Large scale high-energy density science facilities continue to grow in scale and complexity worldwide. The increase in driver capabilities, including pulsed-power and lasers, continue to push the boundaries of temperature, pressure, and densities, opening up new physics regimes. X-ray imaging is one of the many diagnostic techniques that are used to probe states of matter in these extreme conditions. Improved fabrication and polishing methods have provided improved x-ray microscope performance, while improving detector and x-ray sources now enable pico-second imaging with few micron resolutions. This Review will cover x-ray imaging methods, primarily absorption imaging, and their improvements over the last few decades.