Could transthoracic ultrasound be useful to suggest a small airways disease in severe uncontrolled asthma?

BACKGROUND: Transthoracic ultrasound (TUS) is an accepted complementary tool in the diagnostic process of several pleuro-pulmonary diseases. However, to the best of our knowledge, TUS findings in patients with severe asthma have never been systematically described. OBJECTIVE: To explore if TUS examination is a useful imaging method in suggesting the presence of a "small airways disease" in patients with severe uncontrolled asthma. METHODS: Seventy-two consecutive subjects with a diagnosis of severe uncontrolled asthma were enrolled. The presence of a "small airways disease" was assessed through the execution of pulmonary function tests. All the patients underwent a complete TUS examination and a chest high resolution computed tomography (HRCT), which was regarded as the reference standard for comparison with TUS findings. RESULTS: Pulmonary function tests results have confirmed a reduction in expiratory flows relative to the small airways and a condition of hyperinflation in 78% and 82% of our patients, respectively. The main signs observed in the TUS examination were a thickened and/or irregular pleural line and the lack or reduction of the "gliding sign." TUS showed high sensitivity and specificity in suggesting the presence of hyperinflation and distal airways inflammation according to the HRCT scan. K Cohen's coefficients showed substantial agreement between the 2 diagnostic tests. CONCLUSION: TUS in patients with severe uncontrolled asthma can provide useful information on the state of the peripheral lung, suggesting the execution of a second-line HRCT scan for better assessment of eventual alterations that may represent the underlying causes of nonresponse to treatment.

Low Sensitivity of Admission Lung US Compared to Chest CT for Diagnosis of Lung Involvement in a Cohort of 82 Patients with COVID-19 Pneumonia.

Background and Objectives: The potential role of lung ultrasound (LUS) in characterizing lung involvement in Coronavirus disease 2019 (COVID-19) is still debated. The aim of the study was to estimate sensitivity of admission LUS for the detection of SARS-CoV-2 lung involvement using Chest-CT (Computed Tomography) as reference standard in order to assess LUS usefulness in ruling out COVID-19 pneumonia in the Emergency Department (ED). Methods: Eighty-two patients with confirmed COVID-19 and signs of lung involvement on Chest-CT were consecutively admitted to our hospital and recruited in the study. Chest-CT and LUS examination were concurrently performed within the first 6-12h from admission. Sensitivity of LUS was calculated using CT findings as a reference standard. Results: Global LUS sensitivity in detecting COVID-19 pulmonary lesions was 52%. LUS sensitivity ranged from 8% in case of focal and sporadic ground-glass opacities (mild disease), to 52% for a crazy-paving pattern (moderate disease) and up to 100% in case of extensive subpleural consolidations (severe disease), although LUS was not always able to detect all the consolidations assessed at Chest-CT. LUS sensitivity was higher in detecting a typical Chest-CT pattern (60%) and abnormalities showing a middle-lower zone predominance (79%). Conclusions: As admission LUS may result falsely negative in most cases, it should not be considered as a reliable imaging tool in ruling out COVID-19 pneumonia in patients presenting in ED. It may at least represent an expanded clinical evaluation that needs integration with other diagnostic tests (e.g., nasopharyngeal swab, Chest-CT).

The artificial count of artifacts for thoracic ultrasound: what is the clinical usefulness?

Many works in the literature have shown that the increase in the number of B lines is a nonspecific sign of underlying pulmonary disease. Actually these artifacts are the result of a physical effect of ultrasound between the chest wall and the pulmonary air. Nevertheless the intra- and inter-operator variability in B-lines counting does not only reside only in the count itself but depends also on the type and frequency of the probe used, as well as the ultrasound scan machine setting and the patient's chest shape. In our opinion, proposing a software algorithm to count lines B seems like an unproductive effort.

Safety maximization of percutaneous transthoracic needle biopsy with ultrasound guide in subpleural lesions in the evaluation of pulmonary consolidation.

The study by Kiranantawat et al. "Clinical role, safety and diagnostic accuracy of percutaneous transthoracic needle biopsy in the evaluation of pulmonary consolidation" highlights how "pulmonary consolidation can be safely evaluated with CT-guided percutaneous needle biopsy". Even if we agree about the role of CT guidance, we would like to point out how Thoracic Ultrasound could be better than CT for biopsy of subpleural lesions that could easily be detected and reached with this "real-time" and quicker technique.

Contrast-enhanced ultrasound does not discriminate between community acquired pneumonia and lung cancer.

We investigated if contrast-enhanced ultrasound (CEUS) may differentiate community acquired pneumonia (CAP) from lung cancer (LC). Among 1374 patients admitted in a 5-year period for lung opacities, 728 (329 CAP and 399 LC) were investigated by CEUS, comparing the time of appearance, disappearance, duration and pattern of distribution of contrast enhancement (CE). The patients with CAP and LC did not differ in terms of age, time of CE appearance, disappearance and duration or CE distribution. Our data show that the timing and pattern of CE detected by chest CEUS does not distinguish between CAP and LC and overly optimistic beliefs on this matter should be abandoned.

Assessment of thoracic ultrasound in complementary diagnosis and in follow up of community-acquired pneumonia (cap).

BACKGROUND: Chest X-ray (CXR) is the primary diagnostic tool for community-acquired pneumonia (CAP). Some authors recently proposed that thoracic ultrasound (TUS) could valuably flank or even reliably substitute CXR in the diagnosis and follow-up of CAP. We investigated the clinical utility of TUS in a large sample of patients with CAP, to challenge the hypothesis that it may be a substitute for CXR. METHODS: Out of 645 consecutive patients with a CXR-confirmed CAP diagnosed in the emergency room of our hospital over a three-years period, 510 were subsequently admitted to our department of Internal Medicine. These patients were evaluated by TUS by a well-trained operator who was blinded of the initial diagnosis. TUS scans were performed both at admission and repeated at day 4-6th and 9-14th during stay. RESULTS: TUS identified 375/510 (73.5%) of CXR-confirmed lesions, mostly located in posterior-basal or mid-thoracic areas of the lungs. Pleural effusion was detected in 26.9% of patients by CXR and in 30.4% by TUS. TUS documented the change in size of the consolidated areas as follows: 6.3 ± 3.4 cm at time 0, 2.5 ± 1.8 at 4-6 d, 0.9 ± 1.4 at 9-14 d. Out of the 12 patients with delayed CAP healing, 7 of them turned out to have lung cancer. CONCLUSIONS: TUS allowed to detect lung consolidations in over 70% of patients with CXR-confirmed CAP, but it gave false negative results in 26.5% of cases. Our longitudinal results confirm the role of TUS in the follow-up of detectable lesions. Thus, TUS should be regarded as a complementary and monitoring tool in pneumonia, instead of a primary imaging modality.

Lung transthoracic ultrasound elastography imaging and guided biopsies of subpleural cancer: a preliminary report.

BACKGROUND: Despite the usefulness of elastography in assessing the stiffness/elasticity of tissues, and its proven diagnostic accuracy in thyroid, breast, and prostate cancers, among others, it is not yet applied in transthoracic ultrasound (TUS) scans to investigate lung nodules. PURPOSE: To investigate the potential clinical utility of TUS elastography in diagnosing lung cancer proven by fine-needle aspiration biopsy (FNAB). MATERIAL AND METHODS: TUS elastography was performed in 95 consecutive patients (71 men, 24 women; age, 62.84 ± 7.37 years) with lesions suspected of involving the chest wall or the pleura detected on chest X-ray or computed tomography (CT). Patients with pleural effusions were not enrolled, but were further evaluated by pleural fluid cytology. Patients were excluded from the study if a diagnosis had already been made based on sputum cytology and/or bronchoscopic histology (making TUS biopsy unnecessary) or if their lung lesions could not be visualized under standard US. Under FNAB, 34 consolidations were ascribed to pneumonia and 65 to cancer. Under TUS, tissue stiffness, detected using a convex multifrequency 2-8-mHz probe and a MyLab™Twice - ElaXto, was scored from 1 (greatest elasticity) to 5 (no elasticity). Subpleural solid masses (2-5 cm) were initially detected by TUS and subsequently assessed by FNAB. RESULTS: Histological diagnoses were: small cell lung cancer (4/61), adenocarcinoma (29/61), squamous cell carcinoma (SCC) (12/61), large cell lung carcinoma (12/61), and lymphomas (4/61). Patients' age and mass sizes (3.06 ± 0.88 cm) were not significantly associated with any histological type. A significant lower elasticity of SCC (4.67 ± 0.492) was observed versus other types of lung cancer (P < 0.005), and versus pneumonia (2.35 ± 0.48). CONCLUSION: Since only squamous cell lung carcinoma displays the feature of significantly reduced elasticity, and since no clear-cut diagnostic key is yet available, the clinical usefulness of TUS elastography is currently limited with a view to characterizing tumors. Nevertheless, it does enable good non-invasive imaging of lung nodules, providing information on their stiffness, and can improve the accuracy and yield of FNAB.

Transthoracic ultrasound in the assessment of pleural and pulmonary diseases: use and limitations.

Interest in transthoracic ultrasound (US) procedures increased after the availability of portable US equipment suitable for use at the patient's bedside. It is possible to detect space-occupying lesions of the pleura, pleural effusion, focal or diffuse pleural thickening and subpleural lesions of the lung, even in emergency settings. Transthoracic US is useful as a guidance system for thoracentesis and peripheral lesion biopsy, where it minimises the occurrence of pneumothorax and haemorrhage. Transthoracic US imaging is strongly influenced by physical interaction of the ultrasonic beam at the tissue/air interface, which gives rise to reverberations classified as simple (A-line), "comet tail" and "ring down"(B-line) artifacts. Although these artifacts can be suggestive of a disease condition, they are essentially imaging errors present even in normal subjects and in empty-pleura post-pneumonectomy patients. In order to clarify some confusion and to report on the state of the art, we present a review of the literature on transthoracic US in diseases of the pleura and peripheral lung regions and our own clinical experience over 3 decades. The review focuses on quality assurance procedures and their value in diagnostic imaging and patient monitoring and warns against possible inappropriate indications and misleading information. Thoracic US is much more than "fishing for the moon in the well".

The Unveiled Triad: Clinical, Radiological and Pathological Insights into Hypersensitivity Pneumonitis.

Hypersensitivity pneumonitis (HP) is a diffuse parenchymal lung disease (DLPD) characterized by complex interstitial lung damage with polymorphic and protean inflammatory aspects affecting lung tissue targets including small airways, the interstitium, alveolar compartments and vascular structures. HP shares clinical and often radiological features with other lung diseases in acute or chronic forms. In its natural temporal evolution, if specific therapy is not initiated promptly, HP leads to progressive fibrotic damage with reduced lung volumes and impaired gas exchange. The prevalence of HP varies considerably worldwide, influenced by factors like imprecise disease classification, diagnostic method limitations for obtaining a confident diagnosis, diagnostic limitations in the correct processing of high-resolution computed tomography (HRCT) radiological parameters, unreliable medical history, diverse geographical conditions, heterogeneous agricultural and industrial practices and occasionally ineffective individual protections regarding occupational exposures and host risk factors. The aim of this review is to present an accurate and detailed 360-degree analysis of HP considering HRCT patterns and the role of the broncho-alveolar lavage (BAL), without neglecting biopsy and anatomopathological aspects and future technological developments that could make the diagnosis of this disease less challenging.