Search PubMed⌕ Search

Biomedical subjects

J G Im

Publications and source records attributed to J G Im.

At least 37 records · Page 2Linked to original sources
PubMed1999

Subaortic left innominate vein: radiologic findings and consideration of embryogenesis.

To propose a hypothesis about the embryogenesis of the subaortic left innominate vein, the authors reviewed the radiologic features of 14 patients diagnosed with subaortic left innominate vein made by computed tomography or magnetic resonance imaging scan. The authors retrospectively analyzed the level of the aortic arch, associated aortic arch anomalies, and the presence or absence of obliteration of the prevascular space. A high aortic arch was seen in 10 patients, five with a cervical, two with a right and, one with a double aortic arch. The prevascular space was occupied by the aortic arch, the great arteries, or both in all 10 patients with a high arch. In the remaining four patients with a normal aortic arch, the prevascular space was preserved, but abnormal elongation of the aortic segment between the left common carotid artery and the left subclavian artery was seen in three. The authors postulate that precardinal anastomosis can develop in any pathway where there is the available space. In the presence of abnormal elongation of the aortic arch and resultant widening of the subaortic space, the chance of the development of a subaortic left innominate vein increases.

Adult↗
PubMed1999

Pulmonary lymphangioleiomyomatosis in Korea.

BACKGROUND: Pulmonary lymphangioleiomyomatosis (LAM) is a rare disease occurring in women of reproductive age and leading to progressive respiratory failure in spite of treatment. In Korea the first case was reported in 1984 and by 1997 a total of 23 cases had been reported. The clinical findings of these Korean cases are reviewed. METHODS: The details of 10 cases of LAM on file at Seoul National University Hospital were reviewed together with those of 13 cases previously reported from other Korean institutes. Two, including the only one to be reported in a man, were excluded after reviewing the clinical, radiological, and pathological findings, leaving a total of 21 cases in the present study. RESULTS: All 21 patients were women and in all cases the disease was proven pathologically. The mean (SD) age at onset of symptoms was 32 (8.6) years. The most common symptoms were dyspnoea and pneumothorax which were seen in 19 (90%) and 13 (76%) patients, respectively. Pulmonary function tests showed decreased transfer factor (TLCO) (100%) and airflow limitation (67%). All the cases had characteristic cysts on high resolution computed tomographic (HRCT) scanning. The overall severity score based on HRCT scans correlated with the percentage predicted TLCO/VA (p = 0.03) and FEV1/FVC (p = 0.02). The patients were all treated with medroxyprogesterone and/or tamoxifen. Follow up was possible in 10 cases. Two of these patients appeared to stabilise with no appreciable change clinically or in lung function on medroxyprogesterone and/or tamoxifen, but the remaining patients all deteriorated with two dying of respiratory insufficiency and one of infection following lung transplantation. CONCLUSIONS: As in other countries, in Korea LAM occurs exclusively in women and progresses despite hormonal treatment.

Adult↗
PubMed1999

Shark liver oil-induced lipoid pneumonia in pigs: correlation of thin-section CT and histopathologic findings.

PURPOSE: To evaluate sequential changes in thin-section computed tomographic (CT) findings after inducement of lipoid pneumonia and provide the histopathologic bases of these findings. MATERIALS AND METHODS: Shark liver oil was administered to 12 sites in seven pigs. Thin-section CT scans were obtained within 1 hour and at 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, and 16 weeks after oil administration. Scans were assessed for opacity, distribution, location at the lobular level, extent, and volume of the lesions. The CT number in consolidation areas also was measured. Findings at CT were correlated with those in the histopathologic specimens. RESULTS: Diffuse ground-glass opacity was noted on all immediately obtained scans. The opacity of the lesions was highest at 1 week; then it decreased gradually to an area of ground-glass opacity. The extent and volume of the lesions decreased at follow-up CT. Histopathologically, the lesions showed a lobular distribution sharply demarcated from the normal lungs. The lobules of decreased volume showed residual thickening of the alveolar walls with bronchiolectasis and mild collagen deposition of the interlobular septa. Pathologic examination of the low-attenuating consolidation area at CT revealed evidence of partial aeration. CONCLUSION: Thin-section CT findings of lipoid pneumonia include ground-glass opacity and airspace consolidation, followed by complete or incomplete resolution with volume loss and septal thickening. Low-attenuating consolidation at CT does not always indicate the presence of fat.

Animals↗
PubMed1999

Mucoepidermoid carcinoma of the tracheobronchial tree: radiographic and CT findings in 12 patients.

PURPOSE: To determine the radiographic and computed tomographic (CT) findings and clinical features of mucoepidermoid carcinoma of the tracheobronchial tree. MATERIALS AND METHODS: Chest radiographic and CT findings and clinical features of 12 histopathologically proved mucoepidermoid carcinomas in 12 consecutive patients (five male, seven female; age range, 9-72 years; mean age, 36 years) were reviewed retrospectively. RESULTS: The tumors were located at the distal trachea (n = 1) or at a main (n = 2), lobar (n = 1), or segmental (n = 8) bronchus. On chest radiographs, the tumors appeared as central masses with post-obstructive pneumonia or peripheral atelectasis in four patients and as solitary pulmonary or endotracheobronchial nodules in eight. At CT, the tumors were all smoothly oval (n = 6) or lobulated (n = 6) in shape (ranging 9-40 mm in diameter), adapting to the branching features of the airways. Punctate calcification within the tumor was seen in six patients. Neither metastasis nor recurrence was seen after the surgical resection (follow-up of 8-103 months; mean, 30 months). CONCLUSION: Mucoepidermoid carcinoma of the tracheobronchial tree, usually located in a segmental bronchus, appears at CT as a smoothly oval or lobulated airway mass. It adapts to the branching features of the airways.

Adolescent↗
PubMed1999

Right paratracheal air cysts in the thoracic inlet: clinical and radiologic significance.

OBJECTIVE: The purpose of our study was to determine the CT appearance and clinical significance of a right paratracheal air cyst at the level of the thoracic inlet. MATERIALS AND METHODS: Sixty-five consecutive patients with paratracheal air cysts were included in this study. The location, level, size, and shape of the paratracheal air cysts on CT were analyzed. The spirometric data, tracheal indexes, and CT-determined emphysema scores of these patients were compared with those of 60 consecutive patients in a control group. RESULTS: The air cysts were located at the right posterolateral aspect of the trachea in 64 (98%) of 65 patients and at T1-T2 vertebral levels in 57 (88%) of 65 patients. The mean diameter of the right paratracheal cysts was 10 mm in the axial plane and 14 mm in the vertical plane. CT showed a communicating channel with the trachea in five patients. The ratio of forced expiratory volume obtained in 1 sec to forced vital capacity, and forced expiratory flow between 25% and 75% of vital capacity in patients with paratracheal air cysts, were significantly lower than those of the control group (p < .05). Differences in the tracheal indexes and CT-determined emphysema scores between the study group and the control group were found to be statistically significant (p = .001). CONCLUSION: The most probable nature of a right paratracheal cyst in the thoracic inlet is tracheal diverticulum with a narrow stalk. The presence of a right paratracheal air cyst on CT could be a sign of obstructive lung disease clinically and of the presence of emphysema radiologically.

Adolescent↗
PubMed1999

Pulmonary tuberculosis in patients with systematic lupus erythematosus.

OBJECTIVE: The purpose of our study was to describe radiologic manifestations of pulmonary tuberculosis in patients with systemic lupus erythematosus. CONCLUSION: The prevalence of pulmonary tuberculosis was high in patients with systemic lupus erythematosus. Imaging of these patients showed miliary dissemination and patchy consolidation. However, cavitation was rare. These findings may reflect impaired immune response against tuberculous bacilli.

Adult↗
PubMed1998

Experimentally induced pulmonary arterial occlusion with detachable balloon in pigs: thin-section CT findings.

RATIONALE AND OBJECTIVES: The authors evaluated changes of lung attenuation in pigs, with special attention to the mosaic pattern of low attenuation, at thin-section computed tomography (CT) after obstruction of the proximal pulmonary artery with a detachable balloon. MATERIALS AND METHODS: In seven pigs, nine sites of the descending pulmonary artery were obstructed with detachable balloons. This-section CT scans of the lungs were obtained immediately (n = 9) and at 1 week (n = 5), 2 weeks (n = 1), 3 weeks (n = 2), 4 weeks (n = 1), 6 weeks (n = 1), 8 weeks (n = 1), and 12 weeks (n = 1) after pulmonary artery obstruction. RESULTS: No statistically significant difference was found between the measured lung attenuation of the normal lung and that of the lung distal to the obstruction. Of the nine sites of pulmonary artery obstruction, five (56%) showed an irregular area of increased lung attenuation without lobular architecture. The diameter of the pulmonary artery after obstruction, compared with the diameter before obstruction, decreased by a range of 13%-57% (mean, 35%) and by 0-67% (mean, 44%) at levels 1 cm and 2 cm distal to the obstruction, respectively. CONCLUSION: This experimental study reveals that regional low-attenuation areas do not develop for up to 12 weeks after the obstruction of proximal pulmonary artery, despite a marked decrease in the diameter of the pulmonary artery distal to the obstruction.

Angiography↗
PubMed1998

Hypertrophied bronchial artery at thin-section CT in patients with bronchiectasis: correlation with CT angiographic findings.

PURPOSE: To evaluate hypertrophied bronchial arteries on thin-section computed tomographic (CT) scans in patients with bronchiectasis by using CT angiographic correlation. MATERIALS AND METHODS: Spiral CT angiography was performed prospectively in 14 patients (eight men, six women; age range, 34-71 years) with bronchiectasis who were suspected of having bronchial arterial hypertrophy at thin-section CT (performed without contrast medium). The inclusion criteria were tubular (in six patients) or nodular (in 14 patients) areas of soft-tissue attenuation that had an appearance unlike that of lymph nodes at thin-section CT and that were within the mediastinum and around the central airway. These findings were subsequently correlated with the spiral CT angiographic findings. RESULTS: At comparative analysis of thin-section CT scans and CT angiograms, seven of the eight (88%) tubular lesions and 19 of the 36 (53%) nodular lesions in the mediastinal soft tissue were proved to be hypertrophied bronchial arteries. All of the six (100%) tubular and 19 of the 21 (90%) nodular lesions around the walls of the main (primary) and lobar bronchi were hypertrophied bronchial arteries. In eight (57%) patients, CT angiograms showed 11 intraluminal protrusions caused by hypertrophied bronchial arteries in the main bronchi, lobar bronchi, or both. CONCLUSION: Nodular and tubular structures in the mediastinum and around the central airway on thin-section CT scans in the patients with bronchiectasis are suggestive of hypertrophied bronchial arteries. Recognition of the hypertrophied bronchial artery can be critical for the bronchoscopist.

Adult↗
PubMed1998

Thoracic actinomycosis: CT findings.

PURPOSE: To characterize computed tomographic (CT) findings of thoracic actinomycosis. MATERIALS AND METHODS: Chest CT scans and radiographs obtained in 22 patients with histopathologically proved thoracic actinomycosis were retrospectively reviewed. All patients were immunocompetent; they were aged 12-73 years (mean, 42.6 years; 14 male, eight female). CT findings were correlated with histopathologic findings in nine patients who underwent surgery (lobectomy [n = 8] or segmental resection [n = 1]). RESULTS: All of the lesions were unilateral, with an average diameter of 6.5 cm (range, 2-12 cm). Patchy air-space consolidation (n = 20) or a mass (n = 2) was seen on CT scans. Fifteen (75%) of the 20 patients with air-space consolidation had central areas of low attenuation (5-30 mm in diameter) within the consolidation. Thirteen of the 15 patients underwent contrast medium-enhanced CT. Ten (77%) of the 13 patients showed ring-like rim enhancement. Adjacent pleural thickening was seen in 16 patients (73%). At histopathologic examination, central low-attenuation areas at CT were seen as microabscesses with sulfur granules or a dilated bronchus that contained inflammatory cells and Actinomyces colonies. Peripheral enhancement of the low-attenuation areas was wall of the microabscess or surrounding parenchyma composed of granulation tissue rich in vascularity. CONCLUSION: Findings of chronic segmental air-space consolidation that contained low-attenuation areas with peripheral enhancement or adjacent pleural thickening at CT were suggestive of thoracic actinomycosis.

Actinomycosis↗
PubMed1998

Mediastinal tuberculous lymphadenitis: CT findings of active and inactive disease.

OBJECTIVE: The purpose of this study was to analyze CT findings of active and inactive disease in patients with mediastinal tuberculous lymphadenitis. MATERIALS AND METHODS: Using biopsy and culture results, we categorized 49 consecutive patients with mediastinal tuberculous lymphadenitis studied with CT scans as patients with active disease (n = 37) or patients with inactive disease (n = 12). Follow-up CT scans were obtained after antituberculous therapy in 25 patients with active disease and three patients with inactive disease. In 10 patients (seven with active disease and three with inactive disease), CT findings were analyzed and correlated with pathologic findings. RESULTS: In all 37 patients with active disease, the nodes (n = 151) varied in size (1.5-6.7 cm; mean, 2.8 +/- 1.0 cm) and had central low attenuation and peripheral rim enhancement. Calcifications within the nodes were seen in seven patients (19%). In the 12 patients with inactive disease, the nodes (n = 34) varied in size (1.0-4.7 cm; mean, 2.1 +/- 1.0 cm) but were usually smaller than nodes in patients with active disease. In the patients with inactive disease, the diseased nodes were homogeneous and without low-attenuation areas. Calcifications within the nodes were seen in 10 (83%) of the 12 patients with inactive disease. Low-attenuation areas within the nodes corresponded pathologically to areas of caseation necrosis in seven patients with active disease and in no patients with inactive disease. After treatment, enlarged mediastinal nodes in patients with active disease shrunk and low-attenuation areas within the nodes disappeared in all 25 patients. However, the findings of calcified nodes in the three patients with inactive disease did not change after 6 months of follow-up. CONCLUSION: In these 49 patients with mediastinal tuberculous lymphadenitis, CT findings of nodes with central low attenuation and peripheral rim enhancement suggested active disease, and findings of homogeneous and calcified nodes suggested inactive disease. Low-attenuation areas within the nodes had pathologic correspondence to areas of caseation necrosis and may be a reliable indicator for disease activity.

Adolescent↗
PubMed1997

Pericaval fat collection that mimics thrombosis of the inferior vena cava: demonstration with use of multi-directional reformation CT.

PURPOSE: To evaluate the causes for localized fat collection that seemed to be within the subdiaphragmatic inferior vena cava (IVC) on axial computed tomographic (CT) scans. MATERIALS AND METHODS: Six consecutive patients with presumed intracaval fat collection at routine abdominal CT (n = 2) or thin-section CT of the lung (n = 4) were studied prospectively with helical CT. Three patients had chronic liver diseases. Multi-directional, two-dimensional, reformatted images were obtained from the helical CT data for identification of the relation between the IVC and fat collection. Six patients without intracaval fat collection were studied as control subjects. RESULTS: On axial CT scans, the fat collection had a round or oval shape (in four of six patients) and was located posteromedial to the IVC (in four of six patients). On coronal reformatted images, the fat collection was outside the IVC between the diaphragm and subdiaphragmatic IVC, which was contiguous to the fat around the subdiaphragmatic esophagus. In the fat collection group, the IVC angled toward the right and narrowed to half in diameter as it passed down to the diaphragm. In the control group, the IVC was straight, although the diameter decreased similarly. CONCLUSION: A localized fat collection adjacent to the subdiaphragmatic IVC that mimics intracaval fat on axial CT scans is due to acute angulation of the IVC, which is probably a result of anatomic variation, chronic liver disease, or both.

Adipose Tissue↗
PubMed1997

Congenital cystic adenomatoid malformation of the lung: CT-pathologic correlation.

OBJECTIVE: The purpose of this study was to correlate CT findings of congenital cystic adenomatoid malformation (CCAM) of the lung with pathologic findings. MATERIALS AND METHODS: CT scans of CCAM from 21 consecutive patients were analyzed retrospectively by two chest radiologists who achieved consensus. Pathologic findings were assessed by an experienced pulmonary pathologist. Preoperative CT findings were correlated with pathologic findings. RESULTS: Areas with small cysts (< 2 cm in diameter) were seen on CT scans in 19 (90%) of 21 patients, whereas areas with a large cyst (> 2 cm in diameter) were observed in 18 patients (86%). Areas of consolidation (n = 9; 43%) with heterogeneous attenuation on enhanced scans and areas of low attenuation (lower than normal lung) around cystic lesions (n = 6; 29%) were also seen on CT scans. The diameter of the largest cyst seen on CT scans in each patient ranged from 1.0 to 8.0 cm (median, 4.5 cm). Cysts that CT showed to be filled with air, fluid, or both correlated completely with the pathologic findings. Areas of consolidation corresponded histologically to areas of glandular or bronchiolar structures with or without areas of endogenous lipoid or organizing pneumonia or mucus plugs. Areas of low attenuation corresponded to areas of microcysts blended with normal lung parenchyma. CONCLUSION: CT scans show the variable internal characteristics of CCAM and can suggest the underlying pathology of such lesions.

Adolescent↗
PubMed1997

Pulmonary tuberculosis in children: evaluation with CT.

OBJECTIVE: The purpose of our study was to describe the CT findings of pulmonary tuberculosis in children and to define indications for the use of CT. MATERIALS AND METHODS: CT findings in 41 consecutive children with confirmed tuberculosis were retrospectively analyzed by two radiologists. Chest radiographs and medical records were also reviewed to determine whether additional information provided by CT scans had altered clinical management of the disease. RESULTS: Mediastinal and hilar lymphadenopathy was seen in 34 patients (83%). In 29 of these patients, enlarged nodes had low-attenuation centers and enhancing rims. In the five other patients, enlarged nodes had calcification. Segmental (n = 12) or lobar (n = 8) air space consolidation was seen in 20 patients (49%), nodules of bronchogenic spread were seen in 12 patients (29%), and miliary nodules were seen in seven patients (17%). Bronchial (n = 15), pleural (n = 7), pericardiac (n = 1), or chest wall (n = 1) complications of tuberculosis were seen in 22 patients (54%). In eight (20%) of 41 patients, a diagnosis of tuberculosis was suggested only on CT scans, which revealed low-attenuation nodes with rim enhancement, calcifications, and nodules of bronchogenic spread or miliary nodules. These findings were not seen on chest radiographs. In 15 patients (37%), CT scans provided information that altered clinical management. Also two of these patients underwent surgery because of pleural and chest wall complications that were seen only on CT scans. CONCLUSION: Mediastinal or hilar lymphadenopathy revealed as low-attenuation nodes with rim enhancement or calcification was the most characteristic CT finding of pulmonary tuberculosis in children. CT can be useful when tuberculosis or its complications are suspected in children and the radiographic findings are normal or inconclusive.

Adolescent↗
PubMed1997

Tuberculosis of the central airways: CT findings of active and fibrotic disease.

OBJECTIVE: Management of patients with central airways tuberculosis differs according to the activity of the disease. The purpose of this study was to analyze CT findings of active and fibrotic disease in patients with central airways tuberculosis. MATERIALS AND METHODS: According to bronchoscopic findings and biopsy results, 41 patients with tuberculosis of the trachea and main bronchi were categorized as having active disease (n = 30) or fibrotic disease (n = 11). Follow-up CT scans were obtained after antituberculous therapy in 11 patients with active disease and two patients with fibrotic disease. All CT scans were retrospectively analyzed with particular attention to the locations of airway lesions, patterns of luminal narrowing, wall thickening of diseased airways, and presence of abnormal adjacent lymph nodes. RESULTS: Active disease in 30 patients involved the trachea (n = 20), the right main bronchus (n = 14), or the left main bronchus (n = 13). Seventeen patients had multiple lesions. On CT scans, these airways showed irregular (n = 24) or smooth (n = 4) narrowing in 28 patients: minimal (n = 5) or marked (n = 18) wall thickening with contrast enhancement in 23 patients: and obstruction with peribronchial cuffing in nine patients. Enlarged mediastinal lymph nodes were seen in 26 patients. Fibrotic disease in 11 patients involved the trachea (n = 6), the right main bronchus (n = 2), or the left main bronchus (n = 9). Six patients had multiple lesions. On CT scans, the airways showed smooth (n = 7) or irregular (n = 2) narrowing without (n = 5) or with minimal (n = 4) wall thickening in nine patients and obstruction without peribronchial cuffing in four patients. On follow-up CT scans, the findings for the airway lesions were almost normal in nine patients who had had initial active disease. However, the findings for airway narrowing did not change in two patients with fibrotic disease after 6 months of follow-up. CONCLUSION: Principal CT findings in our patients depended on disease stage. Central airways narrowing was seen in both active and fibrotic stages. However, in patients with active disease, CT scans showed irregular and thick-walled airways, a pattern that was reversible, whereas patients with fibrotic disease generally had smooth narrowing of airways and minimal wall thickening, a pattern that was not reversible during the follow-up period.

Adolescent↗
PubMed1997

Idiopathic pulmonary fibrosis vs. pulmonary involvement of collagen vascular disease: HRCT findings.

The purpose of this study is to assess the differences of high-resolution CT (HRCT) findings in patients with idiopathic pulmonary fibrosis (IPF) and pulmonary involvement of collagen vascular disease (CVD). We analyzed the HRCT findings of 33 patients with IPF and 23 patients with CVD in terms of predominant pattern, site of involvement, mediastinal lymph node enlargement, pleural change, and pulmonary volume loss. The predominant HRCT pattern was honeycombing for IPF (58%), and ground-glass opacity for CVD (57%). Predominantly subpleural involvement was seen in 90% of IPF and 83% of CVD patients. Mediastinal lymph node enlargement was seen in 61% of the patients with IPF and 13% with CVD (p = 0.0004). Pleural thickening was seen in 97% of the patients with IPF and 35% with CVD and the severity of pleural thickening is statistically significant (p = 0.00001). Pleural effusion was seen in 6% of the patients with IPF and 26% with CVD (p = 0.0351). The hilar height ratio was more than 1.5 in 52% of the patients with IPF and 30% with CVD (p = 0.2620). Although HRCT findings of IPF and pulmonary involvement of CVD are similar and overlap considerably, but patients with IPF showed a tendency to more progressed fibrosis than patients with CVD.

Adult↗
PubMed1996

Predicting the histology of anterior mediastinal masses: comparison of chest radiography and CT.

The objective of this study was to compare chest radiography with computed tomography (CT) in the prediction of a specific diagnosis in adult patients with anterior mediastinal masses. Chest radiographs and CT scans of 128 patients with anterior mediastinal masses were randomized and analyzed retrospectively by two independent observers. The observers listed the three most likely diagnoses in order of probability and recorded the degree of confidence in their first-choice diagnosis. Findings from chest radiographs and CT scans were recorded by each observer and used for a stepwise discriminant analysis between diagnoses. Results showed that the correct first-choice diagnosis, regardless of the degree of confidence, was made in 36% of chest radiographs and 48% of CT scans (p < 0.05). The correct diagnosis was included among top three diagnoses in 59% and 72% of the studies, respectively (p < 0.001). A high confidence diagnosis (level 1) was reached in 9% and 34% of each study, respectively, (p < 0.001), and was correct in 58% and 80% of the studies, respectively. Interobserver agreement (k statistics) on the correct first-choice diagnosis was 0.45 and 0.53, respectively. Interpretations of the CT scans were most often accurate in the confident diagnosis of benign germ cell tumors (n = 10, 100%), thymolipomas (n = 3, 100%), and omental hernia (n = 2, 100%). Seven of 15 radiographic findings and 11 of 22 CT findings were discriminant. We conclude that although CT is better then chest radiography in determining the pathologic diagnosis of an anterior mediastinal mass, CT is still poor at making that prediction with confidence. However, several anterior mediastinal masses could be diagnosed accurately by CT.

Adolescent↗