Publications by authors named "Kum Ju Chae"

32 Publications

Generation-based study of airway remodeling in smokers with normal-looking CT with normalization to control inter-subject variability.

Eur J Radiol 2021 Mar 13;138:109657. Epub 2021 Mar 13.

Department of Radiology & Department of Biomedical Engineering, The University of Iowa, Iowa City, IA, USA.

Purpose: With the help of quantitative computed tomography (QCT), it is possible to identify smoking-associated airway remodeling. However, there is currently little information on whether QCT-based airway metrics are sensitive to early airway wall remodeling in subclinical phases of smoking-associated airway disease. This study aimed to evaluate a predictive model that normalized airway parameters and investigate structural airway alterations in smokers with normal-looking CT using the normalization scheme.

Methods: In this retrospective analysis, 222 non-smokers (male 97, female 125) and 69 smokers (male 66, female 3) from January 2014 to December 2016 were included, and airway parameters were quantitatively analyzed. To control inter-subject variability, multiple linear regressions of tracheal wall thickness (WT), diameter (D), and luminal area (LA) were performed, adjusted for age, sex, and height. Using this normalization scheme, airway parameters with matched generation were compared between smokers and non-smokers.

Results: Using the normalization scheme, it was possible to assess generation-based structural alterations of the airways in subclinical smokers. Smokers showed diffuse luminal narrowing of airways for most generations (P < 0.05, except 3rd generation), no change in wall thickness of the proximal bronchi (1st-3rd generation), and a thinning of distal airways (P <0.05, ≥4th generation).

Conclusion: QCT assessment for subclinical smokers can help identify minimal structural changes in airways induced by smoking.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejrad.2021.109657DOI Listing
March 2021

An Unusual Manifestation of Rapidly Progressing Granulomatosis with Polyangiitis Involving Uterine Adnexa and Lung.

Am J Respir Crit Care Med 2021 Jan 29. Epub 2021 Jan 29.

Jeonbuk National University Medical School, 90158, Department of Internal Medicine, Jeonju, Korea (the Republic of);

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1164/rccm.202001-0118IMDOI Listing
January 2021

A 3D-CNN model with CT-based parametric response mapping for classifying COPD subjects.

Sci Rep 2021 Jan 8;11(1):34. Epub 2021 Jan 8.

School of Mechanical Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566, Republic of Korea.

Chronic obstructive pulmonary disease (COPD) is a respiratory disorder involving abnormalities of lung parenchymal morphology with different severities. COPD is assessed by pulmonary-function tests and computed tomography-based approaches. We introduce a new classification method for COPD grouping based on deep learning and a parametric-response mapping (PRM) method. We extracted parenchymal functional variables of functional small airway disease percentage (fSAD%) and emphysema percentage (Emph%) with an image registration technique, being provided as input parameters of 3D convolutional neural network (CNN). The integrated 3D-CNN and PRM (3D-cPRM) achieved a classification accuracy of 89.3% and a sensitivity of 88.3% in five-fold cross-validation. The prediction accuracy of the proposed 3D-cPRM exceeded those of the 2D model and traditional 3D CNNs with the same neural network, and was comparable to that of 2D pretrained PRM models. We then applied a gradient-weighted class activation mapping (Grad-CAM) that highlights the key features in the CNN learning process. Most of the class-discriminative regions appeared in the upper and middle lobes of the lung, consistent with the regions of elevated fSAD% and Emph% in COPD subjects. The 3D-cPRM successfully represented the parenchymal abnormalities in COPD and matched the CT-based diagnosis of COPD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-79336-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7794420PMC
January 2021

Establishment of a Nationwide Korean Imaging Cohort of Coronavirus Disease 2019.

J Korean Med Sci 2020 Nov 30;35(46):e413. Epub 2020 Nov 30.

Department of Radiology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, Korea.

Background: The Korean Society of Thoracic Radiology (KSTR) recently constructed a nation-wide coronavirus disease 2019 (COVID-19) database and imaging repository, referred to the Korean imaging cohort of COVID-19 (KICC-19) based on the collaborative efforts of its members. The purpose of this study was to provide a summary of the clinico-epidemiological data and imaging data of the KICC-19.

Methods: The KSTR members at 17 COVID-19 referral centers retrospectively collected imaging data and clinical information of consecutive patients with reverse transcription polymerase chain reaction-proven COVID-19 in respiratory specimens from February 2020 through May 2020 who underwent diagnostic chest computed tomography (CT) or radiograph in each participating hospital.

Results: The cohort consisted of 239 men and 283 women (mean age, 52.3 years; age range, 11-97 years). Of the 522 subjects, 201 (38.5%) had an underlying disease. The most common symptoms were fever (n = 292) and cough (n = 245). The 151 patients (28.9%) had lymphocytopenia, 86 had (16.5%) thrombocytopenia, and 227 patients (43.5%) had an elevated CRP at admission. The 121 (23.4%) needed nasal oxygen therapy or mechanical ventilation (n = 38; 7.3%), and 49 patients (9.4%) were admitted to an intensive care unit. Although most patients had cured, 21 patients (4.0%) died. The 465 (89.1%) subjects underwent a low to standard-dose chest CT scan at least once during hospitalization, resulting in a total of 658 CT scans. The 497 subjects (95.2%) underwent chest radiography at least once during hospitalization, which resulted in a total of 1,475 chest radiographs.

Conclusion: The KICC-19 was successfully established and comprised of 658 CT scans and 1,475 chest radiographs of 522 hospitalized Korean COVID-19 patients. The KICC-19 will provide a more comprehensive understanding of the clinical, epidemiological, and radiologic characteristics of patients with COVID-19.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3346/jkms.2020.35.e413DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7707929PMC
November 2020

2020 Clinical Practice Guideline for Percutaneous Transthoracic Needle Biopsy of Pulmonary Lesions: A Consensus Statement and Recommendations of the Korean Society of Thoracic Radiology.

Korean J Radiol 2021 02 19;22(2):263-280. Epub 2020 Nov 19.

Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.

Percutaneous transthoracic needle biopsy (PTNB) is one of the essential diagnostic procedures for pulmonary lesions. Its role is increasing in the era of CT screening for lung cancer and precision medicine. The Korean Society of Thoracic Radiology developed the first evidence-based clinical guideline for PTNB in Korea by adapting pre-existing guidelines. The guideline provides 39 recommendations for the following four main domains of 12 key questions: the indications for PTNB, pre-procedural evaluation, procedural technique of PTNB and its accuracy, and management of post-biopsy complications. We hope that these recommendations can improve the diagnostic accuracy and safety of PTNB in clinical practice and promote standardization of the procedure nationwide.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3348/kjr.2020.0137DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7817630PMC
February 2021

Interstitial Lung Abnormalities: What Radiologists Should Know.

Korean J Radiol 2021 03 30;22(3):454-463. Epub 2020 Oct 30.

Department of Pathology, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea.

Interstitial lung abnormalities (ILAs) are radiologic abnormalities found incidentally on chest CT that are potentially related to interstitial lung diseases. Several articles have reported that ILAs are associated with increased mortality, and they can show radiologic progression. With the increased recognition of ILAs on CT, the role of radiologists in reporting them is critical. This review aims to discuss the clinical significance and radiologic characteristics of ILAs to facilitate and enhance their management.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3348/kjr.2020.0191DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7909860PMC
March 2021

Quantitative CT-based image registration metrics provide different ventilation and lung motion patterns in prone and supine positions in healthy subjects.

Respir Res 2020 Oct 2;21(1):254. Epub 2020 Oct 2.

Department of Radiology, University of Iowa, Iowa City, USA.

Background: Previous studies suggested that the prone position (PP) improves oxygenation and reduces mortality among patients with acute respiratory distress syndrome (ARDS). However, the mechanism of this clinical benefit of PP is not completely understood. The aim of the present study was to quantitatively compare regional characteristics of lung functions in the PP with those in the supine position (SP) using inspiratory and expiratory computed tomography (CT) scans.

Methods: Ninety subjects with normal pulmonary function and inspiration and expiration CT images were included in the study. Thirty-four subjects were scanned in PP, and 56 subjects were scanned in SP. Non-rigid image registration-based inspiratory-expiratory image matching assessment was used for regional lung function analysis. Tissue fractions (TF) were computed based on the CT density and compared on a lobar basis. Three registration-derived functional variables, relative regional air volume change (RRAVC), volumetric expansion ratio (J), and three-dimensional relative regional displacement (s*) were used to evaluate regional ventilation and deformation characteristics.

Results: J was greater in PP than in SP in the right middle lobe (P = 0 .025), and RRAVC was increased in the upper and right middle lobes (P < 0.001). The ratio of the TF on inspiratory and expiratory scans, J, and RRAVC at the upper lobes to those at the middle and lower lobes and that ratio at the upper and middle lobes to those at the lower lobes of were all near unity in PP, and significantly higher than those in SP (0.98-1.06 vs 0.61-0.94, P < 0.001).

Conclusion: We visually and quantitatively observed that PP not only induced more uniform contributions of regional lung ventilation along the ventral-dorsal axis but also minimized the lobar differences of lung functions in comparison with SP. This may help in the clinician's search for an understanding of the benefits of the application of PP to the patients with ARDS or other gravitationally dependent pathologic lung diseases.

Trial Registration: Retrospectively registered.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12931-020-01519-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7531138PMC
October 2020

Patterns of percutaneous transthoracic needle biopsy (PTNB) of the lung and risk of PTNB-related severe pneumothorax: A nationwide population-based study.

PLoS One 2020 10;15(7):e0235599. Epub 2020 Jul 10.

School of Medicine, Inha University, Incheon, Republic of Korea.

Background: As percutaneous transthoracic needle biopsy (PTNB) of the lung is a well-established diagnostic method for the evaluating pulmonary lesions, evidence of safety based on representative data is limited. This study investigated the practice patterns of PTNB of the lung and assessed the incidence and risk factors of PTNB-related severe pneumothorax in Korea.

Methods: We used a national-level health insurance database between January 1, 2007 and December 31, 2015. Patients who underwent PTNB of the lung were identified using procedure codes for organ biopsy, fluoroscopy, computed tomography, chest radiography, and lung-related diagnosis codes. The annual age-/sex-standardized rate of PTNB and the incidence of PTNB-related severe pneumothorax were calculated. We defined severe pneumothorax as the pneumothorax requiring intervention. The odds ratios of risk factors were assessed by a generalized estimating equation model with exchangeable working correlation matrix to address clustering effect within institution.

Results: A total of 66,754 patients were identified between 2007 and 2015. The annual age-/sex-standardized rate of PTNB per 100,000 population was 19.6 in 2007 and 22.4 in 2015, and it showed an increasing trend. The incidence of severe pneumothorax was 2.4% overall: 2.5% in men and 1.2% in women, and 2.6%, 2.7%, 2.1%, 2.1%, 1.9%, 2.4%, and 2.4% from 2009 to 2015. Older age (≥60), male sex, presence of chronic obstructive pulmonary disease, receiving treatment in an urban or rural area versus a metropolitan area, and receiving treatment at a general hospital were significantly associated with the risk of severe pneumothorax.

Conclusions: Considering the increasing trend of PTNB, more attention needs to be paid to patients with risk factors for severe pneumothorax.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0235599PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7351186PMC
September 2020

Positive conversion of COVID-19 after two consecutive negative RT-PCR results: A role of low-dose CT.

Eur J Radiol 2020 08 9;129:109122. Epub 2020 Jun 9.

Department of Preventive Medicine, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, South Korea.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejrad.2020.109122DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7282766PMC
August 2020

Quantitative CT-based structural alterations of segmental airways in cement dust-exposed subjects.

Respir Res 2020 May 29;21(1):133. Epub 2020 May 29.

School of Mechanical Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566, South Korea.

Background: Dust exposure has been reported as a risk factor of pulmonary disease, leading to alterations of segmental airways and parenchymal lungs. This study aims to investigate alterations of quantitative computed tomography (QCT)-based airway structural and functional metrics due to cement-dust exposure.

Methods: To reduce confounding factors, subjects with normal spirometry without fibrosis, asthma and pneumonia histories were only selected, and a propensity score matching was applied to match age, sex, height, smoking status, and pack-years. Thus, from a larger data set (N = 609), only 41 cement dust-exposed subjects were compared with 164 non-cement dust-exposed subjects. QCT imaging metrics of airway hydraulic diameter (D), wall thickness (WT), and bifurcation angle (θ) were extracted at total lung capacity (TLC) and functional residual capacity (FRC), along with their deformation ratios between TLC and FRC.

Results: In TLC scan, dust-exposed subjects showed a decrease of D (airway narrowing) especially at lower-lobes (p < 0.05), an increase of WT (wall thickening) at all segmental airways (p < 0.05), and an alteration of θ at most of the central airways (p < 0.001) compared with non-dust-exposed subjects. Furthermore, dust-exposed subjects had smaller deformation ratios of WT at the segmental airways (p < 0.05) and θ at the right main bronchi and left main bronchi (p < 0.01), indicating airway stiffness.

Conclusions: Dust-exposed subjects with normal spirometry demonstrated airway narrowing at lower-lobes, wall thickening at all segmental airways, a different bifurcation angle at central airways, and a loss of airway wall elasticity at lower-lobes. The airway structural alterations may indicate different airway pathophysiology due to cement dusts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12931-020-01399-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7260806PMC
May 2020

Rapidly Progressive COVID-19 Pneumonia: What Radiologists Should Do.

Korean J Radiol 2020 06;21(6):773-776

Department of Radiology, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3348/kjr.2020.0364DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7231620PMC
June 2020

Adenocarcinoma-Papillary Cystic Pattern Arising in a Mixed Squamous and Glandular Papilloma of the Lung.

Int J Surg Pathol 2020 Sep 25;28(6):658-662. Epub 2020 Feb 25.

Jeonbuk National University, Jeonju, Korea.

Mixed squamous and glandular papilloma (mixed papilloma) of the lung has been reported in fewer than 25 cases in the English literature. Although it is known as a benign tumor, malignant transformation has been reported. Papillary cystic carcinoma is characterized by papillary and cystic growth patterns and has been reported as a subtype of adenocarcinoma, mainly in the salivary glands, breast, and pancreas. In this article, we report a case of adenocarcinoma-papillary cystic pattern arising from mixed papilloma of the lung in a 76-year-old male patient. Chest computed tomography scan revealed an endobronchial mass growing at the right medial segmental bronchus. Middle lobe lobectomy was performed, revealing a 4.9 × 1.9 cm-sized mass that protruded into the bronchus. Microscopically, the tumor showed numerous cysts lined by micropapillary projections. The tumor cells had round and vesicular nuclei with prominent nucleoli, and mitosis was frequent. A limited portion of the tumor consisted of benign mixed papilloma. The tumor showed diffuse immunoreactivity for thyroid transcription factor-1 and strong expression of p16. We investigated the mutational status of cancer-related genes using targeted next-generation sequencing and identified a genetic alteration in the gene. This is the first case report of papillary cystic carcinoma arising in mixed papilloma of the lung.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1066896920908330DOI Listing
September 2020

Right-Angled Traction Bronchiectasis in Differentiating Idiopathic Pulmonary Fibrosis Without Honeycombing From Idiopathic Nonspecific Interstitial Pneumonia.

Invest Radiol 2020 06;55(6):387-395

Department of Radiology, Korea University Ansan Hospital, Gyeonggi-do.

Objectives: The aim of this study was to conduct a radiopathologic evaluation of right-angled traction bronchiectasis to differentiate idiopathic pulmonary fibrosis (IPF) without honeycombing from idiopathic nonspecific interstitial pneumonia (NSIP).

Materials And Methods: The derivation cohort included 78 consecutive patients with idiopathic NSIP (n = 39) or IPF (n = 39) without honeycombing who underwent preoperative thin-section computed tomography scans at a single tertiary hospital. The validation cohort comprised 22 patients (14 IPF and 8 NSIP) from another institution. We assessed conventional computed tomography findings, right-angled traction bronchiectasis on minimum intensity projection (MinIP) images, and pathologic features associated with right-angled bronchiectasis. Right-angled traction bronchiectasis was defined as abrupt kinking of a single bronchus by over 90 degrees or an abrupt angle close to 180 degrees of branching bronchi in the background of fibrosis. In the validation cohort, we evaluated the proportion of correct IPF diagnoses and interobserver agreement of 4 radiologists before and after reviewing MinIP images.

Results: A probable usual interstitial pneumonia (UIP) pattern (odds ratio [OR], 6.948; 95% confidence interval [CI], 1.525-31.654; P = 0.012) and right-angled traction bronchiectasis (OR, 6.004; 95% CI, 1.980-18.209; P = 0.002) were independently associated with IPF. Patients with right-angled traction bronchiectasis were more likely to have extensive reticular opacity (OR, 1.149; 95% CI, 1.077-1.225; P < 0.001) and pathologically were more likely to have a broad extent of subpleural fibrosis (OR, 4.000; 95% CI, 1.457-10.987; P = 0.007) and relatively thick fibrosis (OR, 7.750; 95% CI, 2.504-23.991; P < 0.001). After reviewing MinIP images, the proportion of correct diagnoses increased from 40.9% to 54.5% to 50.0% to 77.3%. The mean kappa value for right-angled traction bronchiectasis was 0.489 ± 0.192.

Conclusions: Right-angled traction bronchiectasis pathologically reflected a subpleural predominance of fibrosis and partly supported the radiologic differentiation of IPF without honeycombing from idiopathic NSIP.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/RLI.0000000000000651DOI Listing
June 2020

Relative Regional Air Volume Change Maps at the Acinar Scale Reflect Variable Ventilation in Low Lung Attenuation of COPD patients.

Acad Radiol 2020 11 3;27(11):1540-1548. Epub 2020 Feb 3.

Departments of Radiology, Medicine and Biomedical Engineering, University of Iowa, Iowa City, Iowa; Department of Radiology, College of Medicine, University of Iowa, Iowa City, Iowa; Department of Radiology, Seoul National University Hospital, Seoul, South Korea; Department of Radiology, Seoul National University College of Medicine, Institute of Radiation Medicine, Seoul, South Korea. Electronic address:

Objectives: The purpose of this study was to investigate regional air volume changes at the acinar scale of the lung in chronic obstructive pulmonary disease (COPD) patients using an image registration technique.

Materials And Methods: Thirty-four emphysema patients and 24 subjects with normal chest CT and pulmonary function test (PFT) results were included in this retrospective study for which informed consent was waived by the institutional review board. After lung segmentation, a mass-preserving image registration technique was used to compute relative regional air volume changes (RRAVCs) between inspiration and expiration CT scans. After determining the appropriate thresholds of RRAVCs for low ventilation areas (LVAs), they were displayed and analyzed using color maps on the background inspiration CT image, and compared with the low attenuation area (LAA) map. Correlations between quantitative CT parameters and PFTs were assessed using Pearson's correlation test, and parameters were compared between emphysema and normal-CT patients using the Student's t-test.

Results: LVA percentage with an RRAVC threshold of 0.5 (%LVA) showed the strongest correlations with FEV/FVC (r = -0.566), FEV (r = -0.534), %LAA (r = 0.712), and %LAA (r = 0.775). %LVA was significantly higher (P < 0.001) in COPD patients than normal subjects. Despite the identical appearance of emphysematous lesions on the LAA map, the RRAVC map depicted a wide range of ventilation differences between these LAA clusters.

Conclusion: RRAVC-based %LVA correlated well with FEV/FVC, FEV, %LAA and %LAA. RRAVC holds the potential for providing additional acinar scale functional information for emphysematous LAAs in inspiratory CT images, providing the basis for a novel set for emphysematous phenotypes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.acra.2019.12.004DOI Listing
November 2020

Non-diagnostic Results of Percutaneous Transthoracic Needle Biopsy: A Meta-analysis.

Sci Rep 2019 08 27;9(1):12428. Epub 2019 Aug 27.

Department of Radiology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.

Non-diagnostic results can affect the diagnostic performance of percutaneous transthoracic needle biopsy (PTNB) but have not been critically meta-analyzed yet. To meta-analyze the incidence and malignancy rate of non-diagnostic results, 3-by-2 table approaches rather than the conventional 2-by-2 approaches are needed to know its impact on the diagnostic performance of PTNB. A systematic literature search identified studies evaluating the diagnostic performance of PTNB with extractable outcomes. A total of 143 studies with 35,059 biopsies were included. The pooled incidence of non-diagnostic results was 6.8% (95% CI, 6.0-7.6%; I = 0.91). The pooled malignancy rate of non-diagnostic results was 59.3% (95% CI, 51.7-66.8%; I = 0.80), and was correlated with the prevalence of malignancy (correlation coefficient, 0.66; 95% CI, 0.42-0.91). Pooled percentage decrease of sensitivity and specificity due to non-diagnostic results were 4.5% (95% CI, 3.2-5.7%; I = 0.64) and 10.7% (95% CI, 7.7-13.7%; I = 0.70), respectively, and the pooled incidence of non-diagnostic results was 4.4% (95% CI, 3.2-5.8%; I = 0.83) in lesions ultimately diagnosed as malignancies and 10.4% (95% CI, 7.5-13.8%; I = 0.74) in benign disease. In conclusion, non-diagnostic results averagely occurred in 6.8% of PTNB and more than half of the results were malignancies. The non-diagnostic results decreased specificity and sensitivity by 10.7% and 4.5%, respectively, demanding efforts to minimize the non-diagnostic results in PTNB.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-019-48805-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6711972PMC
August 2019

Structural and Functional Features on Quantitative Chest Computed Tomography in the Korean Asian versus the White American Healthy Non-Smokers.

Korean J Radiol 2019 07;20(7):1236-1245

School of Mechanical Engineering, Kyungpook National University, Daegu, Korea.

Objective: Considering the different prevalence rates of diseases such as asthma and chronic obstructive pulmonary disease in Asians relative to other races, Koreans may have unique airway structure and lung function. This study aimed to investigate unique features of airway structure and lung function based on quantitative computed tomography (QCT)-imaging metrics in the Korean Asian population (Koreans) as compared with the White American population (Whites).

Materials And Methods: QCT data of healthy non-smokers (223 Koreans vs. 70 Whites) were collected, including QCT structural variables of wall thickness (WT) and hydraulic diameter (D) and functional variables of air volume, total air volume change in the lung (ΔV), percent emphysema-like lung (Emph%), and percent functional small airway disease-like lung (fSAD%). Mann-Whitney U tests were performed to compare the two groups.

Results: As compared with Whites, Koreans had smaller volume at inspiration, ΔV between inspiration and expiration ( < 0.001), and Emph% at inspiration ( < 0.001). Especially, Korean females had a decrease of ΔV in the lower lobes ( < 0.001), associated with fSAD% at the lower lobes ( < 0.05). In addition, Koreans had smaller D and WT of the trachea (both, < 0.05), correlated with the forced expiratory volume in 1 second (R = 0.49, 0.39; all < 0.001) and forced vital capacity (R = 0.55, 0.45; all < 0.001).

Conclusion: Koreans had unique features of airway structure and lung function as compared with Whites, and the difference was clearer in female individuals. Discriminating structural and functional features between Koreans and Whites enables exploration of inter-racial differences of pulmonary disease in terms of severity, distribution, and phenotype.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3348/kjr.2019.0083DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6609438PMC
July 2019

Effect of CT Acquisition Parameters on Iodine Density Measurement at Dual-Layer Spectral CT.

AJR Am J Roentgenol 2018 10 7;211(4):748-754. Epub 2018 Aug 7.

1 Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Korea.

Objective: We aimed to evaluate the effect of tube voltage, tube current-time product, and iterative reconstruction on iodine quantification using a dual-layer spectral CT scanner.

Materials And Methods: Two mediastinal iodine phantoms, each containing six tubes of different iodine concentrations (0, 1, 2.5, 5, 10, and 20 mg I/mL; the two phantoms had tubes with contrast media diluted in water and in 10% amino acid solution, respectively), were inserted into an anthropomorphic chest phantom and scanned with varying acquisition parameters (120 and 140 kVp; 20, 40, 60, 80, 100, 150, and 200 mAs; and spectral reconstruction levels 0 and 6). Thereafter, iodine density was measured (in milligrams of iodine per milliliter) using a dedicated software program, and the effect of acquisition parameters on iodine density and on its relative measurement error (RME) was analyzed using a linear mixed-effects model.

Results: Tube voltages (all, p < 0.001) and tube current-time products (p < 0.05, depending on the interaction terms for iodine density; p = 0.023 for RME) had statistically significant effects on iodine density and RME. However, the magnitude of their effects was minimal. That is, estimated differences between tube voltage settings ranged from 0 to 0.8 mg I/mL for iodine density and from 1.0% to 4.2% for RME. For tube current-time product, alteration of 100 mAs caused changes in iodine density and RME of approximately 0.1 mg I/mL and 0.6%, respectively. Spectral level was not an affecting factor for iodine quantification (p = 0.647 for iodine density and 0.813 for RME).

Conclusion: Iodine quantification using dual-layer spectral CT was feasible irrespective of CT acquisition parameters because their effects on iodine density and RME were minimal.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2214/AJR.17.19381DOI Listing
October 2018

Bronchial Impaction of Arterial Coil.

Am J Respir Crit Care Med 2018 06;197(11):1481-1482

1 Department of Internal Medicine.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1164/rccm.201708-1582IMDOI Listing
June 2018

The Potential Role of Grid-Like Software in Bedside Chest Radiography in Improving Image Quality and Dose Reduction: An Observer Preference Study.

Korean J Radiol 2018 May-Jun;19(3):526-533. Epub 2018 Apr 6.

Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 03080, Korea.

Objective: To compare the observer preference of image quality and radiation dose between non-grid, grid-like, and grid images.

Materials And Methods: Each of the 38 patients underwent bedside chest radiography with and without a grid. A grid-like image was generated from a non-grid image using SimGrid software (Samsung Electronics Co. Ltd.) employing deep-learning-based scatter correction technology. Two readers recorded the preference for 10 anatomic landmarks and the overall appearance on a five-point scale for a pair of non-grid and grid-like images, and a pair of grid-like and grid images, respectively, which were randomly presented. The dose area product (DAP) was also recorded. Wilcoxon's rank sum test was used to assess the significance of preference.

Results: Both readers preferred grid-like images to non-grid images significantly ( < 0.001); with a significant difference in terms of the preference for grid images to grid-like images ( = 0.317, 0.034, respectively). In terms of anatomic landmarks, both readers preferred grid-like images to non-grid images ( < 0.05). No significant differences existed between grid-like and grid images except for the preference for grid images in proximal airways by two readers, and in retrocardiac lung and thoracic spine by one reader. The median DAP were 1.48 (range, 1.37-2.17) dGycm in grid images and 1.22 (range, 1.11-1.78) dGycm in grid-like images with a significant difference ( < 0.001).

Conclusion: The SimGrid software significantly improved the image quality of non-grid images to a level comparable to that of grid images with a relatively lower level of radiation exposure.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3348/kjr.2018.19.3.526DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5904480PMC
February 2019

Erratum: Application of Deconvolution Algorithm of Point Spread Function in Improving Image Quality: An Observer Preference Study on Chest Radiography.

Korean J Radiol 2018 Mar-Apr;19(2):368. Epub 2018 Feb 22.

Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 03080, Korea.

[This corrects the article on p. 147 in vol. 19, PMID: 29354011.].
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3348/kjr.2018.19.2.368DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5840068PMC
February 2018

Improving the prediction of lung adenocarcinoma invasive component on CT: Value of a vessel removal algorithm during software segmentation of subsolid nodules.

Eur J Radiol 2018 Mar 31;100:58-65. Epub 2018 Jan 31.

Department of Software Convergence, Seoul Women's University, Seoul, Republic of Korea.

Purpose: To evaluate the value of a vessel removal algorithm in segmentation of subsolid nodules by comparing the software solid component measurement on CT, before and after vessel removal, with the measurement of the invasive component on pathology in lung adenocarcinomas manifesting as subsolid nodules.

Materials And Methods: Between January 2014 and June 2015, 73 subsolid nodules with an invasive component of ≤10 mm on pathology were selected for analyses. For each nodule, semi-automated segmentation was performed by 2 radiologists and 3-dimensional (D) longest, axial longest and effective diameters of solid component were obtained from software, before and after using a vessel removal tool. These measurements were compared with the invasive component diameter on pathology using the paired t-test and Pearson's correlation test.

Results: Sixty-eight successfully segmented subsolid nodules were included. The mean maximal diameter of the invasive component on pathology was 4.6 mm (range, 0-10 mm). The correlation between software and pathology measurements was significant (p < 0.01) and the correlation after vessel removal (r = 0.49-0.54) was better than before vessel removal (r = 0.27-0.41). The mean measurement difference between solid component on CT and invasive tumor on pathology was significantly larger before vessel removal than after vessel removal in all measurements. The smallest mean measurement difference was obtained with 3D longest diameter of solid component after vessel removal in both readers (-0.26 mm to 0.10 mm), with no significant difference from pathology (p = 0.53-0.83).

Conclusion: By adding a vessel removal algorithm in software segmentation of subsolid nodules, the prediction of invasive component in lung adenocarcinomas can be improved.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejrad.2018.01.016DOI Listing
March 2018

Application of Deconvolution Algorithm of Point Spread Function in Improving Image Quality: An Observer Preference Study on Chest Radiography.

Korean J Radiol 2018 Jan-Feb;19(1):147-152. Epub 2018 Jan 2.

Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 03080, Korea.

Objective: To evaluate the preference of observers for image quality of chest radiography using the deconvolution algorithm of point spread function (PSF) (TRUVIEW ART algorithm, DRTECH Corp.) compared with that of original chest radiography for visualization of anatomic regions of the chest.

Materials And Methods: Prospectively enrolled 50 pairs of posteroanterior chest radiographs collected with standard protocol and with additional TRUVIEW ART algorithm were compared by four chest radiologists. This algorithm corrects scattered signals generated by a scintillator. Readers independently evaluated the visibility of 10 anatomical regions and overall image quality with a 5-point scale of preference. The significance of the differences in reader's preference was tested with a Wilcoxon's signed rank test.

Results: All four readers preferred the images applied with the algorithm to those without algorithm for all 10 anatomical regions (mean, 3.6; range, 3.2-4.0; < 0.001) and for the overall image quality (mean, 3.8; range, 3.3-4.0; < 0.001). The most preferred anatomical regions were the azygoesophageal recess, thoracic spine, and unobscured lung.

Conclusion: The visibility of chest anatomical structures applied with the deconvolution algorithm of PSF was superior to the original chest radiography.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3348/kjr.2018.19.1.147DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5768495PMC
November 2018

Comparison of Iodine Density Measurement Among Dual-Energy Computed Tomography Scanners From 3 Vendors.

Invest Radiol 2018 06;53(6):321-327

Objectives: The aims of this study were to analyze the effect of dual-energy computed tomography (DECT) scanners and fluid characteristics on iodine quantification and to calculate the measurement variability range induced by those variables.

Methods: We performed an experimental phantom study with 4 mediastinal iodine phantoms. Each phantom contained 6 tubes of different iodine concentrations (0, 1.0, 2.5, 5.0, 10.0, and 20.0 mg/mL) diluted in a specific solvent, which was water, 10% amino acid solution, 20% lipid emulsion, or 18% calcium solution, respectively. Mediastinal phantoms were inserted into an anthropomorphic chest phantom and were scanned with 3 different DECT scanners from 3 vendors using 2 radiation dosage settings. Iodine density (IoD) and computed tomography (CT) attenuation at virtual monoenergetic 70-keV images and virtual nonenhanced images were measured for the iodine phantoms. The effects of DECT scanners, solvents, and radiation dosage on the absolute measurement error of IoD and on the CT attenuation profiles were investigated using linear mixed-effects models. Measurement variability range of IoD was also determined.

Results: Absolute error of IoD was not significantly affected by the DECT systems, kind of solvents, and radiation dosage settings. However, CT attenuation profiles were significantly different among the DECT vendors and simulated body fluids. Measurement variability range of IoD was from -0.6 to 0.4 mg/mL for the true iodine concentration 0 mg/mL.

Conclusions: Dual-energy CT systems and fluid characteristics did not have a significant effect on the IoD measurement accuracy. A cutoff of IoD for the determination of a truly enhancing lesion on DECT would be 0.4 mg/mL.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/RLI.0000000000000446DOI Listing
June 2018

Repeat biopsy of patients with acquired resistance to EGFR TKIs: implications of biopsy-related factors on T790M mutation detection.

Eur Radiol 2018 Feb 7;28(2):861-868. Epub 2017 Aug 7.

Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Centre, Seoul, Korea.

Objectives: To find predictors of non-diagnostic repeat biopsy specimen acquisition for mutational analysis and detection of epidermal growth factor receptor (EGFR) T790M mutation.

Methods: We retrospectively reviewed 90 non-small cell lung cancer patients harbouring EGFR mutations who underwent repeat cone-beam CT-guided transthoracic needle biopsy. Clinical characteristics as well as biopsy-related factors were compared between patients with and without diagnostic specimen acquisition and between patients with and without T790M mutation. After univariate analysis, multivariate logistic regression analysis was performed to reveal independent predictors.

Results: Diagnostic biopsy specimens for mutational test were obtained in 90% (81/90) of patients, of which 62% (50/81) possessed T790M mutation. None of the analysed variables were significantly associated with non-diagnostic specimen acquisition. For T790M detection, duration of EGFR tyrosine kinase inhibitor treatment (p = 0.066), duration of total chemotherapy (p = 0.026), tumour size (p = 0.066), and metastatic lung lesion as a biopsy target (p = 0.029) showed p values less than 0.10. Multivariate analysis revealed that target tumour size (odds ratio, 0.765; p = 0.031) was an independent predictor of T790M mutation. Metastatic lesions as biopsy targets (odds ratio, 4.194; p = 0.050) showed marginal statistical significance.

Conclusions: Non-diagnostic repeat biopsy specimen acquisition was not related to the clinical or technical factors. However, detection of T790M at repeat biopsy might be associated with smaller target tumour size and selection of metastatic lesions as biopsy targets.

Key Points: • Cone-beam CT-guided repeat biopsy yielded high diagnostic specimen acquisition rate. • Biopsy-related features were associated with the detection of T790M mutation. • Target tumour size was an independent predictor of the T790M detection. • Biopsy targeting metastatic lung nodules might help detect the T790M mutation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00330-017-5006-6DOI Listing
February 2018

Differentiating Smoking-Related Interstitial Fibrosis (SRIF) from Usual Interstitial Pneumonia (UIP) with Emphysema Using CT Features Based on Pathologically Proven Cases.

PLoS One 2016 9;11(9):e0162231. Epub 2016 Sep 9.

Department of Pathology, Chonbuk National University Medical School, Research Institute of Clinical Medicine, Jeonju, Jeonbuk, South Korea.

Objective: To differentiate smoking-related interstitial fibrosis (SRIF) from usual interstitial pneumonia (UIP) with emphysema on CT in combined pulmonary fibrosis and emphysema (CPFE) patients.

Materials And Methods: This study was approved by the institutional review board and informed consent was waived. We included 65 patients who underwent lung biopsy under the suspicion of UIP pattern on HRCT, and after radiologic-pathologic correlation, they were divided into three groups: UIP without emphysema (n = 30), UIP with emphysema (n = 26), and SRIF (n = 9). The quantitative extent of emphysema in the entire lung was visually assessed and fibrotic patterns were qualitatively analyzed based on six characteristics (asymmetry, juxta-subpleural sparing, emphysema beside the honeycombing area, absence of ground grass attenuation/reticulation in honeycombing area, inhomogeneous honeycombing, and absence of honeycombing in the upper lobes). Kaplan-Meier analysis was used for survival analysis, and logistic regression with a receiver operating characteristic curve was used to predict the possibility of SRIF.

Results: In qualitative analysis of fibrotic patterns, SRIF tended to exhibit more than three of six fibrotic features, whereas UIP with emphysema demonstrated about two of these characteristics (p = 0.035). In addition, SRIF had a higher extent of emphysema than UIP with emphysema when they have same amount of fibrosis (p = 0.014). In patients with SRIF, 5-year survival rate was 85.7%, while it was 40.7% in UIP with emphysema patients (p = 0.035).

Conclusion: Fibrotic CT patterns and survival rate differed between SRIF and UIP with emphysema among CPFE patients, which explains the variable prognosis of CPFE.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0162231PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5017577PMC
August 2017

Carpal Tunnel Syndrome and Motor Dysfunction Caused by Tophaceous Gout Infiltrating 12 Tendons.

J Clin Rheumatol 2016 Aug;22(5):272-3

From the Departments of *Plastic and Reconstructive Surgery and †Radiology, Chonbuk National University Medical School, Jeonju, Korea.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/RHU.0000000000000366DOI Listing
August 2016

Is Angiosome-Targeted Angioplasty Effective for Limb Salvage and Wound Healing in Diabetic Foot? : A Meta-Analysis.

PLoS One 2016 21;11(7):e0159523. Epub 2016 Jul 21.

Department of Plastic and Reconstructive Surgery, Chonbuk National University Hospital, Jeonju, Korea.

Purpose: Given that the efficacy of employing angiosome-targeted angioplasty in the treatment of diabetic foot remains controversial, this study was conducted to examine its efficacy.

Methods: We performed a systematic literature review and meta-analysis using core databases, extracting the treatment modality of angiosome-targeted angioplasty as the predictor variable, and limb salvage, wound healing, and revision rate as the outcome variables. We used the Newcastle-Ottawa Scale to assess the study quality, along with the Cochrane Risk of Bias Tool. We evaluated publication bias using a funnel plot.

Results: The search strategy identified 518 publications. After screening these, we selected four articles for review. The meta-analysis revealed that overall limb salvage and wound healing rates were significantly higher (Odds ratio = 2.209, 3.290, p = 0.001, p<0.001) in patients who received angiosome-targeted angioplasty than in those who received nonangiosome-targeted angioplasty. The revision rate between the angiosome and nonangiosome groups was not significantly different (Odds ratio = 0.747, p = 0.314).

Conclusion: Although a further randomized controlled trial is required for confirmation, angiosome-targeted angioplasty in diabetic foot was more effective than nonangiosome-targeted angioplasty with respect to wound healing and limb salvage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0159523PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4956043PMC
July 2017

Factors associated with abnormal pulmonary function test among subjects with normal chest radiography: The Korean National Health and Nutrition Examination Survey.

Respirology 2016 10 20;21(7):1330-2. Epub 2016 Jun 20.

Department of Preventive Medicine, Chonbuk National University Medical School, Jeonju, Korea.

Determinants of abnormal lung function among subjects with normal chest radiography have not been widely evaluated. We investigated 12 109 participants with normal chest radiographs from the Korean National Health and Nutrition Examination Survey. Factors associated with abnormal pulmonary function were male gender, age ≥50, smoking history and a clinical history of cough or sputum production. Pulmonary function tests should be considered in population-based screening, especially in men over 50 years old with a smoking history.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/resp.12833DOI Listing
October 2016

A Well-Differentiated Mediastinal Liposarcoma from the Posterior Mediastinum with Separated Solid and Lipomatous Regions: A Case Report.

Am J Med 2016 Jul 9;129(7):e71-2. Epub 2016 Feb 9.

Department of Radiology, Chonbuk National University Medical School and Hospital, Institute of Medical Science, Research Institute of Clinical Medicine, Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Jeonbuk, South Korea; Department of Pathology, Chonbuk National University Medical School and Hospital, Institute of Medical Science, Research Institute of Clinical Medicine, Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Jeonbuk, South Korea.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.amjmed.2016.01.028DOI Listing
July 2016