Comparative Evaluation of Super High-Resolution CT Scan and Virtual Bronchoscopy for the Detection of Tracheobronchial Malignancies: Materials and Methods
VB (also known as CT bronchography) employs three-dimensional (3-D) reconstruction of high-resolution helical CT images of the tracheobronchial tree. The contrast between the airway lumen and wall enables the generation of a 3-D anatomic model of tracheobronchial anatomy that provides views similar to those obtained during FB. Furthermore, VB enables the visualization of the tracheobronchial anatomy from multiple angles, thereby facilitating the analysis of bronchial lesions beyond the limits of FB and the assessment of airway patency distal to high-grade obstructions.
Currently, limited information is available regarding the utility of SHR-CT scanning and VB relative to conventional diagnostic modalities of tracheobronchial lesions in oncology patients. Following an initial preliminary study to determine the feasibility of VB, the current study was undertaken to evaluate directly the diagnostic potential of conventional CT, SHR-CT scanning, and VB scans relative to FB for the detection of tracheobronchial lesions. Thus, this study explores the utility of SHR-CT scanning and VB to evaluate the tracheobronchial anatomy with respect to the diagnosis and selection of patients for resection, dilation, and laser, or photodynamic ablation of high-grade stenoses, as well as enabling the sequential evaluation of treatment response in patients with tracheobronchial neoplasms. Indeed, a practical algorithm employing noninvasive techniques for patients who are at high risk for airway pathology may have important clinical benefits. other
Forty-four consecutive patients with thoracic malignancies were prospectively enrolled on an institutional review board-approved protocol evaluating novel imaging modalities between November 1999 and June 2001. The inclusion criteria included the presence of an intrathoracic malignancy and the willingness to undergo novel diagnostic imaging of the chest. After SHR-CT scans and VB images were successfully acquired in the first 10 patients, an additional 34 individuals were accrued with the intent of obtaining correlative FBs within 1 month of the noninvasive imaging. Two of these 34 patients were excluded from analysis due to a time delay between imaging and FB. Of the 32 patients who underwent correlative FBs, 25 (78%) had undergone standard conventional CT scans in addition to novel diagnostic imaging. Twenty of these subjects formed the basis of a preliminary evaluation of the VB technique.