Purpose: The deep learning time-of-flight (DL-ToF) aims to replicate the ToF effects through post-processing, applying deep learning-based enhancement to PET images. This study evaluates the effectiveness of DL-ToF using a chest-abdomen phantom that simulates human anatomical structures. Methods: The 3 DL-ToF intensities (Low-DL-ToF: LDL, Middle-DL-ToF: MDL, High-DL-ToF: HDL) were adopted for the PET image of the chest-abdomen phantom. We assessed the mean SUV of the liver, kidneys, and soft tissue, as well as the maximum SUV of lung and liver tumors. Additionally, non-ToF images were subjected to 3 types of filtering. Texture analysis and shape index maps were used to evaluate filter effects. Results: No significant differences were observed in the mean SUV between the 3 DL-ToF and non-ToF images. LDL sharpened lung tumors and smoothed liver tumors, while HDL exhibited more pronounced sharpening effects. Conclusion: The DL-ToF produces image effects similar to ToF in PET imaging.

Purpose: This study aimed to compare the compressed SENSE (C-SENSE) accelerated fat-suppressed 3D-turbo spin echo (TSE) method and the conventional SENSE accelerated fat-suppressed 3D-TSE method to examine the usefulness of C-SENSE technology in reducing imaging time. Methods: Fat-suppressed 3D-TSE using either C-SENSE or SENSE technology was utilized to capture consecutive preoperative images of 34 patients with tongue cancer. SNR, CNR, and visual evaluation were then used to compare both types of technology. Results: No significant differences were observed in the SNR and CNR values between SENSE (SNR=21.8±7.5, CNR=27.2±8.9) and C-SENSE (SNR=20.1±5.2, CNR=25.6±8.4) (p=0.168 and p=0.125, respectively). Conclusion: C-SENSE reduced the imaging time of the oral cavity by approximately 30% while maintaining the same image quality when using the fat-suppressed 3D-TSE method.

Purpose: The purpose of this study was to determine the distribution of spatial scattered radiation during mobile dynamic chest radiography and to develop protective measures. Methods: We measured the spatial scattered radiation, assuming both mobile chest radiography and mobile dynamic chest radiography. We placed the chest phantom on a stretcher. Gatch-up angles were varied from 75°(seated position), 35°(semi-seated position), and 0°(supine position). We measured spatial scattered radiation using the ionization chamber survey meter. The height of the measurement points was 100 cm and 150 cm, assuming the position of the abdomen and lens. We also measured spatial scattered radiation using the radiation shielding screen. Results: Spatial scattered radiation dose in mobile dynamic chest radiography was approximately five to six times higher than in mobile chest radiography. In the seated position, the spatial scattered radiation dose was about 1.5 times higher on the caudal side of the phantom compared to the cranial side. Behind the radiation shielding screen, the spatial scattered radiation dose decreased significantly. Conclusion: If the examination is performed in a seated position, the radiological technologist can reduce exposure by moving to the patient's head side. Radiation shielding screens are very effective in reducing radiation exposure in mobile dynamic chest radiography.

Kiken-yochi Training (KYT) has been introduced in many hospitals as medical safety education in many departments, with the exception of radiology. KYT is also not used in the contents of medical safety lectures in the education of students for radiological technologists. One of the reasons for this is that the images for KYT (KYT images) cannot be created at each hospital or easily obtained on the website. The purpose of this research is to construct a database of KYT images (KYTDB) that can be used for medical safety education at hospitals and educational facilities. We also investigate the usefulness of KYTDB in FROC observer experiments. The KYT images were taken in various scenarios of routine medical examination (or treatment) in the radiology department of the two hospitals. A total of 367 KYT images were taken in seven sections of the radiology department, some containing dangerous (inappropriate) locations and languages, and some containing normal scenes. In addition, educational training materials in PowerPoint with audio were created for self-study of KYT. A FROC observer study was conducted using sample images extracted from the KYTDB that were not used in the educational materials, and figures of merit values were used to quantify the predictive risk reduction capacity of KYT. The results demonstrated that the KYTDB is useful for KYT education.

Purpose: Investigating the status and challenges associated with radiological technologists acting as assistants during angiography and interventional radiology (IVR) through task shift/share. Methods: The survey period was from August 1, 2023 to September 30, 2023. A 10-item questionnaire survey was conducted nationwide, targeting 676 hospitals equipped with angiography facilities. Results: Of the 676 hospitals surveyed, 184 facilities responded. Thirty-four hospitals (18.5%) implemented the role of assistant work, whereas 22 hospitals (12%) carried out these duties during nights and holidays. Of the facilities that did not carry out assistant work roles, >80% were concerned about securing personnel, securing training time, and establishing educational methods. Additionally, 19 facilities (12.3%) had requests from doctors regarding assistant work, highlighting the relationship between the availability of assistant work and facility-specific factors. Conclusion: We have identified the status and challenges associated with radiological technologists acting as assistants during angiography and IVR, including issues such as personnel allocation and establishing educational methods.

Purpose: The objective of this study is to elucidate the current status of procedural radiation doses for endovascular treatment (EVT) of lower extremity artery disease (LEAD) in Japan and to validate the diagnostic reference level (DRL) quantity. Methods: Survey requests were mailed to 493 facilities across Japan. The study targeted cases of EVT for LEAD performed between April 1, 2020, and March 31, 2022, with a maximum of 10 cases collected per facility. We investigated the displayed values of cumulative air kerma at the patient entrance reference point (K_a.r), the air kerma–area product (P_KA) and the fluoroscopy time (FT) for all EVT procedures for LEAD (All EVT) and by treatment site. Results: Data were collected from 1638 cases across 167 facilities. The median values for All EVT were K_a.r: 150 mGy, P_KA: 30 Gy·cm², and FT: 28.6 min. The highest K_a.r and P_KA were observed in the aortoiliac (AI) region (286 mGy, 59 Gy·cm²), while the lowest were in the below-the-knee (BTK) region (81 mGy, 15 Gy·cm²) (p<0.001). The shortest FT was recorded in the AI region with a median of 23.8 min and the longest in the BTK region at 32.2 min (p<0.001). Significant differences in K_a.r, P_KA, and FT were observed across the treatment sites for EVT for LEAD (p<0.001). Conclusion: In EVT for LEAD, it is necessary to set the DRL quantity according to the anatomical site being treated, using the dose values indicated by the angiographic equipment, such as K_a.r and P_KA.