Joshi Anagha R, Khanna P C, Merchant S A, Khandelwal A, Agrawal N, Karnik N D
Department of Radiology, LTMG Hospital, Sion, Mumbai 400 022.
J Assoc Physicians India. 2003 Sep;51:871-6.
To study the technique and utility of virtual bronchoscopy (virtual reality endobronchial simulation, VRES) as a tool to evaluate post-tracheostomy tracheal stenoses and to correlate the findings of virtual and invasive bronchoscopy and to follow-up treated lesions or those currently under treatment that were initially diagnosed with VRES.
This prospective study comprised nine patients in the age group 13 to 65 years presenting with breathlessness and stridor following one or multiple tracheostomies. They underwent plain CT using a multidetector CT (MDCT) scanner (Siemens Volume Zoom) using narrow (1 mm) collimation. These thin slice images were post-processed using an Irix-based workstation with a 'Fly-Through' endoscopy application. These patients also underwent a rigid (three patients) or fiberoptic (six patients) bronchoscopy.
Of the nine patients that underwent VRES, five were found to have stenoses, three had obstructing granulation tissue, one had an obstructing membrane and one had synechiae. The invasive bronchoscopic findings supported the VRES diagnosis in all but one case of stenosis, one of granulation tissue and the case with synechiae. Membranes and synechiae were relatively difficult to diagnose without the corresponding axial and multiplanar images. VRES achieved a higher sensitivity, while invasive bronchoscopy a higher specificity.
VRES proved to be comparable to invasive bronchoscopy in the depiction of post-tracheostomy tracheal stenoses, with a notable advantage in critical stenoses in that the airway distal to the stenosis could be assessed with VRES but not with invasive bronchoscopy. A preliminary VRES was found to be of assistance in the selection of patients for the more invasive therapeutic procedures such as laser ablation of granulation tissue and its follow-up.
研究虚拟支气管镜检查（虚拟现实支气管内模拟，VRES）作为评估气管切开术后气管狭窄的工具的技术和效用，将虚拟支气管镜检查和侵入性支气管镜检查的结果进行关联，并对最初通过VRES诊断出的已治疗病变或当前正在治疗的病变进行随访。
这项前瞻性研究纳入了9例年龄在13至65岁之间、在一次或多次气管切开术后出现呼吸急促和喘鸣的患者。他们使用多排探测器CT（MDCT）扫描仪（西门子Volume Zoom）进行平扫CT检查，准直宽度为1毫米。这些薄层图像使用基于Irix的工作站和“飞越”内镜应用程序进行后处理。这些患者还接受了硬质（3例）或纤维支气管镜检查（6例）。
在接受VRES检查的9例患者中，5例发现有狭窄，3例有阻塞性肉芽组织，1例有阻塞性膜，1例有粘连。除1例狭窄、1例肉芽组织和粘连病例外，侵入性支气管镜检查结果支持VRES诊断。没有相应的轴向和多平面图像时，膜和粘连相对难以诊断。VRES具有更高的敏感性，而侵入性支气管镜检查具有更高的特异性。
在描绘气管切开术后气管狭窄方面，VRES被证明与侵入性支气管镜检查相当，在严重狭窄方面具有显著优势，即VRES可以评估狭窄远端的气道，而侵入性支气管镜检查则无法做到。初步的VRES被发现有助于选择患者进行更具侵入性的治疗程序，如激光消融肉芽组织及其随访。
