The invention relates to a mobile radiation image capturing system and a method for operating a mobile radiation image capturing system, the system comprising system comprising: a radiation generation unit configured to generate X-ray radiationa mobile carriage on which the radiation generation unit is mounted a drive unit configured to move the carriage over the floor by linear motion in two dimensions and/or by rotationat least one detection unit configured to capture a radiation image of an object based on X-ray radiation generated by the radiation generation unit and transmitted and/or reflected by the object at least one sensor unit(10, 11) configured to determine an orientation and/or a position of the radiation generation unit and the detection unit relative to each other, at least one output unit(31) configured to output information to a user, a processing unit(30)configured to determine, based on the orientation and/or position of the radiation generation unit and the detection unit relative to each other, whether the radiation generation unit and the detection unit have a predetermined orientation and/or position relative to each other and, in the negative, to determine a positioning information on how the carriage and/or the radiation generation unit has to be moved in order to bring the radiation generation unit and the detection unit into a predetermined orientation and/or position relative to each other, and to control the output unit(31)to output the determined positioning information and/or to control the drive unit(33) to move the carriage based on the determined positioning information.Linvention concerne un système de capture dimage par rayonnement mobile et un procédé pour faire fonctionner un système de capture dimage par rayonnement mobile. Le système comprend : une unité de génération de rayonnement conçue pour générer un rayonnement de rayons X un chariot mobile sur lequel lunité de génération de rayonnement est montée une unité dentraîneme
