Recent advancements have enhanced the detection of left atrial appendage (LAA) thrombi in patients with atrial fibrillation (AF), offering alternatives to transesophageal echocardiography (TEE)
Recent advancements have enhanced the detection of left atrial appendage (LAA) thrombi in patients with atrial fibrillation (AF), offering alternatives to transesophageal echocardiography (TEE). 
Cardiac Computed Tomography (CCT):
A meta-analysis demonstrated that CCT, particularly with delayed imaging, achieves high sensitivity (96%) and specificity (92%) in detecting LAA thrombi, comparable to TEE. Delayed imaging improves differentiation between thrombus and slow blood flow. 
Cardiac Magnetic Resonance Imaging (CMR):
CMR has proven effective in identifying LAA thrombi. Among its sequences, delayed-enhancement CMR (DE-CMR) shows the highest diagnostic accuracy, with sensitivity and specificity reaching 100% and 99%, respectively.  
Dual-Energy Computed Tomography (DECT):
DECT offers promising results by measuring iodine concentration and effective atomic number (Z_eff) in early-phase cardiac CT. This technique achieves 100% sensitivity and 99.2% specificity in detecting LAA thrombi, effectively distinguishing thrombi from spontaneous echo contrast. 
In summary, while TEE remains a standard, imaging modalities like CCT with delayed imaging, DE-CMR, and DECT provide accurate, non-invasive alternatives for detecting LAA thrombi in AF patients. 
Background :
Atrial fibrillation (AF) is the most common arrhythmia in adults and is associated with an increased risk of embolic stroke. The primary prevention strategy for cerebral embolic events involves the use of oral anticoagulant therapy (OAT). Left atrial appendage occlusion (LAAO) has demonstrated non-inferiority to OAT in clinical trials for stroke prevention in non-valvular atrial fibrillation (NVAF). However, some patients with NVAF may experience ischemic strokes despite adequate OAT, a phenomenon whose pathophysiological substrate remains unclear. Approaches to secondary prevention in these ‘resistant strokes’ are largely empirical. Several therapeutic strategies have been proposed, including LAAO, which should be considered in well-selected patients. The procedure requires careful planning but can be successfully performed in most cases.
https://academic.oup.com/eurheartjsupp/article/27/Supplement_1/i12/8023304
