Comparison of X-ray image quality and scattered radiation among portable, mobile, and stationary X-ray machines.

Chest radiography is a sensitive method for tuberculosis (TB) detection, and portable X-ray systems offer a practical solution for community-based screening. However, whether the image quality of portable systems is diagnostically comparable to that of mobile and stationary systems remains insufficiently addressed. This study compared image quality and ambient dose equivalent H*(10) per radiographic exposure across one portable, three mobile, and three stationary X-ray systems. Image quality was evaluated using a test object for radiography (TOR) contrast-detail phantom at acrylic thicknesses of 13 cm, 22.5 cm, and 32 cm, and using an anthropomorphic chest phantom assessed by two radiologists and one pulmonologist according to the European guidelines on quality criteria for diagnostic radiographic images. Spatial resolution, low-contrast sensitivity, and high-contrast sensitivity were analysed using AutoPIA and, where automated analysis was not possible, visual scoring with ImageJ (median values from three independent observers). Scattered radiation was quantified as ambient dose equivalent H*(10) per exposure at 1.0 m from the centre of the phantom. Values were measured directly at 1.0 m for the 13 cm and 22.5 cm acrylic thicknesses and the anthropomorphic chest phantom; for the 32 cm thickness, the 1.0 m value was estimated by inverse square law extrapolation from a measurement obtained at 1.5 m. For the TOR phantom, the portable system produced spatial resolution and contrast sensitivity values generally within the range observed for the mobile and stationary systems across the tested thickness conditions. For the anthropomorphic phantom, the portable system achieved the highest median total score (45 out of 45), with all systems meeting the defined threshold for acceptable diagnostic quality (median score of 4 or higher per criterion). H*(10) per exposure from the portable system ranged from 0.12 to 0.97 µSv across acrylic thicknesses and were within the ranges observed for the mobile and stationary systems. These findings support the potential use of the evaluated portable X-ray system for chest imaging and TB screening in community-based settings; however, the scattered-radiation measurements should be interpreted as baseline reference data, and further clinical and workload-based studies are needed to confirm real-world image quality and occupational radiation exposure.