• Korean Journal of Radiology
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• v.22 no.3
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• pp.464-475
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• 2021

Objective: This study aimed to evaluate the tumor doubling time of invasive lung adenocarcinoma according to the International Association of the Study for Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) histologic classification. Materials and Methods: Among the 2905 patients with surgically resected lung adenocarcinoma, we retrospectively included 172 patients (mean age, 65.6 ± 9.0 years) who had paired thin-section non-contrast chest computed tomography (CT) scans at least 84 days apart with the same CT parameters, along with 10 patients with squamous cell carcinoma (mean age, 70.9 ± 7.4 years) for comparison. Three-dimensional semiautomatic segmentation of nodules was performed to calculate the volume doubling time (VDT), mass doubling time (MDT), and specific growth rate (SGR) of volume and mass. Multivariate linear regression, one-way analysis of variance, and receiver operating characteristic curve analyses were performed. Results: The median VDT and MDT of lung cancers were as follows: acinar, 603.2 and 639.5 days; lepidic, 1140.6 and 970.1 days; solid/micropapillary, 232.7 and 221.8 days; papillary, 599.0 and 624.3 days; invasive mucinous, 440.7 and 438.2 days; and squamous cell carcinoma, 149.1 and 146.1 days, respectively. The adjusted SGR of volume and mass of the solid-/micropapillary-predominant subtypes were significantly shorter than those of the acinar-, lepidic-, and papillary-predominant subtypes. The histologic subtype was independently associated with tumor doubling time. A VDT of 465.2 days and an MDT of 437.5 days yielded areas under the curve of 0.791 and 0.795, respectively, for distinguishing solid-/micropapillary-predominant subtypes from other subtypes of lung adenocarcinoma. Conclusion: The tumor doubling time of invasive lung adenocarcinoma differed according to the IASCL/ATS/ERS histologic classification.

• Journal of agricultural medicine and community health
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• v.29 no.2
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• pp.303-314
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• 2004

Objectives: This study was carried out to assess exposure levels of organic dusts and ammonia in poultry farms in Korea. Methods: A total of six poultry farms were investigated. The farms were located in Namwon, Chonlabuk-do and in Kae-San, Chungchongbuk-do. This study consisted of a questionnaire and measuring organic dusts and ammonia. The questionnaire included the characteristics of the farms, work patterns and the tasks of the poultry farms. Results and Conclusions: The farmers raised the chickens 45 times a year and the average number of years in the poultry farm were eight years ranging from 2 to 12 years. They worked for seven days per week and the average hours spent caring the chickens are 6.3 hours per day. The duration of staying in the confinement buildings was 3.3 hours per day. The work time in summer was longest. The feed and the water supply systems were automatic and the control of ventilation windows used "winch curtain" was semiautomatic. They used mechanical ventilation system in winter and used dilution ventilation system in the other seasons. The geometric mean concentration of total and respirable dust sampled in the poultry confinement buildings was 4.0 mg/$m^3$and 0.9 mg/$m^3$ respectively. The ratio of respirable to total dusts range from 9 to 49 percent. There was no sample exceeding the criteria 10 mg/$m^3$ for total dust and 3 mg/$m^3$ for respirable dust in farms. The criteria have been recommended by Korean Ministry of Labor and American Conference of Governmental Industrial Hygienist. The personal respirable dusts measured during a circle work averaged geometric mean concentration 1.4 mg/$m^3$ Two personal samples were exceeded the threshold 3 mg/$m^3$. There was a positive relation between an index and the personal samples of respirable dusts($R^2$=0.98). The index is calculated by multipling the total number of chickens in the farm by the age of the chickens and then dividing by the volume of the confinement building. The geometric mean concentration of area and personal ammonia samples was 23.3 ppm and 22.2 ppm, respectively. Some of the ammonia samples, both area and personal samples, exceeded the short term exposure limit value 35 ppm.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.37-43
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• 2015

Purpose $^{99m}Tc-DMSA$ renal scintigraphy serves as location, size and shape of kidney, so it has been used for diagnosis and passage observation after the operation or treatment. There are 3 methods of calculating the relative renal uptake ratio such as geometric mean of the counts from the anterior and posterior views, arithmetical mean from the only posterior view and posterior view which applied the renal depths. In this study, we seek to correlation between the change of total relative uptake ratio according to different inspection methods of obtaining the renal count rate. Materials and Methods The phantom experiments proceeded 5 times depending on each renal depth with the kidney phantom and tissue equivalent materials. In the clinical research, we investigated 36 adult patients who had visited our hospital from february to october, 2014 and received $^{99m}Tc-DMSA$ renal scan. The equipment was used as a gamma camera named INFINIA (General Electric Healthcare, milwaukee, USA) and we drew the region of interests through semiautomatic method by using Xeleris Ver. 2.1220 of GE. In addition, we obtained the lateral view of kidney to measure the renal depth of each patient. Then the results were compared with 3 methods of calculating relative renal uptake ratio. Results The phantom studies show when the difference between the left ant right kidney depth were less than 1 cm, there were no statistically significant difference among values calculated through anterior and posterior views and only posterior view (P>0.05), while the excess of 1cm, the results showed a statistically significant change in the value (P<0.05). In case of clinical research, the correlation between total relative uptake ratio by obtaining both sides of image and posterior view applied the kidney depth (r=0.999) was higher than by obtaining only posterior view and applying the kidney depth to one side image (r=0.988). Conclusion This study has found that, the difference of calculating total relative uptake ratio compared with obtaining anterior and posterior views and only posterior view. In order to reduce the error, we recommend the method of obtaining anterior and posterior views and is considered to be useful, particularly the patients have similar uptake ratio of left and right kidney and difficulties of measurements of kidney depth.