Tracheal Luminal Diameter on Chest Radiographs: Demographic Data in 690 Normals

PURPOSE: To assess the normal range of transverse and AP diameter of the trachea on simple chest radiographs and to determine whether or not there is any correlation between tracheal diameter and age, sex, height, or bodyweight. MATERIALS AND METHODS: Six hundred and ninety patients with no lesion on chest radiographs and noclinical evidence of respiratory disease were involved in this study. To obtein transverse and lateral diameters,the internal diameter of the tracheal air column was measured at a level 2 cm above the top of the aortic arch onboth posteroanterior and lateral radiographs. RESULTS: The normal ranges of AP and transverse diameters of thetrachea were 16 to 25mm, and 14 to 22mm in men, respectively and 12 to 20mm and 12 to 18mm in women. Statistically significant differences were observed between AP and transverse diameter in both in men and women, the former being consistently larger than the latter in both sexes. In men, significant correlations were observed between transverse diameter and patients' height, and between AP diameter and age as well as height. In women, significant differences were observed between AP diameter and patients' height, and transverse diameter and height as well asbody weight of patients. CONCLUSIONS: Normal tracheal diameter was larger in men than in women. and AP diameter was larger than transverse diameter. Patients' height showed persistent correlation with luminal diameter.

Transcatheter Instillation of Urokinase into Loculated Pleural Effusion: Analysis of Treatment Effect

PURPOSE: To evaluate the indication for intracavitary Urokinase(UK) in the treatment of Ioculated pleural effusion. MATERIALS AND METHODS: We analyzed CT and US in 31 patients who were treated with intracavitary UK in Ioculated pleural effusion. In each patient, a single chest catheter (10-12F) was insected under imaging guidance. When the amount of drainage was less than 100ml/day, UK was instilled through the catheter until less than 50ml/day was drained. On follow-up chest radiographs of more than 1 month, we classified the results of treatment into 3 groups:(1) completely effective (lung expansion, over 80%);(2) partially effective (20-80%); (3) ineffective (below 20%) group. Sonographic pattern of pleural fluid was classified into anechoic, septated, and honeycomb appearances and the thickness of parietal pleura was measured on CT. RESULTS: Sixteen patients were completely effective, nine were partially effective, and six were ineffective. patients with completely or partially effective outcome had anechoic and linear septated appearance on had less than 4mm of parietal pleural thickness on CT. Of six ineffective patients, US showed linear septated in one patient and honeycomb appearance in five patients and the thickness of parietal pleura on CT was 3 mm in one patient, 4ram in two patients, 5mm in one patient, and 6mm in two patients. CONCLUSION: UK instillation through percutaneous catheter was an effective method in the treatment of Ioculated pleural effusion. However, we found near complete reaccumulation of pleural fluid when honeycomb appearance of pleural fluid on US or more than 5mm parietal pleural thickness on CT was observed, which might suggest that we should consider the other kinds of treatment method in those patients.

CT Findings of Palpable Neck Masses in Children

PURPOSE: We performed this study to assess the value of CT in the differential diagnosis of palpable neck masses in children. MATERIALS AND METHODS: We retrospectively reviewed the CT scans of the palpable neck masses in 30 children. The masses were proved histopathologically and classified into cystic, solid, and inflammatory mass and their CT findings were analyzed. RESULTS: Twelve cases were cystic masses, 4 were solid masses, and 14 were inflammatory lesions. Cystic masses included cystic lymphangiomas (n=6), branchial cleft cysts (n=3), thyroglossal duct cysts (n=2), and ranula (n=l). Cystic lymphangiomas showed insinuating appearances into adjacent structures and 4 cases occurred in the posterior cervical space. All branchial cleft cysts were round cystic masses with smooth wall and displaced the submandibular gland anteriorly and the sternocleidomastoid muscle posteriorly. Two thyroglossal duct cysts occurred centrally adjacent to the hyoid bone and 1 ranula in the submental area. Solid masses were juvenile hemangioma, pleomorphic adenoma in submandibular gland, neurilemmoma, and fibromatosis colli. Juvenile hemangioma showed well-enhancing mass with indistinct margin and the other solid masses had well-defined margin with their characteristic location. Inflammatory lesions were abscess (n=4), deep neck infections with lymphadenopathy (n=4), submandibular gland inflammation (n=3), and tuberculous lymphadenitis (n=3) and they showed strand-like enhancement in adjacent subcutaneous tissues. Tuberculous lymphadenitis had multiple lymph node enlargement with internal low attenuation areas and showed less surrounding strand-like enhancement than suppurative lymphadenopathies. CONCLUSION: Most neck masses in infants and children were of congenital or inflammatory origin. CT is useful for the evaluation of the child presenting with a neck mass, because it can differentiate various forms of neck masses and is able to reveal the relationship of the masses to the adjacent structures with their characteristic location.