Dual-Enhanced Cardiac CT for Detection of Left Atrial Appendage Thrombus in Patients With Stroke: A Prospective Comparison Study With Transesophageal Echocardiography

OBJECTIVES: A noninvasive method with high reliability and accuracy comparable to transesophageal echocardiography for identification of left atrial appendage thrombus would be of significant clinical value. The aim of this study was to assess the diagnostic performance of a dual-enhanced cardiac CT protocol for detection of left atrial appendage thrombi and for differentiation between thrombus and circulatory stasis in patients with stroke.

METHODS: We studied 83 consecutive patients with stroke (56 men and 27 women; mean age, 62.6 years) who had high risk factors for thrombus formation and had undergone both dual-source CT and transesophageal echocardiography within a 3-day period. CT was performed with prospective electrocardiographic gating, and scanning began 180 seconds after the test bolus.

RESULTS: Among the 83 patients, a total of 13 thrombi combined with spontaneous echo contrast and 14 spontaneous echo contrasts were detected by transesophageal echocardiography. All 13 thrombi combined with spontaneous echo contrast were correctly diagnosed on CT. Using transesophageal echocardiography as the reference standard, the overall sensitivity and specificity of CT for the detection of thrombi and circulatory stasis in the left atrial appendage were 96% (95% CI, 78% to 99%), and 100% (95% CI, 92% to 100%), respectively. On CT, the mean left atrial appendage/ascending aorta Hounsfield unit ratios were significantly different between thrombus and circulatory stasis (0.15 Hounsfield unit versus 0.27 Hounsfield unit, P=0.001). The mean effective radiation dose was 3.11 mSv.

CONCLUSIONS: Dual-enhanced cardiac CT with prospective electrocardiographic gating is a noninvasive and sensitive modality for detecting left atrial appendage thrombus with an acceptable radiation dose. Dalvin Cook Womens Jersey

PMID: 21757676

Posted in Computed Tomography, Echo and tagged , , , , .


  1. More data to support the use of CTA in order to detect LAA thrombus! Although, not the first study to report high sensitivity or specificity of CTA, the evaluation of the modality in stroke patients increases the strength of the results.

  2. The aim of the study was to assess a dual-enhanced protocol for differentiation between thrombus and circulatory stasis in these groups of patients. The results are really good. I wonder how this injection protocol fares when doing the study for other reasons (such as pre PV isolations) when LAA thrombi may be incidentally found.

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