Tree-in-Bud Pattern of Pulmonary Tuberculosis on Thin-Section CT: Pathological Implications

The “tree-in-bud-pattern” of images on thin-section lung CT is defined by centrilobular branching structures that resemble a budding tree. We investigated the pathological basis of the tree-in-bud lesion by reviewing the pathological specimens of bronchograms of normal lungs and contract radiographs of the post-mortem lungs manifesting active pulmonary tuberculosis. The tree portion corresponds to the intralobular inflammatory bronchiole, while the bud portion represents filling of inflammatory substances within alveolar ducts, which are larger than the corresponding bronchioles. Inflammatory bronchiole per se represents the “tree” (stem) and inflammatory alveolar ducts constitute the “buds” or clubbing. “Clusters of micronodules”, seen on 7-mm thick post-mortem radiographs with tuberculosis proved to be clusters of tree-in-bud lesions within the three-dimensional space of secondary pulmonary lobule based on radiological/pathological correlation. None of the post-mortem lung specimens showed findings of lung parenchymal lymphatics involvement.

Physicians for 'here and now'

Three reports published in the 20th century have functioned as standard guidelines for medical education: the General Professional Education of the Physician report by the Association of American Medical Colleges, Tomorrow's Doctors from the General Medical Council of the UK, and Korean Physicians for the 21st Century by the Korean Association of Medical Colleges. At the moment, a great deal of innovation is occurring in Korean medical societies. However, these innovations bring to mind the parable of the blind men and an elephant in which each blind man feels part of an elephant with his hands and misunderstands the elephant's nature because he cannot see the whole animal. In the same way, there is no comprehensive picture of 'what is the good doctor' for here and now. Korean society is changing more and more rapidly in the 21st century due to influences such as an influx of immigration and resulting multiculturalism. We could not predict these changes even in the 1990s, when Korean Association for Medical Colleges was preparing its report. In light of a dynamically changing society, we must review and revise our definitions of a 'physician for here and now' every ten or twenty years.

Vision of the Korean Association of Medical Colleges / 한국의학교육

The Korean Association of Medical Colleges (KAMC) has launched as a corporate aggregate in August 2008, since the inauguration meeting as "Korean Association of Medical School Deans" 24 years before. The mission of KAMC is to be the representing agency of medical education in Korea, producing policies and strategies, suggesting and influencing government agencies related to medical education. The KAMC will consolidate its basic role and continue to expand its role as well; evaluation of basic medical education, representative of graduate medical education, policy making of medical manpower education system.

Quantitative Analysis of Airway Walls Using CT Software

PURPOSE: The purpose of this study was to develop dedicated software for quantitative analysis of the airways and to validate the software using airway phantoms and excised swine lung. MATERIALS AND METHODS: The dedicated software was validated in airway phantoms and excised swine lung through comparison of the actual values with the measurements acquired with dedicated software. The accuracy of the measurements according to the reconstruction methods (standard, lung, sharp) and spatial resolution were compared using airway phantoms. Repeatability of the measurement of airway phantoms was assessed with follow-up CT scans three months later. RESULTS: Airway dimension measurements obtained in airway phantoms and excised swine lung showed good agreements with actual values. Airway measurements were more accurate when the sharp reconstruction algorithm was used and when the spatial resolution was improved using pixels smaller than conventional size. There was good agreement between the initial airway measurements and those obtained three months later. CONCLUSION: We developed and validated dedicated software for quantitative airway measurement. Recon-struction with sharp algorithms and high spatial resolution images is recommended for obtaining airway measurements.

Localized-Low Attenuation of the Lung on Thin-Section CT in Experimentally Induced Pulmonary Arterial Occlusion with Balloon Catheter in Pigs

PURPOSE: To determine whether a localized low-attenuation (LLA) is induced on a thin-section CT (TSCT) during an acute pulmonary arterial occlusion in pigs. MATERIALS AND METHODS: In eight pigs, 14 sites of the descending pulmonary artery were obstructed using balloon catheters. The lung TSCTs were obtained immediately after pulmonary artery obstruction (n=13), 10 min (n=10), 30 min (n=14) and 60 min (n=14) after pulmonary artery obstruction at the end of expiration. The TSCTs were also obtained after balloon-deflation at the end of expiration (n=11) and with the balloon-reinflation at inspiration (n=6). RESULTS: Of the 14 sites of pulmonary artery obstruction, 11 (79%) showed LLA. However, LLA progressively became fainter or disappeared on a follow-up CT in seven sites. When the balloon was deflated, 10 of the 11 sites measured showed no change in lung attenuation. After full inspiration, LLA disappeared in three of the six sites. The corresponding areas of LLA on the CT showed a statistically significant increase compared to the baseline CT immediately after inflation (p = 0.021) and 30 minutes after inflation (p =0.041), and after balloon deflation (p =0.036). CONCLUSION: LLA was induced by acute pulmonary artery obstruction. However, LLA, gradually faded over the 60 minutes following obstruction. LLAs were maintained despite the restoration of pulmonary arterial flow, but disappeared as a result of a full inspiration. Thus, LLA might be caused by air trapping.

A New Method of Measuring the Amount of Soft Tissue in Pulmonary Ground-Glass Opacity Nodules: a Phantom Study

OBJECTIVE: To devise a new method to measure the amount of soft tissue in pulmonary ground-glass opacity nodules, and to compare the use of this method with a previous volumetric measurement method by use of a phantom study. MATERIALS AND METHODS: Phantom nodules were prepared with material from fixed normal swine lung. Forty nodules, each with a diameter of 10 mm, were made with a variable mean attenuation. The reference-standard amount of soft tissue in the nodules was obtained by dividing the weight by the specific gravity. The imaging data on the phantom nodules were acquired with the use of a 16-channel multidetector CT scanner. The CT-measured amount of soft tissue of the nodules was calculated as follows: soft tissue amount = volume x (1 + mean attenuation value / 1,000). The relative percentage error (RPE) between the CT-measured amount of the soft tissue and the reference-standard amount of the soft tissue was also measured. The RPEs determined with use of the new method were compared with the RPEs determined with the current volumetric measurement method by the use of the paired t test. RESULTS: The CT-measured amount of soft tissue showed a strong correlation with the reference-standard amount of soft tissue (R(2) = 0.996, p < 0.01). The mean RPE of the CT-measured amount of soft tissue in the nodules was -7.79 +/- 1.88%. The mean RPE of the CT-measured volume was 114.78 +/- 51.02%, which was significantly greater than the RPE of the CT-measured amount of soft tissue (p < 0.01). CONCLUSION: The amount of soft tissue measured by the use of CT reflects the reference-standard amount of soft tissue in the ground-glass opacity nodules much more accurately than does the use of the CT-measured volume.

Serial CT Findings of Paragonimus Infested Dogs and the Micro-CT Findings of the Worm Cysts

OBJECTIVE: To investigate the serial CT findings of Paragonimus westermani infected dogs and the microscopic structures of the worm cysts using Micro-CT. MATERIALS AND METHODS: This study was approved by the committee on animal research at our institution. Fifteen dogs infected with P. westermani underwent serial contrast-enhanced CT scans at pre-infection, after 10 days of infection, and monthly thereafter until six months for determining the radiologic-pathologic correlation. Three dogs (one dog each time) were sacrificed at 1, 3 and 6 months, respectively. After fixation of the lungs, both multi-detector CT and Micro-CT were performed for examining the worm cysts. RESULTS: The initial findings were pleural effusion and/or subpleural ground-glass opacities or linear opacities at day 10. At day 30, subpleural and peribronchial nodules appeared with hydropneumothorax and abdominal or chest wall air bubbles. Cavitary change and bronchial dilatation began to be seen on CT scan at day 30 and this was mostly seen together with mediastinal lymphadenopathy at day 60. Thereafter, subpleural ground-glass opacities and nodules with or without cavitary changes were persistently observed until day 180. After cavitary change of the nodules, the migratory features of the subpleural or peribronchial nodules were seen on all the serial CT scans. Micro-CT showed that the cyst wall contained dilated interconnected tubular structures, which had communications with the cavity and the adjacent distal bronchus. CONCLUSION: The CT findings of paragonimiasis depend on the migratory stage of the worms. The worm cyst can have numerous interconnected tubular channels within its own wall and these channels have connections with the cavity and the adjacent distal bronchus.

Nodular Ground-Glass Opacities on Thin-section CT: Size Change during Follow-up and Pathological Results

OBJECTIVE: To evaluate the inter-group differences in growth and the pathological results of nodular ground-glass opacities (GGOs) according to their size and focal solid portions. MATERIALS AND METHODS: Ninety-six nodular GGOs in 55 individuals followed by CT for at least one month from an initial chest CT were included. Forty nodular GGOs in 30 individuals were pathologically confirmed to be: adenocarcinoma (n = 15), bronchioloalveolar carcinoma (BAC) (n = 11), atypical adenomatous hyperplasia (AAH) (n = 8), focal interstitial fibrosis (n = 5) and aspergillosis (n = 1). Lesions were categorized based on high-resolution CT findings: pure nodular GGO (PNGGO) 10 mm, mixed nodular GGO (MNGGO) 10 mm. In each group, the change in size during the follow-up period, the pathological results and the rate of malignancy were evaluated. RESULTS: Three MNGGO lesions, and none of the PNGGO, grew during the follow-up period. Resected PNGGOs 10 mm were focal interstitial fibrosis (n = 4), AAH (n = 2), BAC (n = 2), and adenocarcinoma (n = 2). Resected MNGGOs 10 mm were adenocarcinoma (n = 11), BAC (n = 3), and aspergillosis (n = 1). CONCLUSION: Mixed nodular GGOs (MNGGOs) had the potential for growth; most were pathologically adenocarcinoma or BAC. By contrast, PNGGOs were stable for several months to years; most were AAH, BAC, or focal interstitial fibrosis.

The Right to Die in Dignity and Comfort

The right to die in dignity and comfort is one of the gravest concerns due to the ever-increasing number of patients with incapacitating illnesses who experience a prolonged painful death, and to the modern trend to place an emphasis on the improvement of quality of life whenever possible. According to the guidelines issued by the Korean Medical Association in 2002, in cases of incurable illnesses, such as terminal stage cancer, meaningless life-maintaining management may be terminated to allow patients to die with dignity. However, the Korean Ministry of Health and Welfare maintains the stance that such guidelines overtly support the institutionalization of "passive euthanasia", and that those who follow such guidelines should be charged with murder, in accordance with the requirements of the existing Korean law. Given that, any one of us may be confronted with such a miserable death, we all have a compelling interest in the revision of the existing legislation, perhaps by using the "U.S. Living Will Registry" as a model.

Reproducibility of Computer-Aided Detection Marks in Digital Mammography

OBJECTIVE: To evaluate the performance and reproducibility of a computer-aided detection (CAD) system in mediolateral oblique (MLO) digital mammograms taken serially, without release of breast compression. MATERIALS AND METHODS: A CAD system was applied preoperatively to the full-field digital mammograms of two MLO views taken without release of breast compression in 82 patients (age range: 33-83 years; mean age: 49 years) with previously diagnosed breast cancers. The total number of visible lesion components in 82 patients was 101: 66 masses and 35 microcalcifications. We analyzed the sensitivity and reproducibility of the CAD marks. RESULTS: he sensitivity of the CAD system for first MLO views was 71% (47/66) for masses and 80% (28/35) for microcalcifications. The sensitivity of the CAD system for second MLO views was 68% (45/66) for masses and 17% (6/35) for microcalcifications. In 84 ipsilateral serial MLO image sets (two patients had bilateral cancers), identical images, regardless of the existence of CAD marks, were obtained for 35% (29/84) and identical images with CAD marks were obtained for 29% (23/78). Identical images, regardless of the existence of CAD marks, for contralateral MLO images were 65% (52/80) and identical images with CAD marks were obtained for 28% (11/39). The reproducibility of CAD marks for the true positive masses in serial MLO views was 84% (42/50) and that for the true positive microcalcifications was 0% (0/34). CONCLUSION: The CAD system in digital mammograms showed a high sensitivity for detecting masses and microcalcifications. However, reproducibility of microcalcification marks was very low in MLO views taken serially without release of breast compression. Minute positional change and patient movement can alter the images and result in a significant effect on the algorithm utilized by the CAD for detecting microcalcifications.

False Positive and False Negative FDG-PET Scans in Various Thoracic Diseases

Fluorodeoxyglucose (FDG)-positron emission tomography (PET) is being used more and more to differentiate benign from malignant focal lesions and it has been shown to be more efficacious than conventional chest computed tomography (CT). However, FDG is not a cancer-specific agent, and false positive findings in benign diseases have been reported. Infectious diseases (mycobacterial, fungal, bacterial infection), sarcoidosis, radiation pneumonitis and post-operative surgical conditions have shown intense uptake on PET scan. On the other hand, tumors with low glycolytic activity such as adenomas, bronchioloalveolar carcinomas, carcinoid tumors, low grade lymphomas and small sized tumors have revealed false negative findings on PET scan. Furthermore, in diseases located near the physiologic uptake sites (heart, bladder, kidney, and liver), FDG-PET should be complemented with other imaging modalities to confirm results and to minimize false negative findings. Familiarity with these false positive and negative findings will help radiologists interpret PET scans more accurately and also will help to determine the significance of the findings. In this review, we illustrate false positive and negative findings of PET scan in a variety of diseases.

CT Findings of Atypical Adenomatous Hyperplasia in the Lung

OBJECTIVE: The aim of this study was to analyze the computed tomographic (CT) findings of atypical adenomatous hyperplasia (AAH) in the lung. MATERIALS AND METHODS: The CT findings of AAHs in eight patients were retrospectively reviewed. The CT findings of each AAH lesion were evaluated for multiplicity, location, shape, size and internal density of the lesion, the interface between the normal lung and the lesion, the internal features within the lesion and any change of the lesion on the follow-up CT scans (range: 33 to 540 days; average: 145.3 days). RESULTS: The eight patients consisted of three men and five women (age range: 43-71 years). Six of eight patients were asymptomatic. Four of them (50%) had synchronous malignancies in the lung: adenocarcinoma of the lung (n = 3), and metastatic squamous cell carcinoma from the uterus (n = 1). We could identify and evaluate eleven AAH nodules in seven patients on the CT scans. Three patients had multiple AAHs. Seven of the 11 lesions (64%) were located in the upper lobe. All the AAHs showed a well-defined oval or round shape and pure ground-glass opacity (GGO) without any solid component (size: 3.9x3 mm to 19x17 mm; internal attenuation: -467 to -785 HU). All the AAHs showed no change of their size and internal density on the follow-up CT scans. CONCLUSION: Atypical adenomatous hyperplasia is often associated with malignancy. This tumor is shown on CT as persistent well-defined oval or round nodular GGOs without solid components, and it does not change on the follow-up CT.

Implementation of Electronic Medical Records at Seoul National University Hospital / 대한의료정보학회지

OBJECTIVE: This study aims to describe the basic features of Electronic Medical Records at the Seoul National University Hospital and Seoul National University Bundang Hospital and to discuss the process we developed and adopted the system. We also aim to suggest potential risks and success factors in our processes. METHODS: Seoul National University Hospital, a tertiary teaching hospital with 100-year-old history, 1000 medical staffs, and 1700 in-patient beds has successfully adopted Electronic Medical Records system from October 2004 and runs very well for more than one year. Our system is fully integrated with Computerized Physician's Order Entry (CPOE) and Picture Archiving and Communication System (PACS). RESULTS: We identified that the key step for the successful adoption of the full system was to overcome physicians' resistance to their use of Electronic Medical Records and to help their earlier accommodation to new practice environment. We then found that five important success factors were the clinical leadership, adoption strategy, young doctors' participation, outsourcing of the department of information technology and the accumulated domain knowledge. Our experience shows it is important to expose young medical staffs to the change before the main Electronic Medical Records system opens and "patient-centered" was the most important concept to make these reform processes successful. CONCLUSION: Development and adoption of Electronic Medical Records at large teaching hospital are not easy but are very important and powerful tool for patient-centered medical practice.

CT Analysis of the Anterior Mediastinum in Idiopathic Pulmonary Fibrosis and Nonspecific Interstitial Pneumonia

OBJECTIVE: We wanted to determine whether the amount and shape of the anterior mediastinal fat in the patients suffering with usual interstitial pneumonia (UIP) or nonspecific interstitial pneumonia (NSIP) was different from those of the normal control group. MATERIALS AND METHODS: We selected patients who suffered with UIP (n = 26) and NSIP (n = 26) who had undergone CT scans. Twenty-six controls were selected from individuals with normal CT findings and normal pulmonary function tests. All three groups (n = 78) were individually matched for age and gender. The amounts of anterior mediastinal fat, and the retrosternal anteroposterior (AP) and transverse dimensions of the anterior mediastinal fat were compared by one-way analysis of variance and Bonferroni's test. The shapes of the anterior mediastinum were compared using the Chi-square test. Exact logistic regression analysis and polychotomous logistic regression analysis were employed to assess whether the patients with NSIP or UIP had a tendency to show a convex shape of their anterior mediastinal fat. RESULTS: The amount of anterior mediastinal fat was not different among the three groups (p = 0.175). For the UIP patients, the retrosternal AP dimension of the anterior mediastinal fat was shorter (p = 0.037) and the transverse dimension of the anterior mediastinal fat was longer (p = 0.001) than those of the normal control group. For the NSIP patients, only the transverse dimension was significantly longer than those of the normal control group (p < 0.001). The convex shape of the anterior mediastinum was predictive of NSIP (OR = 19.7, CI 3.32-infinity, p < 0.001) and UIP (OR = 24.42, CI 4.06-infinity, p < 0.001). CONCLUSION: For UIP patients, the retrosternal AP and transverse dimensions are different from those of normal individuals, whereas the amounts of anterior mediastinal fat are similar. UIP and NSIP patients have a tendency to have a convex shape of their anterior mediastinal fat.

Digital Chest Radiography with an Amorphous Silicon Flat-Panel-Detector Versus a Storage-Phosphor System: Comparison of Soft-Copy Images

PURPOSE: We compared the soft-copy images produced by an amorphous silicon flat-panel-detector system with the images produced by a storage-phosphor radiography system for their ability to visualize anatomic regions of the chest. MATERIALS AND METHODS: Two chest radiologists independently analyzed 234 posteroanterior chest radiographs obtained from 78 patients on high-resolution liquid crystal display monitors (2560x2048x8 bits). In each patient, one radiograph was obtained with a storage-phosphor system, and two radiographs were obtained via amorphous silicon flat-panel-detector radiography with and without spatial frequency filtering. After randomizing the 234 images, the interpreters rated the visibility and radiographic quality of 11 different anatomic regions. Each image was ranked on a five-point scale (1 = not visualized, 2 = poor visualization, 3 = fair visualization, 4 = good visualization, and 5 = excellent visualization). The statistical difference between each system was determined using the Wilcoxon's signed rank test. RESULTS: The visibility of three anatomic regions (hilum, heart border and ribs), as determined by the chest radiologist with 14 years experience (p<0.05) and the visibility of the thoracic spine, as determined by the chest radiologist with 8 years experience (p=0.036), on the amorphous silicon flat-panel-detector radiography prior to spatial frequency filtering were significantly superior to that on the storage-phosphor radiography. The visibility of 11 anatomic regions, as determined by the chest radiologist with 14 years experience (p<0.0001) and the visibility of five anatomic regions (unobscured lung, rib, proximal airway, thoracic spine and overall appearance), as determined by the chest radiologist with 8 years experience (p<0.05), on the amorphous silicon flat-panel-detector radiography after spatial frequency filtering were significantly superior to that on the storage-phosphor radiography. CONCLUSION: The amorphous silicon flat-panel-detector system depicted the anatomic structures on chest radiographs comparably or significantly better as compared to the storage-phosphor system. The superiority of the amorphous silicon flat-panel-detector system compared to the storage-phosphor system was more obvious after performing spatial frequency filtering.

Detection of the Anatomic Structure and Pathology in Animal Lung Specimens: Comparison of Micro CT and Multi-Detector Row CT

PURPOSE: We wanted to compare the capability of micro CT and the clinically available thin-slice multi-detector row CT (MDCT) for demonstrating fine anatomic structures and pathological lesions in formalin-fixed lung specimens. MATERIALS AND METHODS: The porcine lung with shark liver oil-induced lipoid pneumonia and the canine lung with pulmonary paragonimiasis were fixed by ventilating them with formalin vapor, and they were then sliced into one-centimeter thick sections. Micro CT (section thickness, 18 micrometer) and MDCT (section thickness, 0.75 mm) images were acquired in four of the lung slices of the lipoid pneumonia specimen and in five of the lung slices of the paragonimiasis specimen. On 62 pairs of micro CT and MDCT images, 169 pairs of rectangular ROIs were manually drawn in the corresponding locations. Two chest radiologists recorded the detectability of three kinds of anatomic structures (lobular core structure, interlobular septum and small bronchiolar lumen) and two kinds of pathological lesions (ground-glass opacity and consolidation) with using a five-point scale. The statistical comparison was performed by using the Wilcoxon signed rank test. Interobserver agreement was evaluated with kappa statistics. RESULTS: For all observers, all the kinds of anatomic structures and pathological lesions were detected better on the micro CT images than on the MDCT images (p<0.01). Agreement was fair between two observers (kappa = 0.38, p<0.001). CONCLUSION: The fine anatomic structures and pathological lesions of the lung were more accurately demonstrated on micro CT than on thin-slice MDCT in the inflated and fixed lung specimens.

The Effect of Dose Reduction on Image Quality in Digital Radiography Using a Flat-panel Detector: Experimental Study in Rabbits

PURPOSE: To evaluate the effect of dose reduction on image quality in digital radiography using a flat-panel detector. MATERIALS AND METHODS: Digital radiographs of 30 rabbits were obtained at two different dose levels (33.23 µGy for the standard dose group and 20.09 µGy for the reduced dose group). The amorphous selenium-based flat-panel detector system had a panel size of 7x8.5 inches, a matrix of 1280x1536 (pixels?), and a pixel pitch of 138 µm. Four observers evaluated the soft-copy images on a high-resolution video monitor (2560x2048x8 bits) in random order. The observers rated the visibility of 13 different anatomic structures on a 5-point scale, viz. the retrocardiac lung, subdiaphragmatic lung, heart border, diaphragmatic border, proximal airway, unobscured lung, liver border, kidney border, bowel gas, flank stripe, ribs, and vertebrae in the mediastinal and abdominal regions. Statistical significance was determined using Wilcoxon's signed rank test. RESULTS: There was no statistically significant difference in the visibility of the anatomic structures on digital radiography between the standard and reduced dose groups. CONCLUSION: Digital radiography using an amorphous selenium-based flat-panel detector can preserve the image quality, even though the does is reduced to 40% of the standard level.

Evaluation of Computer Aided Volumetry for Simulated Small Pulmonary Nodules on Computed Tomography

PURPOSE: To determine the accuracy of automated computer aided volumetry for simulated small pulmonary nodules at computed tomography using various types of phantoms MATERIALS AND METHODS: Three sets of synthetic nodules (small, calcified and those adjacent to vessels) were studied. The volume of the nodules in each set was already known, and using multi-slice CT, volumetric data for each nodule was acquired from the three-dimensional reconstructed image. The volume was calculated by applying three different threshold values using Rapidia(R) software (3D-Med, Seoul, Korea). RESULTS: Relative errors in the measured volume of synthetic pulmonary nodules were 17.3, 2.9, and 11.5% at -200, -400, and -600 HU, respectively, and there was good correlation between true volume and measured volume at -400 HU (r=0.96, p<0.001). For calcified nodules, relative errors in measured volume were 10.9, 5.3, and 16.5% at -200, -400, and -600 HU, respectively, and there was good correlation between true volume and measured volume at -400 HU (r=1.03, p<0.001). In cases involving synthetic nodules adjacent to vessels, relative errors were 4.6, 16.3, and 31.2 % at -200, -400, and -600 HU, respectively. There was good correlation between true volume and measured volume at -200 HU (r=1.1, p<0.001). CONCLUSION: Using computer-aided volumetry, the measured volumes of synthetic nodules correlated closely with their true volume. Measured volumes were the same at each threshold level, regardless of window setting.

Mediastinal and Extrapleural Fat Hypertrophy in Idiopathic Pulmonary Fibrosis on High-resolution CT: Comparison with Normal Individuals

PURPOSE: We wished to compare the amount of mediastinal and extrapleural fat on high resolution CT for patients with idiopathic pulmonary fibrosis (IPF) with that of normal individuals, and we wished to evaluate the correlation between the amount of fat and the degree of pulmonary fibrosis. MATERIALS AND METHODS: We selected a group of 25 patients with radiologically and clinically diagnosed IPF and we also selected another group of 25 age and gender-matched patients having no abnormalities on pulmonary function testing as well as HRCT as controls from our radiologic database search (mean age: 59 years, M:F=11:14). We measured the area of mediastinal and extrapleural fat at the levels of the aortic arch and at the origin of the right pulmonary artery and right inferior pulmonary vein on three sections of HRCT by using software (Rapidia; 3DMED, Seoul, Korea). The total amount of fat was calculated by summing up the areas of the mediastinal and extrapleural fat, which is corrected by the body mass index; we also evaluated statistical differences between the two groups. At same sections of CT, the ratio (%) of the honeycombing area to the total areas of the lung was calculated. We evaluated the relationship between the amount of extrapleural or mediastinal fat with the ratio (%) of the honeycombing area. RESULTS: The total amount of fat in patients with IPF and normal individuals were 67.24+/-19.03 cm2 and 32.55+/-11.91 cm2, respectively. The fat amount corrected by body mass index was 280.48+/-74.43 mm2/kg/m2 in the IPF patients and 137.06+/-41.76 mm2/kg/m2 in normal individuals. The differences between two groups for the total amount of fat and fat amount, as corrected for by the body mass index, were statistically significant (p<0.0001). The ratio (%) of the honeycombing area and the total amount of fat showed a moderate correlation (rho= 0.43, p= 0.032). CONCLUSION:Patients with IPF have a larger amount of mediastinal and extrapleural fat than normal individuals. The hypertrophy of mediastinal and extrapleural fat in IPF may be affected by the severity of the interstitial fibrosis of the lung.

Hodgkin's Lymphoma Mimicking Necrotizing Pneumonia: Case Report

This study describes a case of pulmonary Hodgkin's lymphoma of the nodular sclerosing type presenting as a large cavitary mass with air-fluid levels. We also conduct a review of the previous articles on pulmonary Hodgkin's lymphoma.