Multidetector CT and postprocessing in planning and assisting in minimally invasive bronchoscopic airway interventions

Endobronchial ultrasound-guided transbronchial fine needle aspiration of mediastinal lymphadenopathy: Diagnostic performance and clinical implications of the World Health Organization reporting system

INTRODUCTION

Lymph node fine-needle aspiration cytology (LN-FNAC) is a common, rapid, minimally invasive and cost-effective diagnostic method. For mediastinal lymph nodes, endobronchial ultrasound (EBUS) guided LN-FNAC is a first-line investigation and has an indispensable role in the diagnosis and staging of patients with suspected lung cancer. Recently, a new WHO system has been proposed for classification of LN-FNAC heralding five different diagnostic categories; insufficient, benign, atypical, suspicious for malignancy and malignant. The aim of this study was to evaluate the diagnostic accuracy and risk of malignancy (ROM) of these categories in EBUS-guided LN-FNAC from mediastinal lymph nodes.

METHOD

We evaluated 2110 consecutive mediastinal lymph nodes during this one-year retrospective study. Corresponding radiological images and histologic material were used as ground truth to calculate accuracy, sensitivity, specificity and ROM.

RESULTS

The WHO system showed an overall accuracy of 93.7% with a sensitivity of 83.0% and a specificity of 97.5%. The positive predictive value was 92.3% and the negative predictive value 94.2%. The overall ROM for each category in the WHO classification system was 12.8% for the inadequate, 2.4% for the benign, 47.4% for the atypical, 81.0% for the suspicious for malignancy and 93.6% for the malignant category.

CONCLUSION

The results of the present study indicate that the new WHO system entails a high diagnostic accuracy regarding EBUS-guided LN-FNAC assessment of mediastinal lymph nodes and supports its integration into clinical practice. Application of the WHO system standardizes risk assessment thus facilitating communication between cytopathologists and clinicians and minimizes the need for histopathological analysis.

Self-Expandable Metal Stent in the Management of Malignant Airway Disorders

Background

Self-expanding metallic stent (SEMS) is a palliative therapy for patients with malignant central airway obstruction (CAO) or tracheoesophageal fistula (TEF). Despite this, many patients experience death shortly after SEMS placement.

Aims

We aimed to investigate the effect of SEMS on the palliative treatment between malignant CAO and malignant TEF patients and investigate the associated prognostic factors of the 3-month survival.

Methods

We performed a single-center, retrospective study of malignant CAO or TEF patients receiving SEMS placement. Clinical data were collected using the standardized data abstraction forms. Data were analyzed using SPSS 22.0. A two-sided P-value <0.05 was statistically significant.

Results

106 malignant patients (82 CAO and 24 TEF) receiving SEMS placement were included. The body mass index (BMI), hemoglobin levels, and albumin levels in the malignant TEF group were lower than in the malignant CAO group (all P < 0.05). The procalcitonin levels, C-reactive protein levels, and the proportion of inflammatory lesions were higher in the malignant TEF group than in the malignant CAO group (all P < 0.05). The proportion of symptomatic improvement after the SEMS placement was 97.6% in the malignant CAO group, whereas 50.0% in the malignant TEF group, with a significant difference (P = 0.000). Three months after SEMS placement, the survival rate at was 67.0%, significantly lower in the malignant TEF group than in the malignant CAO group (45.8% vs. 73.2%, P = 0.013). Multivariate analysis revealed that BMI [odds ratio (OR) = 1.841, 95% certificated interval (CI) (1.155-2.935), P = 0.010] and neutrophil percentage [OR = 0.936, 95% CI (0.883–0.993), P = 0.027] were the independent risk factors for patients who survived three months after SEMS placement.

Conclusions

We observed symptom improvement in malignant CAO and TEF patients after SEMS placement. The survival rate in malignant TEF patients after SEMS placement was low, probably due to aspiration pneumonitis and malnutrition. Therefore, we recommend more aggressive treatment modalities in patients with malignant TEF, such as strong antibiotics, nutrition support, and strategic ventilation. More studies are needed to investigate the prognostic factors in patients with malignant airway disorders receiving SEMS placement.

Malignant Central Airway Obstruction: What's New?

Malignant central airway obstruction (MCAO) is a debilitating and life-limiting complication that occurs in an unfortunately large number of individuals with advanced intrathoracic cancer. Although the management of MCAO is multimodal and interdisciplinary, the task of providing patients with prompt palliation falls increasingly on the shoulders of interventional pulmonologists. While a variety of tools and techniques are available for the management of malignant obstructive lesions, advancements and evolution in this therapeutic venue have been somewhat sluggish and limited when compared with other branches of interventional pulmonary medicine (e.g., the early diagnosis of peripheral lung nodules). Indeed, one pragmatic, albeit somewhat uncharitable, reading of this article's title might suggest a wry smile and shug of the shoulders as to imply that relatively little has changed in recent years. That said, the spectrum of interventions for MCAO continues to expand, even if at a less impressive clip. Herein, we present on MCAO and its endoscopic and nonendoscopic management-that which is old, that which is new, and that which is still on the horizon.

Imaging of therapeutic airway interventions in thoracic oncology

Tracheobronchial obstruction, haemoptysis, and airway fistulas caused by airway involvement by primary or metastatic malignancies may result in dyspnoea, wheezing, stridor, hypoxaemia, and obstructive atelectasis or pneumonia, and can lead to life-threatening respiratory failure if untreated. Complex minimally invasive endobronchial interventions are being used increasingly to treat cancer patients with tracheobronchial conditions with curative or, most often, palliative intent, to improve symptoms and quality of life. The selection of the appropriate treatment strategy depends on multiple factors, including tumour characteristics, whether the lesion is predominately endobronchial, shows extrinsic compression, or a combination of both, the patient's clinical status, the urgency of the clinical scenario, physician expertise, and availability of tools. Pre-procedure multidetector computed tomography (MDCT) imaging can aid in the most appropriate selection of bronchoscopic treatment. Follow-up imaging is invaluable for the early recognition and management of any potential complication. This article reviews the most commonly used endobronchial procedures in the oncological setting and illustrates the role of MDCT in planning, assisting, and follow-up of endobronchial therapeutic procedures.

ACR Appropriateness Criteria® Pneumonia in the Immunocompetent Child

Pneumonia is one of the most common acute infections and the single greatest infectious cause of death in children worldwide. In uncomplicated, community-acquired pneumonia in immunocompetent patients, the diagnosis is clinical and imaging has no role. The first role of imaging is to identify complications associated with pneumonia such as pleural effusion, pulmonary abscess, and bronchopleural fistula. Radiographs are recommended for screening for these complications and ultrasound and CT are recommended for confirmation. The second role of imaging is to identify underlying anatomic conditions that may predispose patients to recurrent pneumonia. CT with intravenously administered contrast is recommended for this evaluation. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Quantified evaluation of tracheal compression in pediatric complex congenital vascular ring by computed tomography

Clinically, early diagnosis and treatment is important for survival of pediatric with vascular ring (VR) associated with congenital heart disease (CHD), and accurate evaluation of VR is a prerequisite for repair surgical. The study aimed to assess the quantitative characteristics of tracheal compression in pediatrics with VR and CHD using dual-source computed tomography (DSCT), and further provided effective information for surgical decisions. A total of 49 VR patients with CHD and 56 controls were enrolled. The tracheal quantitative measurements (short diameter, long diameter, tracheal area and tracheal length) were obtained, and the degree of tracheal compression was assessed. Our results indicated that VR associated with CHD may cause more serious and complex symptoms, and the greater tracheal compression were found on DSCT when more severe symptoms were present (r = 0.84). The degree of tracheal compression was significantly different within the VR group between those with and without surgery (P = 0.002). Finally, there were good agreement among (1-long diameter ratio), (1-short diameter ratio) and (1-area ratio) in patients and controls, respectively. This study indicated that DSCT enables provides accurate quantitative tracheal compression information for VR pediatrics associated with CHD, and evaluation of the degree of tracheal compression by 1-area ratio may contribute to the repair surgical of VR.

The Direct Oblique Method: A New Gold Standard for Bronchoscopic Navigation That is Superior to Automatic Methods

BACKGROUND

The purpose of this study was to identify bronchi on computed tomographic (CT) images, manual analysis is more accurate than automatic methods. Nonetheless, manual bronchoscopic navigation is not preferred as it involves mentally reconstructing a route to a bronchial target by interpreting 2-dimensional CT images. Here, we established the direct oblique method (DOM), a form of manual bronchoscopic navigation that does not necessitate mental reconstruction, and compared it with automatic virtual bronchoscopic navigation (VBN).

METHODS

Routes were calculated to 47 identical targets using 2 automatic VBNs (LungPoint and VINCENT-BFsim) and the DOM, using 3 general application CT viewers (Aquarius, Synapse Vincent, and OsiriX). Results of all analyses were compared.

RESULTS

The DOM drew routes to more targets than the VBNs [94% (the DOM on any viewer) vs. 49% (LungPoint) vs. 62% (VINCENT-BFsim), P<0.0001]. For the 44 targets with the CT-bronchus or CT-artery signs, 100% of the DOM routes led to targets. In the bronchoscopic simulation phase, the DOM covered 100% of the bifurcations identified on CT, whereas some bifurcations were skipped and some bronchial walls appeared partially transparent in the VBNs. Manual analysis identified more bronchi near the targets than the VBNs [32.1±3.4 (manual analysis) vs.18.9±2.1 (LungPoint) vs. 22.9±2.7 (VINCENT-BFsim), mean±SEM, P<0.0001]. The DOM took around 5 minutes on average.

CONCLUSION

On the basis of precise manual CT analysis using general application CT viewers, the DOM drew routes leading to more targets and provided better bronchoscopic simulation than the automatic route calculation of the VBNs.

[Computed tomography imaging of non-small cell lung cancer]

Computed tomography (CT) plays a key role in the initial evaluation of non-small cell lung cancer. It allows initial staging and helps targeting lesions for pathological analysis. The aim of initial imaging work-up is to differentiate between localized disease, eligible to a local treatment, and advanced disease requiring medical treatment. CT is very useful for the assessment of local extension but is less accurate than positron emission tomography (PET)-CT for the assessment of lymphatic and metastatic spread. However, initial staging should include CT examination of the brain and upper abdomen, and PET-CT should be only be performed in patients eligible to a local treatment after initial CT assessment. Propositions for the 8th edition of lung cancer TNM bring several changes for T staging. In particular, the weight of lesion size is increased. Similarly, N1 and N2 stages are now divided in subgroups according the number of involved stations.

Demystifying the persistent pneumothorax: role of imaging

Evaluation for pneumothorax is an important indication for obtaining chest radiographs in patients who have had trauma, recent cardiothoracic surgery or are on ventilator support. By definition, a persistent pneumothorax constitutes ongoing bubbling of air from an in situ chest drain, 48 h after its insertion. Persistent pneumothorax remains a diagnostic dilemma and identification of potentially treatable aetiologies is important. These may be chest tube related (kinks or malposition), lung parenchymal disease, bronchopleural fistula, or rarely, oesophageal-pleural fistula. Although radiographs remain the mainstay for diagnosis and follow up of pneumothorax, computed tomography (CT) is increasingly being used for problem solving. Aetiology of persistent air leak determines the optimal treatment. For some, a simple repositioning of the chest tube/drain may suffice; others may require surgery. In this pictorial review, we will briefly describe the physiology of pneumothorax, discuss imaging features of identifiable causes for persistent pneumothorax and provide a brief overview of treatment options. Specific aetiology of a persistent air leak may often not be immediately discernible, and will need to be carefully sought. Accurate interpretation of imaging studies can expedite diagnosis and facilitate prompt treatment.

Key points

• Persistent pneumothorax is defined as a leak persisting for more than 2 days.

• Radiographs can identify chest-tube-related causes of pneumothorax.

• CT is the most useful test to identify other causes.

• Penetrating thoracic injury can cause fistulous communication resulting in a persistent pneumothorax.

• Discontinuity of visceral pleura identified by CT may indicate a bronchopleural fistula.

Multidetector CT evaluation of airway stents: what the radiologist should know

Airway stents are increasingly used to treat symptomatic patients with obstructive tracheobronchial diseases who are not amenable to surgical resection or who have poor performance status, precluding them from resection. The most common conditions that are treated with tracheobronchial stents are primary lung cancer and metastatic disease. However, stents have also been used to treat patients with airway stenosis related to a variety of benign conditions, such as tracheobronchomalacia, relapsing polychondritis, postintubation tracheal stenosis, postoperative anastomotic stenosis, and granulomatous diseases. Additionally, airway stents can be used as a barrier method in the management of esophagorespiratory fistulas. Many types of stents are available from different manufacturers. Principally, they are classified as silicone; covered and uncovered metal; or hybrid, which are made of silicone and reinforced by metal rings. The advantages and disadvantages of each type of airway stent are carefully considered when choosing the most appropriate stent for each patient. Multidetector computed tomography plays an important role in determining the cause and assessing the location and extent of airway obstruction. Moreover, it is very accurate in its depiction of complications after airway stent placement.

Imaging of the central airways with bronchoscopic correlation: pictorial essay

A wide variety of pathologic processes, both benign and malignant, affect the central airways. These processes may be classified into 4 distinct groups: anatomic variants, lesions that result in focal or diffuse airway narrowing, and those that result in multinodular airway disorder. Key to the accurate assessment of the central airways is meticulous imaging technique, especially the routine acquisition of contiguous high-resolution, 1-mm to 1.5-mm images. These images enable high-definition axial, coronal, and sagittal reconstructions, as well as advanced imaging techniques, including minimum intensity projection images and virtual bronchoscopy. Current indications most commonly include patients presenting with signs and symptoms of possible central airway obstruction, with or without hemoptysis. In addition to diagnosing airway abnormalities, computed tomography (CT) also serves a critical complementary role to current bronchoscopic techniques for both diagnosing and treating airway lesions. Advantages of CT include noninvasive visualization of the extraluminal extent of lesions, as well as visualization of airways distal to central airways obstructions. As discussed and illustrated later, thorough knowledge of current bronchoscopic approaches to central airway disease is essential for optimal correlative CT interpretation.

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.

Feasibility and safety of fiber optic micro-imaging in canine peripheral airways

PURPOSE

To assess the feasibility and safety of imaging canine peripheral airways (<1 mm) with an experimental micro-imaging fiber optic bronchoscope.

METHODS

Twenty healthy dogs were scoped with a micro-imaging fiber optic bronchoscope (0.8 mm outer diameter). Images at various levels of the bronchioles, mucosal color, and tracheal secretions were recorded. The apparatus was stopped once it was difficult to insert. CT imaging was performed simultaneously to monitor progression. The safety of the device was evaluated by monitoring heart rate (HR), respiratory rate (RR), mean artery pressure (MAP), peripheral oxygen saturation (SpO2) and arterial blood gases (partial pressure of arterial carbon-dioxide, PaCO2, partial pressure of arterial oxygen, PaO2, and blood pH).

RESULTS

(1) According to the CT scan, the micro-imaging fiber was able to access the peripheral airways (<1 mm) in canines. (2) There was no significant change in the values of HR, MAP, pH and PaCO2 during the procedure (P>0.05). Comparing pre-manipulation and post-manipulation values, SpO2 (F = 13.06, P<0.05) and PaO2 (F = 3.01, P = 0.01) were decreased, whereas RR (F = 3.85, P<0.05) was elevated during the manipulation. (3) Self-limited bleeding was observed in one dog; severe bleeding or other complications did not occur.

CONCLUSION

Although the new apparatus had little effect on SpO2, PaO2 and RR, it can probe into small peripheral airways (<1 mm), which may provide a new platform for the early diagnosis of bronchiolar diseases.