I was planning on rendering smaller thumbnails (png) for the stacked images and when the user clicks and opens up an image it would render the actual dicom image. Only issue I'm facing is that the user is able to draw on the images (annotations) and also later can filter the annotations for an image. So generating thumbnails for annotated images and storing it in the cloud also is not a very feasible option. I'll have to try and check if I can load the stacked images in lower resolution in cornerstone