Purpose: Delayed images may not be acquired due to severe pain, drowsiness, or worsening vital signs while waiting after blood pool imaging in three-phase bone scintigraphy. If the hyperemia in the blood pool image contains information from which increased uptake on the delayed images can be inferred, the generative adversarial network (GAN) can generate the increased uptake from the hyperemia. We attempted to apply pix2pix, a type of conditional GAN, to transform hyperemia into increased bone uptake. Methods: We enrolled 1464 patients who underwent three-phase bone scintigraphy for inflammatory arthritis, osteomyelitis, complex regional pain syndrome (CRPS), cellulitis, and recent bone injury. Blood pool images were acquired 10 min after intravenous injection of Tc-99 m hydroxymethylene diphosphonate, and delayed bone images were obtained after 3 h.The model was based on the open-source code of the pix2pix model with perceptual loss. Increased uptake in the delayed images generated by the model was evaluated using lesion-based analysis by a nuclear radiologist in areas consistent with hyperemia in the blood pool images. Results: The model showed sensitivities of 77.8% and 87.5% for inflammatory arthritis and CRPS, respectively. In osteomyelitis and cellulitis, their sensitivities of about 44% were observed. However, in cases of recent bone injury, the sensitivity was only 6.3% in areas consistent with focal hyperemia. Conclusion The model based on pix2pix generated increased uptake in delayed images matching the hyperemia in the blood pool image in inflammatory arthritis and CRPS.

Objective: The assessment of cortical integrity following renal injuries with planar Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy depends on measuring relatively decreased cortical uptake (i.e., split renal function [SRF]). We analyzed the additive values of the volumetric and quantitative analyses of the residual cortical integrity using single-photon emission computed tomography (SPECT) compared to the planar scintigraphy. Materials and Methods: This prospective study included 47 patients (male:female, 32:15; age, 47 ± 22 years) who had nonoperatively managed renal injuries and underwent DMSA planar and SPECT imaging 3–6 months after the index injury. In addition to planar SRF, SPECT SRF, cortical volume, and absolute cortical uptake were measured for the injured kidney and both kidneys together. The correlations of planar SRF with SPECT SRF and those of SRF with volumetric/quantitative parameters obtained with SPECT were analyzed. The association of SPECT parameters with renal function, grades of renal injuries, and the risk of renal failure was also analyzed. Results: SPECT SRF was significantly lower than planar SRF, with particularly higher biases in severe renal injuries. Planar and SPECT SRF (dichotomized with a cutoff of 45%) showed 19%–36% of discrepancies with volumetric and quantitative DMSA indices (when dichotomized as either high or low). Absolute cortical uptake of the injured kidney best correlated with glomerular filtration rate (GFR) at follow-up (ρ = 0.687, P < 0.001) with significant stepwise decreases by GFR strata (90 and 60 mL/min/1.73 m2 ). Total renal cortical uptake was significantly lower in patients with moderate-to-high risk of renal failure than those with low risk. However, SRF did not reflect GFR decrease below 60 mL/min/1.73 m2 or the risk of renal failure, regardless of planar or SPECT (count- or volume-based SRF) imaging. Conclusion Quantitative measurements of renal cortical integrity assessed with DMSA SPECT can provide more clinically relevant and comprehensive information than planar imaging or SRF alone.

Background: and Purpose: In this study we aimed to find the association between neuropsychological performance and body mass index (BMI) in patients with mild cognitive impairment (MCI). In addition, we investigated the effects of the apolipoprotein E (APOE) genotype in the relationship between the BMI and cognition in MCI. Methods: We enrolled a cohort of 3,038 subjects with MCI aged 65–90 from the Clinical Research Center for Dementia of South Korea and a dementia cohort of the Ewha Womans University Mokdong Hospital. MCI patients were classified into three subgroups according to the Asian standard of BMI. We compared cognitive performances between groups by one-way analysis of variance. To investigate the effects of the APOE genotype, we used multivariate linear regression models after adjusting for possible confounders. Results: Even though normal BMI groups were younger, had more females, and had less comorbidities, the higher BMI groups had better cognitive functions. Among subjects with APOE ε4 carriers, there was a positive relationship between the BMI and the memory task alone. Conclusions Our findings suggested that higher BMI in patients with MCI were associated with better cognitive performance. The effects of the APOE ε4 genotype in the associations between BMI and cognition were distinguishing. Therefore, according to physical status, APOE ε4 genotype-specific strategies in the assessments and treatments may be necessary in elderly patients with MCI.

Purpose: We investigated whether response classification after total thyroidectomy and radioactive iodine (RAI) therapy could be affected by serum levels of recombinant human thyrotropin (rhTSH)-stimulated thyroglobulin (Tg) measured at different time points in a follow-up of patients with papillary thyroid carcinoma (PTC). Methods: A total of 147 PTC patients underwent serum Tg measurement for response assessment 6 to 24 months after the first RAI therapy. Serum Tg levels were measured at 24 h (D1Tg) and 48–72 h (D2-3Tg) after the 2nd injection of rhTSH. Responses were classified into three categories based on serum Tg corresponding to the excellent response (ER-Tg), indeterminate response (IR-Tg), and biochemical incomplete response (BIR-Tg). The distribution pattern of response classification based on serum Tg at different time points (D1Tg vs. D2-3Tg) was compared. Results: Serum D2-3Tg level was higher than D1Tg level (0.339 ng/mL vs. 0.239 ng/mL, P < 0.001). The distribution of response categories was not significantly different between D1Tg-based and D2-3Tg-based classification. However, 8 of 103 (7.8%) patients and 3 of 40 (7.5%) patients initially categorized as ER-Tg and IR-Tg based on D1Tg, respectively, were reclassified to IR-Tg and BIR-Tg based on D2-3Tg, respectively. The optimal cutoff values of D1Tg for the change of response categories were 0.557 ng/mL (from ER-Tg to IR-Tg) and 6.845 ng/mL (from IR-Tg to BIR-Tg). Conclusion D1Tg measurement was sufficient to assess the therapeutic response in most patients with low level of D1Tg. Nevertheless, D2-3Tg measurement was still necessary in the patients with D1Tg higher than a certain level as response classification based on D2-3Tg could change.

Purpose: Today's students have distinctive generational characteristics and increased psychopathology and generational tension. The authors investigated the negative experiences of Late Millennial students in medical school to draw implications for student support. Methods: The authors explored medical students’ negative experiences using the critical incident technique. The authors conducted semi-structured in-depth interviews with 13 medical students, between February and May 2016. The authors focused on occurrences that significantly influenced medical students’ school lives negatively from the students’ perspective. All interviews were recorded and transcribed. The authors classified incidents into frames of reference for the use of faculty development for student support. Results: The authors extracted 22 themes from a total 334 codes and classified them into eight subcategories. Finally, four categories emerged from frames of reference. Students manipulate relationships and colluding for better specialty choice. They experience uncontrolled rifts in interpersonal relationships between peers including lawsuits, sexual assaults, and social network service conflicts. Today’s students feel resentment towards dependent hierarchical relationships with seniors. They struggle with gender discrimination but perpetuate outdated gender role toward the opposite gender. Conclusion Faculty members should understand today’s students’ level of career stress and desire for work life balance. They should motivate students’ professional identity, promote assertiveness against unfair authorities, and focus on mental health, teamwork, and relationship building. All generations need to understand other generations and develop appropriate leadership and gender sensitivity.

Background: and Purpose: Previous studies suggest that cognitive intervention can mitigate the development of dementia in patients with mild cognitive impairment (MCI). However, the previous cognitive intervention was mostly provided as a group session, in which MCI patients sometimes had difficulty in regularly attending sessions or were reluctant to participate in group-based classes. Additionally, experienced instructors for traditional cognitive intervention may be unavailable in some chronic-care facilities or community centers. Considering these reasons, we have developed 5 programs for home-based cognitive intervention using a personal robot for MCI patients. In this preliminary study, we aimed to demonstrate the effects of our newly developed home-based cognitive intervention with robots on cognitive function in MCI patients. Methods: We conducted a single-blind randomized controlled trial enrolling 46 MCI patients. Participants were randomized into 2 groups: the robot cognitive intervention (robot) (n=24) group and without cognitive intervention (control) (n=22) group. The interventions comprised 60-min sessions per day for 4 weeks. The primary outcome was the change in cognitive function measured using the Cambridge Neuropsychological Test Automated Battery. Results: There were no significant baseline demographic or clinical differences between the robot and control groups. After the 4-week cognitive intervention, the robot group showed greater improvement in working memory than did the control group. Conclusions Our home-based cognitive intervention with a personal robot improved the working memory in MCI patients. Further studies with larger samples and longer study periods are required to demonstrate the effects of these programs in other cognitive domains in MCI patients.

Purpose: Ixeris strigosa (IS) is a perennial plant that commonly grows in meadows. The leaves and roots of IS have been used in medicine as a sedative. This study evaluated the antioxidant and carbohydrate-digestive-enzyme inhibitory effects of IS to determine its potential as an essential antioxidant and glycemic inhibitor for type 2 diabetics. Methods: The antioxidative and α-amylase and α-glucosidase inhibitory activities were examined using the water extracts (ISW), ethanol extracts (ISE), and solvent fractions from IS. The antioxidative activities were measured using in vitro methods by measuring the 1,1-diphenyl-2-picrylhydrazyl and 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity. Results: Investigations of the total polyphenol, flavonoid content, in vitro antioxidant activity, and α-amylase and α-glucosidase inhibitory activities of the IS extract showed that the ISE had higher total phenolic and flavonoid contents than the ISW, as well as high antioxidant activity. The ethanolic extracts of IS (70%) had an α-amylase inhibitory activity of 78.55%. The ethyl acetate fraction (90.56%) showed higher α-glucosidase inhibitory activity than the positive control, acarbose (83.01%). Conclusion Among the ISE fractions, the ethyl acetate and butanol fractions showed the best digestive enzyme inhibitory activity. Moreover, the antioxidant activity of the extract and the carbohydrate, α-amylase, and α-glucosidase inhibitory effects showed a stronger correlation with the total phenol and flavonoid contents compared to the ISW. As a result, the antioxidant and digestive enzyme inhibitory activities of high ISE are due to the phenolic compounds, particularly the flavonoid compounds. Therefore, ethyl acetate and butanol fractions of the 70% ethanol extract are excellent anti-diabetic functional materials.

PURPOSE: There is substantial need for optimizing radiation protection in nuclear medicine imaging studies. However, the diagnostic reference levels (DRLs) have not yet been established for nuclear medicine imaging studies in Korea.MATERIALS AND METHODS: The data of administered activity in 32 nuclear medicine imaging studies were collected from the Korean Society of Nuclear Medicine (KSNM) dose survey database from 2013 and 2014. Through the expert discussions and statistical analyses, the 75th quartile value (Q3) was suggested as the preliminary DRL values. Preliminary DRLs were subjected to approval process by the KSNM Board of Directors and KSNM Council, followed by clinical applications and performance rating by domestic institutes.RESULTS: DRLs were determined through 32 nuclear medicine imaging studies. The Q3 value was considered as appropriate selection as it was generally consistent with the most commonly administered activity. In the present study, the final version of initial DRL values for nuclear medicine imaging in Korean adults is described including various protocols of the brain and myocardial perfusion imaging.CONCLUSION: The first DRLs for nuclear medicine imaging in Korean adults were confirmed. The DRLs will enable optimized radiation protection in the field of nuclear medicine imaging in Korea.
Academies and Institutes ; Adult ; Brain ; Humans ; Korea ; Myocardial Perfusion Imaging ; Nuclear Medicine ; Radiation Protection

PURPOSE: There is substantial need for optimizing radiation protection in nuclear medicine imaging studies. However, the diagnostic reference levels (DRLs) have not yet been established for nuclear medicine imaging studies in Korea. MATERIALS AND METHODS: The data of administered activity in 32 nuclear medicine imaging studies were collected from the Korean Society of Nuclear Medicine (KSNM) dose survey database from 2013 and 2014. Through the expert discussions and statistical analyses, the 75th quartile value (Q3) was suggested as the preliminary DRL values. Preliminary DRLs were subjected to approval process by the KSNM Board of Directors and KSNM Council, followed by clinical applications and performance rating by domestic institutes. RESULTS: DRLs were determined through 32 nuclear medicine imaging studies. The Q3 value was considered as appropriate selection as it was generally consistent with the most commonly administered activity. In the present study, the final version of initial DRL values for nuclear medicine imaging in Korean adults is described including various protocols of the brain and myocardial perfusion imaging. CONCLUSION The first DRLs for nuclear medicine imaging in Korean adults were confirmed. The DRLs will enable optimized radiation protection in the field of nuclear medicine imaging in Korea.