A few small studies have documented additional incremental benefits of review of 2-D multiplanar, 3-D reformatted, and VB images, including changes in surgical approach or identification of associated findings such as small fistulae [11]. Chest CT is also used for evaluation of suspected posttreatment complications of tracheal interventions. CT is commonly used for planning for tracheal stent implantation; a study of 69 patients with stenosis due to malignancy used CT to select stent diameter by measuring proximal and distal landing zone diameters and to determine desired stent length by measuring length of the involved segment [25]. A small study of 17 stenoses in 14 patients with postintubation stenosis confirmed at surgery found a detection rate of stenosis of 94% (16 of 17 lesions) of CT with VB and 88% (15 of 17) by rigid bronchoscopy; assessment of length was accurate for 87% of stenotic segments by CT and VB and 73% of segments by rigid bronchoscopy [13]. In a study of contrast-enhanced CT of 46 adenoid cystic carcinomas of the trachea and 36 other tracheal tumors, several imaging characteristics were predictive of poor disease-free survival, including longitudinal length >34 mm, transmural growth, and transverse length >20 mm, although only the latter remained significant in multivariate analysis [19]. A retrospective study of 31 tumors of the trachea or main bronchi compared a combination of pre- and postcontrast CT axial images, volume-rendered, and VB postprocessing techniques with surgical and pathology findings, finding good correlations for tumor locations, morphologies, longitudinal involvement, extent and morphology of stenosis, extramural invasion, and distance from the carina [12]. In a study of 52 patients comparing VB with bronchoscopy, VB had a high sensitivity and accuracy (both 93%) for detection of central airway tumors and had a high sensitivity (90%) and accuracy (96%) for characterization of airway stenosis [26].
Tracheobronchial Disease. A few small studies have documented additional incremental benefits of review of 2-D multiplanar, 3-D reformatted, and VB images, including changes in surgical approach or identification of associated findings such as small fistulae [11]. Chest CT is also used for evaluation of suspected posttreatment complications of tracheal interventions. CT is commonly used for planning for tracheal stent implantation; a study of 69 patients with stenosis due to malignancy used CT to select stent diameter by measuring proximal and distal landing zone diameters and to determine desired stent length by measuring length of the involved segment [25]. A small study of 17 stenoses in 14 patients with postintubation stenosis confirmed at surgery found a detection rate of stenosis of 94% (16 of 17 lesions) of CT with VB and 88% (15 of 17) by rigid bronchoscopy; assessment of length was accurate for 87% of stenotic segments by CT and VB and 73% of segments by rigid bronchoscopy [13]. In a study of contrast-enhanced CT of 46 adenoid cystic carcinomas of the trachea and 36 other tracheal tumors, several imaging characteristics were predictive of poor disease-free survival, including longitudinal length >34 mm, transmural growth, and transverse length >20 mm, although only the latter remained significant in multivariate analysis [19]. A retrospective study of 31 tumors of the trachea or main bronchi compared a combination of pre- and postcontrast CT axial images, volume-rendered, and VB postprocessing techniques with surgical and pathology findings, finding good correlations for tumor locations, morphologies, longitudinal involvement, extent and morphology of stenosis, extramural invasion, and distance from the carina [12]. In a study of 52 patients comparing VB with bronchoscopy, VB had a high sensitivity and accuracy (both 93%) for detection of central airway tumors and had a high sensitivity (90%) and accuracy (96%) for characterization of airway stenosis [26].