Meta Learning based Pneumonia detection using stacking ensemble of CNN Snapshots

Pneumonia is a respiratory infection caused by bacteria, virus or fungi. This infection affects the lungs by filling the air sacs(alveoli) with fluid or pus. Chest X-ray(CXR) imaging is the preferred diagnostic examination to locate the inflammation in the lungs. Examining the chest X-rays with high diagnostic accuracy is very difficult for the medical practitioners. To counteract this, computer-aided diagnosis system is used in this study for classifying the Chest X-ray (CXR) images into pneumonia and normal lungs. This research uses transfer learning based stacked ensemble CNN snapshots for the pneumonia prediction from the chest X-ray images. The DenseNet-121 architecture is used as the base learner. To reduce the computational time, the model is trained once to yield several CNN snapshots. The created snapshots give various details regarding the features taken from the CXR. The decision scores of multiple snapshots are combined using the stacking ensemble technique through a metalearner(Random Forest). The proposed ensemble model obtains an accuracy score of 98.36% on the publicly available Kermany dataset.