title: 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.
abstract: OBJECTIVE
  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.
  
  
  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 %.
  
  
  CONCLUSIONS
  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.
  
  
  CONCLUSIONS
  • 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.
authors.affiliation: Department of Radiology, University of Bonn, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Homsi
authors.affiliation: Department of Medicine I - Cardiology, SHG-Kliniken Völklingen, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Nath
authors.affiliation: Department of Radiology, University of Bonn, Germany.
authors.forename: J A
authors.initials: JA
authors.lastname: Luetkens
authors.affiliation: Department of Medicine - Cardiology, University of Bonn, Germany.
authors.forename: J O
authors.initials: JO
authors.lastname: Schwab
authors.affiliation: Department of Radiology, University of Bonn, Germany.
authors.forename: H H
authors.initials: HH
authors.lastname: Schild
authors.affiliation: Department of Radiology, University of Bonn, Germany.
authors.forename: C P
authors.initials: CP
authors.lastname: Naehle
mesh_terms: D000328:Adult; D000368:Aged; D020517:Atrial Appendage / Q000473:pathology*; D003287:Contrast Media; D004452:Echocardiography / Q000379:methods; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013927:Thrombosis / Q000175:diagnosis*
chemical_list: D003287:Contrast Media