Biomedical subjects
Publications and source records attributed to J G Im.
The CT findings in a case of lobar bronchioloalveolar carcinoma included stretching, spreading, and uniform narrowing of the involved bronchi without obstruction.
The CT quantification of both the extent and severity of emphysema was undertaken in 30 subjects. The CT scans at five preselected anatomic levels were analyzed using two methods. Correlation of the results of the CT methods were with pulmonary function results of airway obstruction and alveolar diffusion for carbon monoxide. Analysis by direct observation of the CT scans gave insignificantly different results for a complex grid method of analysis. The emphysema score with the observational method had a positive correlation with airflow obstruction (r = -0.817) as did the score with the grid method (r = -0.873). The diffusing capacity for carbon monoxide also correlated with both emphysema scores. The CT methods for quantifying emphysema correlate closely with functional abnormalities. As previously demonstrated with pathological assessment of lung slices for emphysema, direct observation of CT scans is as precise as a more complex grid method.
Two patients with relapsing polychondritis presented with tracheobronchial stenosis without clinical manifestation of nasal septum or ear lobe cartilage involvement. The CT findings included diffuse, smooth tracheobronchial wall thickening with narrowing and deformity of the lumen. Areas of dense calcium deposition within the thickened tracheal cartilage were seen. On follow-up after steroid medication, tracheobronchial wall thickening was decreased and the configuration of the tracheal lumen returned to normal.
The CT findings are described in five patients with esophagomediastinal fistula due to tuberculous lymphadenitis. In all five patients periesophageal amorphous gas collections were found along with enlarged mediastinal lymph nodes. In four patients esophagograms demonstrated the fistulas. All fistulas closed with antituberculous therapy alone. The presence of periesophageal gas in patients with tuberculous mediastinal lymphadenitis suggests esophago-nodal fistula. The treatment of choice is antituberculous therapy.
Thin-section CT scans were performed in 40 patients to demonstrate the normal appearance of the lingular division (LD) bronchus and its segmental and subsegmental bronchi and to search out the possible anatomical landmark dividing the anterior segment and LD of the left upper lobe. The LD bronchus was identified in all patients. The complete branching pattern of the lingular segmental and subsegmental bronchi could be traced in 19 (47.5%) patients. Since the lower branch of the draining vein of the anterior segment of the left upper lobe (V3b) runs horizontally between the anterior segment and the LD of the left upper lobe, it is a good landmark dividing the anterior segment and LD of the left upper lobe. Familiarity with thin-section CT anatomy of the lingular segmental and subsegmental bronchi and surrounding vascular structures is helpful in identifying the lingular bronchial tree precisely and localizing a lesion in the left upper lobe correctly.
Computed tomography of five cases of thymic carcinoma was reviewed. The subtypes of thymic carcinoma were squamous (two cases), lymphoepithelioma-like (one case), undifferentiated (one case), and basaloid (one case). The patients ranged from 52 to 72 years of age. Computed tomography showed anterior mediastinal tumors infiltrating along the pleura or mediastinum with frequent internal necrosis or calcifications. The three nonsquamous cell cases developed extrathymic metastases to the mediastinal lymph nodes, lung, or chest wall. Although the CT features of thymic carcinomas were similar to those of invasive thymoma, the former showed more aggressive behavior. Among the four variants of thymic carcinoma, squamous carcinomas were less aggressive and had less tendency to develop necrosis than the others.
We reviewed CT of eight patients with malignant schwannomas arising in the thorax. Only one patient had neurofibromatosis. Five lesions occurred in the posterior mediastinum, one lesion was in the middle mediastinum, and two lesions were in the chest wall. Common CT findings were the presence of low-density areas (six of eight), compression of adjacent structures (six of eight), pleural abnormalities (six of eight), such as pleural effusion or pleural nodules, and metastatic pulmonary nodules (five of eight). Pleural abnormalities or pulmonary nodules were detected in seven of eight patients. These CT findings can help in differentiating malignant schwannoma from benign neurogenic tumor.
To devise a new method for counting ribs on CT scan, we evaluated the CT anatomy of the costal cartilages and the proximal xiphoid in 20 control patients without rib pathology. The sternal end of costal cartilages seen on the same image as the proximal xiphoid was always the seventh (n = 20). These costal cartilages were located anterolateral (n = 13) or lateral (n = 7) to the proximal xiphoid. In fifteen patients with rib pathology, 23 abnormal ribs were localized by our method. All of these ribs correlated with those seen on chest radiographs and rib cage views or with resected ribs on postoperative films.
Tuberculosis is the most common inflammatory lesion of the ribs, second only to metastatic neoplasm as a destructive cause of a rib lesion. We retrospectively analyzed CT findings of 13 lesions in eight patients with pathologically proven rib tuberculosis. The presenting symptoms were painful mass in five, chest pain in two, and nontender mass in one. Five patients had concomitant pulmonary tuberculosis. On CT, all showed a juxtacostal soft tissue mass with central low attenuation and peripheral rim enhancement (a so called "cold abscess"). Only 4 of 13 lesions demonstrated bone destruction: two were osteolytic expansile lesions with cortical disruption and two were mild cortical irregularities. Five lesions were located at the costochondral junction, five were in the rib shaft, two were in the sternochondral junction, and one was in the costovertebral joint. There was no evidence of direct extension into the lung parenchyma.
OBJECTIVE: Chest radiography and CT findings of five patients with milk of calcium pleural collections are described. MATERIALS AND METHODS: The diagnosis was based on needle aspiration in four patients and the presence of a fat-calcium level on CT in the remaining one. Four patients had a prior history of pleurisy. RESULTS: Characteristic radiographic findings were homogeneous increased opacity with a double contour at the interface with the lung. Computed tomography showed that the lateral contour was the margin of the milk of calcium and the medial contour was the margin of the thickened visceral pleural facing the lung. On CT milk of calcium collection appeared as a homogeneous area of increased attenuation. CONCLUSION: Recognition of the characteristic double contour on plain radiography would help prevent or avoid an erroneous diagnosis of pleural or extrapleural solid mass.
OBJECTIVE: Sclerosing hemangioma is a rare pulmonary tumor. This article describes CT features of the tumor on the basis of CT-pathology correlation. MATERIALS AND METHODS: The CT features of eight patients with sclerosing hemangioma of the lung were studied retrospectively and were correlated with the pathologic findings of the resected specimens. All eight patients had an incidental lung mass found on chest radiographs. Seven patients were female. Contrast enhancement of the masses was assessed visually by two radiologists independently, and the density was measured before and after contrast enhancement by using a standard cursor in three patients. RESULTS: On CT, sclerosing hemangiomas appeared as well defined juxtapleural masses in all cases. The tumors enhanced by visual criteria in all but one patient with the smallest mass. The CT density of the enhancing mass ranged from 96 to 157 HU. Three patients had calcification and two had well defined areas of low attenuation. On CT-pathology correlation, the higher, iso-, and lower attenuation areas corresponded with angiomatous, solid and sclerotic, and cystic areas, respectively. CONCLUSION: A well defined juxtapleural mass with marked contrast enhancement coupled in select cases with foci of sharply marginated areas of low attenuation and calcification are characteristic CT findings of sclerosing hemangioma and should suggest this diagnosis especially in women with these findings.
OBJECTIVE: Our objective was to characterize the CT findings of mediastinal Castleman disease. MATERIALS AND METHODS: We reviewed the CT findings of mediastinal Castleman disease in 10 patients. RESULTS: In nine cases of hyaline-vascular type Castleman disease, lymph nodes were 2-7 cm in diameter and located in the hilum in six patients, superior mediastinum in two patients, and posterior mediastinum in one patient. On CT the tumors were well-demarcated round masses showing dense homogeneous enhancement after contrast medium injection. Dynamic CT in one case showed gradual centripetal enhancement of the mass. In one case of hyaline-vascular type Castleman disease, lumpy and irregular calcifications were noted in the center of the mass. In the one case of plasma cell type Castleman disease, multiple small homogeneously enhancing nodes were found in the mediastinal and supraclavicular area. CONCLUSION: CT findings may suggest the preoperative diagnosis of mediastinal Castleman disease.
OBJECTIVE: To assess the CT findings of lipoid pneumonia. METHODS: Chest radiography and CT performed in six patients with proven lipoid pneumonia were reviewed by two observers. Diagnosis was confirmed by biopsy (five cases) or bronchoalveolar lavage (one case). The clinical history of taking oily substance could be obtained retrospectively in all patients. RESULTS: Chest radiography showed bilateral air space consolidation in three cases, irregular mass-like lesions in two, and a reticulonodular pattern in one case. Computed tomography demonstrated diffuse parenchymal consolidation in three cases, localized areas of consolidation in two, and subpleural pulmonary fibrosis in one case. In two cases, fat with localized areas of consolidation could be seen on CT. In three cases with diffuse consolidation the attenuation was decreased but higher than that of subcutaneous fat. In one case with subpleural fibrosis no areas of low attenuation could be seen on CT. CONCLUSION: We conclude that in patients with lipoid pneumonia CT may demonstrate areas with low attenuation diagnostic of fat or areas with nonspecific low attenuation or soft tissue density.
OBJECTIVE: To evaluate CT findings of pulmonary nocardiosis in immunocompromised patients. MATERIALS ALND METHODS: Five patients with bacteriologically confirmed pulmonary nocardiosis were evaluated. Four patients were receiving corticosteroids with or without other immunosuppressive drugs for lupus nephritis (two patients), idiopathic thrombocytopenic purpura (one patient), and renal transplantation (one patient), and one patient had long-standing diabetes. Nocardia asteroides was isolated from blood culture, bronchial washing, pleuropulmonary aspirates, or open lung biopsy. Plain chest radiography and CT were performed on all patients, and follow-up CT was performed on one patient. RESULTS: On CT there were pleural effusion (four patients), air-space consolidation with internal low attenuation with or without cavities (four patients), multiple noncavitating pulmonary nodules and subpleural pulmonary nodules (three patients), and chest wall extension (three patients). Follow-up CT after treatment showed marked improvement of the pleural and pulmonary lesions. CONCLUSION: In the immunocompromised and chronically debilitated host, pulmonary nocardiosis should be included in differential diagnosis if chest CT shows consolidation with low attenuation areas with or without cavitation, multiple pulmonary nodules, pleural effusion, and chest wall extension.
OBJECTIVE: To evaluate the CT features of complicated Klebsiella pneumonia. MATERIALS AND METHODS: We retrospectively reviewed 15 CT examinations from 11 consecutive patients with complicated Klebsiella pneumonia with special attention to internal architecture of pneumonic consolidation and its changes on follow-up CT. On plain radiography, abscess or cavitation was suspected in all patients. The diagnosis was established by isolation of Klebsiella pneumoniae from blood in six patients, from sputum in two, and from both in three. Five patients underwent follow-up CT due to progression (one) or incomplete resolution (four) of the disease despite antimicrobial therapy. RESULTS: In all patients pneumonic consolidation was composed of two intermingled components: enhancing homogeneous areas and poorly marginated low-density areas with multiple small air cavities, suggesting necrotizing pneumonia. In nine patients scattered enhancing structures probably due to atelectatic lung and pulmonary vessels were noted within necrotic areas of consolidated lung. In eight patients pleural complications such as effusion (all) or diffuse pleural enhancement (five) were seen. In two patients with multilobar disease and delayed treatment, multiple small abscess cavities coalesced to form a large cavity with sloughing of lung tissue, suggesting pulmonary gangrene and lung abscess formation on 18 and 45 day follow-up CT, respectively. In three other patients necrotizing pneumonia resolved slowly from the periphery to the center with residual fibrosis on follow-up CT at 2-3 months. CONCLUSION: The most common CT manifestation of complicated Klebsiella pneumonia was necrotizing pneumonia associated with pleural abnormalities. In extensive cases, pulmonary gangrene or lung abscess was a rare complication.
OBJECTIVE: Differentiation of invasive thymoma from thymic carcinoma is important because of their different clinical behaviors. Retrospectively, we evaluated the CT findings of invasive thymomas and thymic carcinomas to determine the differential points between them. MATERIALS AND METHODS: We reviewed the CT scans of 12 patients with invasive thymoma and 10 patients with thymic carcinoma that were confirmed by surgery or percutaneous needle aspiration. We analyzed CT scans, paying special attention to homogeneity, attenuation, invasion of adjacent mediastinal structures, pleural implants, mediastinal nodes, and extramediastinal metastases. RESULTS: Most of the invasive thymomas and thymic carcinomas were homogeneous and isodense with chest wall muscle. Irregular infiltration into the adjacent organ suggesting invasion was seen in 11 patients (92%) with invasive thymoma and 8 patients (80%) with thymic carcinoma. Pleural implants were observed in four patients (33%) with invasive thymoma and one patient (10%) with thymic carcinoma. Mediastinal lymphadenopathy was seen in one patient (8%) with invasive thymoma and four patients (40%) with thymic carcinoma. Metastases to the lung, adrenal glands, or liver were observed in four patients (40%) with thymic carcinoma but none with invasive thymoma. CONCLUSION: Despite the similarities of CT findings between invasive thymoma and thymic carcinoma, there are some differential points. Thymic carcinomas were infiltrating tumor and were more commonly associated with mediastinal nodes and extrathymic metastases, but less commonly associated with pleural implants than invasive thymoma.
OBJECTIVE: We undertook this study to evaluate the normal values of the artery-bronchus ratio (ABR) and the bronchial lumen ratio (BLR) at subsegmental levels and to determine whether these values can be used as objective parameters for evaluation of various diseases involving the bronchovascular trees. MATERIALS AND METHODS: We analyzed high-resolution CT of 30 patients without cardiopulmonary diseases. The CT studies were performed with 5 mm collimation at 5 mm intervals from the carina to the level of the inferior pulmonary vein and with 1.5 mm collimation at 10 mm intervals through the remainder of the lung. Both ABR, defined as the outer diameter of the pulmonary artery were divided by the outer diameter of its accompanying bronchus, and BLR, defined as the inner diameter of the bronchus divided by its outer diameter, were measured at the subsegmental level on the display console. RESULTS: The mean ABR was 0.98 +/- 0.14 (range, 0.53-1.39), and the mean BLR was 0.66 +/- 0.06 (range, 0.51-0.86). Although BLR revealed no statistical differences between segments, lobes, and lungs, there were statistically significant differences between the ABRs of segments and between those of lobes. CONCLUSION: There was a wide range of normal values of ABR and BLR. This wide range of values would make these parameters of less value in the evaluation of bronchovascular bundles.
PURPOSE: Our goal was to analyze patients with pulmonary lobular low attenuation (LLA) on thin section CT with regard to the underlying pulmonary diseases and the dynamic changes occurring in the low attenuation regions during respiration. METHOD: Forty-eight consecutive patients with LLA on thin section CT were analyzed retrospectively. Forty-six patients (95%) had symptoms related to respiratory disease, such as productive cough (n = 25) and hemoptysis (n = 18). Only two patients, one with chronic pulmonary embolism and one with Takayasu arteritis combined with bronchiectasis, had pulmonary vascular disease. Six patients, four with bronchiectasis and two with vascular disease, were studied with dynamic CT during forced vital capacity maneuver. Attenuation values for LLA areas and adjacent lung were measured and time-density curves were plotted. RESULTS: Forty-one (85%) patients had bronchiectasis, typically in other than the regions of the LLA. Areas with proximal bronchiectasis showed low attenuation but without notable lobular distribution. Pulmonary vessels in the LLA areas were smaller than those of adjacent normal lung (n = 45). Of 22 patients who underwent pulmonary function tests, 15 had obstructive pattern of impairment. Respiratory dynamic CT showed expiratory air trapping in LLA areas in all six patients. The mean attenuation values of LLA areas were lower than those of the adjacent normal lung by 67 HU at end-inspiration and by 165 HU at end-expiration (p = 0.002). CONCLUSION: The majority of the patients with LLA shown by thin section CT had bronchiectasis elsewhere in the lung, and evidence of air trapping in the LLA was clearly demonstrated. Bronchiolar obstruction may be the most prevalent cause for the development of LLA.