Do technical parameters affect the diagnostic accuracy of virtual bronchoscopy in patients with suspected airways stenosis?

A comparison of virtual bronchoscopy versus flexible bronchoscopy in the diagnosis of tracheobronchomalacia in children

INTRODUCTION

Flexible bronchoscopy (FB) is the current gold standard for diagnosing tracheobronchomalacia. However, it is not always feasible and virtual bronchoscopy (VB), acquired from chest multi-detector CT (MDCT) scan is an alternative diagnostic tool. We determined the sensitivity, specificity, and positive and negative predictive values of VB compared to FB in diagnosing tracheobronchomalacia.

METHODS

Children aged <18-years scheduled for FB and MDCT were recruited. FB and MDCT were undertaken within 30-min to 7-days of each other. Tracheobronchomalacia (mild, moderate, severe, very severe) diagnosed on FB were independently scored by two pediatric pulmonologists; VB was independently scored by two pairs (each pair = pediatric pulmonologist and radiologist), in a blinded manner.

RESULTS

In 53 children (median age = 2.5 years, range 0.8-14.3) evaluated for airway abnormalities, tracheomalacia was detected in 37 (70%) children at FB. Of these, VB detected tracheomalacia in 20 children, with a sensitivity of 54.1% (95%CI 37.1-70.2), specificity = 87.5% (95%CI 60.4-97.8), and positive predictive value = 90.9% (95%CI 69.4-98.4). The agreement between pediatric pulmonologists for diagnosing tracheomalacia by FB was excellent, weighted κ = 0.8 (95%CI 0.64-0.97); but only fair between the pairs of pediatric pulmonologists/radiologists for VB, weighted κ = 0.47 (95%CI 0.23-0.71). There were 42 cases of bronchomalacia detected on FB. VB had a sensitivity = 45.2% (95%CI 30.2-61.2), specificity = 95.5% (95%CI 94.2-96.5), and positive predictive value = 23.2 (95%CI 14.9-34.0) compared to FB in detecting bronchomalacia.

CONCLUSION

VB cannot replace FB as the gold standard for detecting tracheobronchomalacia in children. However, VB could be considered as an alternative diagnostic modality in children with symptoms suggestive of tracheobronchomalacia where FB is unavailable. Pediatr Pulmonol. 2017;52:480-486. © 2016 Wiley Periodicals, Inc.

Comparison of virtual bronchoscopy with fiberoptic bronchoscopy findings in patients exposed to sulfur mustard gas

BACKGROUND

Fiberoptic bronchoscopy (FB) is the best modality for evaluation of tracheobronchial endoluminal lesions. Virtual bronchoscopy (VB) with the aid of computed tomography (CT) makes it possible to reconstruct endoscopic-like visualization of major airways. Sulfur mustard (SM) used during the Iraq-Iran war affects respiratory tracts and can lead to tracheobronchial stenosis.

PURPOSE

To compare VB with FB in SM-exposed patients suspected for airway stenosis.

MATERIAL AND METHODS

Thirty-one patients were evaluated with CT and bronchoscopic studies about 15 years after chemical attacks. The median age of patients was 40 years. Spiral CT scans were obtained and data were transferred to a workstation to generate VB images of major airways. Less than one week after CT scan, FB was performed.

RESULTS

For the tracheal pathologies seen in FB, the sensitivity, specificity, and accuracy of VB was 90.9%, 95%, and 93.5% for tracheal stenosis, 40%, 96.2%, and 87.1% for vocal cord problems, 100%, 100%, and 100% for postoperative changes, and 100%, 96.7%, and 96.8% for intratracheal nodule. The inflammation of mucosal surface could not be assessed by VB. The bronchial pathologies seen in FB included eight cases of stenosis, and one case of nodule. Sensitivity, specificity, and accuracy of VB for detection of bronchial stenosis was 62.5%, 97.8% and 92.6%, respectively. Overall sensitivity, specificity and accuracy of VB in detecting tracheobronchial stenosis were 78.9%, 97.0%, and 92.9%, respectively.

CONCLUSION

Our study indicates that VB is an accurate method for evaluating stenoses, endoluminal nodules, and poststenotic areas within the tracheobronchial tree of SM-exposed victims. This complementary method could be helpful in revealing hidden post-stenotic lesions and also better depict the long tracheal strictures and their actual length.

Virtual bronchoscopy: clinical applications and limitations

Virtual bronchoscopy (VB) is a term that describes a variety of software-based three-dimensional visualizations created from noninvasive medical imaging methods such as CT or MRI scans, with the goal of creating results similar to minimally invasive bronchoscopy procedures of the trachea and upper airways. This technique offers a detailed, noninvasive view of the airways, with reduced risk of infection or perforation, and facilitates preoperative planning for airway interventions that would otherwise not be possible. It is unlikely that VB will replace fiberoptic bronchoscopy; however, as VB techniques become more sophisticated and as sufficient computing and imaging power become more readily available, noninvasive visualization of the airways will play an important and useful role in the evaluation of airway diseases in well defined clinical situations.