A mobile radiography unit, also known as a portable X-ray system, is a compact X-ray machine that can be used to take medical images in a variety of settings: 
Hospitals: Used when patients are too unwell to be moved to the radiology department 
Nursing homes: Used for point-of-care imaging 
Home healthcare: Used for imaging patients who are bedridden 
Clinics: Used for point-of-care imaging 
Field hospitals: Used for point-of-care imaging 
Mobile radiography units are designed to be lightweight and maneuverable, and can be easily transported by a single operator. They can be used to perform complete exams, including chest and musculoskeletal X-rays, at the patient's bedside or in other departments. 
Here are some examples of mobile radiography units:
Amadeo M-DR mini: A lightweight, battery-powered unit that can be used in home visits, retirement homes, and aid organizations. It includes an X-ray detector, generator, and image processing station. 
!M1 Mobile X-Ray Unit: A unit with LED lights, a power cable, charging indicator, and precision control joysticks. It also has an optional tube head touch monitor and wireless remote control. 
GMM MAC: A mobile radiographic unit from Wolverson X-Ray Ltd.