  Since the appearance of Covid-19 in late 2019, Covid-19 has become an active
research topic for the artificial intelligence (AI) community. One of the most
interesting AI topics is Covid-19 analysis of medical imaging. CT-scan imaging
is the most informative tool about this disease. This work is part of the 3nd
COV19D competition for Covid-19 Severity Prediction. In order to deal with the
big gap between the validation and test results that were shown in the previous
version of this competition, we proposed to combine the prediction of 2D and 3D
CNN predictions. For the 2D CNN approach, we propose 2B-InceptResnet
architecture which consists of two paths for segmented lungs and infection of
all slices of the input CT-scan, respectively. Each path consists of ConvLayer
and Inception-ResNet pretrained model on ImageNet. For the 3D CNN approach, we
propose hybrid-DeCoVNet architecture which consists of four blocks: Stem, four
3D-ResNet layers, Classification Head and Decision layer. Our proposed
approaches outperformed the baseline approach in the validation data of the 3nd
COV19D competition for Covid-19 Severity Prediction by 36%.
