Aside from the technical issues with the machine, ultrasound imaging is harder to perform (in terms of scanning technique) and very difficult to interpret compa

Aside from the technical issues with the machine, ultrasound imaging is harder to perform (in terms of scanning technique) and very difficult to interpret compared to a high-resolution MRI or even simple X-ray. It takes significant training to even find specific organs, and distinguishing between, eg, a gas bubble in the small intestine vs a potentially dangerous foreign object or even a tumor takes a lot of education and experience.