Handcrafted features vs ConvNets in 2D echocardiographic images

In this paper, we address the problem of automated pose clas-sification and segmentation of the left ventricle (LV) in 2Dechocardiographic images. For this purpose, we compare twocomplementary approaches. The first one is based on engi-neering ad-hoc features according to the traditional machinelearning paradigm. Namely, we extract phase features to buildan unsupervised LV pose estimator, as well as a global im-age descriptor for view type classification. We also apply theSupervised Descent Method (SDM) to iteratively refine theLV contour. The second approach follows the deep learn-ing framework, where a Convolutional Network (ConvNet)learns the visual features automatically. Our experiments ona large database of apical sequences show that the two ap-proaches yield comparable results on view classification, butSDM outperforms ConvNet on LV segmentation at a signifi-cantly lower training computational cost

Meta-Analysis of the Prognostic Role of Late Gadolinium Enhancement and Global Systolic Impairment in Left Ventricular Noncompaction.

The objective of this meta-analysis was to assess the predictive value of late gadolinium enhancement (LGE) and global systolic impairment for future major adverse cardiovascular events in left ventricular noncompaction (LVNC). The prognosis of patients with LVNC, with and without left ventricular dysfunction and LGE, is still unclear. A systematic review of published research and a meta-analysis reporting a combined endpoint of hard (cardiac death, sudden cardiac death, appropriate defibrillator firing, resuscitated cardiac arrest, cardiac transplantation, assist device implantation) and minor (heart failure hospitalization and thromboembolic events) events was performed. Four studies with 574 patients with LVNC and 677 with no LVNC and an average follow-up duration of 5.2 years were analyzed. In patients with LVNC, LGE was associated with the combined endpoint (pooled odds ratio: 4.9; 95% confidence interval: 1.63 to 14.6; p = 0.005) and cardiac death (pooled odds ratio: 9.8; 95% confidence interval: 2.44 to 39.5; p < 0.001). Preserved left ventricular systolic function was found in 183 patients with LVNC: 25 with positive LGE and 158 with negative LGE. In LVNC with preserved ejection fraction, positive LGE was associated with hard cardiac events (odds ratio: 6.1; 95% confidence interval: 2.1 to 17.5; p < 0.001). No hard cardiac events were recorded in patients with LVNC, preserved ejection fraction, and negative LGE. Patients with LVNC but without LGE have a better prognosis than those with LGE. When LGE is negative and global systolic function is preserved, no hard cardiac events are to be expected. Currently available criteria allow diagnosis of LVNC, but to further define the presence and prognostic significance of the disease, LGE and/or global systolic impairment must be considered for better risk stratification