Seok Jeong Lee

Ultra-Low-Dose CT of the Thorax Using Iterative Reconstruction: Evaluation of Image Quality and Radiation Dose Reduction

OBJECTIVE The purpose of this study is to assess the image quality and radiation dose reduction of ultra-low-dose CT using sinogram-affirmed iterative reconstruction (SAFIRE). SUBJECTS AND METHODS This prospective study enrolled 25 patients who underwent three consecutive unenhanced CT scans including low-dose CT (120 kVp and 30 mAs) and two ultra-low-dose CT protocols (protocol A, 100 kVp and 20 mAs; protocol B, 80 kVp and 30 mAs) with image reconstruction using SAFIRE. The image quality and radiation dose reduction were assessed. RESULTS The mean (± SD) effective radiation dose was 1.06 ± 0.11, 0.44 ± 0.05, and 0.31 ± 0.03 mSv for low-dose CT, ultra-low-dose CT protocol A, and ultra-low-dose CT protocol B, respectively. Overall image quality was determined as diagnostic in 100% of low-dose CT scans, 96% of ultra-low-dose CT protocol A scans, and 88% of ultra-low-dose CT protocol B scans. All patients with nondiagnostic quality images had a body mass index (weight in kilograms divided by the square of height in meters) greater than 25. There was no statistically significant difference in detection frequencies of 14 lesion types among the three CT protocols, but pulmonary emphysema was detected in fewer patients (3/25) in ultra-low-dose CT protocol B scans compared with ultra-low-dose CT protocol A scans (5/25) or low-dose CT scans (6/25). We measured the longest dimensions of 33 small solid nodules (3.8-12.4 mm in long diameter) and found no statistically significant difference in the values afforded by the three CT protocols (p = 0.135). CONCLUSION Iterative reconstruction allows ultra-low-dose CT and affords acceptable image quality, allowing size measurements of solid pulmonary nodules to be made.

A Case of Autoimmune Progesterone Dermatitis Misdiagnosed as Allergic Contact Dermatitis

Autoimmune progesterone dermatitis is a rare autoimmune response to endogenous progesterone that usually occurs in fertile females. Cutaneous or mucosal lesions develop cyclically during the luteal phase of the menstrual cycle when progesterone levels are elevated. Symptoms usually start 3-10 days before menstruation and resolve 1-2 days after menstruation ceases. We report the case of a 48-year-old woman with intermittent eczematous skin lesions of the legs, forearms, and buttocks. She was diagnosed with allergic contact dermatitis, and topical steroids were prescribed. Her skin eruptions waxed and waned for 6 years and were associated with her menstrual cycle. We performed an intradermal test using progesterone, which was positive, and prescribed gonadotropin-releasing hormone analogues monthly for 3 months. The patients skin lesions improved, confirming the diagnosis. Autoimmune progesterone dermatitis should be included in the differential diagnosis of recurrent eczema that is refractory to treatment in women of child-bearing age.

Characteristics and self-rated health of overlap syndrome.

Background and objective Overlap syndrome shares features of both asthma and chronic obstructive pulmonary disease (COPD). The aim of this study was to investigate characteristics of overlap syndrome and their effect on self-rated health (SRH). Methods We analyzed data from the Fourth Korea National Health and Nutrition Examination Survey of 2007–2009. Subjects with acceptable spirometry and available wheezing history were included. Subjects were classified into four groups based on forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) results and the presence or absence of self-reported wheezing for the previous 12 months: 1) COPD group, defined as having FEV1/FVC <0.7 without self-reported wheezing history; 2) asthma group, defined as having self-reported wheezing history without FEV1/FVC <0.7; 3) overlap syndrome group, having both FEV1/FVC <0.7 and wheezing history; and 4) non-obstructive disease (NOD) group, having neither FEV1/FVC <0.7 nor self-reported wheezing. SRH was categorized as better or lower based on responses to a questionnaire. Results From a total 9,104 subjects, 700 were assigned to the COPD group, 560 to the asthma group, 210 to the overlap syndrome group, and 7,634 to the NOD group. Compared to the other groups, subjects in the overlap syndrome group were more likely to have low lung function, a high proportion of smokers, low socioeconomic status, short education duration, lower SRH, and past diagnosis of pulmonary tuberculosis or bronchiectasis. Multiple logistic regression analysis revealed that both overlap syndrome and asthma groups were independently associated with lower SRH after adjustment for age, sex, socioeconomic status, education level, smoking status, comorbidities, and lung function. Female, old age, low education level, low economic status, smoker and other comorbidities were also associated with lower SRH. Conclusion Overlap syndrome was accompanied by high morbidity and was associated with lower SRH, which needs more appropriate care.

Mobilization Kinetics of CD34+ Cells in Association with Modulation of CD44 and CD31 Expression during Continuous Intravenous Administration of G‐CSF in Normal Donors

The aim of the present study is to evaluate the kinetics of CD34+ cells and investigate the potential modulation of CD44 and CD31 expression on CD34+ cells during continuous i.v. administration of G‐CSF, thus to elucidate the possible mechanism of peripheral blood progenitor cell (PBPC) mobilization. Fifteen healthy donors were enrolled in this study. G‐CSF (10 μg/kg/day) was administered for four consecutive days through continuous 24‐h i.v. infusion. For measurement of complete blood counts, CD34+ cell levels and their expression of CD44 and CD31, PB sampling was performed immediately before the administration of G‐CSF (steady‐state) and after 4, 8, 24, 48, 72, 96, and 120 h of G‐CSF administration. The percentage and absolute number of CD34+ cells significantly increased at day 3 (0.55 ± 0.09%, 51.12 ± 24.83 × 103/ml) and day 4 (0.47 ± 0.09%, 46.66 ± 24.93 × 103/ml), compared to the steady‐state level (0.06 ± 0.09%, 2.03 ± 5.69 × 103/ml). At day 3 to day 5 following the onset of G‐CSF administration, a strong decrease of CD44 and CD31 expression was observed on mobilized CD34+ cells compared to controls: the relative fluorescence intensity of CD44 and CD31 was, respectively, 50%‐70% and 40%‐90% lower than that of controls. We conclude that continuous i.v. administration of G‐CSF apparently results in more rapid mobilization of CD34+ cells, and downregulation of CD44 and CD31 on CD34+ cells is likely to be involved in the mobilization of PBPC after treatment with G‐CSF.

Risk factors for chronic obstructive pulmonary disease among never-smokers in Korea

Background Chronic obstructive pulmonary disease (COPD) patients include those who have never smoked. However, risk factors other than smoking in never-smokers have not been elucidated sufficiently. This study investigated the risk factors for COPD among never-smokers in Korea using population-based data. Methods The data were retrieved from the Korean National Health and Nutrition Survey IV conducted from 2007 to 2009. Among subjects aged 40 years or older who underwent appropriate pulmonary function tests, never-smokers not diagnosed with asthma and not showing a restrictive pattern on pulmonary function tests were enrolled. Risk factors of COPD in never-smokers were analyzed using logistic regression models. Results Among 24,871 participants in the representative Korean cohort, 3,473 never-smokers were enrolled. COPD patients accounted for 7.6% of the never-smokers. In the logistic regression analysis, low education status (odds ratio [OR]: 2.0; 95% confidence interval [CI]: 1.2–3.2), occupational exposure (OR: 2.6; 95% CI: 1.3–5.3), a history of tuberculosis (OR: 4.5; 95% CI: 2.3–8.7), bronchiectasis (OR: 6.0; 95% CI: 1.4–25.4), male sex (OR: 4.2; 95% CI: 2.6–6.7), advanced age (60–69 years vs 40–49 years; OR: 3.8; 95% CI: 2.0–7.0), and being underweight (body mass index <18.5 vs 18.0–24.9 kg/m2; OR: 3.1; 95% CI: 1.0–9.4) were associated with the development of COPD. Conclusion Low education status, manual labor, a history of tuberculosis and bronchiectasis, as well as male sex, advanced age and being underweight were risk factors for COPD in Korean never-smokers.

The efficacy and safety of prone positioning in adults patients with acute respiratory distress syndrome: a meta-analysis of randomized controlled trials

BACKGROUND Prone positioning for acute respiratory distress syndrome (ARDS) has no impact on mortality despite significant improvements in oxygenation. However, a recent trial demonstrated reduced mortality rates in the prone position for severe ARDS. We evaluated effects of prone position duration and protective lung strategies on mortality rates in ARDS. METHODS We extensively searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials to identify randomized controlled trials (RCTs) reporting on prone positioning during acute respiratory failure in adults for inclusion in our meta-analysis. RESULTS Eight trials met our inclusion criteria, Totals of 1,099 and 1,042 patients were randomized to the prone and supine ventilation positions. The mortality rates associated with the prone and supine positions were 41% and 47% [risk ratio (RR), 0.90; 95% confidence interval (CI), 0.82-0.98, P=0.02], but the heterogeneity was moderate (P=0.01, I(2)=61%). In a subgroup analysis, the mortality rates for lung protective ventilation (RR 0.73, 95% CI, 0.62-0.86, P=0.0002) and duration of prone positioning >12 h (RR 0.75, 95% CI, 0.65-0.87, P<0.0001) were reduced in the prone position. Prone positioning was not associated with an increased incidence of cardiac events (RR 1.01, 95% CI, 0.87-1.17) or ventilator associated pneumonia (RR 0.88, 95% CI, 0.71-1.09), but it was associated with an increased incidence of pressure sores (RR 1.23, 95% CI, 1.07-1.41) and endotracheal dislocation (RR 1.33, 95% CI, 1.02-1.74). CONCLUSIONS Prone positioning tends to reduce the mortality rates in ARDS patients, especially when used in conjunction with a lung protective strategy and longer prone position durations. Prone positioning for ARDS patients should be prioritized over other invasive procedures because related life-threatening complications are rare. However, further additional randomized controlled design to study are required for confirm benefit of prone position in ARDS.

Clinical Practice Guideline of Acute Respiratory Distress Syndrome

There is no well-stated practical guideline for mechanically ventilated patients with or without acute respiratory distress syndrome (ARDS). We generate strong (1) and weak (2) grade of recommendations based on high (A), moderate (B) and low (C) grade in the quality of evidence. In patients with ARDS, we recommend low tidal volume ventilation (1A) and prone position if it is not contraindicated (1B) to reduce their mortality. However, we did not support high-frequency oscillatory ventilation (1B) and inhaled nitric oxide (1A) as a standard treatment. We also suggest high positive end-expiratory pressure (2B), extracorporeal membrane oxygenation as a rescue therapy (2C), and neuromuscular blockage for 48 hours after starting mechanical ventilation (2B). The application of recruitment maneuver may reduce mortality (2B), however, the use of systemic steroids cannot reduce mortality (2B). In mechanically ventilated patients, we recommend light sedation (1B) and low tidal volume even without ARDS (1B) and suggest lung protective ventilation strategy during the operation to lower the incidence of lung complications including ARDS (2B). Early tracheostomy in mechanically ventilated patients can be performed only in limited patients (2A). In conclusion, of 12 recommendations, nine were in the management of ARDS, and three for mechanically ventilated patients.

Risk Factors Related with Mortality in Patient with Pulmonary Tuberculosis

Background The prevalence rate of pulmonary tuberculosis (PTB) is steadily decreasing in South Korea. However, PTB is a disease with relatively high mortality and morbidity rates throughout Korea. Although there are many studies and statistics about the risk factors of PTB mortality in many countries, there are only a limited number of domestic papers on this topic. The aim of this study is to determine predictive factors for mortality among in-hospital patients associated with PTB. Methods From December 2006 to January 2011, we reviewed medical records of 2,122 adult patients diagnosed with tuberculosis at a single tertiary hospital in a suburban area. In this study period, 960 patients were diagnosed with PTB by positive Acid fast bacilli smear and/or mycobacterial culture of the respiratory specimen. We compared the groups of patients deceased and patients discharged alive with PTB. The number of dead patients was 82 (47 males, 35 females). Results Mortality was significantly associated with increased values of white blood cells (WBC), blood urine nitrogen (BUN), creatinine, C-reactive protein (CRP), numbers of involved lung field, and length of hospitalization. Also, it was associated with the decreased values of hemoglobin, lymphocyte, sodium, albumin, and cholesterol. Furthermore, admission through the emergency department, initial intensive care unit admission, and drug resistant PTB affected mortality in PTB patients. Independent predictors associated with PTB mortality are BUN, initial intensive care unit care, and admission during treatment of tuberculosis. Conclusion In our study, mortality of pulmonary tuberculosis was related with parameters associated with nutritional status, disease severity at the time of admission, and drug resistance.

Acute Eosinophilic Pneumonia Following Secondhand Cigarette Smoke Exposure

Acute eosinophilic pneumonia (AEP) is a disease characterized by an acute febrile onset, eosinophilia in bronchoalveolar lavage fluid, and a dramatic response to corticosteroids. Although many studies have reported a close relationship between direct cigarette smoking and AEP, few studies have identified an association between passive smoking and AEP. Here, we report a case of AEP in a 19-year-old female with cough, fever, and dyspnea after 4 weeks of intense exposure to secondhand smoke for 6 to 8 hours a day in an enclosed area.

Clinical Features and Prognostic Factors in Elderly Koreans with Advanced Non-Small-Cell Lung Cancer in a Tertiary Referral Hospital

Background More than half of cases for advanced non-small-cell lung cancer (NSCLC) occur in elderly patients with a median age at diagnosis of 70 years. The aim of our study was to examine the clinical features and prognostic factors contributing to mortality in elderly patients with advanced NSCLC. Methods Following a retrospective review of clinical data, 122 patients aged 70 years and over with a histopathological diagnosis of locally advanced (stage IIIB, n=32) and metastatic (stage IV, n=90) NSCLC between 2005 and 2011 were enrolled. Results The median age was 76 years (interquartile range, [IQR], 72-80 years), and 85 (70%) patients were male. Fifty-seven (46%) patients had never smoked, and 17 (19%) were in a malnourished state with a body mass index (BMI) of <18.5 kg/m2. The initial treatments included chemotherapy (40%) and radiotherapy (7%), but 57% of the patients received supportive care only. The 1-year survival rate was 32%, and the 3-year survival rate was 4%, with a median survival duration of 6.2 months (IQR, 2.5-15.3 months). Male gender (hazard ratio [HR], 2.2; 95% confidence interval [CI], 1.3-3.9; p=0.005), low BMI (HR, 2.3; 95% CI, 1.3-3.9; p=0.004), and supportive care only (HR, 1.9; 95% CI, 1.2-2.9; p=0.007) were independent predictors of shorter survival based on a Cox proportional hazards model. Conclusion Elderly patients with advanced NSCLC had a poor prognosis, particularly male patients, those with a low BMI, and those who received supportive care only.