44].