Purpose: To assess the diagnostic value of contrast-enhanced multi-detector computed tomography (MD-CT) for identifying patients with left atrial appendage (LAA) thrombus or circulatory stasis.
Materials and Methods: 124 patients with a history of atrial fibrillation and/or cerebral ischemia (83 men, mean age 58.6???12.4 years) and with a clinical indication for MD-CT of the heart and for transesophageal echocardiography (TEE) were included in the study. LAA thrombus or thrombogenic milieu was visually identified in TEE and MD-CT. In addition, MD-CT was analyzed quantitatively measuring the Hounsfield units (HU) of the left atrium (LA), the LAA and the ascending aorta (AA), and calculating the HU ratios LAA/AA (HU [LAA/AA]) und LAA/LA (HU [LAA/LA]). Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were calculated.
Results: The prevalence of a thrombus or thrombogenic milieu as assessed by TEE was 21.8?%. The HU ratio was lower in patients with thrombus or thrombogenic milieu (HU [LAA/AA]: 0.590???0.248 vs. 0.909???0.141; p?0.001 und HU [LAA/LA] 0.689???0.366 vs. 1.082???0.228; p?0.001). For the diagnosis of thrombus or a thrombogenic milieu, visual analysis yielded a sensitivity of 81.5?%, a specificity of 96.9?%, a PPV of 87.5?% and a NPV of 95.2?%. By combining visual and quantitative analysis with one criterion being positive, the specificity decreased to 91.8?%, the sensitivity to 77.8?%, the PPV to 72.4?%, and the NPV to 94.9?%.
Conclusion: Visual analysis of the LAA in the evaluation of thrombus or thrombogenic milieu yields a high NPV of 95.1?% and may especially be useful to rule out LAA thrombi in patients with contraindications for TEE. Additional calculation of HU ratios did not improve the diagnostic performance of MD-CT.
Key Points:
??MD-CT can reliably exclude atrial appendage thrombi/thrombogenic milieu.
??MD-CT is an alternative method in patients with contraindications to TEE.
??Calculation of relative HU ratios does not improve the diagnostic value of MD-CT.
Citation Format:
??Homsi R, Nath B, Luetkens JA et?al. Can Contrast-Enhanced Multi-Detector Computed Tomography Replace Transesophageal Echocardiography for the Detection of Thrombogenic Milieu and Thrombi in the Left Atrial Appendage: A Prospective Study with 124 Patients. Fortschr R?ntgenstr 2016; 188: 45???52