Pulmonary inhalation-perfusion scintigraphy in the evaluation of bronchoscopic treatment of bronchopleural fistula

Targeted alveo-pleural fistula endobronchial valve treatment using ventilation scintigraphy

Persistent air-leaks can be difficult to localize in radiology. Bronchoscopic management of air-leaks requires identification of the leak's location to allow suitable targeted treatment. One-way endobronchial valves have become a suitable option for persistent air-leaks. In this report, a combination scintigraphy and one-way endobronchial valve treatment successfully resolved a persistent air-leak.

Aerosolised micro and nanoparticle: formulation and delivery method for lung imaging

Purpose

The application of contrast and tracing agents is essential for lung imaging, as indicated by the wide use in recent decades and the discovery of various new contrast and tracing agents. Different aerosol production and pulmonary administration methods have been developed to improve lung imaging quality. This review details and discusses the ideal characteristics of aerosol administered via pulmonary delivery for lung imaging and the methods for the production and pulmonary administration of dry or liquid aerosol.

Methods

We explored several databases, including PubMed, Scopus, and Google Scholar, while preparing this review to discover and obtain the abstracts, reports, review articles, and research papers related to aerosol delivery for lung imaging and the formulation and pulmonary delivery method of dry and liquid aerosol. The search terms used were "dry aerosol delivery", "liquid aerosol delivery", "MRI for lung imaging", "CT scan for lung imaging", "SPECT for lung imaging", "PET for lung imaging", "magnetic particle imaging", "dry powder inhalation", "nebuliser", and "pressurised metered-dose inhaler".

Results

Through the literature review, we found that the critical considerations in aerosol delivery for lung imaging are appropriate lung deposition of inhaled aerosol and avoiding toxicity. The important tracing agent was also found to be Technetium-99m (^99mTc), Gallium-68 (⁶⁸Ga) and superparamagnetic iron oxide nanoparticle (SPION), while the essential contrast agents are gold, iodine, silver gadolinium, iron and manganese-based particles. The pulmonary delivery of such tracing and contrast agents can be performed using dry formulation (graphite ablation, spark ignition and spray dried powder) and liquid aerosol (nebulisation, pressurised metered-dose inhalation and air spray).

Conclusion

A dual-imaging modality with the combination of different tracing or contrast agents is a future development of aerosolised micro and nanoparticles for lung imaging to improve diagnosis success.

Graphical abstract

Giant bronchopleural fistula and empyema in a tuberculosis patient with diabetes mellitus: Vista from a high tuberculosis burden country in Southeast Asia

Bronchopleural fistula is a pathological tract between the bronchial tree and the pleural space, which can be life-threatening due to tension pneumothorax. It is a rare complication in tuberculosis cases with highly variable in clinical manifestations and persistent air leaks which might lead to complications such as empyema. Herein, we present a tuberculosis and diabetic patient complicated with giant bronchopleural fistula and empyema. A 48-year-old man presented with shortness of breath for two weeks and cough with phlegm for two months. The patient was a smoker with severe Brinkman Index and diabetes. Physical examination revealed hyper resonant percussion and vesicular diminished on the left hemithorax. Laboratory results indicated the patient had anemia, leukocytosis, and hypoalbuminemia. GeneXpert sputum confirmed the presence of Mycobacterium tuberculosis and chest X-ray indicated a collapsed left lung. The patient was diagnosed with left secondary spontaneous pneumothorax, pulmonary tuberculosis, and diabetes. The patient was treated with chest tube drainage and anti- tuberculosis drugs. There was no improvement based on serial chest X-ray, and empyema appeared from the chest tube. CT-scan showed tuberculosis lesion, the collapsed of the left lung and fistula in segments 7-8 inferior lobe. Exploratory thoracostomy was performed, in which a giant bronchopleural fistula was detected and then repaired with BioGlue surgical adhesive. Unfortunately, the thoracostomy led to extensive subcutaneous emphysema and was treated by cervical mediastinotomy. The drainage was unable to be removed, and the patient was discharged with Heimlich-type drainage valves on day 28 of treatment. The empyema fluid was cultured and revealed Staphylococcus haemolyticus. This case highlights that tuberculosis could cause a bronchopleural fistula and empyema may occur secondary to late diagnosis that needs immediate surgery.

Ventilation-Perfusion Scan: A Primer for Practicing Radiologists

Lung scintigraphy, or ventilation-perfusion (V/Q) scan, is one of the commonly performed studies in nuclear medicine. Owing to variability in clinical applications and different departmental workflows, many trainees are not comfortable interpreting the results of this study. This article provides a simplified overview of V/Q imaging, including a review of its technique, interpretation methods, and established and emerging clinical applications. The authors review the role of V/Q imaging in evaluation of acute and chronic pulmonary embolism, including the role of SPECT/CT and comparing V/Q scan with CT angiography. In addition, a variety of other applications of pulmonary scintigraphy are discussed, including congenital heart disease, pretreatment planning for lung cancer and emphysema, posttransplant imaging for bronchiolitis obliterans, and less common vascular and nonvascular pathologic conditions that may be detected with V/Q scan. This article will help radiologists and residents interpret the results of V/Q scans and understand the various potential clinical applications of this study. Online supplemental material is available for this article. ^©RSNA, 2021.

Minimizing the Risk of Aerosol Contamination During Elective Lung Resection Surgery

BACKGROUND

In the setting of the COVID-19 pandemic, the conduct of elective cancer surgery has become an issue because of the need to balance the requirement to treat patients with the possibility of transmission of the virus by asymptomatic carriers. A particular concern is the potential for viral transmission by way of aerosol which may be generated during perioperative care. There are currently no guidelines for the conduct of elective lung resection surgery in this context.

METHODS

A working group composed of 1 thoracic surgeon, 2 anesthesiologists and 1 critical care specialist assessed the risk for aerosol during lung resection surgery and proposed steps for mitigation. After external review, a final draft was approved by the Committee for the Governance of Perioperative and Surgical Activities of the Hôpital Maisonneuve-Rosemont, in Montreal, Canada.

RESULTS

The working group divided the risk for aerosol into 6 time-points: (1) intubation and extubation; (2) Lung isolation and patient positioning; (3) access to the chest; (4) conduct of the surgical procedure; (5) procedure termination and lung re-expansion; (6) chest drainage. Mitigating strategies were proposed for each time-point.

CONCLUSIONS

The situation with COVID-19 is an opportunity to re-evaluate operating room protocols both for the purposes of this pandemic and similar situations in the future. In the context of lung resection surgery, specific time points during the procedure seem to pose specific risks for the genesis of aerosol and thus should be the focus of attention.

Use of PET/CT to aid clinical decision-making in cases of solitary pulmonary nodule: a probabilistic approach

Objective

To determine the frequency with which ¹⁸F-FDG-PET/CT findings change the probability of malignancy classification of solitary pulmonary nodules.

Materials and Methods

This was a retrospective analysis of all ¹⁸F-FDG-PET/CT examinations performed for the investigation of a solitary pulmonary nodule between May 2016 and May 2017. We reviewed medical records and PET/CT images to collect the data necessary to calculate the pre-test probability of malignancy using the Swensen model and the Herder model. The probability of malignancy was classified as low if < 5%, intermediate if 5-65%, and high if > 65%. Cases classified as intermediate in the Swensen model were reclassified by the Herder model.

Results

We reviewed the records for 33 patients, of whom 17 (51.5%) were male. The mean age was 68.63 ± 12.20 years. According to the Swensen model, the probability of malignancy was intermediate in 23 cases (69.7%). Among those, the application of the Herder model resulted in the probability of malignancy being reclassified as low in 6 (26.1%) and as high in 8 (34.8%).

Conclusion

¹⁸F-FDG-PET/CT was able to modify the probability of malignancy classification of a solitary pulmonary nodule in more than 50% of the cases evaluated.