A meta-analysis of 7 studies showed that delayed contrast-enhanced cardiac MR had a pooled sensitivity of 100% and a specificity of 99% for detecting left atrial and left atrial appendage thrombus in patients with atrial fibrillation [45]. In another meta-analysis, there was no significant difference in sensitivity and specificity between cardiac CT and cardiac MR in the detection of left atrial appendage thrombus [29]. Contrast- enhanced cardiac MR had a sensitivity of 88% and a specificity of 99% compared to surgical or pathological 9 Workup of Noncerebral Systemic Arterial Embolic Source confirmation of left ventricular thrombus [46]. Cardiac MR is also an accurate imaging modality for the evaluation of valvular disease, including aortic and mitral valve vegetations, which can dislodge and result in arterial embolism [37,47]. Additionally, cardiac MR offers detailed soft tissue characterization for the analysis of benign and malignant intracardiac neoplasms [39,48]. MRI Heart Function and Morphology Without IV Contrast Cardiac MR without contrast provides a detailed anatomic evaluation of the heart chambers. In the workup of embolic sources, the primary role of cardiac MR is in the identification of intracardiac thrombus. A meta-analysis of 7 studies showed that cine cardiac MR had a pooled sensitivity of 91% and a specificity of 93% for detecting left atrial and left atrial appendage thrombus in patients with atrial fibrillation [45]. Furthermore, cine cardiac MR had an 82% sensitivity and a 100% specificity in detecting left ventricle thrombus in postmyocardial infarction patients compared with a standard delayed enhancement cardiac MR [49]. Cardiac MR without contrast is also capable of identifying valvular pathology and cardiac neoplasms, although data on its applicability in the setting of systemic arterial embolism are lacking.
Workup of Noncerebral Systemic Arterial Embolic Source. A meta-analysis of 7 studies showed that delayed contrast-enhanced cardiac MR had a pooled sensitivity of 100% and a specificity of 99% for detecting left atrial and left atrial appendage thrombus in patients with atrial fibrillation [45]. In another meta-analysis, there was no significant difference in sensitivity and specificity between cardiac CT and cardiac MR in the detection of left atrial appendage thrombus [29]. Contrast- enhanced cardiac MR had a sensitivity of 88% and a specificity of 99% compared to surgical or pathological 9 Workup of Noncerebral Systemic Arterial Embolic Source confirmation of left ventricular thrombus [46]. Cardiac MR is also an accurate imaging modality for the evaluation of valvular disease, including aortic and mitral valve vegetations, which can dislodge and result in arterial embolism [37,47]. Additionally, cardiac MR offers detailed soft tissue characterization for the analysis of benign and malignant intracardiac neoplasms [39,48]. MRI Heart Function and Morphology Without IV Contrast Cardiac MR without contrast provides a detailed anatomic evaluation of the heart chambers. In the workup of embolic sources, the primary role of cardiac MR is in the identification of intracardiac thrombus. A meta-analysis of 7 studies showed that cine cardiac MR had a pooled sensitivity of 91% and a specificity of 93% for detecting left atrial and left atrial appendage thrombus in patients with atrial fibrillation [45]. Furthermore, cine cardiac MR had an 82% sensitivity and a 100% specificity in detecting left ventricle thrombus in postmyocardial infarction patients compared with a standard delayed enhancement cardiac MR [49]. Cardiac MR without contrast is also capable of identifying valvular pathology and cardiac neoplasms, although data on its applicability in the setting of systemic arterial embolism are lacking.