Development of the Press-Through Package Recognizable with Abdominal X-Ray Image of Abdominal Soft Tissue Phantom

Background: Patients with dementia who accidentally swallowed a press- through package (PTP) have been increased in recent years. Swallowed PTP is usually detected with CT having a risk of radiation exposure since PTP is very difficult to detect with abdominal X-ray image. Purpose: This study is aimed at developing the new PTP sheet recognizable with abdominal X-ray by improving the conventional PTP sheet. Material and Methods: The PTP sheet samples used in this study are: No. 1 Control: Commercially available tablet 100 mg, No. 2 Triple-stacked aluminum foil, 6-overcoated with BaSO₄ 10.3 g/m², No. 3 Aluminum foil, 6-overcoated with BaSO₄ 10.3 g/m², No. 4 Five-stacked aluminum foil, 6-overcoated with BaSO₄ No. 5 Aluminum foil, single-coated with WO₃ 2.55 g/m², No. 6 Aluminum foil, double-coated with WO₃ 5.1 g/m², No. 7 Aluminum foil, triple-coated with WO₃ 7.66 g/m², No. 8 Three-stacked aluminum foil, triple-coated with WO₃. PTP sheets (No. 1 - No. 8) were placed inside the abdominal soft tissue phantom, and the images were obtained using FUJIFILM DR CALNEO PT. Region of interest (ROI) was placed on PTP sheets (No. 1 - No. 8) and abdominal soft tissue liquid phantom, and each contrast was measured from the average pixel of the two ROIs. Contrast was calculated by the calculation formula. Each ROI was measured three times, and their average value and standard deviation were estimated. Results: Statistical significance in contrast was not observed in commercial PTP sheet (No. 1), PTP sheet (No. 3), and PTP sheet (No. 5), while there was a significant difference between PTP sheet (No. 1) and PTP sheet (No. 2), PTP sheet (No. 4) PTP sheet (No. 6), PTP sheet (No. 7) (p < 0.05). Significant difference in contrast was observed also between commercial PTP sheet (No. 1) and PTP sheet (No. 8) (P < 0.01). PTP sheet (No. 1), PTP sheet (No. 3), and PTP sheet (No. 5) were not recognized at all by plain abdominal X-ray photography. Conclusion: The other all prototype PTP sheets (No. 2, No. 4, No. 6, No. 7 and No. 8) were well recognized. PTP sheets (No. 2, No. 4) of BaSO₄ is considered to be more suitable than PTP sheets of WO₃ (No. 6, No. 7, No. 8) because it is easier to produce. We will develop oral PTP sheets for patients with dementia for abdominal X-ray in the future.