A computer-implemented method comprising: acquiring a calibration image of a pipe wall at a first location of an insulated pipe; generating a calibration model of the pipe wall at the first location based on the calibration image, the calibration model including an attenuation coefficient associated with the pipe wall at the first location, an attenuation coefficient of insulation at the first location, and the calibration thickness of the pipe wall at the first location in the calibration image; acquiring an inspection image of the pipe wall at a second location of the insulated pipe, the second location different than the first location; determining an inspection thickness of the pipe wall at the second location based on applying the attenuation coefficient associated with the pipe wall at the first location and the attenuation coefficient of insulation at the first location to the inspection image; determining a wall loss measurement of the pipe wall at the second location, the wall loss measurement determined based on a difference of a calibration thickness of the pipe wall at the first location and the determined inspection thickness, the wall loss measurement characterizing an amount of wall loss in the insulated pipe at the second location; and outputting the wall loss measurement; wherein the acquiring steps are performed by a modular acquisition system including a radiographic source, a radiographic detector, and a crawler device including a processor, a controller, and a plurality of positioning mechanisms configured to position the radiographic source and the radiographic detector at one or more locations along the length of the pipe. acquiring a calibration image of a pipe wall at a first location of an insulated pipe; generating a calibration model of the pipe wall at the first location based on the calibration image, the calibration model including an attenuation coefficient associated with the pipe wall at the first location, an attenuation coefficient of insulation at the first location, and the calibration thickness of the pipe wall at the first location in the calibration image; acquiring an inspection image of the pipe wall at a second location of the insulated pipe, the second location different than the first location; determining an inspection thickness of the pipe wall at the second location based on applying the attenuation coefficient associated with the pipe wall at the first location and the attenuation coefficient of insulation at the first location to the inspection image; determining a wall loss measurement of the pipe wall at the second location, the wall loss measurement determined based on a difference of a calibration thickness of the pipe wall at the first location and the determined inspection thickness, the wall loss measurement characterizing an amount of wall loss in the insulated pipe at the second location; and outputting the wall loss measurement; wherein the acquiring steps are performed by a modular acquisition system including a radiographic source, a radiographic detector, and a crawler device including a processor, a controller, and a plurality of positioning mechanisms configured to position the radiographic source and the radiographic detector at one or more locations along the length of the pipe.