Hwa Jung Kim

A cluster of lung injury cases associated with home humidifier use: an epidemiological investigation

Background In April 2011 a tertiary hospital in Seoul, Korea reported several cases of severe respiratory distress of unknown origin in young adults. Methods To find the route of transmission, causative agent and patient risk factors of the outbreak, an investigation of the epidemic was initiated. Clinicopathological conferences led to the suspicion that the cases related to an inhalation injury. An age- and sex-matched case–control study was therefore performed to examine the inhalation exposure of the patients to various agents. Results Of the 28 confirmed cases, 18 agreed to participate. A total of 121 age- and sex-matched controls with pulmonary, allergic or obstetric disease were selected. All patients and controls completed questionnaires with questions about exposure to various inhalants. The crude ORs for patient exposure to indoor mould, humidifier use, humidifier detergent use and insecticide use were 4.4 (95% CI 1.5 to 13.1), 13.7 (95% CI 1.8 to 106.3), 47.3 (95% CI 6.1 to 369.7) and 3.9 (95% CI 1.3 to 11.7), respectively. However, when considered concurrently, indoor mould and insecticide use lost statistical significance. Moreover, humidifier use was ruled out as the cause because of a lack of biological plausibility and the weak strength of the association. This suggested that humidifier disinfectant was the cause of the outbreak. This information led the Korean government to order the removal of humidifier detergents from the market. In the years following the ban, no additional cases were detected. Conclusions Epidemiological evidence strongly suggests that the lung injury outbreak was caused by humidifier detergent use at home.

A cluster of lung injury associated with home humidifier use: clinical, radiological and pathological description of a new syndrome

Background Over a few months in the spring of 2011, a cluster of patients with severe respiratory distress were admitted to our intensive care unit (ICU). Household clustering was also observed. Extensive laboratory investigations failed to detect an infectious cause. Methods Clinical, radiological and pathological investigations were conducted and the Korean Center for Disease Control performed epidemiological studies. Results The case series consisted of 17 patients. Their median age was 35 (range 28–49) years. Six were pregnant at presentation and four had given birth 2u2005weeks previously. All presented with cough and dyspnoea. In the majority of patients (14/17), multifocal areas of patchy consolidation were identified in the lower lung zones on the initial CT. As the condition progressed, the patchy consolidation disappeared (10/13) and diffuse centrilobular ground-glass opacity nodules started to predominate and persist. Pathological specimens (11/17) showed a bronchiolocentric, temporally homogenous, acute lung injury pattern with sparing of the subpleural and peripheral alveolar areas. Ten patients required mechanical ventilation, eight of whom subsequently received extracorporeal life support. Four of the latter underwent lung transplantation. Five of the six patients in the ICU who did not receive lung transplantation died. An epidemiological investigation revealed that all patients had used humidifier disinfectants in their homes. Conclusions This case series report showed that lung injury and respiratory failure can occur as a result of inhaling humidifier disinfectants. This emphasises the need for more stringent safety regulations for potentially toxic inhalants that might be encountered in the home.

Advanced Lung Adenocarcinoma Harboring a Mutation of the Epidermal Growth Factor Receptor: CT Findings after Tyrosine Kinase Inhibitor Therapy

PURPOSEnTo study chest computed tomography (CT) in tyrosine kinase inhibitor (TKI) treatment of epidermal growth factor receptor (EGFR)-mutant adenocarcinoma.nnnMATERIALS AND METHODSnThis retrospective study was approved by the institutional review board. Informed consent was waived. One hundred thirty consecutive patients with stage IV adenocarcinoma and EGFR mutations at a single tertiary center from November 2004 to April 2010 were enrolled retrospectively. CT images were analyzed with Response Evaluation Criteria in Solid Tumor guidelines. Target lesions were classified by size, type, axial location, and metastasis. Patients were followed after TKI therapy, and treatment response was classified as partial response, stable disease, or progressive disease. A Cox proportional hazards model was used to correlate baseline CT features and EGFR mutations with progression-free survival (PFS) and overall survival.nnnRESULTSnAll patients underwent TKI therapy after identifying exon mutations in the EGFR gene, comprising exon 19 deletion (19del) (n = 77), L858R (n = 43), and exon 18 (n = 10). Outcomes were partial response (n = 103), stable disease (n = 22), and progressive disease (n = 5). In univariate analysis, PFS was significantly longer with small lesions (hazard ratio [HR], 1.02; 95% confidence interval [CI]: 1.01, 1.03; P < .01), nodular main lesions (HR, 0.55; 95% CI: 0.34, 0.88; P = .01), or peripheral lesions (HR, 0.62; 95% CI: 0.42, 0.93; P = .02). In univariate analysis, PFS was significantly longer with smaller lesions (HR, 1.02; 95% CI: 1.01, 1.03; P < .01), nodular main lesions (HR, 0.55; 95% CI: 0.34, 0.88; P = .01), peripheral lesions (HR, 0.62; 95% CI: 0.42, 0.93; P = .02), 19del (HR, 0.33; 95% CI: 0.14, 0.77; P = .01), or L858R (HR, 0.39; 95% CI: 0.16, 0.97; P = .04). In multivariate analysis, PFS was significantly longer with 19del (HR, 0.30; 95% CI: 0.11, 0.84; P = .02) and shorter with scattered metastases (HR, 2.25; 95% CI: 1.44, 5.51; P < .01).nnnCONCLUSIONnSmaller nodular lesions, peripheral lesions, and 19del relate to longer PFS after EGFR TKI treatment.

Clinical Outcome of Transcatheter Arterial Embolization With N-Butyl-2-Cyanoacrylate for Control of Acute Gastrointestinal Tract Bleeding

OBJECTIVE. The purpose of this article is to evaluate the clinical effectiveness of trans-catheter arterial embolization (TAE) with N-butyl-2-cyanoacrylate (NBCA), with or without other embolic materials for acute nonvariceal gastrointestinal tract bleeding, and to determine the factors associated with clinical outcomes. MATERIALS AND METHODS. TAE using NBCA only or in conjunction with other materials was performed for 102 patients (80 male and 22 female patients; mean age, 61.3 years) with acute nonvariceal gastrointestinal tract bleeding. Technical success, clinical success, and clinical factors, including age, sex, bleeding tendency, endoscopic attempts at hemostasis, number of transfusions, and bleeding causes (i.e., cancer vs noncancer), were retrospectively evaluated. Univariate and multivariable logistic regression analyses were performed to evaluate clinical factors and their ability to predict patient outcomes. Survival curves were obtained using Kaplan-Meier analyses and log-rank tests. RESULTS. There were 36 patients with cancer-related bleeding and 66 with non-cancer-related bleeding. Overall technical and clinical success rates were 100% (102/102) and 76.5% (78/102), respectively. Procedure-related complications included bowel infarction, which was noted in two patients. Recurrent bleeding and bleeding-related 30-day mortality rates were 15.7% (16/102) and 8.8% (9/102), respectively. Cancer-related bleeding increased clinical failure significantly (p = 0.003) and bleeding-related 30-day mortality with marginal significance (p = 0.05). Overall survival was poorer in patients with cancer-related bleeding. CONCLUSION. TAE with NBCA with or without other embolic agents showed high technical and clinical effectiveness in the management of acute nonvariceal gastrointestinal tract bleeding. Cancer-related bleeding was the only factor related to clinical failure, and possibly related to bleeding-related 30-day mortality.

The value of 15-minute delayed contrast-enhanced CT to differentiate hyperattenuating adrenal masses compared with chemical shift MR imaging

ObjectivesTo investigate the diagnostic performance of 15-min delayed contrast-enhanced computed tomography (15-DECT) compared with that of chemical shift magnetic resonance (CSMR) imaging in differentiating hyperattenuating adrenal masses and to perform subgroup analysis in underlying malignancy and non-malignancy.MethodsThis study included 478 adrenal masses in 453 patients examined with 15-DECT and 235 masses in 217 patients examined with CSMR. Relative percentage washout (RPW) and absolute percentage washout (APW) on 15-DECT, and signal intensity index (SII) and adrenal-to-spleen ratio (ASR) on CSMR were measured. Sensitivity, specificity and accuracy of 15-DECT and CSMR were analysed for characterisation of adrenal adenoma. Subgroup analyses were performed in patients with and without underlying malignancy. Attenuation and size of the masses on unenhanced CT correlated with the risk of non-adenoma.ResultsRPW calculated from 15-DECT showed the highest diagnostic performance for characterising hyperattenuating adrenal masses regardless of underlying malignancy, and the sensitivity, specificity and accuracy were 91.7xa0%, 74.8xa0% and 88.1xa0%, respectively in all patients. The risk of non-adenoma increased approximately threefold as mass size increased 1xa0cm or as its attenuation value increased by 10 Hounsfield units.Conclusions15-DECT was more accurate than CSMR in characterising hyperattenuating adrenal masses regardless of underlying malignancy.Key Points• Delayed contrast-enhanced CT and chemical shift magnetic resonance (CSMR) characterise adrenal lesions.• 15-min DECT is more accurate than CSMR in characterising hyperattenuating adrenal masses.• Sensitivity of CSMR decreases as the CT attenuation of adenomas increases.• Risk of non-adenoma is increased 2.9-fold as size increased by 1xa0cm.• Risk of non-adenoma is increased 2.9-fold as attenuation increased by 10 HU.

Predictors of Clinical Progression of Subjective Memory Impairment in Elderly Subjects: Data from the Clinical Research Centers for Dementia of South Korea (CREDOS)

Background/Aims: The aims of this study were to determine baseline factors related to the progression of subjective memory impairment (SMI) in elderly subjects and to develop a new modeling scale to predict progression. Methods: Elderly subjects with SMI were recruited from the nationwide Clinical Research Centers for Dementia of South Korea (CREDOS) multicenter cohort and divided into two groups: (1) progressed to mild cognitive impairment or Alzheimers disease or (2) stable without progression. Baseline clinical characteristics were compared between the groups, and the most relevant predictors of progression were assessed. A new modeling scale combining the predictors was developed. Results: In total, 129 subjects with SMI were analyzed. The follow-up duration was 0.5-4.7 years, and the median time to event was 3.64 years. The progressing group (n = 29) differed from the stable group (n = 100) in terms of baseline age, apolipoprotein E4 (APOE4) status, and some cognitive domains. Older age, a lower Mini-Mental State Examination recall score, APOE4 carrier, and a lower verbal delayed recall score were the most relevant predictors of progression, and a new modeling scale with these 4 predictors provided a better explanation of progression. Conclusion: SMI subjects with a higher risk of progression can be identified using a new modeling scale and might need further evaluations and more frequent follow-up.

Humidifier disinfectant-associated lung injury in adults: Prognostic factors in predicting short-term outcome

AbstractObjectivesTo identify clinical and radiologic findings that affect disease severity and short-term prognosis of humidifier disinfectant-associated lung injury in adults and to compare computed tomography (CT) findings between the patients with and without death or lung transplantation.MethodsFifty-nine adults (mean age, 34xa0years; M/Fu2009=u200912:47) were enrolled in this retrospective study. Medical records and prospective surveillance data were used to assess clinical and radiological factors associated with a poor clinical outcome. Multivariate generalized estimating equation models were used to analyse serial CT findings. Overall cumulative major events including lung transplantation and mortality were assessed using the Kaplan–Meier method.ResultsAlmost half needed ICU admission (47.5xa0%) and 17 died (28.8xa0%). Young age, peripartum and low O2 saturation were factors associated with ICU admission. On initial chest radiographs, consolidation (Pu2009<u20090.001) and ground-glass opacity (Pu2009=u20090.01) were significantly noted in patients who required ICU admission. CT findings including consolidation (odds ratio (OR), 1.02), pneumomediastinum (OR, 1.66) and pulmonary interstitial emphysema (OR, 1.61) were the risk factors for lung transplantation and mortality.ConclusionClinical and radiologic findings are related to the risks of lung transplantation and mortality of humidifier disinfectant-associated lung injury. Consolidation, pneumomediastinum and pulmonary interstitial emphysema were short-term prognostic CT findings.Key Points• Young age, peripartum and low O2saturation were associated with ICU admission.n • Consolidation, pneumomediastinum and pulmonary interstitial emphysema were short-term prognostic CT findings.n • Consolidation and ground-glass opacity disappeared within 3xa0months and replaced by centrilobular nodules.n • Radiologic findings are related to the outcome of humidifier disinfectant-associated lung injury.

Impact of pannus formation on hemodynamic dysfunction of prosthetic aortic valve: pannus extent and its relationship to prosthetic valve motion and degree of stenosis

BackgroundAlthough pannus is an important cause of prosthetic valve dysfunction, the minimum pannus size that can induce hemodynamic dysfunction has not yet been determined. This study investigated the correlation between the limitation of motion (LOM) of the prosthetic valve and pannus extent and determined the pannus extent that could induce severe aortic stenosis.MethodsThis study included 49 patients who underwent mechanical aortic valve replacement (AVR) and showed pannus on cardiac computed tomography (CT). Pannus width, ratio of pannus width to valve diameter, pannus area, effective orifice area, encroachment ratio by pannus, pannus involvement angle and percent LOM of mechanical valves were evaluated on CT. Transvalvular peak velocity (TPV) and transvalvular pressure gradient (TPG) were measured by transesophageal echocardiography to determine the degree of aortic stenosis. The relationship between percent LOM of the prosthetic valve and pannus extent and the cut-off of pannus extent required to induce severe aortic stenosis were evaluated.ResultsThe mean interval between AVR and pannus formation was 11xa0years and was longer in patients with than without severe aortic stenosis (14.0 vs. 7.3xa0years). On CT, the percent LOM of the prosthetic valve was significantly associated with the extent of pannus only in patients with pannus involvement angleu2009>u2009180° (ru2009=u20090.55–0.68, Pu2009<u20090.01). Pannus width, effective orifice area, and encroachment ratio were significantly associated with increased TPV and TPG (ru2009=u20090.51–0.62, Pu2009<u20090.01). Pannus widthu2009>u20093.5xa0mm, pannus width/valve inner diameteru2009>u20090.15, and encroachment ratiou2009>u20090.14 were significantly associated with severe aortic stenosis (TPVu2009>u20094xa0m/s; mean TPGu2009≥u200935xa0mmHg), with c-indices of 0.74–079 (Pu2009<u20090.005).ConclusionCT-derived pannus extent parameters are good indicators of significant hemodynamic changes with increased TPV and mean TPG.

Clinical impact of preoperative brain MR angiography and MR imaging in candidates for liver transplantation: a propensity score-matching study in a single institution.

ObjectivesTo investigate the prevalence of cerebrovascular stenosis and white matter lesions on preoperative magnetic resonance angiography (MRA) and magnetic resonance imaging (MRI) in liver transplantation candidates.MethodsThis retrospective study included 1,460 consecutive patients with liver cirrhosis (LC) who underwent MRA with/without brain MRI for pretransplantation evaluation. These patients were matched with 5,331 controls using propensity scores, and the prevalences of significant cerebrovascular stenosis and white matter lesions were compared.ResultsA matched analysis of 1,264 pairs demonstrated that the prevalence of significant stenosis was comparable between LC patients and controls (2.2% vs. 1.4%, Pu2009=u20090.143). LC and most ofxa0LC-related parameters were not associated with stenosis. Significant white matter lesions were more common in LC patients (2.8% vs. 1.3%, Pu2009=u20090.036). A high Model for End-Stage Liver Disease (MELD) score (OR 1.11, CI 1.03–1.20, Pu2009=u20090.008, for infarction; OR 1.1, CI 1.04–1.16, Pu2009=u20090.001, for haemorrhage) and stroke history (OR 179.06, CI 45.19–709.45, Pu2009<u20090.001) were predictors of perioperative stroke.ConclusionsLC patients and control subjects demonstrated similar cerebrovascular stenosis prevalences, whereas white matter lesions were more common in LC patients. A high MELD score and stroke history contribute as predictors of perioperative stroke.Key points• Routine preoperative MR imagingin liver transplantation candidates may not be necessary.• Liver cirrhosis patients and control subjects had similar prevalences of significant cerebrovascular stenosis.• Liver cirrhosis and cirrhosis-related parameters were not correlated with significant cerebrovascular stenosis.• Significant white matter lesions were more frequent in liver cirrhosis patients.

Computed tomography findings for a gastric lymphoepithelioma-like carcinoma: How often does it present as a submucosal mass?

ObjectivesTo describe the anatomical location, size, tumour characteristics and morphology on CT of gastric lymphoepithelioma-like carcinoma (LELC) in order to determine the proportion of lesions that present as submucosal masses, and to review the clinicopathological findings.MethodsThis retrospective study reviewed CT images of 186 lesions from 178 patients with LELC. CT morphologies and other findings were also analyzed. Pathology and medical records were reviewed. A pathology slide review of the lesions that presented with submucosal masses was performed.ResultsGastric LELC presenting as a submucosal mass was found in 9.1xa0%. The most common CT morphology was eccentric wall thickening (67.7xa0%). On the pathology review, 14/17 submucosal mass lesions (82.4xa0%) had a central ulceration. 105 lesions were T1/T2 stage (94.1xa0%), and N0 stage was diagnosed in 66.1xa0%. Fifty-six of 63 metastatic lymph nodes (LNs) (88.9xa0%) demonstrated homogeneous enhancement, regardless of size. Male predominance (85.4xa0%), upper stomach location (45.7xa0%) and multiplicity (4.5xa0%) were found.ConclusionsGastric LELC presenting as a submucosal mass is only detected in a small portion of all patients, and the most common finding is eccentric wall thickening. Central ulceration and enlarged LNs with homogeneous enhancement are occasionally other features on CT.Key Points• LELCs as submucosal masses on CT were detected in only 9.1u2009%.• The most common CT finding was eccentric wall thickening (67.7u2009%).• Central ulceration and enlarged LNs with homogeneous enhancement might be seen.