A Computer‐Aided Diagnostic Algorithm Improves the Accuracy of Transesophageal Echocardiography for Left Atrial Thrombi

• Published in: Journal of ultrasound in medicine 2014-01, Vol.33 (1), p.83-91
• Main Authors: Sun, Lin, Li, Yang, Zhang, Ying Tao, Shen, Jing Xia, Xue, Feng Hua, Cheng, Heng Da, Qu, Xiu Fen
• Format: Article
• Language: English
• Subjects: computer-aided diagnosis; left atrial/left atrial appendage thrombus; morphologic analysis; texture analysis; transesophageal echocardiography; vascular ultrasound
• ISSN: 0278-4297; 1550-9613
• DOI: 10.7863/ultra.33.1.83

Objectives We investigated whether transesophageal echocardiography (TEE) assisted with a computer‐aided diagnostic (CAD) algorithm was superior to TEE in diagnosing left atrial (LA)/left atrial appendage (LAA) thrombi in patients with atrial fibrillation (AF) in a single prospective study. Methods Transesophageal echocardiography was performed in patients with AF, and images were reconstructed. Gray level co‐occurrence matrix–based features were calculated and then classified using an artificial neural network. The original data and processed images by the CAD system were studied by 5 radiologists independently in a blind manner. The diagnostic performance of each radiologist was evaluated. Results One hundred thirty patients with AF were investigated. Thirty‐one patients (23.9%) had a diagnosis of LA/LAA thrombi. The mean sensitivity ± SD of TEE for LA/LAA thrombi was 0.933 ± 0.027, which was noticeably improved by CAD (0.955 ± 0.021; P < .05). The specificity of TEE was 0.811 ± 0.055, which was markedly lower than that by TEE plus CAD (0.970 ± 0.009; P < .05). The positive predictive value of TEE was low (0.613 ± 0.073) compared to that of TEE plus CAD (0.908 ± 0.027; P < .001), whereas the negative predictive values were comparable for TEE, CAD, and TEE plus CAD. Diagnosis of an LA/LAA thrombus by TEE plus CAD had a higher accuracy rate (0.966 ± 0.011) than that by TEE (0.840 ± 0.047; P < .01). The mean area under the receiver operating characteristic curve (Az) for TEE was 0.834 ± 0.009 (95% confidence interval [CI], 0.815–0.852), which was markedly lower than the Az for TEE plus CAD (0.932 ± 0.005; 95% CI, 0.921–0.943). The use of CAD significantly improved the Az values for all 5 radiologists (P < .001). Conclusions The CAD algorithm significantly improves the diagnostic accuracy of TEE for LA/LAA thrombi in patients with AF.