Purpose: Left ventricular (LV) chamber quantification using automatic endocardial border tracking has been introduced into clinical practice and it is attracting wide attention as a useful method with high accuracy and reproducibility. However, it remains unclear whether there is any difference in measurements among devices of different vendors.
Methods: This study compared LV chamber volume and ejection fraction (EF) measurements between different ultrasound machines manufactured by two vendors (A and B), in 74 patients in sinus rhythm (58±12 years old, 67 men, EF=52±14%, EF≤50% in 29 patients). End-systolic and end-diastolic volume (ESV and EDV) and EF were measured first automatically and then after manually correcting the endocardial border detection, using the two machines. Single regression analysis and Bland-Altman analysis were used to assess measurement errors.
Results: Although automatic LV chamber measurements generally showed a significant linear correlation with corresponding manual measurements, there were different patterns in systematic errors and in the effect of the manual correction on the errors between the vendors. For vendor A, although EDV and ESV were underestimated proportionally with an increase in LV volume (bias: −11.7 ml for EDV and −9.1 ml for ESV), EF was sufficiently accurate (bias: 1.2%). The manual correction produced a more accurate volume (bias: 2.5 ml for EDV and 1.1 ml for ESV) without any effects on EF measurement (bias: 0.7%). On the other hand, for vendor B, EF was overestimated proportionally with a decrease in EF (bias: 7.4%) owing to the underestimation of ESV (bias: −13.1 ml); the errors persisted even after equivalent manual correction procedure (bias: 7.5%).
Conclusions: There was an inter-vendor difference in systematic errors of LV volume and EF measurements and in the effect of the manual correction on the errors.
Purpose: Ultrasonography (US) is a non-invasive method to confirm the presence of undercutaneous tumors, to measure their size and depth, and to evaluate their characteristics. The purpose of this study was to assess the diagnostic accuracy of US in comparison with histopathological findings of skin tumors.
Subjects and Methods: Ninety-three patients were retrospectively studied who had undergone both US and histopathological examinations for the diagnosis of skin lesions from January 2016 to June 2016. The diagnostic accuracy of US was evaluated by two methods, one was subjective and the other was objective and it used Receiver Operating Characteristic curve (ROC) analysis.
Results: Histopathological results showed that 74 cases were benign and 19 cases were malignant skin tumors. The sensitivity and the specificity for the subjective US evaluation ware 94.7% and 90.5%, respectively. On the other hand, the objective US evaluation using ROC found that the area under the curve was 0.739, and the sensitivity was 84.2% and the specificity was 64.9% at the optimal cutoff value of 6.
Conclusion: The present results suggest that there is a limitation using only the objective assessment of US imaging for the diagnosis of skin tumors, therefore it is important to understand the histological features of various skin tumors to increase the diagnostic accuracy.