Semi-Automatic Measurement of the Airway Dimension by Computed Tomography Using the Full-Width-Half-Maximum Method: a Study on the Measurement Accuracy according to the CT Parameters and Size of the Airway

OBJECTIVE: To assess the influence of variable factors such as the size of the airway and the CT imaging parameters such as the reconstruction kernel, field-of-view (FOV), and slice thickness on the automatic measurement of airway dimension. MATERIALS AND METHODS: An airway phantom was fabricated that contained eleven poly-acryl tubes of various lumen diameters and wall thicknesses. The measured density of the poly-acryl wall was 150 HU, and the measured density of the airspace filled with polyurethane foam was -900 HU. CT images were obtained using a 16-MDCT (multidetector CT) scanner and were reconstructed with various reconstruction kernels, thicknesses and FOV. The luminal radius and wall thickness were measured using in-house software based on the full-width-half-maximum method. The measured values as determined by CT and the actual dimensions of the tubes were compared. RESULTS: Measurements were most accurate on images reconstructed with use of a standard kernel (mean error: -0.03 +/- 0.21 mm for wall thickness and -0.12 +/- 0.11 mm for the luminal radius). There was no significant difference in accuracy among images with the use of variable slice thicknesses or a variable FOV. Below a 1-mm threshold, the measurement failed to represent the change of the real dimensions. CONCLUSION: Measurement accuracy was strongly influenced by the specific reconstruction kernel utilized. For accurate measurement, standardization of the imaging protocol and selection of the appropriate anatomic level are essential.

Semi-Automatic Measurement of the Airway Dimension by Computed Tomography Using the Full-With-Half-Maximum Method: a Study of the Measurement Accuracy according to the Orientation of an Artificial Airway

OBJECTIVE: To develop an algorithm to measure the dimensions of an airway oriented obliquely on a volumetric CT, as well as assess the effect of the imaging parameters on the correct measurement of the airway dimension. MATERIALS AND METHODS: An airway phantom with 11 poly-acryl tubes of various lumen diameters and wall thicknesses was scanned using a 16-MDCT (multidetector CT) at various tilt angles (0, 30, 45, and 60degree). The CT images were reconstructed at various reconstruction kernels and thicknesses. The axis of each airway was determined using the 3D thinning algorithm, with images perpendicular to the axis being reconstructed. The luminal radius and wall thickness was measured by the full-width-half-maximum method. The influence of the CT parameters (the size of the airways, obliquity on the radius and wall thickness) was assessed by comparing the actual dimension of each tube with the estimated values. RESULTS: The 3D thinning algorithm correctly determined the axis of the oblique airway in all tubes (mean error: 0.91 +/- 0.82degree). A sharper reconstruction kernel, thicker image thickness and larger tilt angle of the airway axis resulted in a significant decrease of the measured wall thickness and an increase of the measured luminal radius. Use of a standard kernel and a 0.75-mm slice thickness resulted in the most accurate measurement of airway dimension, which was independent of obliquity. CONCLUSION: The airway obliquity and imaging parameters have a strong influence on the accuracy of the airway wall measurement. For the accurate measurement of airway thickness, the CT images should be reconstructed with a standard kernel and a 0.75 mm slice thickness.

Unusual CT Findings of a Benign Metastasizing Leiomyoma Presenting with Multiple Cavitary Nodules: A Case Report

A benign metastasizing leiomyoma is a rare condition that affects women with a history of uterine leiomyoma, usually after a myomectomy or hysterectomy. Typical radiographic findings include well-circumscribed solitary or multiple pulmonary nodules ranging from a few millimeters to several centimeters in diameter and scattered among the normal interstitium. We report a case of a benign metastasizing leiomyoma that manifested with multiple cavitary nodules in a 46-year-old woman with no previous history of a myomectomy or hysterectomy.

Differentiation of Recently Infarcted Myocardium from Chronic Myocardial Scar: The Value of Contrast-Enhanced SSFP-Based Cine MR Imaging

The purpose of this study is to demonstrate whether the signal intensity (SI) of myocardial infarction (MI) on contrast enhanced (CE)-cine MRI is useful for differentiating recently infarcted myocardium from chronic scar. This study included 24 patients with acute MI (36-84 years, mean age: 57) and 19 patients with chronic MI (44-80 years, mean age: 64). The diagnosis of acute MI was based on the presence of typical symptoms, i.e. elevation of the cardiac enzymes and the absence of any remote infarction history. The diagnosis of chronic MI was based on a history of MI or coronary artery disease of more than one month duration and on the absence of any recent MI within the previous six months. Retrospectively, the ECG-gated breath-hold cine imaging was performed in the short axis plane using a segmented, balanced, turbo-field, echo-pulse sequence two minutes after the administration of Gd-DTPA at a dose of 0.2 mmol/kg body weight. Delayed contrast-enhanced MRI (DCE MRI) in the same plane was performed 10 to 15 minutes after contrast administration, and this was served as the gold standard of reference. The SI of the infarcted myocardium on the CE-cine MRI was compared with that of the normal myocardium on the same image. The area of abnormal SI on the CE-cine MRI was compared with the area of hyperenhancement on the DCE MRI. The area of high SI on the CE-cine MRI was detected in 23 of 24 patients with acute MI (10 with homogenous high SI, 13 high SI with subendocardial low SI, and one with iso SI). The area of high SI on the CE-cine MRI was larger than that seen on the DCE MRI (p < 0.05). In contrast, the areas of chronic MI were seen as iso-SI with thin subendocardial low SI on the CE-cine MR in all the chronic MI patients. The presence of high SI on both the CE-cine MRI and the DCE MRI is more sensitive (95.8%) for determining the age of a MI than the presence of myocardial thinning (66.7%). This study showed the different SI patterns between recently infarcted myocardium and chronic scar on the CE-cine MRI. CE-cine MRI is thought to be quite useful for determining the age of myocardial infarction, in addition to its utility for assessing myocardial contractility.

Comparison of Transaxial Source Images and 3-Plane, Thin-Slab Maximal Intensity Projection Images for the Diagnosis of Coronary Artery Stenosis with Using ECG-Gated Cardiac CT

OBJECTIVE: We wanted to compare the transaxial source images with the optimized three plane, thin-slab maximum intensity projection (MIP) images from electrocardiographic (ECG)-gated cardiac CT for their ability to detect hemodynamically significant stenosis (HSS), and we did this by means of performing a receiver operating characteristic (ROC) analysis. MATERIALS AND METHODS: Twenty-eight patients with a heart rate less than 66 beats per minute and who were undergoing both retrospective ECG-gated cardiac CT and conventional coronary angiography were included in this study. The contrast-enhanced CT scans were obtained with a collimation of 16x0.75-mm and a rotation time of 420 msec. The transaxial images were reconstructed at the mid-diastolic phase with a 1-mm slice thickness and a 0.5-mm increment. Using the transaxial images, the slab MIP images were created with a 4-mm thickness and a 2-mm increment, and they covered the entire heart in the horizontal long axis (4 chamber view), in the vertical long axis (2 chamber view) and in the short axis. The transaxial images and MIP images were independently evaluated for their ability to detect HSS. Conventional coronary angiograms of the same study group served as the standard of reference. Four radiologists were requested to rank each image with using a five-point scale (1 = definitely negative, 2 = probably negative, 3 = indeterminate, 4 = probably positive, and 5 = definitely positive) for the presence of HSS; the data were then interpreted using ROC analysis. RESULTS: There was no statistical difference in the area under the ROC curve between transaxial images and MIP images for the detection of HSS (0.8375 and 0.8708, respectively; p > 0.05). The mean reading time for the transaxial source images and the MIP images was 116 and 126.5 minutes, respectively. CONCLUSION: The diagnostic performance of the MIP images for detecting HSS of the coronary arteries is acceptable and this technique's ability to detect HSS is comparable to that of the transaxial source images.

Subtle Pleural Metastasis without Large Effusion in Lung Cancer Patients: Preoperative Detection on CT

OBJECTIVE: We wanted to describe the retrospective CT features of subtle pleural metastasis without large effusion that would suggest inoperable lung cancer. MATERIALS AND METHODS: We enrolled 14 patients who had open thoracotomy attempted for lung cancer, but they were proven to be inoperable due to pleural metastasis. Our study also included 20 control patients who were proven as having no pleural metastasis. We retrospectively evaluated the nodularity and thickening of the pleura and the associated pleural effusion on the preoperative chest CT scans. We reviewed the histologic cancer types, the size, shape and location of the lung cancer and the associated mediastinal lymphadenopathy. RESULTS: Subtle pleural nodularity or focal thickening was noted in seven patients (50%) having pleural metastasis and also in three patients (15%) of control group who were without pleural metastasis. More than one of the pleural changes such as subtle pleural nodularity, focal thickening or effusion was identified in eight (57%) patients having pleural metastasis and also in three patients (15%) of the control group, and these findings were significantly less frequent in the control group patients than for the patients with pleural metastasis (p = 0.02). The histologic types of primary lung cancer in patients with pleural metastasis revealed as adenocarcinoma in 10 patients (71%) and squamous cell carcinoma in four patients (29%). The location, size and shape of the primary lung cancer and the associated mediastinal lymphadenopathy showed no significant correlation with pleural metastasis. CONCLUSION: If any subtle pleural nodularity or thickening is found on preoperative chest CT scans of patients with lung cancer, the possibility of pleural metastasis should be considered.

CT Findings of Diffuse Esophageal Spasm: Case Report

We report the CT findings of diffuse esophageal spasm (DES) in a patient with dysphagia. Although an uncommon condition, DES should be included in the differential diagnosis if relatively long and symmetric segmental esophageal wall thickening and an epiphrenic esophageal diverticulum are noted at CT.

Percutaneous Fine Needle Aspiration Biopsy for the Intrathoracic Lesions: What is the Meaning of Non-Diagnostic Results?

PURPOSE: To know what is the meaning of non-diagnostic results of fine needle aspiration biopsy (FNAB) and whether repeated aspiration is needed or not in those situations. MATERIALS AND METHODS: We reviewed 1845 patients who underwent FNAB from 1997 to 2001. Non-diagnostic results of the first FNAB were divided into four groups: insufficient number of cells, inflammatory cells, necrotic debris and atypical cells. We analyzed final diagnosis of 531 patients who had non-diagnostic results from the first FNAB. Among them, 207 lesions were re-biopsied because of clinical and radiologic suspicion of malignancy. The diagnostic yield of repeated FNAB was analyzed and compared with the results of the first FNAB. RESULTS: Among 255 cases with "inflammatory cells only" results, 120 cases were confirmed benignancy on follow-up. Twenty nine of 50 atypical cells (58%) were malignant on follow-up. One hundred one of 207 repeated FNAB resulted in the non-diagnostic reports, and 106 of 207 repeated FNAB were diagnosed as specific diagnosis. Among thirty lesions showing atypical cells on the repeated FNAB, 22 (73%) were identified as malignant neoplasms. CONCLUSION: When the specimen of FNAB shows atypical cells, the possibility of malignancy is very high. When the results of FNAB is non-diagnostic in the cases with clinical and radiological suspicion of malignancy, repeated FNAB procedures should be seriously considered and will be helpful for accurate specific diagnosis.

Liquid-Crystal Display Monitors and Cathode-Ray Tube Monitors: A Comparison of Observer Performance in the Detection of Small Solitary Pulmonary Nodules

OBJECTIVE: To compare observer performance using liquid-crystal display (LCD) and cathode-ray tube (CRT) monitors in the interpretation of soft-copy chest radiographs for the detection of small solitary pulmonary nodules. MATERIALS AND METHODS: By reviewing our Medical Center's radiologic information system, the eight radiologists participating in this study (three board-certified and five resident) retrospectively collected 40 chest radiographs showing a solitary noncalcified pulmonary nodule approximately 1 cm in diameter, and 40 normal chest radiographs. All were obtained using a storage-phosphor system, and CT scans of the same patients served as the gold standard for the presence of a pulmonary nodule. Digital images were displayed on both high-resolution LCD and CRT monitors. The readers were requested to rank each image using a five point scale (1 = definitely negative, 3 = equivocal or indeterminate, 5 = definitely positive), and the data were interpreted using receiver operating characteristic (ROC) analysis. RESULTS: The mean area under the ROC curve was 0.8901+/-0.0259 for the LCD session, and 0.8716+/-0.0266 for the CRT session (p > 0.05). The reading time for the LCD session was not significantly different from that for the CRT session (37.12 and 41.46 minutes, respectively; p = 0.889). CONCLUSION: For detecting small solitary pulmonary nodules, an LCD monitor and a CRT monitor are comparable.

Superficial Endobronchial Lung Cancer: Radiologic-Pathologic Correlation

OBJECTIVE: To analyze the plain chest radiographic and CT findings of superficial endobronchial lung cancer and to correlate these with the findings of histopathology. MATERIALS AND METHODS: This study involved 19 consecutive patients with pathologically proven lung cancer confined to the bronchial wall. Chest radiographs and CT scans were reviewed for the presence of parenchymal abnormalities, endobronchial nodules, bronchial obstruction, and bronchial wall thickening and stenosis. The CT and histopathologic findings were compared. RESULTS: Sixteen of the 19 patients had abnormal chest radiographic findings, while in 15 (79%), CT revealed bronchial abnormalities: an endobronchial nodule in seven, bronchial obstruction in five, and bronchial wall thickening and stenosis in three. Histopathologically, the lesions appeared as endobronchial nodules in 11 patients, irregular thickening of the bronchial wall in six, elevated mucosa in one, and carcinoma in situ in one. CONCLUSION: CT helps detect superficial endobronchial lung cancer in 79% of these patients, though there is some disagreement between the CT findings and the pathologic pattern of bronchial lesions. Although nonspecific, findings of bronchial obstruction or bronchial wall thickening and stenosis should not be overlooked, and if clinically necessary, bronchoscopy should be performed.

High Resolution CT Findings of Pseudoalveolar Sarcoidosis

PURPOSE: To determine the specific high-resolution CT features of sarcoidosis in which the observed pattern is predominantly pseudoalveolar. MATERIALS AND METHODS: We retrospectively reviewed the HRCT findings in 15 cases in which chest radiography demonstrated pseudoalveolar consolidation. In all 15, sarcoidosis was pathologically proven. The distribution and characterization of the following CT features was meticulously scrutinized: distribution and characterization of pseudoalveolar lesions, air-bronchograms, micronodules, thickening of bronchovascular bundles and interlobular septa, lung distortion, ground-glass opacities and combined hilar and mediastinal lymphadenopathy. Follow-up CT scans were available in three cases after corticosteroid administration. RESULTS: Between one and 12 (mean, 5.6) pseudoalveolar lesions appeared as dense homogeneous or inhomogeneous opacities 1-4.5 cm in diameter and with an irregular margin located either at the lung periphery adjacent to the pleural surface or along the bronchovascular bundles, with mainly bilateral distribution (n=14, 93%). An air-bronchogram was observed in ten cases. Micronodules were observed at the periphery of the lesion or surrounding lung, which along with a thickened bronchovascular bundle was a consistent feature in all cases. Additional CT features included hilar and mediastinal lymphadenopathy (n=14, 93%), thickened interlobular septa (n=12, 80%), and ground-glass opacity (n=10, 67%). Lung distortion was noted in only one case (7%). After steroid administration pseudoalveolar lesions decreased in number and size in all three cases in which follow-up CT was available. CONCLUSION: The consistent HRCT features of pseudoalveolar sarcoidosis are bilateral multifocal dense homogenous or inhomogenous opacity and an irregular margin located either at the lung periphery adjacent to the pleural surface or along the bronchovascular bundles. Micronodules are present at the periphery of the lesion or surrounding lung. The features are reversible at steroid administration.

The Diagnosis of Small Solitary Pulmonary Nodule: Comparison of Standard and Inverse Digital Images on a High-Resolution Monitor using ROC Analysis

PURPOSE: To study the impact of inversion of soft-copy chest radiographs on the detection of small solitary pulmonary nodules using a high-resolution monitor. MATERIALS AND METHODS: The study group consisted of 80 patients who had undergone posterior chest radiography; 40 had a solitary noncalcified pulmonary nodule approximately 1 cm in diameter, and 40 were control subjects. Standard and inverse digital images using the inversion tool on a PACS system were displayed on high-resolution monitors (2048x2560x8 bit). Ten radiologists were requested to rank each image using a five-point scale (1=definitely negative, 3=equivocal or indeterminate, 5=definite nodule), and the data were interpreted using receiver operating characteristic (ROC) analysis. RESULTS: The area under the ROC curve for pooled data of standard image sets was significantly larger than that of inverse image sets (0.8893 and 0.8095, respectively; p0.05). CONCLUSION: For detecting small solitary pulmonary nodules, inverse digital images were significantly inferior to standard digital images.

Diffuse Telangiectatic Type of Pulmonary Arteriovenous Malformation Diagnosed with CT Scan using Slab Maximum Intensity Projection Technique: A Case Report

Diffuse telangiectatic type of pulmonary arteriovenous malformation (AVM) is an uncommon disease entity in which numerous small arteriovenous connections occur throughout the lungs. It has rarely been confirmed by pulmonary angiography. We report a case of diffuse telangiectatic pulmonary AVM occurring in a patient with dyspnea and confirmed by CT using the slab maximum intensity projection (MIP) technique and conventional direct pulmonary angiography.

Ground-Glass Opacity in Lung Metastasis from Adenocarcinoma of the Stomach: A Case Report

Ground-glass opacity is a frequent but nonspecific finding seen on high-resolution CT scans of lung parenchyma. Histologically, this appearance is observed when thickening of the alveolar wall and septal interstitium is minimal or the alveolar lumen is partially filled with fluid, macrophage, neutrophils, or amorphous material. It has been shown that ground-glass opacity may be caused not only by an active inflammatory process but also by fibrotic processes. When a focal area of ground-glass opacity persists or increases in size, the possibility of neoplasm-bronchioloalveolar carcinoma or adenoma, or lymphoma, for example- should be considered. Diffuse nonsegmental ground-glass opacity in both lung fields was incidentally found on follow up abdominal CT in a stomach cancer patient and signet-ring cell-type metastatic lung cancer was confirmed by transbronchial lung biopsy. We report a case of diffuse ground-glass opacity seen in metastatic lung cancer from adenocarcinoma of the stomach.

Pulmonary Nodules Resected for Suspected Metastsis from Extrapulmonary Malignancy: CT-Pathologic Correlation

PURPOSE: To assess the relative frequency of benign and metastatic nodules in patients in whom nodules were resected due to suspected metastasis, and to compare the CT features of these nodules with pathologic findings in resected specimens. MATERIALS AND METHODS: Ninety-four pulmonary nodules resected by pulmonary metastasectomy in 31 patients with extrathoracic malignancies were included in our study. We retrospectively analyzed the CT features of each nodule with regard to size, shape, margin characteristics, the presence or absence of cavity, location and distance from the pleura. RESULTS: Among 94 resected nodules, 67 (71 %) were metastatic, and 27 (29 %), were benign. Among the pathologically benign nodules, involvement was as follows : fibrosis (n=14), intrapulmonary lymph node (n=7), necrosis (n=3), organizing pneumonia (n=2) and xanthogranulomatous inflammation (n=1). The mean diameter of metastatic nodules was 10.9 (range, 1-30) mm, and that of benign nodules 6.0 (range, 1-30) mm. Statistically significant differences in nodule size were found between the two groups (p<0.05), though CT revealed no significant differences in terms of shape, margin, the presence or absence of cavity, location and distance from the pleura. CONCLUSIONS: Twenty-nine percent of surgically resected nodules in patients with extrathoracic malignancies were benign. Although the possibility of metastatic nodule increases with larger nodule size, the correct diagnosis of pulmonary nodules requires histopathologic confirmation or monitoring of serial changes in nodule size.

Pulmonary Nodules Resected for Suspected Metastsis from Extrapulmonary Malignancy: CT-Pathologic Correlation

PURPOSE: To assess the relative frequency of benign and metastatic nodules in patients in whom nodules were resected due to suspected metastasis, and to compare the CT features of these nodules with pathologic findings in resected specimens. MATERIALS AND METHODS: Ninety-four pulmonary nodules resected by pulmonary metastasectomy in 31 patients with extrathoracic malignancies were included in our study. We retrospectively analyzed the CT features of each nodule with regard to size, shape, margin characteristics, the presence or absence of cavity, location and distance from the pleura. RESULTS: Among 94 resected nodules, 67 (71 %) were metastatic, and 27 (29 %), were benign. Among the pathologically benign nodules, involvement was as follows : fibrosis (n=14), intrapulmonary lymph node (n=7), necrosis (n=3), organizing pneumonia (n=2) and xanthogranulomatous inflammation (n=1). The mean diameter of metastatic nodules was 10.9 (range, 1-30) mm, and that of benign nodules 6.0 (range, 1-30) mm. Statistically significant differences in nodule size were found between the two groups (p<0.05), though CT revealed no significant differences in terms of shape, margin, the presence or absence of cavity, location and distance from the pleura. CONCLUSIONS: Twenty-nine percent of surgically resected nodules in patients with extrathoracic malignancies were benign. Although the possibility of metastatic nodule increases with larger nodule size, the correct diagnosis of pulmonary nodules requires histopathologic confirmation or monitoring of serial changes in nodule size.

Extensive acute lung injury following limited thoracic irradiation: radiologic findings in three patients

The aim of our study was to describe the radiologic findings of extensive acute lung injury associated with limited thoracic irradiation. Limited thoracic irradiation occasionally results in acute lung injury. In this condition, chest radiograph shows diffuse ground-glass appearance in both lungs and thin-section CT scans show diffuse bilateral ground-glass attenuation with traction bronchiectasis, interlobular septal thickening and intralobular smooth linear opacities.

The Usefulness of Thin-Section Spiral CT in the Evaluation of Mediastinal Lymph Node Metastasis from Non-Small Cell Lung Cancer: AProspective Study and Comparison with Thick-Section Spiral CT

PURPOSE: To compare the accuracy of thick-and thin-section spiral CT and to determine whether, in diagnosing mediastinal lymph node metastasis from non-small cell lung cancer, the latter is superior to the former. MATERIALS AND METHODS: Between March 1997 and March 1998, 51 patients with pathologically proven non-s-mall cell lung cancer underwent thoracotomy with full nodal dissection. Thick- and thin-section spiral CT were performed in all patients, with a mean interval of 14 days. The former was performed with 10 mm thick-ness and 10 mm interval, and the latter with 3 mm thickness and 3 mm interval. Mediastinal lymph nodes were localized according to the lymph node mapping scheme of the American Thoracic Society and were considered positive for metastasis if they exceeded 10 mm in short-axis diameter. RESULTS: A total of 227 mediastinal nodal stations in 51 patients were obtained. Of these, 188 stations included in thin-section spiral CT were analyzed and the prevalence of ediastinal nodal metastasis was found to be 10%. On a station-by-station basis, and for thick-and thin-section spiral CT, respectively, the overall sensitivi-ties of mediastinal lymph node metastasis were 32% and 53% (p .05). Although there were no statistically significant differences in sensitivity and specificity according to nodal station, thin-section spiral CT tended to be superior to the thick-section type for stations 7 and 10R in terms of sensitivity, and for stations 4L and 5 in terms of specificity. CONCLUSION: Thin-section spiral CT was more sensitive than thick-section spiral CT is the evaluation of medi-astinal lymph node metastasis from non-small cell lung cancer. This may be due to the higher resolution of the former and its ability to discriminate between lymph node and vessel.

The Clinical Characteristics of Lung Cancer in Patients with Idiopathic Pulmonary Fibrosis / 결핵

BACKGROUND: It has been generally known that the incidence of lung cancer is higher in the patients with idopathic pumonary fibrosis (IPF) than those in general population the reported incidences was variable from 4.8 to 43.2%. There were controversies on the most frequent cell type (squamous cell carcinoma vs. adenocarcinoma) and no study was done about the real concordance of cancer and the fibrotic lesion. And the pulmonary fibrosis may influence not only the development of cancer but also the treatment and prognosis of the cancer, but there was no report on that point. METHOD: Total 63 patients (66.8 ? 7.8 year, M:F=61:2) were diagnosed as IPF combined with lung cancer(IPF-CA) at Asan Medical Center. A retrospective analysis was done about the risk factors of the lung cancer, pulmonary function test, the site of cancer(especially the relationship of the cancer with the fibrotic lesion), the histologic types, and the stage of cancer. The histologic types were compared with these of 2,660 patients with lung cancer who were diagnosed at the same institute for the same period. The effect of IPF on the treatment of the cancer was evaluated with the survival time after the detection of lung cancer. RESULTS: The lung cancer was found in 63(22.9%) out of 281 patients with IPF. But in most of them(45 patients), lung cancer was detected at the same time with IPF and only in 18 patients, the cancer was diagnosed during the follow-up (25.2+/-17.7 months) of IPF. So in our study, 6.7% of patients with IPF developed lung cancer during the course of the disease. The age (66.8+/-7.84 vs. 63.4+/-11.1 years), percentage of smoker (88.9 vs. 67.2%), and the male gender (96.8 vs. 67.6%) were significantly higher in IPF-CA compared with lone IPF (p<0.05). The odds ratio of smoking was 4.7 compared with non smoking IPF controls. The lung cancer was located more frequently in the upper lobe and 55.5% was in the periphery of lung. The cancer was developed in the fibrotic lesion in 23 patients (35.9%), and in the majority of the patients, the cancer was separated from the fibrosis. The cell type of the lung cancer in IPF-CA was squamous cell carcinoma 34.9%, adenocarcinoma 30.2%, small cell carcinoma 19.0%, large cell undifferenciated carcinoma 6.3%, and others 9.5%. No significant difference in the distribution of histologic type of the lung cancer was found between IPF-CA and lone lung cancer. There was no significant difference in demographic features, cell types, location and the stage of the cancer between the group with concurrent IPF-CA and the group with cancer diagnosed during the follow up of IPF. There was a tendency (but statistically not significant : p=0.081) of higher incidence of adenocarcinoma among the cancers developed in the fibrotic area (43.5%) (F-CA) than in the cancers in non-fibrotic area (22.5%) (NF-CA). The prognosis of the patients with F-CA was poor (median survival : 4 months) compared with the patients with NF-CA (7 months, p=0.013), partly because the prevalence of severe IPF (the extent of fibrosis in HRCT ?50%) was higher in F-CA group. CONCLUSION: These data suggest that the lung cancer in the patients with IPF has similar features to the ordinary lung cancer.

Aortic Arch Aneurysm: CT and MR Features

PURPOSE: The purpose of this study was to evaluate the CT and MR features of aortic arch aneurysms and todetermine the differences between involved segments and morphologic types according to their causes. MATERIALS AND METHODS: Twenty-nine patients with aortic arch aneurysms who underwent CT scanning(n=24) and/or MR imaging(n=16)were retrospectively evaluated. The aneurysms were analyzed with respect to location of involved segment,morphology, direction and size, and morphologic differences between aneurysms were compared according to causes. RESULTS: The causes of arch aneurysms were atherosclerosis in 25 patients(86%), trauma in three (10%) and infection in one (4%). Arch aneurysms were frequently located at the arch only(n=17,59%), ascending aorta toarch(n=6,21%), arch to descending aorta(n=4,14%), or ascending aorta to descending aorta(n=2,7%). The shape of theaneurysm was fusiform in 15 patients and saccular in 14. Atherosclerotic aneurysms(n=25) were fusiform in 15patients and saccular in ten. Arch aneurysms due to trauma and infection(n=4) were saccular. MRI was more helpfulthan CT scanning involved site, direction, and morphology of the aneurysm. CONCLUSION: Bothe CT scanning and MRIeasily diagnose arch aneurysms, though MRI is a very useful imaging modality for evaluating involved aorticsegments and morphologic types. Aortic arch aneurysms are either fusiform or saccular. Most saccular aneurysmsinvolve the aortic arch, whereas the involvement of fusiform aneurysms is more varied. Atherosclerosis is the mostcommon cause of both fusiform and saccular arch aneurysms.