Purpose: The Scheffé’s method obtains the difference between pair comparisons with that of the interval scale and can judge the superiority or inferiority of the sample to be compared with no restriction in the observation image by the statistical significant difference. However, the Scheffé’s method cannot be judged as a single image quality indicator. Therefore, I examined a method that can evaluate the association of average degree of preference of Scheffé’s method and the physical quantities that make up the image. Methods: This study focuses on the fact that the average degree of preference of the Scheffé’s method is quantitative data on the interval scale and that multiple regression analysis is possible. In the multiple regression analysis, the average degree of preference by imaging simulated pulmonary adenocarcinoma with different exposure doses was used as the objective variable and the exposure doses and noise (standard deviation [SD]) were used as the explanatory variables. The Scheffé’s method used the Nakaya’s modified method. Results: In the multiple regression analysis, SD was P=0.027. By substituting the threshold value of the intersection of the exposure doses and SD into the multiple regression equation (predictive model), the average degree of preference (Ŷ) was calculated. Ŷ_{(Scheffé;Gy,SD)} was −0.147, which was about 1/2 of exposure doses (−0.150). Conclusion: The multiple regression analysis of Scheffé’s (average degree of preference) and physical quantity factors (exposure doses and noise) has made it possible to design images that can reduce exposure doses while maintaining adequate image quality.

Purpose: To distinguish neurodegenerative diseases using ¹²³I-metaiodobenzylguanidine (MIBG). This study proposes a method to evaluate myocardial standardized uptake value (SUV) and assess its accuracy. Methods: We created a 17-segment polar map of the myocardial region from single-photon emission computed tomography-computed tomography (SPECT-CT) images using a cardioliver phantom simulating the standard uptake of MIBG. We clarified the optimal reconstruction conditions with good repeatability and accuracy of quantitative values and compared them with the H/M ratio. Myocardial SUVs were evaluated from eight normal cases using our method established from the phantom experiment and compared with the H/M ratio. Results: The optimal numbers of iterations and subsets in OSEM reconstruction were both 10. The optimal full width at half maximum (FWHM) value of the Gaussian filter was 4 pixels. The RCs and %CV of (1) maximum SUV_max (MaxSUV_max) and (2) average SUV_max (AveSUV_max) were (1) 36.5% and 4.99%, and (2) 33.6% and 4.84%, respectively. The RC and %CV of the H/M ratio was 15.0% and 1.50%, respectively. In clinical cases, average MaxSUV_max and AveSUV_max were 8.27 and 7.58, respectively. Conclusion: Myocardial SUV can provide quantitative values slightly closer to theoretical values than the H/M ratios. Besides, using the optimal reconstruction parameters makes it feasible to quantitatively assess myocardial uptake with good repeatability.

The radiological technologists often assist patients near the X-ray area during mobile radiography. Therefore, it is expected that the lens of eye of radiological technologists is exposed to much radiation. The purposes of this study were to measure the lens dose received by radiological technologists during mobile radiography using radiation protection goggles with a personal dosimeter and a small optically stimulated luminescence dosimeter and discuss the need for radiation protection goggles and additional radiation protection measures. From October 2017 to March 2018, lens doses were measured for eight radiological technologists during mobile radiography using radiation protection goggles with a small optically stimulated luminescence dosimeter and a personal dosimeter. The maximum value of the lens dose received by radiological technologists in mobile radiography was 0.3 mSv per month with a personal dosimeter attached to the neck. The dose-reduction effect of radiation protection glasses during mobile radiography was about 45%. The radiation protection goggles are effective for reducing radiation exposure of lens of eye during mobile radiography. Since there is concern about an increase in lens dose, it is desirable to use the radiation protection goggles for reducing the lens of eye exposure.

Confirmation of patient information is required to ensure the safety of radiation therapy. The purpose of this study was to construct a system that facilitates radiation therapy operations by linking a radiation therapy information system to a smartphone. By linking a smartphone to a radiation therapy operation support system, without using a PC terminal, we were able to input information about the patient’s position and fixation into images taken with a smartphone. In addition, patient information could be directly linked into the radiation therapy information system. In addition, patient information could be verified in the irradiation room by synchronizing the smartphone with the radiation therapy support system. The questionnaire was highly evaluated in terms of radio reception, usability, visibility and barcode reading. In this study, by linking a smartphone to a radiotherapy information system, it was possible to construct a system that facilitates radiotherapy operations by checking and registering patient information at hand.

It is important to obtain accurate anatomical information with little distortion in preoperative examination of brain tumors. Using PETRA, which is an ultrashort echo time (UTE) sequence that is less affected by magnetic susceptibility artifacts, we determined the optimal imaging conditions (radial views [RV] and inversion time [TI]) for IR-PETRA using the inversion recovery (IR) method and compared it with MPRAGE. IR-PETRA was found to be slightly inferior to MPRAGE in sharpness under the optimum conditions (RV=100,000 and TI=500 ms), but it was significantly improved by using a high RV value, and SNR and CNR were higher than or equal to MPRAGE. It is suggested that IR-PETRA may be an alternative sequence of MPRAGE in preoperative examination of brain tumors.