Mediastinal and Hilar Lymphadenopathy: Cross-Referenced Anatomy on Axial and Coronal Images Displayed by Using Multi-detector row CT

The accurate evaluation of mediastinal and pulmonary hilar lymphadenopathy, especially in patients with lung cancer, is important for determining treatment options and evaluating the response to therapy. To indicate nodal location in detail, mediastinal and hilar lymph nodes have been assigned to one of 14 nodal stations. Mediastinal nodes of greater than 10 mm short-axis diameter are regarded as abnormal, irrespective of their nodal station, while hilar nodes are considered abnormal if their diameter is greater than 10 mm in any axis or they are convex compared to surrounding lung. By providing multiplanar images, multi-detector row CT allows detailed evaluation of thoracic anatomic structures more easily than in the past, when axial images only were available. At cross-referenced imaging, a lymph node depicted at axial imaging in one anatomical location can be visualized simultaneously and automatically at coronal imaging at the exactly corresponding anatomical location. Cross-referenced coincidental axial and coronal images help assess both the size and morphology of mediastinal and hilar lymph nodes.

Rapidly Growing Mature Teratoma in the Anterior Mediastinum: Case Report

Mature teratoma is a benign tumor composed of a number of different types of well-differentiated tissues. Mature teratomas of the mediastinum usually grow slowly and are commonly asymptomatic. We report a case of mediastinal mature teratoma with rapid growth resulting in rupture

Changes of Intrathoracic Extrapulmonary Organs after Radiation Therapy for Lung and Esophageal Cancer: CT Findings

PURPOSE: To evaluate the CT findings and incidence of complications occurring in intrathoracic extrapul-monary organs due to radiation therapy. MATERIALS AND METHODS: Among 82 patients who underwent chest CT before and after radiation therapy, 23, in whom the procedure provided no evidence of pericardial invasion or pleural effusion before radiation therapy, nor of significant improvement in the tumor after this therapy, were evaulated. Changes in the pericardium, pleura and mediastinal fat were retrospectively assessed. In comparing the CT findings obtained before radiation therapy with those obtained afterwards, changes in the pericardium and pleura were classified as effusion where low density fluid was present and as thickening where there was no fluid. If an increased abundance of soft tissue strands was seen within mediastinal fat, changes in this fat were deemed to have occurred. RESULTS: Among the 23 patients evaluated, changes in the pericardium [thickening (n=3 ; 13.0%) ; effusion (n=8 ; 34.8%)] were found in 11 patients (47.8%), and changes in the pleura [thickening (n=3 ; 13.1%); effusion (n=9 ; 39.1%)] in 12 (52.2%). In no patient with pericardial or pleural effusion was thickening or contrast enhancement of the pericardium or pleura evident. In seven cases(30.4%), soft tissue strands within mediastinal fat had become more abundant. CONCLUSION: The CT findings which demonstrated complications resulting from radiation therapy were pericardial or pleural thickening or effusion and an increased abundance of soft tissue strands within mediastinal fat. In contrast to previous reports, pericardial and pleural change after radiation therapy was a common finding in our study, occurring in 69.6% of cases.

Mediastinal Lipoblastoma in a Child: A Case Report

Lipoblastoma is a benign tumor which frequently arises in the limbs but rarely in the mediastinum, and is common in children under the age of three years. We report a case of mediastinal lipoblastoma in a 27-month-old female child complaining of dyspnea. Plain radiography demonstrated a huge well-defined mass in the me-diastinum, while CT scanning revealed a soft tissue mass with an internal hypodense portion. When radi-ographic images in children under the age of three reveal a soft tissue mass with a fat component in the mediastinum, especially where there is no calcification or a cystic component, lipoblastoma should be included in the differential diagnosis.

Angiolipoma of the Posterior Mediastinum with Extension into the Spinal Canal: A Case Report

Angiolipoma is a rare benign soft tissue tumor, an unusual variant of lipoma,consisting of fatty and vascular components and located in the subcutis, usually in the trunk and extremities. We report a case of posterior mediastinal angiolipo-ma extending into the spinal canal and showing both fat and angiomatous fea-tures on CT scan.

Thymic Enlargement in Patients with Hyperthyroidism

PURPOSE: To evaluate the radiologic findings and clinical feasibility of thymic enlargement in patients with hyperthyroidism. MATERIALS AND METHODS: Seven patients with hyperthyroidism and anterior mediastinal bulging revealed by chest radiogaphy were evaluated. The CT findings were analyzed with regard to the shape of the anterior mediastinal mass, surrounding infiltration, and enlargement of mediastinal lymph nodes. Whether or not tumor markers (alpha-fetoprotein, beta-human chorionic gonadotrophin, and chorionic embryonic antigen) showed increased levels was determined, and the size and thickness of the anterior mediastinal mass were measured and compared with previously described age-matched thymus data. In addition, changes in the thyroid gland were evaluated. RESULTS: In all seven patients, anterior mediastinal masses were bi-lobed, with no surrounding infiltration or enlarged mediastinal lymph node, and tumor marker levels showed no increase. The masses were therefore considered to be thymus. In six patients, the size of the thymus exceeded two upper standard deviations of mean value and in one patient, it was smaller than this. In three patients, PCNB (percutaneous needle biopsy) revealed normal thymic tissue and in two, follow-up chest PA demonstrated no interval change. CT showed that in three patients, the thyroid glands were diffusely enlarged. CONCLUSION: In patients with hyperthyroidism, an anterior mediastinal mass seen on chest radiographs was due to thymic enlargement. The recognition of CT findings of thymic enlargement in such patients may avoid unnecessary biopsy.

Teratoma with Malignant Transformation in the Anterior Mediastinum: A Case Report

Malignant transformation of teratoma in the anterior mediastinum is rare; the mass usually has a long history and is seen in older patients. We report a case of teratoma with malignant transformation in the anterior mediastinum, complicated by rupture. CT revealed a lobulated, inhomogeneous cystic mass with a fat com-ponent and wall calcifications. The lateral wall was disrupted and consolidation in the adjacent left upper lobe was noted, suggesting rupture. A heterogeneously enhanced solid portion, obliterating the fat plane between the mass and the great vessels was present in the medial aspect of the mass, and pathologic examina-tion demonstrated the presence of adenocarcinoma.

Posterior Mediastinal Panniculitis: A Case Report

Panniculitis is an inflammatory reaction of the subcutaneous fat. Erythema nodosum is its most common form and mesenteric panniculitis is well known. We describe a case of posterior mediastinal panniculitis confirmed by gun biopsy and describe the CT and pathologic findings. CT showed a paraspinal mass containing a small amount of fat in the posterior mediastinum.

Complications of Median Sternotomy: CT Findings

In heart surgery or surgery for mediastinal mass, median sternotomy is the most common surgical approach. Thefrequency of complications after sternotomy is very low (0.5%-5%), but once a complication develops, the high riskinvolved results in high mortality; early detection and treatment are thus essential. In determining the presenceand extent of complications after sternotomy, chest radiography and clinical findings are of limited usefulness,though for detecting the existence of complications and evaluating the extent of lesions, CT is very useful. Weillustrate the clinical characteristics and CT findings of complications after median sternotomy.

Superior Mediastinal Widening from Traumatic Posterior Dislocation of Sternoclavicular Joint: A Case Report

Superior mediastinal widening, as seen on chest radiographs of traumatized patients, has been considered the hallmark of mediastinal injury. The usual causes of superior mediastinal widening are rupture of the aorta, esophagus or trachea, and hematoma as a result of spinal fracture. Posterior dislocation of the sternoclavicular joint is rarely a cause. We report a case of superior mediastinal widening resulting from traumatic posterior dislocation of the stern-oclavicular joint, and describe the CT findings, including those of 3-D imaging.

CT Findings of Ganglioneuroma

PURPOSE: Ganglioneuroma is a relatively uncommon benign tumor and han no pathognomonic radiological findings;diagnosis is therefore difficult. In order to better diagnose this tumor we analysed its CT findings andpathologic correlation. MATERIALS AND METHODS: Seventeen tumors in 16 patients(M:F=9:7) diagnosed asganglioneuroma between 1992 and 1996 were retrospectively analysed with regard to location, size, contour, longaxis of the mass, enhancement pattern, calcification, necrosis and capsulation, all as seen on CT, and comparedwith histo- pathologic findings. RESULTS: Tumors were 1.5 to 10(mean, 5.6)cm in size, and their location wasmediastinal(n=12), cervical(n=2), retroperitoneal (n=2) or adrenal(n=1). Fifteen had an oval or round contour andtwo were dumb-bell-shaped. The long axis of the lesion was craniocaudal in 14 cases and non-specific in three.Thirteen lesions showed heterogeneous enhancement, and four homogeneous. Capsule-like enhancement was noted on CTscans in eight cases;there was no definite correlation between enhancement pattern and pathologic findings.Calcification was seen in six cases and an inner low-density lesion in two. CONCLUSION: Ganglioneuroma is abenign neurogenic tumor, occurring most frequently at the the posterior mediastinum. General CT findings of thistumor are a well-defined oval shape with a variable enhancement pattern, but several cases showed focalcalcification or inner low density. For accurate diagnosis of ganglioneuroma both common and uncommon findingsmust therefore be considered.

Increased Opacity of Left Pericardiac Area on Chest Radiograph: Correlation with CT Findings and its Frequency

PURPOSE: The purpose of this study was to evaluate the incidcnce of extrapericardial fat in the left cardiacborder, and with regard to left extrapericardial fat, to correlate chest radiographs with CT scans. MATERIALS AND METHODS: This study involved 132 consecutive patients who underwent chest PA and lateral radiographs, and chestCT scans. According to the results of chest PA radiograph, patients were divided into three groups: those with aclear left cardiac border; those with an indistinct left cardiac border; and those with an indistinct left cardiacborder with increased density; cardiophrenic angle, as seen on lateral radiograph, the presence of increaseddensity in the anterior cardiophrenic angle, as seen on lateral radiograph radiographs was evaluated. On the basisof the results of CT scanning, patients were classified into four groups according to the amount of leftextrapericardial fat: negative, minimum, moderate, and maximum. Left extrapericardial fat, as seen on CT, wascorrelated with the conspicuity of left cardiac border seen on PA radiograph and the presence of increased densityin the anterior cardiophrenic angle, as seen on lateral radiograph. RESULTS: On CT, left extrapericardial fat wasobserved in 51 patients (38.6%). In 38 of these (28.8%), the amount was minimal, in 12 (9.1%), it was moderate,and in one (0.8%), it was maximal. On posteroanterior chest radiograph, clear, indistinct, and indistinct andincreased density of the left cardiac border was seen in 89 (67.4%), 28 (21.2%), and 15 cases (11.4%),respectively. On lateral radiograph, increased density of the anterior cardiophrenic angle was seen in 115 cases(87.1%) but in 17 (12.9%), increase density was not apparent. There was significant correlation between chestradiographs and CT(p<0.001) (sensitivity: 53%; specificity: 100%; positive predictive value: 100%; negativepredictive value: 84%). CONCLUSION: The conspicuousness of the left cardiac border, as seen on PA chestradiograph, correlated with the presence of left extrapericardial fat, as seen on CT, and was related to theamount of left extrapericardial fat. Increased density of the anterior cardiophrenic angle, as seen on lateralradiographs, correlated with the presence of left extrapericardial fat on CT, but the absence of increased densityon lateral radiograph corresponds to the absence or a minimal amount of left extrapericardial fat, as seen on CT.

T1 Lung Cancer: Role of Mediastinoscopy and CT in the Diagnosis of Mediastinal Adenopathy

PURPOSE: To evaluate the role of mediastinoscopy and CT in the preoperative nodal evaluation in patients with T1 lung cancer. MATERIALS AND METHODS: Between November 1994 and July 1996, 125 patients underwent thoracotomy and/or mediastinoscopy for surgical treatment of lung cancer. Among them, 35 patients had T1 lung cancer(peripheral lung cancer less than 3cm in diameter) on CT. One patient finally proved to have T4 lung cancer with pleural seeding at thoracotomy. In the remaining 34 patients, pathologic evaluation of mediastinal lymph nodemetastasis was feasible and the results were correlated with CT findings. On CT, nodes larger than 10mm in short-axis diameter were regarded as abnormal. RESULTS: The patients had adenocarcinoma in 12, squamous cellcarcinoma in 11, bronchioloalveolar carcinoma (BAC) in 10, and large cell carcinoma in one. Fifteen among total 478 sampled lymph nodes contained malignant tumor. Six (three with adenocarcinoma, two with squamous cell carcinoma, and one with large cell carcinoma) of 34 patients (18%) had nodal metastasis. With 112 sampled nodes, BAC did not show any nodal metastasis. Sensitivity and specificity of CT for nodal detection were 0% and 100% for2R, 0% and 100% for 4R, 100% and 97 % for 5, 50% and 100% for 7 and 0% and 100% for 10R, respectively. CONCLUSION: T1 lung cancer shows relatively high (18%) prevalence of mediastinal lymph node metastasis. Because small nodesless than 10mm in diameter contain malignancy and CT is insensitive in detection of metastatic nodes,mediastinoscopy is still needed for preoperative nodal evaluation except BAC.

Mediastinal Interfaces and Lines: Clinical Significance and Radiographic-CT Correlation

Mediastinal interfaces on a chest radiograph result from contact between mediastinal structures and the adjacent lung, while mediastinal lines result from contact between the two lungs across the midline. A variation of mediastinal interface is mediastinal stripe, a narrow band produced by contact of both sides of a mediastinal structure with the lungs. Alterations in mediastinal interfaces and lines may be due to variations in normal anatomy, or may reflect the presence of abnormalities within the mediastinum. Familiarity with the various normal mediastinal interfaces and lines, and the changes that occur with disease is important for the interpretation of the chest radiograph and in the diagnosis of mediastinal abnormalities. The purpose of this pictorial essay is to illustrate the most important normal and abnormal interfaces and lines and also to correlate radiographic and CT findings.

The Oblique Interface in the Right Cardiophrenic Angle: Chest Radiographic-CT Correlation

PURPOSE: An oblique interface in the right cardiophrenic angle, extending superomedially from rightretrocardiac or supradiaphragmatic region inferolaterally to peridiaphragmatic region, is occasionally observed onposteroanterior chest radiograph. The aim of this study was to evaluate the frequency of visualization of the interface on chest radiographs and to elucidate its nature on radiographic-CT correlation. MATERIALS AND METHODS: Posteroanterior chest radiographs from 300 consecutive subjects were analyzed to evaluate the frequency and demographic data about an oblique interface in the right cardiophrenic angle. Thin-section CT scans(1-mmcollimation and 5-mm intervals) were obtained from the subjects with positive interface on chest radiograph for assessment of the nature of the interface. The demographic data in the subjects with and without the interface were tested statistically to note any difference between two groups. RESULTS: Oblique interface in the right cardiophrenic angle was present in 29 subjects(9.7%) on chest radiograph. The age of the subjects with positive interface(13 men and 16 women) ranged from 19 to 70 years(mean +/-SD, 47+/- 12.7 years) whereas the age of thesubijects without the interface from 16 to 82 years (mean +/-SD, 50+/-9.1 years)(p>0.1). The body weight of thesubjects with the interface ranged from 41 to 72 Kg(mean +/-SD, 60 +/- 8.0Kg) whereas the body weight of thesubjects without the interface from 41 to 85 Kg(mean +/-SD, 63+/-10.1Kg)(p>0.1). On CT scan, it was formed due tocontact between the epipericardial fat and the right middle lobe of the lung in 27 subjects(93%) and between the inferior vena cava and the medial basal segment of the right lower lobe of the lung in two(7%). CONCLUSION: Oblique interface in the right cardiophrenic angle is occasionally visualized on chest radiograph. It is formed due to contact between the right middle lobe of the lung and pericardial fat in most cases. The frequency of visualization of the interface has no relationship to age and body weight of the subjects.

Primary Amyloidosis Involving Mediastinal and Hilar Lymph Nodes: A Case Report

Amyloidosis is a rare systemic disease caused by extracellular accumulation of insolubel fibrillar material invarious tissues. The radiographic findings of amyloidosis involving the lymph nodes have not been previously reported in Korea, and we report a rare case of primary amyloidosis involving the mediastinal and hilar lymphnodes, with CT and radiographic appearances.

Preliminary Study of CT-guided Transthoracic Puncture Biopsy / 介入放射学杂志

Purpose:Evaluation of technique and clinical value of CT-guided transthoracic punc ture biopsy.Materials and methods:Between Feb 1994 and Oct 1997,CT guided transthoracic puncture biopsy was performed in 55cases including unknown pulmonary(44cases),pleural(6 cades)and mediastinal (6 cases)diseases with 20gDFBN and 18g ADGSTN.36 males and 19 females,aged from 23 to 78 years (mean age 55 years)were included.The assembled materials were evaluated cytologically in 25 cases and histopathologically in 55 cases.Results:The needle tip passed through percutaneouslly into the lesion under CT-guided in all 55 cases and obtained specimens for cytology(25 cases)and histopathology(55 cases).Accuracy rate were 60% for cytology and 87.5% for histopathology.Among 35 cases of tumor, histopathologic classification had been done in 26 cases.Complication occurred in 7cases(13%),including pneumothorax(2 cases)and hemoptysis(5 cases).Conclusion:CT-guided TPB is a method of combining advanced imaging tecnique and pathology.It is a simple,highly accurate,safe diagnostic tool,especially for unknown pulmonary,pleura,mediastinal lesions.