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.

Nasal Bone Fractures : Evaluation with Thin-section CP

PURPOSE: To determine the value of thin-section CT in the diagnosis of nasal bone fractures. MATERIALS AND METHODS: We evaluated the thin-section CT scans of 40 patients with nasal bone fracture. CT scans were obtained with both axial and coronal planes, 1.5mm collimation with 2mm interval, and 9.6cm field-of-view. The axial scan plane was kept parallel to the orbitomeatal line from the nasion to the lower limit of the nose and the coronal plane was kept perpendicular to the axial plane. The data were reconstructed with bone algorithm. Nasal bone fracture was classified into 1 of 3 types on thin section CT:(I) simple fracture;(ll) simple fracture with displacement;(III) comminuted fracture. Associated facial bone injuries were also evaluated Simple radiographs of nasal bone were reviewed for comparison. RESULTS: Six patients had simple fracture, 10 patients had simple fracture with displacement, and 24 patients had comminuted fracture. Twenty-six patients had associated facial bone injuries which included fracture of nasal septum (n=15), fracture of frontal process of maxilla (n=9), fracture of ethmoid (n=6), widening of nasofrontal suture (n=5), and fracture of nasolacrimal duct (n=2). In 15 of 40 patients, CT could identify nasal bone fractures not detected on simple radiographs. CONCLUSION: Thin-section CT is a valuable aid in the evaluation of nasal bone fracture for accurate identification, nature, and combined facial injury.