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SE 04 CH-01 Lung cancer associated with cystic air spaces: multimodality imaging findings and follow-up and its differential diagnosisSangjoon Lee, Youkyung Lee, Choong-Ki Park Hanyang University Guri Hospital, Korea. youkyunglee@hanyang.ac.kr

PURPOSE: Lung cancer can present unevenly thickened wall of cystic air space. Lung cancer associated with cystic air spaces is one of causes of missed lung cancer. The purpose of this exhibit is to present CT and FDG PET findings of lung cancers associated with cystic air spaces and their follow-up imaging findings. And to differentiate lung cancers associated with cystic air spaces from benign disease associated with cystic air spaces, and cavitary lung cancer.CONTENTS: Definition of lung cancers associated with cystic air spaces is lung cancers that abut or are in the wall of cystic airspaces identified at CT, regardless of the pathologic findings and irrespective of the presence of the emphysema elsewhere in the lung. There are 4 type morphologic classifications of lung cancer associated with cystic air spaces. Illustration of teaching points includes cases with their previous or follow-up CT and FDG-PET finding. The cases are lung cancer associated with pre-existing bullous or honeycombing lesion, cystic lung cancer, and benign lesion mimicking lung cancers associated with cystic air spaces.CONCLUSION: Lung cancer associated with cystic air space could be a pitfall in interpretation of chest CT. Continued increasing wall thickening of a cystic air space, appearance or increase of nodule or mass abutting a cystic air space should raise suspicion of lung cancer. Nonetheless, benign diseases can mimic a lung cancer associated with cystic air space. Short term CT follow-up or tissue sampling is recommended.

SE 04 CH-02 Using different contrast gradient patterns to recognize underlying pathology in the chest: why only giving contrast just isn't enough? Michael Coords1, Bernheim Adam2, Nicolette Corrao1, Nikhil Goyal3 1Staten Island University Hospital - Northwell Health, 2Emory University, 3Staten Island University Hospital - Northwell Health System, USA. nikmeister98@hotmail.com

Differential contrast opacification of the heart and great vessels can be seen on routine chest and cardiac CT and varies according to injection rate, heart rate, scanner type, and scan delay. In addition to delineating anatomy, contrast gradient patterns can reveal information about flow related to underlying pathology. Knowledge of differential flow patterns of contrast can help reveal entities such as: shunts (ASD, VSD, PDA, unroofed coronary sinus), patent foramen ovale, left/duplicated SVC, Glenn and Fontan circulation and SVC occlusion. We review the differential flow patterns associated with these entities. It is important for thoracic and cardiovascular radiologists to familiarize themselves with different contrast gradient patterns to recognize underlying pathology.

SE 04 CH-03 Chest CT findings of Birt-Hogg-Dubé syndrome: a pictorial reviewJung eun Lee, Yoon Ki Cha, Jeung Sook Kim Dongguk University Ilsan Hospital, Korea. sublime256@naver.com

Birt-Hogg-Dubé (BHD) syndrome is a rare autosomal dominant multiorgan systemic disorder manifesting as cutaneous fibrofolliculomas, renal tumors, and pulmonary cysts with spontaneous pneumothorax. When spontaneous pneumothorax and lung cysts are encountered on chest CT, it is necessary for radiologists to consider BHD syndrome as one of the causes of these findings, because spontaneous pneumothorax may be the initial clinical manifestation of this disease entity and lung cysts may be found incidentally in patients undergoing cancer staging evaluations for a renal mass.In this exhibit, we review BHD syndrome and present the characteristic chest CT findings of the patients with confirmed cases including familial cases. Number, shape, size and distribution of the lung cysts can help differentiate BHD syndrome from other diffuse cystic lung diseases. Being aware of the chest CT findings of BHD syndrome may lead to correct diagnosis and

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appropriate management.

SE 04 CH-04 Fungal diseases of the lungJin-sol Choi, Mi-sook Lee, Jin-ok Choi, In-sup Song, Young-jun Kim, Hui-jun Kim Presbyterian Medical Center, Korea. ms0928l@nate.com

BACKGROUND: The fungal infection is rare but common in immunocompromised patients. Depending on a patient's immune status, there are various clinical and radiologic findings.PURPOSE: To know classification and CT features of fungal diseases in the lung.CONTENTS: We reviewed and analyzed the fungal lung diseases confirmed by operation and biopsy.1. Aspergillosis2. Cryptococcosis3. Mucomycosis4. Actinomycosis5. Pneumocystis jiroveci pneumonia6. CandidiasisTEACHING POINTS: To know the CT features of fungal diseases in the lung for differential diagnosis.

SE 04 CH-05 The evolution of viruses: can we identify emerging viral pneumonia?Hyun Jung Koo, Kyung-Hyun Do, Sang Ho Choi Asan Medical Center, Korea. dokh@amc.seoul.kr

PURPOSE: 1. To review the new members of viruses which have

raised concerns with outbreak of viral pneumonia, including severe acute respiratory syndrome coronavirus (SARS-CoV) or Middle East respiratory syndrome corona virus (MERS-CoV) epidemic and influenza A (H1N1) pandemic

2. To identify characteristic patterns of viral pneumonias depending on the pathogens using CT

3. To learn the clinical characteristics such as age, immune status, seasonal variation, and community outbreaks periods which are also important factors in diagnosis

TABLE OF CONTENTS: Introduction

- Microbiologic evaluation methods- Viral pneumonias in patients who requiring

intensive care unit admissionVarious viral pneumonias

1. Influenza viruses- Influenza A (H1N1)- Avian influenza A (H7N9)- Influenza B

2. Human metapneumovirus3. Coronavirus

- Severe acute respiratory syndorme (SARS)-CoV- Middle east respiratory syndrome (MERS)-CoV

4. Adenovirus5. Respiratory syncytial virus6. Enterovirus7. Herpes simplex virus8. Papilloma virus9. Varicella-zoster virus

10. Cytomegalovirus11. Epstein-Barr virus12. Hantavirus

SE 04 CH-06 Thoracic fungal infection revisited: a variety of CT findings and the mimickersHyun Jung Koo, Mi Young Kim, Sung Han Kim Asan Medical Center, Korea. mimowdr@gmail.com

PURPOSE: 1. To learn the clinical characteristics including patients'

immune status, transplantation or hematologic malignancy conditions and the risk of thoracic fungal infection.

2. To demonstrate suggestive CT findings of thoracic fungal infections using various cases such as aspergillus, candida, or mucormycosis infections focusing on the specific CT signs.

3. To find differential points by comparing other pathogen which could mimic fungal infection.

TABLE OF CONTENTS: 1. Introduction

- Immunity and fungal infection- The role of chest CT to diagnose fungal infection

2. Opportunistic infection1) Aspergillus

- Aspergilloma- Allergic bronchopulmonary aspergillosis- Semi-invasive aspergillosis- Airway invasive aspergillosis- Angioinvasive aspergillosis

2) Candida3) Cryptococcus: focal vs. disseminated4) Zygomycetes including Mucormycosis5) Pneumocystis jirovecii

3. Mimickers- Invasive pulmonary aspergil losis-mimicking

tuberculosis

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SE 04 CH-07 Glossary of Korean medical terms for thoracic radiology: recommendations of the Korean Society of Thoracic RadiologyEun-Young Kang1, Mi Young Kim2, Yookyung Kim3, Yun Hyun Kim4, Chang Hyun Lee5, Kyung Neo Jeon6, Jeong Hwa Hwang7, Mi-Jin Kang8, Hongseok Ko9, Jin Hwan Kim10, Hye Young Kim11, Jae Woo Song2, Go Eun Yang12, Jae Wook Lee1, Jeong Geun Yi13, Jin Seong Lee2, Hye-Jeong Lee14, Hyoun Cho15, Sun Young Jeong16, Gong Yong Jin17, Soo-Youn Ham18 1Korea University Guro Hospital, 2Asan Medical Center, 3Ewha Womans University Mokdong Hospital, 4Chonnam National University Hospital, 5Seoul National University Hospital, 6Gyeongsang National University Hospital, 7Soonchunhyang University Hospital (Seoul), 8Inje University Sanggye Paik Hospital, 9Seoul Metropolitan Dongbu Hospital 10Chungnam National University Hospital, 11National Cancer Center, 12Hallym University College of Medicine, 13Konkuk University Medical Center, 14Severance Hospital, 15SMG-SNU Boramae Medical Center, 16Jeju National University Hospital, 17Chonbuk National University Hospital, 18Korea University Anam Hospital, Korea. keyrad@korea.ac.kr

PURPOSE: Korean medical terms are not always feasible to use, even for Korean medical doctors. Korean medical terms for thoracic radiology suggested by the Korean Academy of Medical Sciences and the Korean Society of Radiology are sometimes inappropriate in clinical practice. For considering clinical and academic needs, the Korean Society of Thoracic Radiology (KSTR) has a fundamental mission to propose uniform, standardized, and optimal Korean medical terms for thoracic radiology. The purpose of this study is to create a Glossary of Korean Medical Terms for Thoracic Radiology which is of optimal use for Korean radiologists as well as Korean medical doctors, medical students, and all health-care workers.MATERIALS AND METHODS: KSTR made an issue entitled “Glossary of Korean Medical Terms for Thoracic Radiology” as a 2016 project. Twenty-one KSTR members participate in this project. A committee for terminology of thoracic radiology (CTTR) was formed and included seven members. Medical terms of thoracic radiology were selected by considering frequency of use in clinical practice, doctor’s examinations and researches in the field of thoracic radiology. These terms were then divided into two groups as anatomic and pathologic terms, and radiologic technical and descriptive terms. CTTR selected medical terms for thoracic radiology. All 21 members directly participated in the translating medical terms to Korean, defining the medical terms, and selecting appropriate radiologic

images represent ing the terms. CTTR and i ts participants reviewed the validity of the Glossary of Korean Medical Terms for Thoracic RadiologyRESULTS: The Glossary of Korean Medical Terms for Thoracic Radiology includes 177 medical terms. All of the medical terms are described in the regular order of English terms, corresponding Korean terms, definition of terms in Korean, appropriate radiologic images and the figure legends in Korean. The Glossary suggests appropriate Korean medical terms and optimal radiologic images, corresponding to radiologic descriptive terms.CONCLUSION: We hope that this Glossary of Korean Medical Terms for Thoracic Radiology could provide a guiding and will be helpful for Korean radiologists as well as Korean medical doctors, medical students, and all health-care workers. We are also pleased to invite readers to offer improvements to this Glossary of Terms in the next version.

SE 04 CH-08 Pulmonary tuberculosis: CT findings of active diseaseKhulan Khurelsukh, Sarnaitsetseg Munkhbat, Ononchimeg Buriad, Duisenbi Zaya, Delgerekh Sainjargal Intermed Hospital, Mongolia. h_ashka@yahoo.com

PURPOSE: Typical CT findings of active pulmonary tuberculosis include centrilobular nodules and branching linear structures (tree-in-bud appearance), lobular consolidation and cavitation. The typical appearance of primary tuberculosis on CT scan is homogeneous, dense, well-defined segmental or lobar consolidation with enlargement of lymph nodes in the hilum or in the mediastinum. Miliary nodules may be seen in primary and postprimary tuberculosis. Atypical radiologic manifestations of tuberculosis are single or multiple nodules or masses, lower lobe consolidations, miliary tuberculosis with diffuse bilateral areas of ground-glass opacity. To assess the findings of active pulmonary tuberculosis on computed tomographic (CT) scans and to evaluate their possible use in determining disease activity.MATERIALS AND METHODS: Forty-seven patients diagnosed pulmonary tuberculosis were included in this study. The diagnosis of active pulmonary tuberculosis was based on positive acid-fast bacilli in sputum and changes on chest CTs. Mean age was 38 years old (1-81 years old).RESULTS: In CT images, centrilobular lesions (nodules or branching linear structures 2-4 mm in diameter) were most commonly seen (n = 29 [61.7%]). Moreover, lobular consolidation was in 24 (51%), cavitation was

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in 19 (40.4%) cases. Two patients had significant lung destructive changes, resulting one death 5-months after CT scan. Two patients had miliary pattern and had indolent clinical symptom. Ten patients had pleural effusion (10 [21.2%]).CONCLUSION: Centrilobular densities around the small airways (tree-in-bud appearance), consolidation and cavitation were the most characteristic CT features of active tuberculosis and could be a reliable criterion for disease activity.

SE 04 CH-09 Diverse and unique features of non-tuberculous mycobacterial infection: thoracic and extrathoracic involvementJae Chun Park, Hee Kang, Bum Sang Cho, Sam Yun Kosin University Gospel Hospital, Korea. soinvain@naver.com

Non-tuberculous mycobacteria (NTM) are ubiquitous organisms in soi l , dust and water. They cause chronic infection mostly in the lung with common and well-recognized patterns including cavitary and bronchiectatic form. Rapid growing mycobacteria may cause disseminated disease including extrathoracic involvement; lymphadenitis, skin and soft tissue infections in immunocompromised patients. NTM infections are difficult to diagnosis and indolent in course with an initial misdiagnosis causing a delay in treatment. We’d like to review the etiology, microbiology, clinical characteristic and propose the radiological findings of various NTM infections with thoracic and extrathoracic involvement.

SE 04 CH-10 Myths and facts: truth of widely accepted misleading concepts in chest radiologyMyeong Im Ahn, Jimin Yoon, Seog Hee Park The Catholic University of Korea, Seoul St. Mary's Hospital, Korea. ami@catholic.ac.kr

Although radiologists, as medical professionals, are well aware of the danger of relying on the thesis without critical thinking, we occasionally encounter ourselves following myths that are conventionally thought to be truth even without sufficient evidence. As John F. Kennedy once stated “The great enemy of the truth is very often not the lie, deliberate, contrived and dishonest, but the myth, persistent, persuasive and unrealistic,” it may be important for us to verify whether the old beliefs are scientifically correct at this time.

Therefore, in here, we tried to bring the truth beyond the following 10 myths among radiologists to light, by reviewing literatures: 1) Galaxy sign in pulmonary tuberculosis represents bronchiolar lesions; 2) Presence of honeycombing can be easily identified at chest CT; 3) Subsolid nodules are reliably differentiated from solid nodules on thin-section CT scans; 4) Two-year stability of pulmonary nodule means benignity; 5) Major fissure is not visible in chest PA; 6) Chest PA should routinely be obtained before surgery; 7) Rib series is the initial imaging test in patients with suspicious rib fractures, 8) Small pericardial effusions typically lie posterior to the left ventricle; 9) Regression of pulmonary nodules or masses means benignity, and 10) Obscuration of left hemidiaphragm means consolidation or pleural effusion.

SE 04 CH-11 Radiologic assessment of the aging chest: normal aging changes versus clinical significancesEun-Young Kang1, Jae Wook Lee1, Hwan Seok Yong1, Ki Yeol Lee2, Yu-Whan Oh3 1Korea University Guro Hospital, 2Korea University Ansan Hospital, 3Korea University Anam Hospital, Korea. keyrad@korea.ac.kr

PURPOSE: Radiologic examinations are performed on the elderly more frequently due to progressive increase in life expectancy. Structural and functional changes occur in the thorax involving lung parenchyma, airways, mediastinum, chest wall, and diaphragm with advancing age. For accurate interpretation of the chest radiographs and CT, distinguishing physiological and pathological changes is important. The purposes of this exhibit are to review age-related changes and to differentiate between normal structural changes related to the aging process and pathological findings in elderly chest radiologic images.TABLE OF CONTENTS/OUTLINE: Which radiologic changes of the chest occur in the elderly?

- Changes in the lung with age- Changes in the airways with age- Changes in the mediastinum with age- Changes in the chest wall with age- Changes in the diaphragm with age

How to discriminate between normal age-related structural changes and pathologic findings in elderly chest radiologic images?

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SE 04 CH-12 Utilization of the 7th edition of the tumor node metastasis (TNM) system and stage for lung cancer in the MongoliaTsevelmaa Dorj, Munkhbaatar Dagvasumberel Mongolian National University of Medical Sciences, Mongolia. dr.tsevelmaa@gmail.com

PURPOSE: Lung cancer is the leading cause of cancer related deaths in the Mongolia, with a 5 survival rate of only 2, 7% due to lung screening is still not investigated for high risk. The TNM classification system for lung cancer is an essential guide for determining appropriate treatment and prognosis. The objective of the study was to evaluate staging for lung cancer by the 7th edition of the tumor node metastasis (TNM) system in the single private hospital.MATERIALS AND METHODS: The study included 21 patients with a new diagnosis of lung cancer undergoing contrast enhancement computed tomography in the single private hospital. TNM and stage grouping were collected separately and followed UICC 7 th edition guidelines.RESULTS: The study was performed with 21 cases; 61.9% of whom were men and 38.1% were women. The mean age was 58.4 (27-74). According to study the incidence of IV staging was 8 (38.1%) case; IIIa was 14.2%; IIIb was 4.7%; IIa was 14.2%; IIb was 19.0%; Ib was 9,5%. M1a includes malignant pleural effusion with median overall survival of 8 months in 1 (4.7%) patient. M1b refers to extra-thoracic metastases and median overall survival was 6 months (n = 7).CONCLUSION: TNM and stage grouping data by the CECT is feasible and usability.

SE 04 CH-13 Pulmonary conditions of underlying pneumatosis intestinalisDa-hoon Kim, Sung Shine Shim, Yookyung Kim Ewha Womans University Mokdong Hospital, Korea. sinisim@ewha.ac.kr

PURPOSE: To determine the clinical features, imaging findings and possible causes of pneumatosis intestinalis (PI) that developed in thoracic disorder patients.MATERIALS AND METHODS: From March 2005 to March 2016, four (6%) of 62 pneumatosis intestinalis patients who developed PI related with thoracic disease were identified. Medical records were reviewed to determine the clinical presentation, laboratory findings and treatment at the time of presentation of PI. Common factors that might explain the cause of the PI with

thoracic disease were discussed. Two experienced chest radiologists reviewed all imaging studies and recorded the specific findings for each patient.RESULTS: All four patients had only symptoms related with thoracic disease including severe dyspnea, cough and sputum without systemic or intestinal disease. Severe dyspnea was the only common symptoms for all four patients and causative thoracic disease for each patient was severe asthma (n = 1) (Fig. 1), pneumonia (n = 2) (Fig. 2) and obstructive lung cancer (n = 1) (Fig. 3). No definite cause except simultaneously developed thoracic disease for the PI could be determined in these patients. The imaging findings of abdomen were similar in three of the patients except one (lung cancer) with the PI dominated by a linear appearance involving mainly the ascending colon (Figs. 1, 2). The one patient with lung cancer showed cystic appearance in distal transverse and descending colon (Fig. 3). One of the four patients with PI had pneumoperitoneum.CONCLUSION: Thoracic disease with severe dyspnea may develop benign PI. Benign PI in thoracic disease patients has a similar and specific linear and cystic appearance and is not due to ischemic bowel.

Fig. 1. Pneumatosis intestinalis in 43-year-old woman with severe asthma.

Fig. 2. Pneumatosis intestinalis in 71-year-old man with choking by food material and aspiration pneumonia.

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Fig. 3. Pneumatosis intestinalis in 79 year old man with lung cancer in left upper lobe.

SE 04 CH-14 Diagnostic confidence and complications of CT-guided core needle lung biopsy in solid and part-solid lesionsHee Kang, Bum Sang Cho, Sam Yun, Jae Chun Park Kosin University Gospel Hospital, Korea. soinvain@naver.com

PURPOSE: To evaluate whether the diagnostic confidence and complications of CT-guided core needle biopsy are different between solid and part-solid lung lesions.MATERIALS AND METHODS: This retrospective study included 319 consecutive patients underwent CT-guided core needle biopsy of lung lesions by a radiologist from April 2012 to March 2016. The demographics of patients, the lung lesion characteristics of solid or part-solid, underlying pulmonary disease; emphysema or fibrosis, distance of path, procedure time, complications; hemorrhage or pneumothorax, histopathological results of biopsy-specimens and final diagnoses were reviewed. The part-solid lesions were classified into two groups according to the percentage of the ground-glass opacity (GGO) area (≥ 50% and < 50%). The false diagnosis, procedure time and occurrence of complications in solid lesions were compared to part-solid lesions. And they were also compared between the two part-solid lesion groups. The factors related to the false diagnosis and complications were analyzed.RESULTS: Overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of CT-guided core needle biopsy for

diagnosing malignancy were 81.8%, 78.6%, 91.1%, 61.7% and 80.9%. There were 249 true diagnoses and 70 false diagnoses of all biopsies consisted of 268 solid lesions and 51 part-solid lesions. There was no significant difference of false diagnosis, procedure time and occurrence of pneumothorax between solid and part-solid lesions. NPV in part-solid lesion was 30.8% significantly lower than 66% in solid lesions (p = 0.01). Occurrence of hemorrhage was higher in patients with part-solid lesion (p = 0.028). The false diagnosis and occurrence of complications were not significantly different between the two part-solid lesion groups (12 lesions with ≥ 50% and 39 lesions with < 50% of GGO area). The procedure time in false diagnosis group was longer than true diagnosis group (p = 0.025). The factors related to the hemorrhage were patients’ BMI, size, characteristic of part-solid, distance of path, and underlying pulmonary emphysema/fibrosis (p < 0.05). The factors related to the pneumothorax were distance of path, size and underlying pulmonary emphysema (p < 0.05).CONCLUSION: Confidence of CT-guided core needle lung biopsy is not significantly affected by characteristics of lung lesion for diagnosing malignancy. However, the part solid lesions had lower NPV and higher risk of hemorrhage as compared to solid lesions.

SE 04 CH-15 Space-filling property of emphysema associated with five-year survival for COPD patientsJeongeun Hwang, Yeon-Mok Oh, Joon Beom Seo, Namkug Kim Asan Medical Center, Korea. namkugkim@gmail.com

PURPOSE: Predicting COPD patient’s survival are very important for providing precision medicine and better decision making for patients, healthcare system, and public. Three-dimensional emphysema morphology are easily detectable from the chest computed tomography (CT) images. We hypothesized that the space-filling property of emphysema may increase over time and associate with five-year survival.MATERIALS AND METHODS: 74 patients with COPD underwent multi detector row CT scanning and three-dimensional emphysema masks were obtained by detecting low attenuation clusters < -950 HU. A box-counting fractal dimensions (DF) were measured using MATLAB to quantify the space-filling property of emphysema for each patients. A binary logistic regression model was used to assess the association between DFs and five-year survivals of patients. Among 74 patients, 40 patients survived over five years, 15 patients died in five years, and 19 patients were

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unknown.RESULTS: COPD patients’ emphysema have various fractal dimensions largely spanning from 2 to 3. Patients with larger DF values associated with more death incidents in five years. By a binary logistic regression model, the odds ratio for DF values and five-year survival was 2.43 x 108 (p = 0.021, Nagelkerke R2 = 0.236, Hosmer-Lemeshow significance = 0.648). Although the number of observation is small, this shows that DF is a potential prognostic factor for a COPD patient’s survival.CONCLUSION: Fractal dimension of emphysema associated with five-year survival in COPD patients. Box-counting fractal dimension method could help future prognosis and precision medicine for COPD patients.

SE 04 CH-16 Imaging spectrum of pulmonary aspergillosis: a pictorial reviewSonali Sethi1, Ruchi Gupta2, Pankaj Kumar1, Puneet Jain1, Vineet Sethia1, Vineeta Mehta1 1Fortis Hospital Shalimar Bagh, New Delhi, 2AIIMS Patna, India. sonali.sethi01@gmail.com

PURPOSE: Aspergillosis is a serious pulmonary infection in the immunocompromised and has specific radiological appearance. The radiologist plays an important role in its diagnosis and differentiation from other similar entities.MATERIALS AND METHODS: A retrospective analysis of CT images of patients with imaging findings typical of aspergillosis in Fortis Hospital Shalimarbagh, New Delhi from December 2015 to April 2016 was done. The findings are presented in the form of a pictorial essay. The imaging characteristics of spectrum of aspergil losis including aspergil loma, Allergic bronchopulmonary aspergillosis, semi-invasive (chronic necrotizing aspergillosis), air-way invasive and angio-invasive aspergillosis is described with emphasis on differentiation from common mimics.RESULTS AND CONCLUSION: The radiologist plays an important role in the differentiation of pulmonary infections in the immunocompromised and diagnosis of the aspergillosis. CT is important if the findings on radiographs are subtle or non-specific and CT appearances are characteristic.

SE 04 CH-17 Tracheobronchial neoplasm and infection: imaging features and histopathologic reviewJieun Kim, Kyung-Won Doo, Jong-Woon Song, Eenyoung Cho, Ji-Hwa Ryu Inje University Haeundae Paik Hospital, Korea. kwdoo00@naver.com

LEARNING OBJECTIVES: 1. To illustrate the various cases of tracheobronchial

neoplastic and infectious disease on chest CT.2. To review the diagnostic approaches, histopathological

findings and managements of tracheobronchial neoplastic and infectious diseases.

BACKGROUD: Even though t racheobronchial neoplastic and infectious diseases are uncommon, they still can induce airway obstruction, result in suffocation, and need proper management. The diagnosis of such disease is frequently delayed, because the signs and symptoms caused by these diseases are nonspecific and chest radiographs are rarely diagnostic. Thus, further evaluation with CT, which is regarded as the standard radiologic tool for diagnosis of tracheobronchial disease, is recommended. So it is important to familiar with imaging features of these diseases to suggest the differential diagnosis. In this exhibit, each tracheobronchial neoplastic and infectious disease will be introduced with radiologic findings and reviewed with histopathological findings and managements.CONTENTS: 1. Classification and Histopathology of Tracheobronchial

disease2. Various Cases of Tracheobronchial disease

1) Neoplasm- Benign tumor: papilloma, hamartoma, lipoma,

leiomyoma- Malignant tumor: squamous cell carcinoma,

small cell carcinoma, adenoid cystic carcinoma, mucoepidermoid carcinoma, carcinoid tumor, mixed squamous and grandular papilloma

- Tracheobronchial metastasis: lung cancer, renal cancer and rectal cancer

2) Infection- Endobronchial tuberculosis- Aspergillosis

3. Diagnostic approaches and ManagementsCONCLUSION: This exhibition presents a review of imaging characteristics of tracheobronchial neoplasm and infection. Several imaging features of tracheobronchial disease may be helpful for differential diagnosis and treatment. This exhibition will help radiologists and clinicians overcome the diagnostic challenges and conduct the appropriate treatment to tracheobronchial disease.

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SE 04 CH-18 Suggestion of lung RADS and radiology report by the Korean Imaging Study Group for Lung CancerSoo-Youn Ham1, Myeong Im Ahn2, Jin Mo Goo3, Hye Young Kim4, Tae Jung Kim5, Hyun Ju Lee6, Chang Min Park3, Sang Hyun Baek7, Soon Ho Yoon3, Semin Chung8, Hwan Seok Yong9, Daehee Han2, Jin Huh10

1Korea University Anam Hospital, 2The Catholic University of Korea, Seoul St. Mary's Hospital, 3Seoul National University Hospital, 4National Cancer Center, 5Samsung Medical Center, 6Asan Medical Center, 7Soonchunhyang University Bucheon Hospital, 8Chung-Ang University Hospital, 9Korea University Guro Hospital, 10Severance Hospital, Korea. syohammd@hanmail.net

BACKGROUNDS: Lung cancer is rising leading cause of death in Korea. Mortality has remained high owing to a disproportionate presentation of lung cancer at an advanced, usually incurable stage. In part because of effective and widely used screening methods, 76% to 93% of breast, colon, and prostate cancer are diagnosed with local or regional disease that can be treated for potential cure, compared with only 37% of patients with lung cancer. And recently increased numbers of screening low dose CT scan give rise to questions for pros and cons for the screening CT scan. Moreover, the interpretation of CT scan and reporting are also occupying hot spots before the managing patients.PURPOSE: To suggest the standard report of screening chest CT scan and supply one channel in the interpretation, between radiologists, even more clinicians, The Korean Imaging Study Group for Lung Cancer (KISLC) designed the structured report system in the screening chest CT scanRESULTS: The form of reporting system was

CONCLUSION: The above form was designed for reports for screening low-dose CT scan, the format is still changeable by feedback from the users. For the data collection and comparison with previous report, including clinical date, such as smoking and previous medical history. We anticipate that this reporting system will be a user friendly tool and promising supports for lung cancer registry.

SE 04 CH-19 Adult Morgagni hernia Nomin-Erdene Odsuren1, Tsevelmaa Dorj2, Munkhbaatar Dagvasumberel2 1Mungunguur Hospital, 2Mongolian National University of Medical Sciences, Mongolia. dr.tsevelmaa@gmail.com

INTRODUCTION: Hernia of Morgagni occurs through an anterior defect in the diaphragm. In our case, there was partial protrusion of liver through retrosternal defect in diaphragm on right side. This case incidentally diagnosed CT scan without intravenous contrast administration.BACKGROUND: Adult Morgagni hernia is uncommon, accounting for only 2-3% of all cases. Hernia of Morgagni occurs through an anterior defect in the diaphragm but usually presents in adulthood through a paramedian defect. In contrast, it occurs in a central retrosternal location in children. It could be an incidental diagnosis in adulthood or can present with obstructing symptoms of the herniated visceraCASE REPORT: A 67-years-old man with hardly breathe with chest pain underwent a CT scan to evaluate his lung parenchyma. Our patient underwent a CT scan without intravenous contrast administration. No focal or diffuse lung parenchyma pathological involvement was found. The mediastinum and lung window same level showed anterior right diaphragmatic hernia with protrusion of the liver and cardiomegaly (Figs. 1-3).

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Fig. 1a. Coronal reformat on NECT.

Fig. 1b. Coronal reformat on NECT.

Fig. 2a. Sagittal reformat on NECT.

Fig. 2b. Sagittal reformat on NECT.

Fig. 3a. Axial reformat on NECT.

Fig. 3b. Axial reformat on NECT.

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DISCUSSION: Hernia of Morgagni is develop due to the lack of fusion of sternal and septum transverses of the diaphragm. The most common viscus to herniate is omentum, small intestine, transverse colon and liver, rarely the stomach. However, most patients remain asymptomatic and the majority of cases are discovered incidentally while investigating unrelated problems. Depending on the contents of the hernia, the images in the chest radiography may appear differently. Most frequently, it will show a solid paracardiac shadow (due to the presence of omentum) and the differential diagnosis should include a pleuropericardial cyst, lipoma, liposarcoma, mesothelioma, pericardial fat mass diaphragmatic and thymoma. This patient had a large amount of liver in the thorax.TREATMENT: Laparoscopic repair was the method of choice.CONCLUSION: The case reported in our study are delayed presentations of CDH in an anterior location detected as an incidental finding on CT scans.

SE 04 CH-20 Do you want to be an excellent radiologist?: focus on the lateral chest imaging around the thoracic aortaDong yoon Han, So Yeon Shin, Dong Wook Sung Kyung Hee University Medical Center, Korea. bpinky@hanmail.net

PURPOSE: 1. To be familiar with normal chest lateral plain

radiograph and to improve reading skill. 2. To be aware of areas revolve around the aorta

which easy to overlook via impressive cases and to increase lesion detection rate without unnecessary CT exam.

CONTENT ORGANIZATION: 1. Normal chest anatomy on chest lateral image and it’s

radiographic technique.2. Divide to three compartment along the aorta.

1) Ascending thoracic aortic area2) Aortic arch area3) Descending thoracic aortic area

3. Impressive cases according to each compartment1) Ascending thoracic aortic area2) Aortic arch area3) Descending thoracic aortic area

4. Limitation of lateral image to interpret1) Technical problem2) Patient’s condition3) Radiation dose4) Miscellaneous

SUMMARY: In summary, familiarity with the normal contour and density of thoracic aorta as well as its

easily-overlooked surrounding structures on lateral image can be helpful in detecting missing lesion.TEACHING POINTS: 1. Smooth margin and continuous density of thoracic

aorta have to be seen in the lateral chest imaging.2. The lateral chest imaging can help to detect location

of lesion which cannot be detected on chest PA.

SE 04 CH-21 Prevalence of sarcopenia according to the histology and stage in patients with lung cancerChang Rae Kim, Eun Young Kim, Yoon Kyung Kim, Yon Mi Sung, Jeong Ho Kim, Hye-Young Choi Gachon University Gil Medical Center, Korea. oneshot0229@gmail.com

PURPOSE: As a component of cancer cachexia syndrome, the importance of sarcopenia has been increasingly recognized in oncologic patients. The purpose of this study was to evaluate the prevalence of sarcopenia according to the histology and disease stage in lung cancer patients using CT images taken at time of lung cancer diagnosis. MATERIALS AND METHODS: This retrospective study consisted of a total of 778 consecutive patients with newly diagnosed lung cancer between June 2012 and February 2015. Cross-sectional muscle areas were evaluated at the level of the third lumbar vertebra (L3) using baseline CT images, and sarcopenia was defined as a L3 muscle index (L3MI, muscle area at L3/height2) of < 55 cm2/m2 for men and as < 39 cm2/m2 for women. Logistic regression analysis was used to identify factors associated with sarcopenia.RESULTS: Mean patient age was 67.7 ± 10.8 years, and most were male (73.1%). The most prevalent histology was adenocarcinoma (44.0%), and 56.8% of patients had extensive disease (stage IIIb or IV for non-small cell lung cancer, NSCLC, and extensive disease for SCLC). Sarcopenia was present in 375 patients (48.2%). In the univariable analysis, sarcopenia was significant prevalent in male, elderly (≥ 65 years), smoker, those with a lower BMI level (< 23 kg/m2), and high comorbidity score (≥ 3), and the prevalence of sarcopenia was significantly low in adenocarcinoma, compared with remaining histologies (all ps < 0.05). In multivariable logistic analyses revealed sarcopenia was significantly associated with a male sex (odds ratio [OR], 11.19; 95% confidence interval [CI], 7.04-17.8), elderly (OR, 1.97; 95% CI, 1.37-2.84) and a low BMI (OR 6.25, 95% CI, 4.36-8.5), advanced stage (OR 1.79, 95% CI, 1.26-2.55), and high comorbidity score (OR 1.88, 95% CI, 1.16-3.04).CONCLUSION: Sarcopenia is prevalent in lung cancer patients of elderly male gender who have high

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comorbidity, low BMI, and advanced stage. Lung cancer histology is not an associated factor for the prevalence of sarcopenia. These finding might provide a better understanding the mechanism of cancer cachexia and enable targeted screening and early therapeutic interventions for sarcopenic patients with lung cancer.

SE 04 CH-22 CT and MRI review of intrathoracic nerve anatomy using neurogenic and nonneurogenic tumorsHyojung Park, Mi Young Kim Asan Medical Center, Korea. mimowdr@gmail.com

PURPOSE: 1. To outline the anatomy of the various nerves in the

thorax using diagram.2. To correlated with cross sectional images.3. To demonstrate the radiological findings of pathologi-

cally proven tumors involving intrathoracic nerves.CONTENT ORGANIZATION: 1. Systematic review of the origin and intrathoracic

anatomy of the nerves based on anatomic landmarks with CT and MRI correlation- Phrenic nerve, vagus nerve, recurrent laryngeal

nerve, intercostal nerves, long thoracic nerve, sympathetic/parasympathetic chains

- Pearls and pitfalls with CT interpretation2. Presentation of cases

- Primary neurogenic tumors according to histologic class including schwannoma, neurofibroma, neurofibrosarcoma, neuroblastoma, ganglioma, ganglioneuroma, ganglioblastoma, paraganglioma, phechromocytoma, plexiform neurofibromatosis, primitive neuroectodermal tumor, others

- Other neoplastic involvement, primary or secondary manifestat ion of var iable tumors involving intrathoracic nerves, including lung cancer, thymoma, etc.

SE 04 CH-24 Influence of radiation dose and iterative reconstruction algorithms for quantification of emphysema and airways: a phantom studyJi Yung Choo1, Ki Yeol Lee1, Eun-Young Kang2, Yu Whan Oh3 1Korea University Ansan Hospital, 2Korea University Guro Hospital, 3Korea University Anam Hospital, Korea. quellquell@naver.com

PURPOSE: To evaluate the influence of radiation dose and iterative reconstruction algorithms for quantification

of emphysema and airways through a phantom study.MATERIALS AND METHODS: Computed tomography (CT) was performed on an airway phantom (CTP674 Lung Phantom [The Phantom Laboratory, Salem, NY, USA]) with variable tube current from low dose to usual dose (30 to 100 mAs, per 5 mAs) and variable reconstruction algorithms (FBP, iDose1~6, IMR R1 and IMR S1). Measurements of each dataset were compared: emphysema volume, airway measurements of the lumen and wall area as well as average wall thickness. Emphysema volume was measured by air columns (30, 10, 5 mm in diameter) and airway measures were evaluated by 4 tubes with different angles and wall thickness. We use the in house software, A-view for quantification. The optimal option of radiation dose and reconstruction algorithm were evaluated by the difference between the measures and object value of phantom with response surface analysis by SAS version 9.4.RESULTS: In quantitative analysis of emphysema, the critical value of radiation dose and reconstruction algorithms are 85.9/2.7, 85.0/2.7, 89.3/2.8 in 30, 10, 5 mm column. Minimal difference between the measures and the object value of phantom is noted at 55, 65, 60 mAs, respectively. And the measures by IMR-S1 are the most accurate in all 3 columns. In airway measures, the influence of radiation dose was not significant (Pr F value > 0.05). Whereas, reconstruction algorithm influenced to the airway measures. Luminal diameter, wall thickness, wall area were accurate by iDose 3, iDose 6 and by IMR-S1, respectively.CONCLUSION: Emphysema volume was influenced by radiation dose and reconstruction algorithms, significantly. Full IMR-S1 and 55-65 mAs can be applied for quantification of emphysema. However, airway measures have no tendency according to the radiation dose and reconstruction algorithms.CLINICAL RELEVANCE: As radiation exposure is becoming a bigger issue in the clinical field, low radiation dose is essential even in quantification for COPD. However, as many factors including radiation dose and noise affect the quantitative parameters, proper or standardized parameters for longitudinal work up for quantification of emphysema and airways is not be established accurately yet. We can suggest proper low radiation dose and reconstruction algorithm for longitudinal follow up studies of quantification for COPD.

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SE 04 CH-25 How do you make sure the pulmonary nodule is calcified?: digital tomosynthesis can help your diagnosis of calcified pulmonary lesions for no further work-upJi Yung Choo1, Eun Sil Kim1, Ki Yeol Lee1, Eun-Young Kang2, Yu Whan Oh3 1Korea University Ansan Hospital, 2Korea University Guro Hospital, 3Korea University Anam Hospital, Korea. quellquell@naver.com

TEACHING POINTS: To understand the technical concept of low dose digital tomosynthesis of the chest and its implementation. To understand which type of calcified lesion can be evaluated under digital tomosynthesis. To recognize the limitations and benefits of digital tomosynthesis of the chest in radiation exposure and image acquisition. TABLE OF CONTENTS/OUTLINE: Our exhibit will be divided into 6 sections and presented with illustration and relevant cases regarding usefulness of tomosynthesis in evaluation of calcified and non-calcified pulmonary lesions:1. Background and physics of digital tomosynthesis of

the chest2. Cases

- Comparison of calcified and non-calcified thoracic lesion

- Calcified versus non-calcific nodules- Calcified pleural lesion- Vascular calcification- Airway calcification- Other high contrast pulmonary lesions

3. Detectable calcification on CXR and DTS- Density (Hounsfield unit), size, location

4. Needs of follow-up or further work-up5. Other high contrast pulmonary lesions6. Benefits and limitation of tomosynthesis of the chest

- Radiation exposure- Image acquisition- Image quality

SE 04 CH-26 Systemic air embolisms after CT-guided percutaneous transthoracic needle biopsy: a single-institution experienceHyunkyung Jang, Sunga Wi, Ji Young Rho CHA Bundang Medical Center, CHA University, Korea. rhochest@cha.ac.kr

PURPOSE: CT-guided percutaneous transthoracic needle biopsy (TTNB) is frequently performed procedure for evaluating pulmonary and mediastinal lesion, but has

several associated complications. The most common complications are simple pneumothorax, intrapulmonary hemorrhage and hemoptysis, which are usually mild and conservatively treated. Systemic air embolism is an extremely rare complication that is potentially fatal. The purpose of our study was to present the details and incidence of systemic air embolism in patients who underwent CT-guided percutaneous TTNB in a single institution.MATERIALS AND METHODS: We retrospectively reviewed 1053 TTNB during the period from March 2005 to May 2016 in our hospital. Prior to the TTNB, CT scan was obtained for targeting the lesion. A limited post-biopsy chest CT scan through the region biopsied was obtained on each patient until the first case of systemic air embolism (569 TTNB); since the first case, the entire thorax was scanned for the examination of systemic air embolisms (484 TTNB). Core biopsies were obtained with an 18-gauge, 10 or 16-cm automatic cutting needle.RESULTS: Four patients developed systemic air embolisms (0.38%); four man, age range 65 to 74 years old. The target lesion was a lung tumor in three patients, and a subpleural consolidation in one patient. In all four patients, a specimen confirmed adenocarcinoma. Air embolisms were located in the left atrium, left ventricle, coronary artery, aorta, pulmonary vein, and cerebral artery/vein. The presence of systemic air was missed in two initially asymptomatic patients, resulting in a subsequent cerebral infarction; brain CT scans revealed gas within the cerebral artery and venous system. In two patients without cardiac or cerebral symptoms, the presence of systemic air was confirmed on post-biopsy chest CT scan before moving to ward; it was resolved without causing morbidity after the immediate and conservative therapy such as administration of 100% oxygen through a mask. Hyperbaric oxygen therapy was not available in all four patients.CONCLUSION: The incidence of systemic air embolism is more frequent than the previously reported rate. A post-biopsy chest CT scan should include the aorto-cardiac region or entire thorax in order to exclude systemic air embolisms before moving asymptomatic patients. In addition, radiologists should concentrate a post-biopsy chest CT images for a prompt recognition and management of systemic air embolisms.

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SE 04 CH-27 Cone-beam CT (CBCT) in interventional chest-radiology: technical considerations and clinical applicationsNa Young Choi, Han Na Lee, Jung Im Kim Kyung Hee University Hospital at Gangdong, Korea. mine147@gmail.com

TEACHING POINTS: 1. To review the physical principles and techniques of

CBCT.2. To present our experience with CBCT-guided thoracic

intervention including common practical difficulties and complications.

3. To discuss the potential benefits and current challenges facing CBCT in interventional chest-radiology.

TABLE OF CONTENTS: 1. Overview of CBCT2. Technical Considerations for Use in chest intervention

1) Technical construct and image acquisition2) Artifacts and limitations3) Radiation dose4) Therapy planning and navigation software

3. Clinical Application in the Chest1) Patient preparation and equipment setup2) Case presentations with depiction of the diffe-

rent techniques used in different locations and demonstration of procedure planning(1) Lung biopsy(2) Mediastinal biopsy(3) Localization before surgery(4) Drainage catheter insertion

4. Future direction and challenges1) Endobronchial navigation 2) Ultrafast CBCT

CONCLUSION: CBCT-guided biopsy can be new biopsy options for lung nodules and mediastinal masses with high diagnostic accuracy and safety. Furthermore, CBCT is feasible for imaging guidance of localization before surgery and drain tube insertion. However, considered this is a new technology, much remains to be established, from practical guidelines to radiation exposure to the patient as well as interventional radiologist.

SE 04 CH-28 Influence of CT parameters on the measurement accuracy of ground-glass nodules: a phantom studySo Won Lee1, Yookyung Kim2, Sung Shine Shim2 1CHA Gangnam Medical Center, CHA University, 2Ewha Womans University Mokdong Hospital, Korea. yookkim@ewha.ac.kr

PURPOSE: To assess the effect of various CT parameters on the measurement accuracy of ground-glass opacity nodule in both manual diameter and semiautomatic volume measurements.MATERIALS AND METHODS: Six nodules (5, 8 and 10 mm -630 and -800HU) were randomly placed inside a chest phantom. CT images were obtained on various tube voltages and currents (120 kVp/10, 20, 30, 40 and 50 mAs; 100 kVp/20 mAs; and 80 kVp/30 mAs). Each CT was reconstructed using filtered back projection (FBP) and iterative reconstruction (IR); bone and soft tissue kernels; and 1, 2, 3, 4 and 5-mm slice thicknesses. Two independent readers measured the nodule size using the longest diameter on axial plane. Also, the nodule volumes were calculated using semiautomatic software. Measurement errors were calculated and the comparison of measurement accuracy among nodules and CT image sets were performed.RESULTS: In manual diameter measurement, RPE and APE were higher in smaller size and lower density of nodules (p < 0.001). Bone kernel and thin slice thickness were significantly associated with RPE and APE improvement (p < 0.05). Radiation dose and use of IR did not affect the measurement accuracy (p > 0.05). In semiautomatic volume measurement, RPE and APE were lower in 10 mm-sized nodule, compared with 5 and 8 mm-sized nodules (p < 0.001). CT parameters including radiation dose, use of IR, and kernel did not affect the measurement accuracy (p > 0.05). Comparing the measurement errors between two methods after converting the volume estimates to unidimensional scale, both RPE and APE were higher in manual measurements of 5 mm-sized nodules of all densities (p < 0.001). In larger nodules, APE in 8 mm-sized -630 HU nodules and 10 mm-sized -800 HU nodules were higher in manual measurement (p = 0.013 and p < 0.001, respectively), whereas RPE were not significantly different (p > 0.05).CONCLUSION: In manual diameter measurement, the use of bone kernel and thinner slice thickness significantly improve RPE and APE. The size and density of a nodule also have influence on the accuracy of size measurement. In semiautomatic volume measurement, the errors were not significantly affected by CT parameters. In 5 mm-sized nodules, the semiautomatic volume measurements were more

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accurate than manual diameter measurements. In larger nodules, manual diameter measurement may be reliable.

SE 04 CH-29 Community-acquired Acinetobacter Baumannii pneumonia: initial chest radiographic findings and follow-up CT findings in helping predict patient outcome Dong Hyun Lee, Jeong Joo Woo, Jin Kyung An Eulji University School of Medicine, Eulji Hospital, Korea. jjblue@eulji.ac.kr

PURPOSE: To retrospectively evaluate whether findings on initial chest radiographs and follow-up CT of community-acquired AB pneumonia patients can help predict clinical outcome.MATERIALS AND METHODS: The study included 20 consecutive patients (M:F = 10:10; age range, 42-88 years; median age, 73.5 years) with community-acquired AB pneumonia who underwent chest radiography within 24 hours. 19 of them underwent chest CT within five days after taking chest radiographs. The radiographic and CT findings were retrospectively analyzed by type, pattern and extent of opacities. Grave outcome measures were mechanical ventilation and death.RESULTS: Initial radiography showed abnormalities in all 20 patients. 10 (50%) of these had grave outcomes. Findings on radiographs were bilateral patchy alveolar opacities in 9 patients, focal alveolar opacity in 5 patients, patchy peribronchial nodular opacities in 4 patients and pleural effusion in 3 patients. On thin-section CT, the findings included bilateral patchy consolidation in 12 patients, patchy GGO in 9 patients, consolidation containing cavity in 2 patients and patchy peribronchial branching nodular opacities in 6 patients. There were no statistically significant findings on initial chest radiographs between recovery group and grave outcome group. Follow-up CT findings of multilobar, bilateral consolidation with extensive GGO occurred with significantly higher frequency in patients with grave outcome compared with patients who had good clinical outcome (70% vs. 30%, p = 0.01). The patients with grave outcomes were significantly older compared with the other patients (mean age, 78 years vs. 67 years, retrospectively, p = 0.04). Almost all of the patients (17 of 20 patients) had underlying chronic illness, including DM, COPD, CKD and heart disease.CONCLUSION: The initial radiograph findings of community-acquired AB pneumonia were nonspecific, with bilateral or focal consolidation being the most common findings. No significantly different findings on initial radiograph were observed between the recovery

group and the grave outcome group. Rapid progress to bilateral consolidation with patchy GGO on follow-up CT taken within a week is associated with grave outcome. Additionally, older age and severe underlying disease were also found to be related with grave outcome.

SE 04 CH-30 Hyperenhancing mediastinal masses: spectrum of causes and imaging findingsYeo Eun Han1, Yu-Whan Oh1, Sung Ho Hwang1, Soo Youn Ham1, Eun-Young Kang2, Ki Yeol Lee3 1Korea University Anam Hospital, 2Korea University Guro Hospital, 3Korea University Ansan Hospital, Korea. yuwhan@kumc.or.kr

Evaluation of a mediastinal mass may seem difficult because mediastinal masses are relatively uncommon and a large variety of entit ies can occur in the mediastinum. Computed tomography (CT) is the modality of choice for imaging them. Although the etiology of a mediastinal mass may not be defined by CT, the differential diagnosis may be limited by CT features of the mass. In our institution, we encountered various cases of enhancing mediastinal masses during the previous 10-year period. These well-enhancing masses included paraganglioma, intrathoracic goiter, ectopic thyroid gland, ectopic parathyroid adenoma, Castleman’s disease, thymoma, and thymic carcinoid.Paraganglioma: Paragangliomas are usually located near aortic arch or paravertebral area. They can be found in pericardial space as our case or rarely within heart. They have homogeneous or heterogeneous soft tissue attenuation with marked contrast enhancement.Ectopic thyroid gland: Thyroid tissue has high attenuation before enhancement and shows intense homogeneous enhancement after IV contrast injection. Ectopic thyroid gland is usually located in anterior and superior mediastinum.Intrathoracic goiter: Intrathoracic goiters have heterogeneous attenuation and some portion has same properties with normal thyroid tissue and show hyperenhancement. They are usually contiguous with cervical thyroid.Ectopic parathyroid adenoma: Ectopic parathyroid adenomas, occurring up to 10% of cases, are usually located near thymus or paraesophageal area. They most commonly present as small enhancing nodules in these sites.Castleman’s disease: Castleman’s diseases usually affect subcarinal or paratracheal lymph nodes. On CT, they present as well demarcated extensive lymphadenopathies and its enhancement is very intense and homogeneous.Thymoma: Most thymomas show mild enhancement,

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but in some cases, they show heterogeneous hyperenhancement. Their most common site is upper anterior mediastinum.Thymic carcinoid: Thymic carcinoids are typically large, heterogeneously enhancing masses. They are usually found in anterior mediastinum and may have calcification. In this exhibit, we present imaging features of various cases of well-enhancing masses occurring in the mediastinum. The acquaintance with hyperenhancement of these mediastinal masses, coupled with other imaging findings, can lead to the confident diagnosis or at least narrow the range of diagnostic possibilities.

SE 04 CH-31 Learning pneumothoraxJae Hwi Park1, Sun Young Jeong2, Im Kyung Hwang2, Seung Hyung Kim2, Bong Soo Kim2 1Jeju National University Hospital, 2Jeju National University School of Medicine, Korea. sy7728.jeong@gmail.com

1. Classification according to etiology2. Imaging finding

1) Chest X-ray- PA: inspiration/expiration- AP- amount measurement- differential diagnosis

2) Chest CT3. Tension pneumothorax4. Re-expansion pulmonary edema

SE 04 CH-32 Ultra-low dose chest CT using iterative reconstruction: preliminary resultsKyungsoo Bae, Kyung Nyeo Jeon, Hye Jin Baek, Soo Buem Cho, Jin IL Moon, Bo Hwa Choi Gyeongsang National University Changwon Hospital, Korea. ksbae@gnu.ac.kr

PURPOSE: To assess the image quality of ultralow dose chest CT (ULDCT) reconstructed with filtered back projection (FBP), hybrid (HIR) and model based iterative reconstruction (MBIR), compared with standard low dose chest CT (LDCT) reconstructed with FBP.MATERIALS AND METHODS: 26 consecutive patients (mean age, 59.4 years; M:F = 11:15) who underwent both low dose chest CT (LDCT) and ultra-low dose chest CT (ULDCT) in the same examination were included in this study. Image noise and subjective image quality

were compared between ULDCT images using FBP (ULDCT-FBP), hybrid iterative reconstruction (ULDCT-HIR), and model-based iterative reconstruction (ULDCT-MBIR), and LDCT using FBP (LDCT-FBP).RESULTS: The mean effective dose for ULDCT and LDCT were 0.15 (0.12-0.17) and 1.26 (0.78-2.02) mSv, respectively. Objective image noise was the lowest in ULDCT-MBIR, followed by ULDCT-HIR, LDCT-FBP, and ULDCT-FBP. The difference between LDCT-FBP and ULDCT-MBIR was significant (p = 0.03). Subjective image noise was not different between ULDCT-HIR and ULDCT-MBIR. Image sharpness was better in all other image sets, compared with ULDCT-FBP (p ≤ 0.01), but not different between LDCT-FBP and ULDCT-MBIR. The overall diagnostic image quality of LDCT-FBP was better than ULDCT-HIR, but not different with ULDCT-MBIR.CONCLUSION: ULDCT-MBIR could reduce image noise and improve image quality. The overall diagnostic image quality of ULDCT-MBIR was comparable to LDCT-FBP.

SE 04 CH-33 Rib unfolding CT software: effect on radiologist’s performance of detecting bone metastases from breast cancerKyung Nyeo Jeon, Kyungsoo Bae, Hye Jin Baek, Bo Hwa Choi, Jin IL Moon, Soo Buem Cho Gyeongsang National University Changwon Hospital, Korea. knjeon@gnu.ac.kr

PURPOSE: To evaluate the effect of CT software generating rib unfolding images and automatic numbering of ribs and thoracic spines called “bone reading” on radiologist’s performance detecting thoracic bone metastases from breast cancer.MATERIALS AND METHODS: 126 consecutive breast cancer patients who underwent chest CT scanning and FDG-PET/CT and/or bone scan were analyzed retrospectively. One board-certified radiologist and one radiology resident independently assessed original chest CT images and bone reading images using a commercially available post-processing software application for evaluation of skeletal metastasis. Standard of reference was determined based on FDG-PET/CT and/or bone scan and follow-up.RESULTS: The reference standard identified 78 metastatic bone lesions in 26 patients. On per patient-based analysis, the “bone reading” analysis yielded a sensitivity of 80.8/76.9, a specificity of 94/94 and an accuracy of 91.3/90.5, while the original CT scan analysis yielded a sensitivity of 73.1/61.5, a specificity of 95/94 and an accuracy of 90.5/87.3, respectively. On per lesion-based analysis, the “bone reading”

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analysis yielded a sensitivity of 85.9/79.5, a specificity of 99.7/99.6 and an accuracy of 99.5/99.3, while the original CT scan analysis yielded a sensitivity of 75.6/66.7, a specificity of 99.6/99.5 and an accuracy of 99.2/98.9, respectively. On per lesion-based analysis, a sensitivity of was significantly higher (p < 0.05) with “bone reading” application for both experienced and unexperienced readers. The mean reading time for “bone reading” software was significantly shorter (reader 1: 84.7 ± 23.1s/reader 2: 56.7 ± 22.2) than the evaluation of the original CT scan (reader 1: 183.9 ± 43.3/reader 2: 154.9 ± 43.3) (p < 0.0001).CONCLUSION: In patient with breast cancer, the use of the “bone reading” generating rib unfolding images and automatic numbering of ribs and thoracic spines improves sensitivity of bone metastasis detection in comparison to CT scan reading and reduces reading time in both experienced and unexperienced readers.

SE 04 CH-34 How to avoid pitfalls in CT radiomic analysis: a case study with NLST datasetHyeongmin Jin1, Jong Hyo Kim2 1Seoul National University, 2Seoul National University College of Medicine, Korea. kimjhyo@snu.ac.kr

Radiomics is at t ract ing research interests for characterization of the tumor phenotype as well as for prediction of patient outcome. However, many radiomic features are known to be affected by a multitudes of variability sources, such as CT acquisition parameters, which might lead to false discovery if unknowingly used. Therefore, in order to avoid such pitfalls, appropriate selection of informative features out of non-informative features is an essential task in radiomic studies. This study investigates the informativeness of radiomic features by comparing the feature distribution from the tumor against those from the aorta. Twenty-five sets of CT data with lung cancer were selected from the National Lung Screening Trial (NLST) database which were acquired using tube voltages of 120 kVp and tube current between 70 and 130 mAs of GE multi-detector CT (LightSpeed 16; GE Healthcare, Waukesha, WI, USA). Thirty-three texture features based on Gray Level Co-occurrence Matrix (GLCM) and Gray Level Run-Length Matrix (GLRM) were extracted on the segmented tumor and aorta. Feature variability range was defined as from 10th to 90th percentile of feature value measured on the homogeneous region. By using the feature variability range, the feature range from tumor was rescaled from 0 to 1. Those tumor features exceeding the variability range was considered as informative (sufficient dynamic range). Texture

features were classified into three groups according to the proportion of informative samples (good ≥ 70%, 70% > moderate ≥ 30%, poor < 30%). Fifteen texture features (45.6%) were shown to have good dynamic, whereas fourteen texture (42.4%) features had only moderate dynamic range. Notably, the gray-level non-uniformity feature which was previously reported as a radiomic signature predictive of patient survival, showed moderate dynamic range. The rest (12.1%) of texture features were shown to have poor dynamic range being unable to represent the tumor heterogeneity. Our study revealed a significant portion of texture features did not have sufficient dynamic range as compared to the feature variability range obtained from aorta. An appropriate feature selection procedure, taking feature variability sources as well as the feature variability range into account, is recommended to avoid pitfalls in radiomic analysis.

SE 04 CH-35 Combined pulmonary fibrosis and emphysema syndrome (CPFE): an unexplored facet in spectrum of smoking related interstitial lung diseasePratik Khokhani1, Ritesh Prajapati2, Hiral Shah2, Bhavik Shah3 1Medical Council of India, 2Xray House, 3Civil Hospital, India. khokhani1988@gmail.com

Smoking, as age old recognit ion, is by far the commonest cause of various lung disease. Its spectrum ranges from emphysema to lung cancer. The focus of this presentation is on interstitial lung disease (ILD) caused by smoking (typically patients smoking > 60 pack years) and in particular the CPFE facet of it. HRCT of thorax is a perfect tool for recognizing various parenchymal changes, ranging from emphysema to interstitial changes. HRCT allows distinct differentiation of smoking related ILD based on parenchymal changes. CPFE represents changes of pulmonary interstitial thickening in lower lobes and changes of emphysema in both upper lobes. The pathogenesis of this particular changes occurring in a patient addicted to smoking may be governed genetically as a susceptibility or may be related to primary damage to intestium due to smoking. The clinical presentation is worth noting, as it is different from smoking related emphysema. The usual presentation is of exertional dyspnea, coughing, low grade fever. The spirometric findings consist of near normal lung volumes and decreased diffusion capacity for carbon monoxide (DLco).The forced expiratory volume at 1 sec (FEV1) may be normal or increased. The pathological correlate consist of presence of fibroblasts, interstitial thickening and

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fibrosis in both lower lobes and changes of emphysema with macrophages in upper lobes. The spectrum of smoking related ILDs also consist of Respiratory bronchiolitis-ILD, pulmonary Langerhans histiocytosis and desquamative interstitial pneumonia (DIP). The DIP pattern is a relatively rare entity, the former two being more common. The increasing evidence of recognizing patterns of CPFE on HRCT has a greater impact on patient prognosis and clinical management. Further the patients with CPFE are also susceptible to development of lung cancer. UIP is the common pattern recognized in CPFE with less commoner pattern of NSIP. Only interstitial thickening without honey combing is not a feature of CPFE. Hence, as evidence is gathering, this facet in spectrum of smoking related ILDs is gaining major importance. We retrospectively analyzed 39 patients, whose HRCT findings were suggesting CPFE syndrome. The clinical, spirometric and biochemical findings were correlated. 35/39 (89%) patients showed lower lobe predominance fibrosis of UIP pattern, 20/35 (57%) showed simultaneous upper lobe emphysema. The features specific to UIP pattern, honeycombing and architectural distortion were shown by 39/39 patients representing p value < 0.001.

SE 04 CH-36Image guided biopsy of thoracic masses and reduction of risk of pneumothorax: 25 year experience in a cancer centerBinoy Kumar Choudhury Dr. B. Borooah Cancer Institute, Guwahati, India. choudhury60@gmail.com

PURPOSE: To determine role, accuracy and reliability of image guidance of thoracic biopsy and to know the efficacy of uses of different measures to reduce the risk of pneumothorax.MATERIALS AND METHODS: Needle aspiration biopsies were performed in 1650 patients from February 1989 to December 2014 using Fluoroscopy, Ultrasound (US) and CT as image guidance. US guidance was used for peripheral lesions. Fluoroscopic and CT guidance were used for both peripheral and central lesions. After reviewing the patient, skiagram, CT and coagulation profile, a plan was formulated for safest approach. A needle was guided to the lesion with an Image technique and material was aspirated with 20 cc syringe and smeared on slides. Several measures were applied to reduce the risk of pneumothorax. Immediately after the technique, puncture site was put on dependent position to reduce the risk of pneumothorax. Other measures included selection of appropriate image guidance, accurate and delicate performance of needle manipulation, extrapleural approach, widening of

extrapleural space by saline injection, pathway through non-aerated lung, minimizing pathway of normal aerated lung, avoiding fissure and bullae, limited no of pleural puncture, small bore needle, slow and careful manipulation of needle. All patients underwent chest radiography to detect a pneumothorax.RESULTS: There were 1285 male and 365 female in the range of 12 to 91 years. Fluoroscopy, US and CT as guidance were used in 170 (10.30%), 270 (16.36%) and 1210 (73.33%) cases respectively. The diameter of masses ranges from 1.2 cm to 12 cm. Procedure time was significantly less under US guidance. 157 cases (9.5%) needed repeat biopsy. Results obtained in 1419 cases (86%). Malignant cases were 1078 (76%). Complications included hemoptysis (7%) and pneumothorax in 38 (2.3%). There was no pneumothorax in US guided biopsy. Pneumothorax occurred in 10 cases following fluoroscopic guidance and 28 cases in CT guidance. Only three cases of pneumothorax required placement of a chest tube, rest were small and resolved spontaneously. Incidence of pneumothorax dropped significantly after starting meticulous planning using several measures.CONCLUSION: Image guided biopsy is a safe and reliable method in tissue diagnosis of thoracic lesions. Morbidity is very low and accuracy is very high. Most common complication is pneumothorax. Risk of pneumothorax can be significantly reduced by meticulous planning using several measures.

SE 04 CH-37 Affecting factors of bronchial foreign body distribution and complicationsHui-jun Li1, Ming Yang2 1Nanjing Children's Hospital Affiliated to Nanjing Medical University, 2Nanjing Children's Hospital, China. yangming19710217@163.com

PURPOSE: To evaluate the factors affecting the distribution of bronchial foreign bodies and the occurring of complications. MATERIALS AND METHODS: 523 cases of bronchial foreign body, which were confirmed by bronchoscope, were retrospectively analyzed. All of the cases were examined with multi-detector CT scanner before bronchoscope. Then the CT data were reconstructed with minimum intensity projection (MinP) and multiple planar reconstruction (MPR). The length, the width, and average size of foreign bodies were measured on MPR. Different characteristics of left and right foreign bodies and its complications including obstructive emphysema and pneumonia were respectively compared and evaluated. The affecting factors of bronchial foreign bodies distribution and its complications were obtained.

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RESULTS: Compared with left bronchial foreign bodies, right bronchial foreign bodies have bigger width and average size, and the difference is statistically significant (p < 0.05). While the age, visiting time, sex ratio, the length and the types of foreign bodies have no difference. Compared with no obstructive emphysema group, obstructive emphysema group has younger age, longer visiting time, and more food foreign bodies (p < 0.05), while the sex ratio, the length, the width, the average size and the types of foreign bodies have no difference. Compared with no pneumonia group, pneumonia group has older age, longer visiting time, bigger length and average size (p < 0.05), while sex ratio and foreign bodies types and the width have no difference. CONCLUSION: The width and average size of foreign bodies are affecting factors of bronchial foreign bodies distribution. The age, visiting time, the types of foreign bodies, the length, the width and the average size of foreign bodies affect the occurring of main bronchial foreign body complications.

SE 04 CH-38How low can we go on dose reduction in evaluation of ground-glass opacity nodules?: assessment using realistic reduced-dose simulationKyongmin Beck1, Myeong Im Ahn1, Jong Hyo Kim2, Zepa Yang3, Jung Im Jung1, Dae Hee Han1 1The Catholic University of Korea, Seoul St. Mary's Hospital, 2Seoul National University Hospital, 3Seoul National University, Suwon, Korea. ami@catholic.ac.kr

PURPOSE: To assess the image quality and effect of radiation dose reduction in detecting ground-glass opacity nodules (GGN) and find out the level of radiation dose at which adequate analysis of GGN is possible using realistic reduced-dose simulation.MATERIALS AND METHODS: This retrospective study included a total of 22 low-dose CT exams with GGNs of varying sizes (from 5 to 20 mm) selected from recent CTs. All CT scans were performed at 120 kVp and 35 mAs. Using realistic reduced-dose simulation, low dose data subsets of 25 mAs, 15 mAs, and 10 mAs were obtained, resulting in total of 88 datasets. Size and density of GGN, diagnostic confidence (1=good, 2=fair, 3=poor), and subjective image quality were assessed. Objective noise measurements were also obtained.RESULTS: Compared to the original images, the simulated low-dose CT images did not show significant difference in size (p=0.06) or the density of GGNs (p = 0.124). Subjective image quality significantly lowered (p = 0.000) and objective noise significantly increased (p = 0.000) as mAs decreased from 35, 25, 15, and to 10. On

average, 100.0%, 100.0%, 93.2%, and 72.3% of GGNs showed fair to good diagnostic confidence on 35 mAs, 25 mAs, 15 mAs, and 10 mAs images respectively.CONCLUSION: On realistic reduced-dose simulation CT images, fair to good diagnostic confidence of GGN evaluation can be achieved with mAs as low as 15.

SE 04 CH-39 Incidental thyroid nodules on thoracic contrast-enhanced computed tomography in clinical practice during a 10-year period: characteristics, outcomes, and factors contributing to further evaluationJu Yong Park, Jun Ho Kim, Kyung Hee Lee, Soon Gu Cho, Ha Young Lee, Yeo Ju Kim, In Ki HongInha University Hospital, Korea.jhkim7227@gmail.com

PURPOSE: The purposes of this study were to assess the prevalence, malignancy rate, and characteristics of incidental thyroid nodules (ITNs), and to identify factors that contribute the additional workup by ultrasound.MATERIALS AND METHODS: The medical records and imaging features of ITNs reported via thoracic computed tomography (CT) were retrospectively reviewed to determine the size, multiplicity, attenuation, shape, and presence of calcification. To identify the factors associated with additional workup, we compared the workup and non-workup groups in terms of nodule characteristics, indications, and CT slices. We identified factors that could distinguish malignant ITNs from non-malignant nodules.RESULTS: A total of 60,921 thoracic CT scans met the inclusion criteria, and ITNs were reported using formal radiology in 2,733 patients (4.5%). Among all patients with reported ITNs, 546 (20.0%) underwent further workup. Of these patients, 62 (2.3%, 62/2773) were diagnosed with malignant nodules. Multivariable analysis identified multiple factors associated with additional workup, including female sex, younger age, larger nodule size, calcification, anteroposterior to transverse dimension ratio >1, heterogeneous attenuation in the nodule, and scanning indications such as infection or screening. However, only calcification was associated with malignant nodules (odds ratio = 2.313).CONCLUSION: We observed discordance between the numbers of reported ITNs and case with additional workup and identified multiple factors associated with additional workup. We have therefore demonstrated a need for reliable subsequent evaluation guidelines and note that the appearance of calcification in an ITN on imaging may be a factor indicating the need for additional workup.

Scientific Exhibitions 503

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SE 04 CH-40 Predictive CT features of visceral pleural invasion by T1-sized peripheral pulmonary adenocarcinomas manifesting as subsolid nodulesSu Yeon Ahn, Chang Min Park, Yoon Kyung Jeon, Jong Hyuk Lee, Eui Jin Hwang, Hyungjin KimSeoul National University Hospital, Korea. cmpark.morphius@gmail.com

PURPOSE: To determine whether visceral pleural invasion (VPI) of T1-sized peripheral pulmonary adenocarcinomas manifesting as subsolid nodules (SSNs) abutting the pleural surface or associated with pleural tags can be predicted by preoperative CT scans.MATERIALS AND METHODS: Our institutional review board approved this retrospective study with waiver of patients’ informed consent. From 2007 to 2013, 188 patients (M:F=68:120; mean age, 61.4±9.5 years) with 188 T1-sized pulmonary adenocarcinomas appearing as SSNs (24 pure ground-glass nodules (GGNs) and 164 part-solid nodules (PSNs); mean size, 18.01±5.59 mm) abutting the pleural surface or associated with pleural tags underwent surgical resection comprising our study population. Logistic regression analysis was performed to identify significant factors in predicting VPI.RESULTS: VPI occurred in 36 out of 188 adenocar-cinomas (19.1%). There were no VPIs in patients with pure GGNs. In PSNs, there were significant differences regarding the presence of pleural contact, pleural thickening, solid portion abutting the pleura, nodule size, solid portion size, solid proportion, interface length, and the length of the solid portion abutting the pleura (P<0.05). Multivariate analysis revealed pleural contact (P<0.001), pleural thickening (P=0.003), solid proportion >50% (P=0.002), and nodule size >20 mm (P=0.015) as significant independent predictive features for VPI with adjusted odds ratios of 8.300, 3.966, 4.636, and 2.993, respectively.CONCLUSION: VPI did not occur in pure GGNs. However, in PSNs, CT features of pleural contact, pleural thickening, solid proportion >50% and nodule size >20 mm were demonstrated to be significant indicators of VPI by T1-sized peripheral adenocarcinomas.

SE 04 CH-41Relationship between coronary calcium score and lung volume in obstructive sleep apnea syndrome: 3D MDCT analysis-clinical and radiological correlationDo Hyung Lee1, Ki Yeol Lee1, Sung Whan Kim1, Chol Shin1, Ji Yung Choo1, Eun Young Kang2, Yu Whan Oh3, Chang Sub Go1 1Korea University Ansan Hospital, 2Korea University Guro Hospital, 3Korea University Anam Hospital, Korea. kiylee@korea.ac.kr

PURPOSE: Obstructive sleep apnea (OSA) is a common and debilitating condition characterized by recurrent episodes of upper airway obstruction, resulting in intermittent occurrences of apnea-hypopnea. We aimed to evaluate the change of coronary calcium score (Agatston score) and total lung volume (TLV) in OSA patients via 3D MDCT.MATERIALS AND METHODS: We evaluated the coronary calcium score, pericardial fat volume, and total lung volume of 468 OSA patients and 505 normal reference subjects by using 3D MDCT. The participants were examined by a standard polysomnography (PSG) and classified into 4 groups according to their respiratory disturbance index (RDI); normal, mild, moderate, severe. Epicardial, left and right perivessel fat volume, Agatston score, and total lung volume were obtained on the MDCT scan. We analyzed the relationship between epicardial, left and right perivessel fat volume, Agatston score, total lung volume and RDI severity. The results were evaluated using the Spearman correlation coefficient.RESULTS: In OSA patients, the moderate and severe RDI groups showed a significant increase in their Agatston score, and left perivessel fat volume, compared to the mild, or normal groups, after adjusting for age, sex, and body mass index. However, there were no significant differences between the 3 groups(mild, moderate, and severe groups) in total lung volume.CONCLUSION: Our results show support for sleep apnea being independently associated with early atherosclerotic plaque burden in OSA patients.

504 KCR 2016

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Chest - Informal Scientific PresentationPresenting

No.Final Abstract

No. Title Presenting Author

Page No.

ISP 01_CH 01 SE 04 CH-04 Fungal diseases of the lung Jin-sol Choi 486

ISP 06_CH 02 SE 04 CH-09Diverse and unique features of non-tuberculous mycobacterial infection: thoracic and extrathoracic involvement

Jae Chun Park 488

ISP 01_CH 04 SE 04 CH-14Diagnostic confidence and complications of CT-guided core needle lung biopsy in solid and part-solid lesions

Hee Kang 490

ISP 06_CH 01 SE 04 CH-17 Tracheobronchial neoplasm and infection: imaging features and histopathologic review Jieun Kim 491

ISP 01_CH 03 SE 04 CH-32 Ultra-low dose chest CT using iterative reconstruction: preliminary results Kyung Nyeo Jeon 499

ISP 01_CH 02 SE 04 CH-33Rib unfolding CT software: effect on radiologist’s performance of detecting bone metastases from breast cancer

Kyung Nyeo Jeon 499