Mobile X-ray equipment

1. X-ray mobile and detector

Portable or mobile x-ray units are considered as mobile equipment as they are equipped with wheels that enable it to me moved to different locations with a Hospital or health care unit. These are powered by an electric motor supplied by a battery that assists the movement when the Radiographer drives the mobile unit with less effort.

Mobile x-ray systems are often used to perform chest radiography to patients who cannot be moved to the Radiology department. As such, a mobile x-ray equipment is designed with such unique characteristics to be able to be moved within limited spaces like in between hospital beds in small wards.

An x-ray mobile system consists of a motorized drive, compact wheelbase that includes the generator, an x-ray tube attached to a positioning column and an exposure control panel. As part of this system the image receptor plays a vital role in terms of the image quality and exposure safety (4). Also, different types of detectors can be used such digital radiography (DR) or computed radiography (CR) systems. DR systems have potential to perform examination at a lower dose, they present a high spatial resolution, image quality, lesion-signal response, and a wide dynamic display range when compared to CR systems. The workflow of DR systems is also better when both systems are compared(5).

Specifications of portable x-ray equipment are different among different vendors and the range of products available from the same vendor. Although, there are some common characteristics that could be highlighted as recommendation (Table 1).

Table 1 – Recommended basic characteristics as minimum requirements for a portable x-ray system
Mobile unit Type Mobile X-ray unit with sliding column
Focal point distance from floor 55 to 205cm
Batteries Separate batteries for drive and generator control
Power for charging Single-phase
DAP meter Yes
Generator and x-ray tube Power 20 kW
Tube voltage 40-125 kV
mAs range 0.1 – 500 mAs
Exposure times 0.001-1.25 s
Focal spot (S/L) 0.3/1.0
Wireless portable detector Type CsI
Housing Carbon fiber
Detector sizes 35 x 43 cm; 24 x 30 cm
Pixel size 148 mm
Image resolution up to 3.4Lp/mm