Advanced visualization of airways with 64-MDCT: 3D mapping and virtual bronchoscopy

3D Virtual Bronchoscopy as an Aid to Airway Management in a Patient with Anterior Mediastinal Mass

ABSTRACT

Mediastinal masses pose one of the great challenges for any anesthesiologist during airway maintenance, underlining the need to devise a well-formulated plan to avoid perioperative complications. As a general rule, such patients are managed with spontaneous ventilation without the use of muscle relaxants and awake intubation. We report a case of a 66-year-old male with severe dyspnea, having a very large invasive anterior mediastinal mass, causing left lung collapse for urgent debulking surgery. The tracheobronchial compromise was ruled out using three-dimensional reconstruction on computed tomography imaging (virtual bronchoscopy) and that helped in using general anesthesia with muscle relaxation for subsequent endotracheal intubation and surgery.

Identification of anatomical types of segmental bronchi in left superior and lingular lobes using multi-slice CT

PURPOSE

The objectives of this study were to evaluate various branching patterns of segmental bronchi in the left superior and lingular lobes and to survey the anatomical diversity and sex-related differences of these branches in a large sample of the study population.

MATERIALS AND METHODS

Overall, 10,000 participants (5428 males, and 4572 females, mean age 50 ± 13.5 years [SD] years; age range: 3-91 years) who underwent multi-slice CT (MSCT) scans between September 2019 and December 2021 were retrospectively included. Using the syngo.via post-processing workstation, the data were applied to generate three-dimensional (3D) and virtual bronchoscopy (VB) simulations of a bronchial tree. The reconstructed images were then interpreted to identify and categorize distinct bronchial patterns in the left superior and lingular lobes. Cross-tabulation analysis and the Pearson Chi-square (χ2) test were used to calculate the constituent ratios of bronchial branch types and determine their significance between male and female groups.

RESULTS

Our results revealed mainly four distinct types for the left superior lobe (LSL) bronchial tree, i.e., (B1 + 2, B3, 76.13%); (B1 + 2 + 3, 17.32%); (B1 + 3, B2, 5.74%); (B1a + B3, B1b + B2, 0.81%) and two types for the left lingular lobe (LLL) bronchial tree, i.e., (B4, B5, 91.05%); (B4, B5, B*, 8.95%). There were no significant sex-related differences in the proportion of bronchial branches in LLL (P > 0.05). However, sex-related differences were significant in the proportion of bronchial branches in LSL (P < 0.05).

CONCLUSION

The current study has validated the presence of segmental bronchial variations in the left superior and lingular lobes. These findings may have a crucial effect on the diagnosis of symptomatic patients, as well as in carrying out procedures such as lung resections, endotracheal intubation, and bronchoscopies.

Identification of anatomical types of segmental bronchi in right middle lobe using multi-slice CT

PURPOSE

The objectives of this study were to evaluate the various branching patterns of segmental bronchi in the right middle lobe (RML) and to survey the anatomical diversity and sex-related differences of these branches in a large sample of the study population.

MATERIALS AND METHODS

In this retrospective board-approved study with informed consent, 10,000 participants (5428 males and 4,572 females, mean age 50 ± 13.5 years [SD]; age range: 3-91 years) who underwent multi-slice CT (MSCT) scans from September 2019 to December 2021 were retrospectively included. The data were applied to generate three-dimensional (3D) and virtual bronchoscopy (VB) simulations of a bronchial tree using the syngo.via post-processing workstation. The reconstructed images were then interpreted to locate and classify distinct bronchial patterns in the RML. Cross-tabulation analysis and the Pearson chi-square test were used to calculate the constituent ratios of bronchial branch types and determine their significance between male and female groups.

RESULTS

Our results revealed that the segmental bronchial ramifications of the RML were classified into two types mainly, i.e., bifurcation (B4, B5, 91.42%) and trifurcation (B4, B5, B*, 8.58%). There were no significant sex-related differences in the proportion of bronchial branches in the RML (P > 0.05).

CONCLUSION

The current study has confirmed the presence of segmental bronchial variations in the RML lobe using 3D reconstruction and virtual bronchoscopy. These findings may have significant implications for the diagnosis of symptomatic patients and for carrying out specific procedures like bronchoscopy, endotracheal intubation, and lung resection.

Three-dimensional catheter navigation of airways using continuous-sweep limited angle fluoroscopy on a C-arm

Purpose: To develop an imaging-based 3D catheter navigation system for transbronchial procedures including biopsy and tumor ablation using a single-plane C-arm x-ray system. The proposed system provides time-resolved catheter shape and position as well as motion compensated 3D airway roadmaps. Approach: A continuous-sweep limited angle (CLA) imaging mode where the C-arm continuously rotates back and forth within a limited angular range while acquiring x-ray images was used for device tracking. The catheter reconstruction was performed using a sliding window of the most recent x-ray images, which captures information on device shape and position versus time. The catheter was reconstructed using a model-based approach and was displayed together with the 3D airway roadmap extracted from a pre-navigational cone-beam CT (CBCT). The roadmap was updated in regular intervals using deformable registration to tomosynthesis reconstructions based on the CLA images. The approach was evaluated in a porcine study (three animals) and compared to a gold standard CBCT reconstruction of the device. Results: The average 3D root mean squared distance between CLA and CBCT reconstruction of the catheter centerline was 1 ± 0.5    mm for a stationary catheter and 2.9 ± 1.1    mm for a catheter moving at ∼ 1    cm / s . The average tip localization error was 1.3 ± 0.7    mm and 2.7 ± 1.8    mm , respectively. Conclusions: The results indicate catheter navigation based on the proposed single plane C-arm imaging technique is feasible with reconstruction errors similar to the diameter of a typical ablation catheter.

Reconstruction of complete tracheal transection with cardiopulmonary bypass support following bull horn injury in neck during coronavirus disease 19 pandemic lockdown

A 22-year-old male had complete tracheal transection 2.5 cm above the carina with distal end retracted into the mediastinum. This was accidental bullhorn injury to the trachea in the lower cervical region, which posed arduous challenge of “cannot intubate” situation, necessitating percutaneous femoro-femoral cardiopulmonary bypass for surgical reconstruction, during coronavirus disease 19 (COVID-19) pandemic lockdown.

Use of an Aortic Cannula for Tracheal Intubation in a Patient With Severe Tracheal Stenosis and Tracheoesophageal Fistula: A Case Report

A one-day-old girl was brought to the OR for the repair of a type C esophageal atresia (EA) [EA with tracheoesophageal fistula (TEF)]. Rigid bronchoscopy was performed to locate the fistula, and it revealed a severe long-segment tracheal stenosis. Therefore, the airway could not have been secured past the fistula using normal-sized endotracheal tubes (ETTs). A nontraditional airway using an aortic cannula was used to intubate the stenotic tracheal segment, and the patient received ventilation during the TEF/EA repair. 

Automatic bronchial segmentation on ultra-HRCT scans: advantage of the 1024-matrix size with 0.25-mm slice thickness reconstruction

PURPOSE

The aim of this study was to evaluate the advantages of ultra-high-resolution computed tomography (U-HRCT) for automatic bronchial segmentation.

MATERIALS AND METHODS

This retrospective study was approved by the Institutional Review Board, and written informed consent was waived. Thirty-three consecutive patients who underwent chest CT by a U-HRCT scanner were enrolled. In each patient, CT data were reconstructed by two different protocols: 512 × 512 matrix with 0.5-mm slice thickness (conventional HRCT mode) and 1024 × 1024 matrix with 0.25-mm slice thickness (U-HRCT mode). We used a research workstation to compare the two CT modes with regard to the numbers and total lengths of the automatically segmented bronchi.

RESULTS

Significantly greater numbers and longer lengths of peripheral bronchi were segmented in the U-HRCT mode than in the conventional HRCT mode (P < 0.001, for fifth- to eighth-generation bronchi). For example, the mean numbers and total lengths of the sixth-generation bronchi were 81 and 1048 mm in the U-HRCT mode and 59 and 538 mm in the conventional HRCT mode.

CONCLUSIONS

The U-HRCT mode greatly improves automatic airway segmentation for the more peripheral bronchi, compared with the conventional HRCT mode. This advantage can be applied to routine clinical care, such as virtual bronchoscopy and automatic lung segmentation.

Localization and shape of stenoses in central lung carcinoma - Sensitivity and precision of MDCT VB and FB

The objective is to present diagnostic capabilities of virtual bronchoscopy (VB) and fiberoptic bronchoscopy (FB) for determining the localization and shape of stenoses in patients with central lung carcinoma. A systematic study was performed on 220 patients aged 11-83 (54.36±17.24) years with endobronchial disease using the FB and VB methods during the 2013-2017 period. Central carcinoma of the lung was found on VB in 130 patients and on FB in 120 patients. Other nosologic diseases were found in 22 patients. Right localization of central carcinoma prevailed over left localization in both sexes. A significant difference in the localization criterion was found in female patients examined by VB (U-test, p=0.01). VB and FB yielded 86.5% vs. 91.60% precision and 85% vs. 94.5% sensitivity. In conclusion, VB was found to be a successful noninvasive method for determining the localization of lung tumors and shape of stenoses, which are essential in the diagnosis of malignant processes.

Diagnosing peripheral lung lesions using endobronchial ultrasonography with guide sheath: A prospective registry study to assess the effect of virtual bronchoscopic navigation using a computed tomography workstation

Bronchoscopy has a lower diagnostic yield for peripheral lung lesions (PLL). Endobronchial ultrasound guide sheath transbronchial lung biopsy (EBUS GS TBLB) has been used to overcome such limitation. Recent studies revealed that combined methods (e.g., EBUS GS TBLB plus electromagnetic navigation [EMN] or virtual bronchoscopic navigation [VBN]) further improve the diagnostic yield. However, those systems are associated with a high cost burden. Accordingly, we attempted to use VBN by computed tomography (CT) workstation (Aquarius iNtuition, TeraRecon) not dedicated only for VBN as an adjunctive tool for EBUS GS TBLB. We performed a prospective registry study to investigate whether VBN by CT workstation could improve the diagnostic yield of PLL.Between February 2017 and February 2018, 128 patients with PLL were divided into 2 groups (VBN and non-VBN [NVBN]). In NVBN group (n = 64), EBUS GS TBLB was performed using a hand-drawn bronchial map based on CT images. VBN group (n = 64) underwent EBUS GS TBLB using VBN images.VBN using CT workstation did not improve the diagnostic yield of EBUS GS TBLB for PLL (VBN vs NVBN, 72% vs 80%, P = .284). VBN slightly reduced procedure time (minute [mean ± SD], 25.31 ± 10.33 vs 25.81 ± 9.22), navigation time (time to find the lesion) (9.10 ± 7.88 vs 9.50 ± 7.14), and fluoroscopy time (2.23 ± 2.39 vs 2.86 ± 4.61), while these differences were not statistically significant.The diagnostic yield of EBUS GS TBLB was not improved with VBN (compared with using a hand-drawn bronchial map). Although VBN slightly shortened the procedure-related times, which were not significantly different.

Multimodality imaging of pediatric airways disease: indication and technique

Congenital and acquired airway anomalies represent a relatively common albeit diagnostic and therapeutic challenge, even for the most skilled operators in dedicated centers. Airway malformations encompass a wide spectrum of pathologies involving the larynx, trachea and bronchi, esophagus, mediastinal vessels. These developmental lesions are often isolated but the association of two or more anomalies is not infrequent. From the traditional chest X-ray to the newest applications of Optical Coherence Tomography, non- or mini-invasive diagnostic techniques represent useful tools to integrate invasive procedures. Comprehensive knowledge of the characteristics of each diagnostic test is mandatory for its useful application. The aim of our paper is to analyze the clinical indications for Imaging the Airway disease in pediatric population, and describe the diagnostic techniques. Only by a close interaction between all the operators involved in diagnosis and treatment of pediatric airway, as it happens in Multidisciplinary Airway Team, the non- or mini-invasive imaging is effective.

Tracheal Diverticula

Extraluminal paratracheal air bubbles are occasionally seen on computed tomography (CT) studies that include the thoracic inlet (ie, CT of the neck, of the cervical spine, and of the chest). In most cases, these paratracheal air bubbles are tracheal diverticula (TD), sometimes also referred to as tracheal pouch, tracheocele, and tracheogenic cyst. TD are most commonly seen at the right posterolateral aspect of the upper trachea at the level T1-T3. Because of their typical location and appearance, they are easily recognized and should not be confused with pneumomediastinum or other causes of air bubbles in the same region. This article describes the prevalence, possible pathophysiology, and associated complications of TD and illustrates the spectrum of their appearance on CT.

Increased prevalence of tracheal diverticula in cystic fibrosis patients

OBJECTIVE

This investigation sought to evaluate the prevalence and imaging characteristics of tracheal diverticula (TD) among patients with cystic fibrosis (CF).

METHODS

A total of 113 patients with CF at our institution, with a median age of 29 years, had chest CT examinations between 2002 and 2014. These imaging studies were retrospectively reviewed to assess for the presence and characteristics of TD, including quantity, size and location. The severity of the CF disease was assessed using the Bhalla CT scoring system and pulmonary function tests.

RESULTS

Of the 113 cases reviewed, 20 (17.7%) patients were found to have 1 or more TD. The presence of TD was associated with more severe disease by imaging criteria, with a Bhalla CT score of 13.9 ± 4.3 in patients with TD and 11.5 ± 4.3 in patients without TD. For the pulmonary function tests, forced expiratory volume in 1 s (FEV1) and FEV1 percent predicted demonstrated a trend towards worsening function in patients with TD, although the difference was not statistically significant.

CONCLUSION

The prevalence of TD in our patient population with CF based on chest CT exams was 17.7%. In addition, the presence of TD was associated with more severe CF disease by imaging criteria.

ADVANCES IN KNOWLEDGE

TD appear to have a higher prevalence in patients with CF than in the general population, are associated with more severe CF pulmonary disease by CT criteria and are frequently underreported by radiologists.

Anatomy and physiology of respiratory system relevant to anaesthesia

Clinical application of anatomical and physiological knowledge of respiratory system improves patient's safety during anaesthesia. It also optimises patient's ventilatory condition and airway patency. Such knowledge has influence on airway management, lung isolation during anaesthesia, management of cases with respiratory disorders, respiratory endoluminal procedures and optimising ventilator strategies in the perioperative period. Understanding of ventilation, perfusion and their relation with each other is important for understanding respiratory physiology. Ventilation to perfusion ratio alters with anaesthesia, body position and with one-lung anaesthesia. Hypoxic pulmonary vasoconstriction, an important safety mechanism, is inhibited by majority of the anaesthetic drugs. Ventilation perfusion mismatch leads to reduced arterial oxygen concentration mainly because of early closure of airway, thus leading to decreased ventilation and atelectasis during anaesthesia. Various anaesthetic drugs alter neuronal control of the breathing and bronchomotor tone.

Diagnostic utility of endobronchial ultrasound with a guide sheath under the computed tomography workstation (ziostation) for small peripheral pulmonary lesions

BACKGROUND AND AIMS

The application of radial probe endobronchial ultrasound (R-EBUS) and virtual bronchoscopic navigation has improved the diagnostic outcome of bronchoscopy for peripheral pulmonary lesions (PPLs). Nonetheless, while existing navigation systems are very useful for selecting the bronchus containing the target lesion, the associated introductory costs are high. Therefore, we focused on virtual bronchoscopy (VB) using the workstation, ziostation that was already available in many countries as an adjunct modality.

METHODS

Consecutive patients who underwent bronchoscopy with R-EBUS for PPLs (major diameter ≤30 mm) were enrolled. From late June 2013 to November 2013, 121 patients were examined with ziostation, and from September 2012 to early June 2013, 113 patients were examined without ziostation. We compared the diagnostic yield, EBUS detection rate and procedure time between two groups to evaluate the utility of the VB.

RESULTS

The ziostation group had significantly higher diagnostic yield than the non-ziostation group (77.7% vs 64.6%, P = 0.030). Following the multivariate analysis, use of ziostation was a significant factor affecting the diagnostic yield. Meanwhile, EBUS detection rate was significantly higher in the ziostation group (94.2% vs 75.2%, P < 0.001). And, procedure time was significantly shorter in the ziostation group (mean ± standard deviation: 24.0 ± 7.4 min vs 26.9 ± 7.9 min, P = 0.005).

CONCLUSION

VB offered by the workstation was a valuable tool that facilitated more accurate and rapid bronchoscopy procedure for diagnosis of PPLs.

CT virtual endoscopy for analyzing variations in the hepatic portal vein

PURPOSE

To evaluate the value of CT virtual endoscopy (CTVE) for accurately distinguishing varying types of portal veins (PVs).

MATERIALS AND METHODS

From 526 consecutive patients whose hepatic portal vein was well visualized, patients who were considered to have trifurcation of the main portal vein (MPV) or right portal vein (RPV) on volume rendering (VR) and maximum intensity projection (MIP) imaging were chosen for the analysis. Two radiologists evaluated the PV anatomy of these patients and re-classified the types of PV variation using the CTVE technique. The Wilcoxon rank sum test was used to calculate differences in age between males and females.

RESULTS

Thirty-two patients (20 males, 12 females; age range 21-68 years; mean age 43 years) were considered to have trifurcation of the MPV (15) or RPV (17) on VR and MIP imaging. Fifteen patients in total had a trifurcation confirmed by CTVE (6 patients were proven to have an MPV trifurcation by CTVE, and 9 were confirmed to have a RPV trifurcation).

CONCLUSIONS

CTVE can differentiate PV variations that cannot be identified accurately on MIP and VR.

Computed Tomography Virtual Bronchoscopy: Normal Variants, Pitfalls, and Spectrum of Common and Rare Pathology

A broad spectrum of pathologies that involve the laryngotracheobronchial airway and imaging plays a crucial role in evaluating these abnormalities. Computed tomography with virtual bronchoscopy has been found to be very helpful in defining the location, extent, and nature of these lesions, and is increasingly being used even in patients with contraindications for fiberoptic bronchoscopy and laryngoscopy. Ionizing radiation, associated with virtual bronchoscopy, can be minimized by using low-dose multidetector computed tomography and hybrid iterative reconstruction techniques. Furthermore, retrospectively generated virtual bronchoscopy from a routinely acquired computed tomography data set eliminates additional cost and radiation. In the future, virtual bronchoscopy assisted with advanced navigational techniques will broaden the diagnostic and therapeutic landscape. This article presents the characteristic features of common and rare laryngotracheobronchial pathologies seen with virtual bronchoscopy.

Airway trauma: a review on epidemiology, mechanisms of injury, diagnosis and treatment

Airway injuries are life threatening conditions. A very little number of patients suffering air injuries are transferred live at the hospital. The diagnosis requires a high index of suspicion based on the presence of non-specific for these injuries symptoms and signs and a thorough knowledge of the mechanisms of injury. Bronchoscopy and chest computed tomography with MPR and 3D reconstruction of the airway represent the procedures of choice for the definitive diagnosis. Endotracheal intubation under bronchoscopic guidance is the key point to gain airway control and appropriate ventilation. Primary repair with direct suture or resection and an end to end anastomosis is the treatment of choice for patients suffering from tracheobronchial injuries (TBI). The surgical approach to the injured airway depends on its location. Selected patients, mainly with iatrogenic injuries, can be treated conservatively as long as the injury is small (<2 cm), a secure and patent airway and adequate ventilation are achieved, and there are no signs of sepsis. Patients with delayed presentation airway injuries should be referred for surgical treatment. Intraoperative evaluation of the viability of the lung parenchyma beyond the site of stenosis/obstruction is mandatory to avoid unnecessary lung resection.

Three-dimensional reconstruction of thoracic structures: based on Chinese Visible Human

We managed to establish three-dimensional digitized visible model of human thoracic structures and to provide morphological data for imaging diagnosis and thoracic and cardiovascular surgery. With Photoshop software, the contour line of lungs and mediastinal structures including heart, aorta and its ramus, azygos vein, superior vena cava, inferior vena cava, thymus, esophagus, diaphragm, phrenic nerve, vagus nerve, sympathetic trunk, thoracic vertebrae, sternum, thoracic duct, and so forth were segmented from the Chinese Visible Human (CVH)-1 data set. The contour data set of segmented thoracic structures was imported to Amira software and 3D thorax models were reconstructed via surface rendering and volume rendering. With Amira software, surface rendering reconstructed model of thoracic organs and its volume rendering reconstructed model were 3D reconstructed and can be displayed together clearly and accurately. It provides a learning tool of interpreting human thoracic anatomy and virtual thoracic and cardiovascular surgery for medical students and junior surgeons.

Proximal pulmonary vein stenosis detection in pediatric patients: value of multiplanar and 3-D VR imaging evaluation

BACKGROUND

One of the important benefits of using multidetector computed tomography (MDCT) is its capability to generate high-quality two-dimensional (2-D) multiplanar (MPR) and three-dimensional (3-D) images from volumetric and isotropic axial CT data. However, to the best of our knowledge, no results have been published on the potential diagnostic role of multiplanar and 3-D volume-rendered (VR) images in detecting pulmonary vein stenosis, a condition in which MDCT has recently assumed a role as the initial noninvasive imaging modality of choice.

OBJECTIVE

The purpose of this study was to compare diagnostic accuracy and interpretation time of axial, multiplanar and 3-D VR images for detection of proximal pulmonary vein stenosis in children, and to assess the potential added diagnostic value of multiplanar and 3-D VR images.

MATERIALS AND METHODS

We used our hospital information system to identify all consecutive children (< 18 years of age) with proximal pulmonary vein stenosis who had both a thoracic MDCT angiography study and a catheter-based conventional angiography within 2 months from June 2005 to February 2012. Two experienced pediatric radiologists independently reviewed each MDCT study for the presence of proximal pulmonary vein stenosis defined as ≥ 50% of luminal narrowing on axial, multiplanar and 3-D VR images. Final diagnosis was confirmed by angiographic findings. Diagnostic accuracy was compared using the z-test. Confidence level of diagnosis (scale 1-5, 5 = highest), perceived added diagnostic value (scale 1-5, 5 = highest), and interpretation time of multiplanar or 3-D VR images were compared using paired t-tests. Interobserver agreement was measured using the chance-corrected kappa coefficient.

RESULTS

The final study population consisted of 28 children (15 boys and 13 girls; mean age: 5.2 months). Diagnostic accuracy based on 116 individual pulmonary veins for detection of proximal pulmonary vein stenosis was 72.4% (84 of 116) for axial MDCT images, 77.5% (90 of 116 cases) for multiplanar MDCT images, and 93% (108 of 116 cases) for 3-D VR images with significantly higher accuracy with 3-D VR compared to axial (z = 4.17, P < 0.001) and multiplanar (z = 3.34, P < 0.001) images. Confidence levels for detection of proximal pulmonary vein stenosis were significantly higher with 3-D VR images (mean level: 4.6) compared to axial MDCT images (mean level: 1.7) and multiplanar MDCT images (mean level: 2.0) (paired t-tests, P < 0.001). Thus, 3-D VR images (mean added diagnostic value: 4.7) were found to provide added diagnostic value for detecting proximal pulmonary vein stenosis (paired t-test, P < 0.001); however, multiplanar MDCT images did not provide added value (paired t-test, P = 0.89). Interpretation time was significantly longer and interobserver agreement was higher when using 3-D VR images than using axial MDCT images or MPR MDCT images for diagnosing proximal pulmonary vein stenosis (paired t-tests, P < 0.001).

CONCLUSIONS

Use of 3-D VR images in the diagnosis of proximal pulmonary vein stenosis in children significantly increases accuracy, confidence level, added diagnostic value and interobserver agreement. Thus, the routine use of this technique should be encouraged despite its increased interpretation time.

Virtual bronchoscopy in the era of multi-detector computed tomography: Is there any reality?

Virtual bronchoscopy, in conjunction with axial and MPR MDCT images, can enhance diagnostic accuracy of tracheo-bronchial endoluminal pathologies. We describe a few cases highlighting the utility of virtual bronchoscopy in the diagnosis of varied tracheo-bronchial pathologies encountered in the setting of a tertiary care Armed Forces Hospital of India.

Five levels of PACS modularity: integrating 3D and other advanced visualization tools

The current array of PACS products and 3D visualization tools presents a wide range of options for applying advanced visualization methods in clinical radiology. The emergence of server-based rendering techniques creates new opportunities for raising the level of clinical image review. However, best-of-breed implementations of core PACS technology, volumetric image navigation, and application-specific 3D packages will, in general, be supplied by different vendors. Integration issues should be carefully considered before deploying such systems. This work presents a classification scheme describing five tiers of PACS modularity and integration with advanced visualization tools, with the goals of characterizing current options for such integration, providing an approach for evaluating such systems, and discussing possible future architectures. These five levels of increasing PACS modularity begin with what was until recently the dominant model for integrating advanced visualization into the clinical radiologist's workflow, consisting of a dedicated stand-alone post-processing workstation in the reading room. Introduction of context-sharing, thin clients using server-based rendering, archive integration, and user-level application hosting at successive levels of the hierarchy lead to a modularized imaging architecture, which promotes user interface integration, resource efficiency, system performance, supportability, and flexibility. These technical factors and system metrics are discussed in the context of the proposed five-level classification scheme.

Virtual and fiber-optic bronchoscopy in patients with indication for tracheobronchial evaluation

OBJECTIVE

The aim of this study was to compare the results of virtual bronchoscopy (VB) images in defining tracheobronchial pathologies with those of fiber-optic bronchoscopy (FOB) in patients with clinical indication for bronchoscopy.

METHODS

Twenty-two patients with bronchoscopy indication were evaluated with FOB and VB. The VB results were evaluated blindly, independent of the FOB results.

RESULTS

In 19 of the 22 patients, tracheobronchial abnormalities were present on FOB, whereas 3 patients had normal findings on FOB. In 17 of 19 patients, VB demonstrated the FOB diagnosis of tracheobronchial abnormality. While FOB detected 11 endoluminal lesions, VB detected 6. While FOB detected 20 obstructive lesions, VB detected 26. In evaluating external compression, FOB detected 2 lesions and VB detected 15.

CONCLUSIONS

VB is a non-invasive, uncomplicated, and reproducible examination method in patients with an indication for thorax examination. Virtual bronchoscopy could find a clinically broader field of application in the future.

Pneumomediastinum in blunt trauma: A review

Pneumomediastinum (PM) is an uncommon finding after blunt trauma to the neck or chest. Motor vehicle collisions are the most common cause in adults, while falls are the most common in children. The majority of traumatic PM results from medial tracking of air from a concomitant pneumothorax. The Macklin effect, of air tracking medially along peribronchial sheaths from alveolar rupture, is responsible for most other cases. Chest pain is the most common symptom, and crepitus the most common sign. The majority of PM will resolve spontaneously, and requires no specific intervention. Only 1—6% of cases result from rupture of the larynx, trachea, bronchi or oesophagus. Hoarseness, dyspnea, persistent lung collapse or air leak should increase suspicion for aerodigestive injury. Computed tomography (CT) can help differentiate benign etiology from those that require surgical correction. High suspicion for aerodigestive injury based on clinical and/or CT findings should prompt diagnostic bronchoscopy and/or oesophagram.

Multiple Tracheal Diverticula Detected by Multidetector-row Computed Tomography

Multiple tracheal diverticula are rare. We report a case of a 62-year-old man who had multiple tracheal diverticula that were detected using multidetector-row computed tomography. Axial computed tomography images showed multiple air collections contiguous to the trachea. The multiple air collections were visible as outpouchings of the parts of the trachea between the cartilages, being located almost symmetrically on both lateral sides of the tracheal wall as seen on coronal multiplanar reconstruction images. Virtual bronchoscopy confirmed the presence of multiple openings in the tracheal wall of the diverticular necks. The alteration of the airway was better seen using volume-rendered reconstruction. Thin-slice multidetector-row computed tomography and advanced imaging techniques may increase the frequency of identification of multiple tracheal diverticula.

Update on multidetector computed tomography imaging of the airways

Recent advances in multidetector computed tomography (MDCT) technology have transformed the imaging evaluation of the trachea and bronchi. Multiplanar 2-dimensional and 3-dimensional volume reconstruction techniques, including external rendering and virtual bronchoscopy, can be generated in mere minutes, thereby complementing conventional axial CT imaging in the depiction of various central airway disease processes including airway stenoses, central airway neoplasms, and congenital airway disorders. Paired inspiratory and dynamic expiratory MDCT imaging, along with newer cine CT imaging methods, have enhanced the assessment of tracheobronchomalacia in both adults and the pediatric population. In addition, MDCT imaging plays an essential complementary role to conventional bronchoscopy, facilitating planning and guidance of bronchoscopic interventions, and providing a noninvasive method for postprocedural surveillance.

Bronchial anatomy of left lung: a study of multi-detector row CT

Familiarity with prevailing pattern and variations in the bronchial tree is not only essential for the anatomist to explain bronchial variation in bronchial specimens, but also useful for guiding bronchoscopy and instructing pulmonary segmental resection. The purpose of this study was designed to demonstrate various branching patterns of left lung with 3D images, with special attention given to identify the major types at transverse thin-section CT. Two hundred and sixteen patients with routine thorax scans were enrolled. The images of bronchial tree, virtual bronchoscopy were reconstructed using post-processing technique of multi-detector row CT. We attempted to classify the segmental bronchi by interpreting the post-processing images, and identified them in transverse thin-section CT. Our results showed that the segmental bronchial ramifications of the left superior lobe were classified into three types mainly, i.e., common stem of apical and posterior segmental bronchi (64%, 138/216); trifurcation (23%, 50/216); common stem of apical and anterior segmental bronchi (10%, 22/216), and they could be identified at two typical sections of transverse thin-section CT. There were two major types in left basal segmental bronchi, i.e., bifurcation (75%, 163/216), trifurcation (18%, 39/216), and they could also be identified at two typical sections of transverse thin-section CT. In conclusion, our study have offered simplified branching patterns of bronchi and demonstrated various unusual bronchial branching patterns perfectly with 3D images, and have also revealed how to identify the main branching patterns in transverse thin-section CT.