A Method to Obtain a Sheet-like X-ray Phantom Made from Iodine Contrast Agent

Abstract

A sheet-like X-ray phantom on which thin Iodine is uniformly coated was developed to facilitate the handling of iodined objects used in any X-ray imaging studies. The most recommendable protocol as follows: (1) prepare undiluted 240 mg/ml Iohexol-based contrast agent and drop around 1.6 g on a horizontal surface. (2) infiltrate the agent into a membrane filter (47 mm in diameter) from the secondary side. (3) one minute later, the excess liquid components should be removed by a softy absorbent paper, and the infiltrated membrane filter should be left until substantially dried. The dried membrane filter can be utilized as a sheet-like X-ray phantom on which the iodine of around 2.45 mg is almost uniformly distributed per 1 cm2. However, since the iodine density is slightly higher on the periphery part of the sheet, less than 80% area of the entire sheet is recommended to be used from a viewpoint of the spatial uniformity. In the practical experiments, the X-ray attenuation factor can be controlled by changing the stacking number of the sheet, and the spatial size and form can also be designed by cutting the sheet. This capability is expected to improve the efficiency of any X-ray experiments and quality control works that requires iodined materials.