Diagnostic potential of virtual bronchoscopy: advantages in comparison with axial CT slices, MPR and mIP?

The aim of this study was to evaluate the diagnostic potential of virtual endoscopy (VE) and to compare it with axial CT slices, multiplanar reconstructions (MPR), minimal intensity projections (mIP), and bronchoscopy in patients diagnosed with bronchogenic carcinoma. Thirty patients underwent a spiral CT. Axial CT images were transferred to an Onyx workstation (Silicon Graphics, Sun Microsystems, Mountain View, Calif.) for performing virtual endoscopy. Accuracy for this procedure was tested by three radiologists on a monitor in comparison with axial CT slices, MPR, mIP, and bronchoscopy concerning the localization and degree of stenoses. Endoluminal tumors were identified by virtual bronchoscopy with no statistically significant difference of localization or grading of stenosis in comparison with bronchoscopy, axial CT slices, MPR and mIP. Axial CT slices, MPR, and mIP showed poorer results with over- or underestimation of stenoses compared with VE and bronchoscopy. Passing of stenoses was only possible with VE in 5 patients. Virtual endoscopy is a non-invasive method for identification of endoluminal tumors and is comparable to real bronchoscopy. Received: 18 March 1999; Revised: 21 May 1999; Accepted: 22 July 1999     

Virtual endoscopy of the upper,central and peripheral airways with multirow detector CT

Virtual endoscopy of the upper, central and peripheral airways (virtual laryngoscopy or virtual bronchoscopy) produces endoluminal images similar to those of fiberoptic endoscopy. In particular, virtual endoscopy is useful for the assessment of endoluminal tumor extent and tracheobronchial stenosis. Especially since the introduction of multirow detector CT, high-resolution virtual-endoscopic images of the airways can be reconstructed. Either surface rendering or volume rendering can be used for realistic depiction of the airways. Semitransparent color-coded volume rendering is advantageous, because adjacent structures can be displayed in addition to endoluminal views. A major advantage of virtual endoscopy over fiberoptic endoscopy is its non-invasiveness. With virtual endoscopy, even a high-grade stenosis is passable, enabling evaluation of the distal airways. Disadvantages are its inability to depict mucosal color and to perform therapeutic maneuvers. In comparison to other CT display modes, virtual endoscopy allows a more realistic assessment of tracheobronchial stenosis than axial CT slices and multiplanar reformats. Virtual endoscopy of the airways can be used complementary to fiberoptic endoscopy before tracheotomy, stent implantation or lung resection and for post-operative follow-up. In the future, virtual airway endoscopy will be increasingly applied for interactive virtual reality guidance of airway procedures such as bronchoscopy and surgery.     

Multidetector CT virtual bronchoscopy to grade tracheobronchial stenosis

OBJECTIVE: The purpose of this study was to compare the efficacy of noninvasive multidetector CT (virtual bronchoscopic images, axial CT slices, coronal reformatted images, and sagittal reformatted images) in depicting and allowing accurate grading of tracheobronchial stenosis with that of flexible bronchoscopy. MATERIALS AND METHODS: Multidetector CT and flexible bronchoscopy were used to examine 200 bronchial sections obtained from 20 patients (15 patients with bronchial carcinoma and five without central airways disease). Multidetector CT was performed using the following parameters: collimation, 4 x 2 mm, pitch, 1.375; and reconstruction intervals, 2 mm. Postprocessing was performed using surface rendering and multiplanar reformatted images. CT images were independently interpreted by two radiologists. The tracheobronchial stenoses revealed on flexible bronchoscopy were graded by a pulmonologist. RESULTS: Virtual bronchoscopic findings, axial CT scans, and multiplanar reformatted images were highly accurate (98% accuracy for virtual bronchoscopic images, 96% for axial slices and coronal reformatted images, and 96.5% for sagittal reformatted images) in revealing tracheobronchial stenosis. In allowing accurate grading of tracheobronchial stenosis, images from virtual bronchoscopy correlated closely (r = 0.91) with those of flexible bronchoscopy. Because use of virtual bronchoscopic images reduced the overestimation of stenosis, these images allowed better assessment of stenosis than did axial CT slices (r = 0.84) or multiplanar reformatted images (r = 0.84) alone. CONCLUSION: Multidetector CT virtual bronchoscopy is a reliable noninvasive method that allows accurate grading of tracheobronchial stenosis. However, it should be combined with the interpretation of axial CT images and multiplanar reformatted images for evaluation of surrounding structures and optimal spatial orientation.     

Virtual bronchoscopy in patients with central endobronchial stenosing lesions. Technique optimisation with single slice spiral CT

PURPOSE: To describe an original protocol for single slice spiral Computed Tomography (CT) virtual bronchoscopy in the evaluation of patients with central airway stenoses and compare the results with fibreoptic bronchoscopy. MATERIALS AND METHODS: Ten patients (4 female and 6 male; age range 22-60 years; mean age 44 years) with endobronchial disease diagnosed by fibreoptic bronchoscopy (8 malignant tumours, 1 benign tumour and 1 fibroid stenosis) underwent virtual bronchoscopy with single slice spiral CT. A panoramic spiral CT scan of the whole chest was first obtained. Once the area of interest had been identified, a new contrast enhanced scan was performed, from bottom to top, with the following parameters: 2 mm slice thickness, 1 mm reconstruction index, 1.3 pitch, 120 Kvp, 80 mAs. Virtual bronchoscopy was generated with an upper threshold of -500 HU from the cross-sectional images of the second scan on a dedicated workstation. Axial, multiplanar reformations (MPR), and virtual endoscopy simulation were simultaneously visualised. Virtual CT bronchoscopy findings were compared with those of fibreoptic bronchoscopy. RESULTS: The protocol we used to perform single slice spiral CT virtual bronchoscopy enabled us to obtain virtual bronchoscopy images that correlated well with fibreoptic bronchoscopy findings in all cases, as well as allowing the visualization of the airways beyond the stenoses. Information about tissues surrounding the tracheobronchial tree was also available from axial and MPR images. Only in 1 case were motion artefacts observed. CONCLUSIONS: The set of the most appropriate parameters for performing virtual bronchoscopy by single slice spiral CT has not yet been standardized. In our opinion the appropriate selection of the protocol to adequately realize virtual bronchoscopic images is crucial when using CT devices such as the above, so as to achieve the correct balance between the quality of image definition and exposure dose.     

Virtual bronchoscopy versus thin section computed tomography in evaluation of moderate and low grade stenoses: receiver operating characteristic curve analysis

Purpose: To evaluate the impact of virtual bronchoscopy, under proper threshold settings, on observer level of confidence in the assessment of bronchial abnormalities producing stenoses ≤75% compared to interpretation of thin section computed tomography (CT) images.

Material and Methods: Sixty-five patients with fiberoptic bronchoscopy positive for tracheobronchial abnormalities were evaluated in a blinded observer study using a commercially available virtual endoscopy software package. The findings of virtual endoscopy were compared with those of fiberoptic bronchoscopy using receiver operating characteristic curves (ROCs) and other statistical tools.

Results: A total of 102 lesions were identified by fiberoptic bronchoscopy, with 44 of these producing bronchial stenoses ≤75%. Concerning the latter lesions, for virtual bronchoscopy the areas under the ROCs were 0.93 and 0.96 for the two observers, respectively, while for thin section CT the corresponding values were 0.86 and 0.88; the differences observed were statistically significant. Contrary to thin section CT, virtual bronchoscopy did not show statistically significant differences from fiberoptic bronchoscopy regarding estimation of degree of stenosis.

Conclusion: Virtual bronchoscopy under proper threshold settings has a statistically significant impact on observer performance where moderate and low-grade bronchial stenoses are concerned and gives an estimate of the degree of stenosis more precisely than thin section CT.     

Evaluation of tracheobronchial lesions with spiral CT: comparison between virtual endoscopy and bronchoscopy]

INTRODUCTION: The aim of this study is to describe the scanning parameters for virtual bronchoscopy in the evaluation of the tracheobronchial tree and to compare the results of this examination with the endoscopic findings. MATERIAL AND METHODS: 27 patients with tracheobronchial neoplasms suspected at preliminary clinical and chest film findings or postoperative follow-up for malignant disease were evaluated with spiral CT of the chest and bronchoscopy. Virtual endoscopy was performed on the pulmonary volume involved by the lesion, using narrow axial images (thickness 2 mm, table index 3 mm, reconstruction index 1 mm.) so as to obtain MPR, MIP and 3D reconstructions with 3D Endo Vew program (Philips Medical System, Eindhoven, Holland). We compared these reconstructions and the findings the normal spiral CT scanning with the corresponding endoscopic examinations. RESULTS: In all patients we were able to study the lobar and segmental bronchi in all patients and in 2 we also evaluated the subsegmental bronchi. 25 lesions in 23 patients were shown by virtual endoscopy (8 occlusions, 8 stenosis, 5 compressions, 3 flogosis with endobronchial mucus, 1 bronchocele) and in 4 patients the examinations were negative. The bronchoscopy was negative in 4 patients and positive in 23 patients with 25 lesions, but we had agreement in 23/27 patients (85,1%). In 2 patients virtual endoscopy showed the lesions in a different bronchus compared to bronchoscopy. In one patient we interpreted the obstruction as neoplastic instead of mucus inside the bronchi and in the last patient bronchoscopy was not performed due to his old age and the virtual endoscopy showed total obstruction of a segmental bronchus. DISCUSSION AND CONCLUSIONS: The results show that virtual endoscopy can study the tracheobronchial tree as far as the segmental bronchi, and sometimes also the subsegmental bronchi and the bronchi below a closed obstruction. In addition, it can evaluate the extraluminal location of the lesions. For these reasons virtual endoscopy provides a road map for bronchoscopy as a guide for transbronchial biopsy and for endobronchial treatment planning. The limitation of this technique is its inability to evaluate the mucosal surface and distinguish flogosis from neoplastic lesions by biopsy. It can be used however in the postoperative follow-up both for cancer and transplant, when immediate biopsy is not necessary.     

CT仿真内窥镜成像技术临床应用的初步探讨

目的探讨ＣＴ仿真内窥镜成像技术的原理、方法及临床应用价值。材料与方法将螺旋ＣＴ容积扫描数据传输到工作站。通过软件功能调整ＣＴ值阈值和透明度，显示含气器官或主动脉的内腔，赋予人工伪彩色，重建出沿空腔器官中轴行程一致的多幅器官内表面图像。再用电影功能依次回放，获得仿真内窥镜效果。用此方法检查２１例患者及正常人，其中喉部８例，气管支气管３例，结肠５例，主动脉５例。全部病例均经纤维内窥镜或手术病理证实。结果喉、气管支气管及结肠ＣＴ仿真内窥镜获得类似纤维内窥镜显示管腔器官腔壁或腔内病变形态的效果。尚能从梗阻远端观察病变情况。主动脉ＣＴ仿真内窥镜能显示血管内壁、假性动脉瘤的破口、夹层动脉瘤的内膜瓣。结论ＣＴ仿真内窥镜提供了一种无创伤性的诊断方法，可作为纤维内窥镜的补充手段，但其敏感性及特异性有待今后进一步研究提高。     

多层螺旋CT血管造影在大血管病变术后复查中的应用

目的 评价多层螺旋CT血管造影术在大血管病变腔内隔绝术或血管搭桥术后复查中的临床应用价值。材料与方法 34例大血管病变腔内隔绝术或血管搭桥术后行多层螺旋CT血管造影术,采用准直2．5mm,层厚3.0mm,螺距为6,重建方法为容积漫游技术（VR）、SSD及MIP,并对三种方法进行比较。结果 主动脉瘤及夹层动脉瘤行腔内隔绝术后23例,血管搭桥术后7例,同时行腔内隔绝术及血管搭桥术后4例;2例出现渗漏,VR均能显示,SSD、MIP显示1例。VR图像能清晰显示内支架的位置及形态,对搭桥血管的位置、形态、吻合口及远侧段血管情况显示良好,明显优于SSD及MIP。结论 多层螺旋CT能在较短时间内进行大范围的扫描,有利于大血管病变的检查;VR图像优于SSD及MIP,能为术后情况提供更多信息。     

2D and 3D CT imaging correlated to rigid endoscopy in complex laryngo-tracheal stenoses

The aim of this study was to compare 2D and 3D CT imaging in the pre- and postoperative evaluation of complex benign larynges-tracheal airway stenoses with rigid endoscopy, considered as the gold standard. Six patients (aged 5–72 years) with a total of nine complex laryngo-tracheal stenoses underwent non-contrast helical CT scans (slice thickness 3 mm, pitch 1.3, reconstruction interval 1.5 mm) before and after surgical resection. With prototype software, virtual endoscopy (VE) post-processing algorithms were applied to the imaging data sets. The VE and multiplanar 2D findings were compared with rigid endoscopy, considered as standard of reference. All nine stenoses were correctly identified on 3D images and their anatomical locations correctly assessed on 2D reconstructions. Artifacts were met when patients were unable to suspend their breath, leading to one false-positive result. Two-dimensional images and 3D VE of tracheal stenoses proved to be efficient and complementary to the rigid endoscopy, permitting a reliable endoluminal 3D view and evaluation of the surrounding anatomical structures. Limitations of this technique relate to the maximal spatial resolution of 1.5 mm, the lack of color, and the inability to assess the mucosa. Virtual endoscopy is for complex laryngo-tracheal stenoses an excellent complement for rigid endoscopy, remaining the method of reference, and may be indicated with complicated pathological structures. Received: 15 September 1999 Revised: 11 February 2000 Accepted: 8 June 2000     

Value of virtual tracheobronchoscopy and bronchography from 16-slice multidetector-row spiral computed tomography for assessment of suspected tracheobronchial stenosis in children

Purpose To evaluate the value of dose-reduced 16-slice multidetector-row spiral computed tomography (16-MDCT) using virtual tracheobronchoscopy (VTB) and virtual bronchography (VBG) in children with suspected tracheobronchial stenosis.Materials and methods 12 children (4 d to 3 years, body weight 1.2 kg to 13.5 kg) with stridor and suspected tracheobronchial stenosis were examined by contrast-enhanced low-dose 16-MDCT. Conventional axial slices, MPRs, VTB, and VBG were calculated. Image findings were correlated with the results of fiberoptic bronchoscopy (12 out of 12) as a gold standard and subsequent surgery (8 out of 12).Results VTB and VBG demonstrated the fiberoptic bronchoscopically suspected tracheal stenosis in 11 of 12 children due to vascular compression because of the brachiocephalic trunk (6), a double aortic arch (2), a vascular compression of the left main bronchus (2), and a right aberrant subclavian artery (1). Eleven out of 12 stenoses were correctly depicted by conventional axial slices, MPRs, VTB, and VBG. Dose reduction was 79 to 85.8% compared to a standard adult chest CT.Conclusion Dose-reduced 16-MDCT with the use of VTB and VBG is effective for the evaluation of tracheobronchial stenosis in children and correlates well with fiberoptic bronchoscopy.     

多层螺旋CT及其三维重组对中央型肺癌的诊断价值

目的:评价多层螺旋CT(MSCT)及其三维重组对中央型肺癌(CLC)的诊断价值。方法:58例CLC患者,经MSCT平扫,增强动、静脉期扫描,二维多平面及曲面重组(MPR及CPR),三维容积重组(VR)、最大密度投影(MIP)及仿真内窥镜重组(CTVE),同时均经支气管镜及其病理检查,44例经术后病理证实。并将各种重组诊断结果与横断面扫描结果进行统计学对比分析。结果:58例CLC MSCT三维重组、支气管镜及手术分三型:腔内结节型5例,环状狭窄型19例,偏心狭窄截断型34例。MPR及CPR、MIP、CTVE诊断结果与横断面扫描相比,差异无显著性;VR差异则有显著性。结论:MSCT三维重组能准确分型诊断CLC,评价气管、支气管树肿瘤侵犯程度与范围,具有较好的临床应用价值。     

多层螺旋CT仿真内镜对中央型肺癌的评价

目的研究多层螺旋CT(MSCT)仿真内镜(VE)在中央型肺癌的应用。资料与方法69例中央型肺癌，行MSCT扫描后进行VE成像。其中43例同期作纤维支气管镜（FBs)检查对照。结果VE下表现为支气管管腔闭塞34例，气管或支气管偏心性狭窄19例，管腔内占位病变16例。VE与FBS一致性达86．1％。差异主要在过诊为闭塞5例。结论MSCT VE可较好地辅助判断中央型肺癌的位置和支气管狭窄程度。     

Internal carotid arterial stenosis: CT angiography with volume rendering

PURPOSE: To determine the reliability of helical computed tomography (CT) with volume rendering for evaluation of internal carotid arterial stenosis. MATERIALS AND METHODS: In 22 patients, 44 carotid arteries were evaluated with helical CT and selective conventional angiography. CT data were displayed on volume-rendered and maximum intensity projection (MIP) images. Stenoses were measured separately on axial, volume-rendered, and MIP images and on conventional angiograms. Each artery was then graded as having no stenosis, mild (< 30%) stenosis, moderate (30%-70%) stenosis, severe (> 70%) stenosis, near occlusion, or occlusion. RESULTS: One case of stenosis was not assessable at axial CT because of an inappropriate scanning plane; four cases were not assessable at MIP CT because of mural calcifications. All carotid arteries were assessable on volume-rendered images despite no depiction of the residual lumen at the site of narrowing in three cases of near occlusion. Correlations between angiography and helical CT were good. Axial, volume-rendered, and MIP images enabled correct classification of stenosis in 88%, 89%, and 90% of arteries, respectively. CT with volume rendering was slightly more sensitive for determining candidates for endarterectomy (i.e., those with > 70% stenosis and near occlusion); sensitivity was 100% and specificity, 92%. CONCLUSION: CT angiography with volume rendering enabled accurate evaluation of carotid disease, even when dense calcifications were present. However, no definite advantage over currently available techniques for CT measurement of stenosis severity was found.     

螺旋CT气管重建技术评价肺癌与气管支气管的关系

目的探讨螺旋CT气管重建技术在评价肺癌与气管支气管的关系中的价值。方法对34例拟手术的病例和5例已手术的病例进行CT扫描,在工作站上进行重建处理,重建方法包括MPR,SSD及VR,分别分析轴位图像和重建图像并进行对比。结果在显示狭窄部位方面,重建图像优于轴位图像,可纠正轴位图像错误3例。在显示肿瘤与支气管的空间关系方面,重建图像可以非常清楚显示,而轴位图像没有一例可以提供这方面的信息。在显示狭窄程度方面,轴位图像判断的敏感性、特异性分别为67．4％,75．3％;重建图像判断的敏感性、特异性分别为86．2％,83．2％。在显示支气管侵犯范围方面,轴位图像判断的敏感性、特异性分别为72．4％,66．5％;重建图像判断的敏感性、特异性为89．3％,90．4％。结论螺旋CT气管重建技术对判断肺癌与气管支气管的关系很有帮助。     

多层螺旋CTA:不同重建方法在主动脉瘤腔内隔绝术后的应用评价

目的：探讨多层螺旋CT血管造影不同重建方法在主动脉瘤腔内隔绝术后的临床应用价值。材料与方法：46例主动脉瘤腔内隔绝术后行多层螺旋CT血管造影，采用准直2.5mm，层厚3.0mm，螺距为6，重建方法为容积显示技术（volume rendering，VR）、表面阴影遮盖显示(shade surface display，SSD)及最大密度投影法（maximum intensity projection，MIP），并对三种方法进行比较。结果：46例中有1例术后内支架出现局限性断裂，VR及MIP均清晰显示了内支架的变化，SSD未能显示。1例内支架展开不良，三种重建方法均明确显示；6例术后出现渗漏，VR清晰显示渗漏的部位、形态及内漏量，MIP、SSD仅显示其中的5例，三者中以VR显示最佳。在显示支架内血流情况及瘤周血栓方面，VR能明确支架内有无血栓形成及腔内隔绝术后的转归变化，VR显示1例术后支架内血栓形成SSD及MIP未能显示。结论：多层螺旋CT能在较短时间内进行大范围的扫描，有利于主动脉病变的检查；VR图像优于SSD及MIP，能为术后内支架情况提供更多更准确的信息，VR技术应作为主动脉瘤内支架术后的首选三维重建方法。     

CT angiography: in vitro comparison of five reconstruction methods

OBJECTIVE: Five image reconstruction techniques have been used with CT angiography: axial (cross-sectional), maximum intensity projection (MIP), curved multiplanar reconstruction (MPR), shaded-surface display, and volume rendering. This study used a phantom to compare the accuracy of these techniques for measuring stenosis. SUBJECTS AND METHODS: A 19-vessel phantom containing various grades of concentric stenoses (0-100%) and three lengths (5, 7.5, and 10 mm) of stenoses was used for this study. Scans were obtained with a slice thickness of 2.0 mm, slice interval of 1.0 mm, pitch of 1.0, 120 kVp, 200 mA, and with the vessels oriented parallel to the z-axis and opacified with nonionic contrast material. CT angiography images were produced using five optimized techniques: axial, MIP, MPR, shaded-surface display, and volume rendering; and measurements were made with an electronic cursor in the normal lumen and mid stenosis by five separate investigators who were unaware of vessel and stenosis diameters. Each of the techniques was first optimized according to the radiology literature and our own preliminary testing. RESULTS: For vessels greater than 4 mm in diameter, axial, MIP, MPR, shaded-surface display, and volume-rendering CT angiography techniques all had a measurement error of less than 2.5%. However, axial, MIP, MPR, and shaded-surface display techniques were less accurate in estimating smaller (相似文献   

多层螺旋CT对小儿气管、支气管非金属异物的诊断价值

目的:探讨多层螺旋CT(MSCT)对气管、支气管非金属异物的诊断价值。方法:50例临床可疑气管、支气管异物病例行MSCT检查,并结合MSCT多模式重组如多平面重建(MPR)、表面遮盖显示法(SSD)、CT仿真支气管镜(CTVB)图像分析诊断,全部病例均经纤维支气管镜或临床证实。结果:50例可疑病例中,有气管、支气管非金属异物30例,MSCT能显示这些支气管异物的位置、形态、大小及异物所致气管、支气管狭窄和堵塞情况,无异物20例,其中18例与临床相一致,2例误诊。结论:利用MSCT的多模式重组,结合轴位图像能提高诊断气管、支气管非金属异物的准确性,具有重要的诊断价值。     

Tracheobronchial stenosis: role of virtual endoscopy in diagnosis and follow-up after therapy

PURPOSE: This study was done to evaluate whether virtual endoscopy can be employed as a preliminary technique to shorten the time required for the subsequent endoscopic procedure and be proposed for treatment planning and, postoperatively, for evaluating response to treatment in patients with cancer or severe stenotic lesions. MATERIALS AND METHODS: From December 2004 to October 2005, 25 patients with suspected obstructive tracheobronchial stenosis were studied by contrast-enhanced computed tomography (CT) with multiplanar reconstruction (MPR) and virtual bronchoscopic navigation, after a preliminary clinical and conventional radiology assessment. RESULTS: Quality of the virtual endoscopy images was excellent in all cases. Out of the 25 patients, four were affected by benign lesions and 21 by malignant lesions. With regard to lesion site, virtual endoscopy proved to be as informative as real endoscopy. The virtual endoscope was able to cross severe stenoses with a residual lumen of 3 mm. Follow-up studies were performed in 15 patients treated with laser and cryotherapy. In all cases, evaluation of the degree of post-treatment stenosis was similar to that obtained with conventional endoscopy. CONCLUSIONS: Our study indicates that virtual bronchoscopy has a high diagnostic potential. The technique, with the integration of MPR images, can be proposed as a preliminary study to obtain accurate characterisation of stenoses, to shorten the time required for the subsequent endoscopic procedure and to plan the most appropriate treatment.     

气管支气管病变的多层螺旋CT诊断

目的:回顾性分析41例气管支气管病变的多层螺旋CT(MDCT)影像资料,探讨MDCT对气管支气管病变的诊断价值。材料和方法:搜集自2006年5至2007年8月共41例气管支气管病变的MDCT资料,常规横断面为6mm层厚,回顾性重建为1mm层厚、1mm层间隔,并于同步工作站进行三维重建,包括CT仿真支气管内镜(CTVE)、多层面/曲面成像(MPP/CPR)、最大/小密度投影(MIP,MinIP)、表面遮盖成像(SSD))和容积重组(VR)。结果:MDCT结合多种三维重建可以很好地显示气管支气管的正常和异常,肺癌、支气管结核、支气管腔内占位以及邻近病变所致气道狭窄各有特点。三维重建对狭窄部位、范围和程度的确定显示很好。结论:MDCT结合多种后处理三维重建对气管支气管的各种类型病变有较好的诊断和鉴别诊断价值。     

Follow-up after stent insertion in the tracheobronchial tree: role of helical computed tomography in comparison with fiberoptic bronchoscopy

The aim of this study was to compare helical CT with fiberoptic bronchoscopy findings to appraise the medium-term results of proximal-airways stenting. Twenty-five patients with 28 endobronchial metallic stents inserted for local advanced malignancy (n=13) or benign diseases (n=12) underwent follow-up CT from 3 days to 50 months (mean 8 months). All studies were obtained using helical CT with subsequent multiplanar reformation and three-dimensional reconstruction including virtual bronchoscopy. The location, shape, and patency of stents and adjacent airway were assessed. The results of CT were compared with the results of fiberoptic bronchoscopy obtained with a mean delay of 2.5 days (SD 9 days) after CT scan. Twelve stents (43%) remained in their original position, patent and without deformity. Sixteen stents were associated with local complications: migration (n=6); external compression with persistent stenosis (n=4); local recurrence of malignancy (n=4); fracture (n=1); and non-congruence between the airway and the stent (n=1). The CT demonstrated all the significant abnormalities demonstrated at fiberoptic bronchoscopy except two moderate stenoses (20%) related to granulomata at the origin of the stent . Ten of 14 stents inserted for benign conditions were without complications as compared with 2 of 14 in malignant conditions (p=0.008). Computed tomography is an accurate noninvasive method for evaluating endobronchial stents. The CT is a useful technique for follow-up of patients who have undergone endobronchial stenting. Electronic Publication