Multidetector CT-generated virtual bronchoscopy: an illustrated review of the potential clinical indications

Abstract

Multidetector computed tomography-generated virtual bronchoscopy (VB) is a recent technical development that allows visualisation of the lumen and wall of the trachea and proximal part of the bronchial tree. A dynamic image is produced that resembles what is seen with fibreoptic bronchoscopy (FB).Although the technique has not yet reached daily clinical practice and it can never replace FB, performing VB can be useful in well-defined clinical situations.In this paper, the value and limitations of virtual bronchoscopy will be reviewed, to illustrate the potential role of virtual bronchoscopy in the evaluation of trachea and bronchial tree pathology. Virtual bronchoscopy (VB) is a novel computed tomography (CT)-based imaging technique that allows a noninvasive intraluminal evaluation of the tracheobronchial tree. Several studies have shown that VB can accurately show the lumen and the diameter of the trachea, the left and right main stem bronchi, and the bronchial tree down to the fourth order of bronchial orifices and branches [1,2]. The morphology of the carinas can be evaluated accurately and the images look very similar to that seen with fibreoptic bronchoscopy (FB).Although VB is a promising imaging tool, this technique is not currently used in daily clinical practice and more randomised clinical trials are necessary to prove its clinical use. Nevertheless, it seems valuable to review its potential clinical indications. The purpose of this paper is to discuss and illustrate these indications based on VBs generated from the CT scans of a randomly selected group of patients. Materials and methodsCases were selected retrospectively and randomly from patients undergoing a multidetector row CT (MDCT) examination of the chest for various reasons. Selection was based on the presence of tracheal and bronchial abnormalities identified on the regular axial images and, when made, on additional coronal and sagittal reconstructions. MDCT was performed on a Phillips 16 slice CT (Philips, Best, the Netherlands). Technical parameters were: Kvp: 120; mAs: 150; collimation: 16*0.75; pitch: 0.9; rotation time: 0.42; slice thickness: 1 mm and an increment of 1 mm. MDCT was either performed with or without IV contrast administration depending on the clinical question. A proprietary virtual endoscopic software program (Endo3D; Philips) was used to reconstruct the CT data into VB images. This software program uses a volume rendering technique. A threshold value between -400 and -600 HU was chosen to evaluate the central bronchial tree. The more distal bronchial tree was evaluated using a threshold of -750 HU.Endo3D generates a perspective three-dimensional view from the inside of an anatomical structure, such as the inner wall of the colon, trachea or abdominal aorta. This insideview is generated step by step, creating a film at the end-point. The thickness of each step is 2 mm. The images are orientated with the posterior side at 12 o9clock, the left side at 3 o9clock, the anterior side at 6 o9clock and the right side at...

A virtual bronchoscopic navigation system under X-ray fluoroscopy for transbronchial diagnosis of small peripheral pulmonary lesions

“…In the present study, we successfully showed the efficacy of VB navigationassisted bronchoscopy under a fluoroscope for diagnosing small PPLs. Formerly, several groups reported using VB images for the simulation of major endobronchial abnormalities [11,12,[15][16][17][18] and guidance in transbronchial aspiration biopsies of mediastinal lymph nodes [12,14]. Asano and colleagues introduced VB navigation system [21,22].…”

“…VB has been used for the evaluation of endobronchial anatomic findings, such as endobronchial lesions, bronchial stenosis, and airway distortion [11,[15][16][17][18] and as guidance for the transbronchial needle biopsy [12,14]. We have utilized VB to simulate the tracing path to peripheral lesions; however, simulation prior to the bronchoscopy could not navigate the actual bronchoscope satisfactorily.…”

“…Virtual bronchoscopy (VB) is the application of a threedimensional display of the bronchial lumen reconstructed from spiral CT scan data that simulates actual bronchoscopy [11][12][13][14][15][16][17][18]. VB has been used for the evaluation of endobronchial anatomic findings, such as endobronchial lesions, bronchial stenosis, and airway distortion [11,[15][16][17][18] and as guidance for the transbronchial needle biopsy [12,14].…”

Virtual endoscopy—a new assessment tool in difficult airway management

“…Virtual endoscopy has been used to evaluate pathology at various sites along the airway, from nasopharynx to larynx to the tracheobronchial tree [28][29][30][31][32]. Here, we have demonstrated that glottic, subglottic, and multilevel lesions can all be accurately reproduced to provide us with a realistic image of the airway and aid us in airway management planning.…”

Annual General Assembly of the Royal Belgian Society of Radiology (RBRS), Leuven, 26.11.2013

“…VB may obviate the need for invasive conventional bronchoscopy in certain circumstances and in special subgroups of patients such as young children, very sick patients or elderly patients who may not be able to tolerate bronchoscopy. VB does not permit tissue sampling, which can be done with endoscopic bronchoscopy (11,13).…”