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.

Findings Chest Radiograph and CT in Mediastinitis: Effcacy of CT in Patients with Delayed Diagnosis

PURPOSE: To analyse the causes and radiologic findings in patients with mediastinitis and to evaluate theefficacy of chest CT scanning in patients with delayed diagnosis. MATERIALS AND METHODS: Seventeen patients withhistopathologically(n=15) or cliniclly diagnosed(n=2) mediastinitis were involved in this study. Eleven of theformer group underwent surgery, and in four, tube drainage was performed. All underwent chest radiography and CTscanning, and in seven patients, the causes of delayed diagnosis were analysed. RESULTS: The most common cause ofmediastinitis was esophageal rupture (n=11). Others were extension from neck abscess to the mediastinum(n=3),complications after a Benthall procedure(n=1), tuberculous lymphadenitis (n=1) and mycotic aneurysm(n=1). Patientswith esophageal rupture suffered from underlying diseases such as esophageal cancer(n=2), iatrogenic esophagealrupture(n=2), Boerhaave's syndrome(n=2), and esophagitis(n=1). In patients with neck abscess(n=3), each wassecondary to infected cystic hygroma, Ludwig angina, or deep neck infection, respectively. On chest CT, patientswith esophageal rupture(n=11) had an abscess in the posterior mediastinum; nine abscesses extended to the cervicalarea along the retropharyngeal space, and the patient with Ludwig angina had an abscess involving all compartmentsof the mediastinum. Among the total of 17 patients, diagnostic delays were found in seven, while five hadspontaneous esophageal ruptures and two suffered complications after a Benthall procedure and Tbc lymphadenitis,respectively. The causes of diagnostic delay varied. Among seven patients, pnevmonia was initially diagnosed intwo, who were treated ; one had multiorgan failure, and one was suffering from pericardial effusion and lungabscess. In three other patients, chest radiographs initially showed non-specific findings, leading to delayed CTexamination. CONCLUSION: The most common cause of mediastinitis was esophageal rupture, and in these patients,chest radiographs and clinical symptoms were sometimes not specific. CT was valuable for the detection ofmediastinitis, and for early diagnosis can be the modality of choice.

Detectability of the Mediastinal Lines: Comparison of Conventional Film-Screen Radiography and DigitalRadiography

PURPOSE: Using dynamic range compression (DRC) processing, this study compared the detectability ofmediastinal lines by conventional film screen rediography (FS) and by storage phosphor digital radiography(DR). MATERIALS AND METHODS: We selected 200 normal consecutive chest radiographs (100 FS, 100 DR) ; dynamic rangecompression was applied to DR processing and moving grids were used in both systems. Seven mediastinal lines (leftfaraspinal, right paraspinal, azygoesophageal, left para-aortic, posterior junctional, anterior junctional andright paratracheal) were scored from 0 point to 3 point(0:not visible, 1:suspiciously visible, 2:visible, but notclear, 3: clearly visible) according to visibility and sharpness, as agreed by a radiologist and a resident. Thedifferences between the two modalities were compared and analyzed by chi-square test. RESULTS: Among the 1400mediastinal lines analyzed, 419 lines by DR(59.9%) and 232 lines by FS(33.1%) were scored more than 2 points. Inall mediastinal lines except the left para-aortic, DR was more detectable and clearer than FS, with statisticalsignificance(P<.01). CONCLUSION: DR processed with DRC visualizes mediastinal lines more frequently and clearlythan conventional FS, and is therefore thought to be useful for the evaluation of mediastinal diseases.

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.

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.