AN EVALUATION OF SOME COMMON LABORATORY MATERIALS BY X-RAY ATTENUATION, FOR USE AS HUMAN TISSUE SUBSTITUTES

Background: Readily available and cost-effective laboratory materials can be used to create imaging phantoms or test objects for radiographic studies, providing alternatives to commercial phantoms. Purpose: To develop and evaluate laboratory materials that can simulate tissue for use in diagnostic radiography image quality studies. Materials and Methods: Laboratory Magnesium Sulphate (MgSO₄) and table salt (NaCl) were mixed with paraffin wax in an 80:20% weight ratio to form test materials (MgSO₄:PW1 and NaCl:PW2). Rice powder and gelatine, separately and in combination (20g gelatine in 100ml warm water + 100g rice powder), were also prepared as test objects. Ratios were optimized using the web-based photon interaction software XCOM (NIST, USA) to closely match tissue data. Test samples were formed into 1 cm blocks and exposed to narrow beam X-rays over the diagnostic energy range (50–150 kV) under automatic exposure conditions. Measured results were compared with calculated values. Results: Good agreement within 10% was observed between measured and calculated values for four out of five tested samples. Mass attenuation coefficients of gelatine, PW1, and the rice-gelatine combination (Rigel) showed acceptable matching with simulated tissue at high photon energies (0.04–0.05 MeV and above). Conclusion: MgSO₄-paraffin, NaCl-paraffin, gelatine, and rice-gelatine test objects provide suitable tissue substitutes and can be used effectively in image quality studies in diagnostic radiography.