The resistible rise of B-line lung ultrasound artefacts

Emergency thoracic ultrasound and clinical risk management

PURPOSE

Thoracic ultrasound (TUS) has been proposed as an easy-option replacement for chest X-ray (CXR) in emergency diagnosis of pneumonia, pleural effusion, and pneumothorax. We investigated CXR unforeseen diagnosis, subsequently investigated by TUS, considering its usefulness in clinical risk assessment and management and also assessing the sustainability of telementoring.

PATIENTS AND METHODS

This observational report includes a period of 6 months with proactive concurrent adjunctive TUS diagnosis telementoring, which was done using freely available smartphone applications for transfer of images and movies.

RESULTS

Three hundred and seventy emergency TUS scans (excluding trauma patients) were performed and telementored. In 310 cases, no significant chest pathology was detected either by CXR, TUS, or the subsequent work-up; in 24 patients, there was full concordance between TUS and CXR (ten isolated pleural effusion; eleven pleural effusion with lung consolidations; and three lung consolidation without pleural effusion); in ten patients with lung consolidations, abnormalities identified by CXR were not detected by TUS. In 26 patients, only TUS diagnosis criteria of disease were present: in 19 patients, CXR was not diagnostic, ie, substantially negative, but TUS detected these conditions correctly, and these were later confirmed by computed tomography (CT). In seven patients, even if chest disease was identified by CXR, such diagnoses were significantly modified by ultrasound, and CT confirmed that TUS was more appropriate. The overall respective individual performances of CXR and TUS for the diagnosis of a pleural-pulmonary disease in emergency are good, with accuracy >95%.

CONCLUSION

About 20% of pneumonia cases were detectable only by CXR and 20% only by TUS and not by CXR; ie, about 40% of patients may have been misdiagnosed if, by chance, only one of the two tools had been used. The concurrent use of TUS and CXR increases the overall sensitivity and specificity. The contribution of expert telementoring and final reappraisal is a valuable and sustainable element for emergency physicians' training and performance, contributing reasonably to mitigation of clinical risks.

Thoracic ultrasound: A complementary diagnostic tool in cardiology

Clinical assessment and workup of patients referred to cardiologists may need an extension to chest disease. This requires more in-depth examination of respiratory co-morbidities due to uncertainty or severity of the clinical presentation. The filter and integration of ecg and echocardiographic information, addressing to the clues of right ventricular impairment, pulmonary embolism and pulmonary hypertension, and other less frequent conditions, such as congenital, inherited and systemic disease, usually allow more timely diagnosis and therapeutic choice. The concurrent use of thoracic ultrasound (TUS) is important, because, despite the evidence of the strict links between cardiac and respiratory medicine, heart and chest US imaging approaches are still separated. Actually, available expertise, knowledge, skills and training and equipment’s suitability are not equally fitting for heart or lung examination and not always already accessible in the same room or facility. Echocardiography is useful for study and monitoring of several respiratory conditions and even detection, so that this is nowadays an established functional complementary tool in pulmonary fibrosis and diffuse interstitial disease diagnosis and monitoring. Extending the approach of the cardiologist to lung and pleura will allow the achievement of information on pleural effusion, even minimal, lung consolidation and pneumothorax. Electrocardiography, pulse oximetry and US equipment are the friendly extension of the physical examination, if their use relies on adequate knowledge and training and on appropriate setting of efficient and working machines. Lacking these premises, overshadowing or misleading artefacts may impair the usefulness of TUS as an imaging procedure.

Thoracic ultrasound: An adjunctive and valuable imaging tool in emergency, resource-limited settings and for a sustainable monitoring of patients

Imaging workup of patients referred for elective assessment of chest disease requires an articulated approach: Imaging is asked for achieving timely diagnosis. The concurrent or subsequent use of thoracic ultrasound (TUS) with conventional (chest X-rays-) and more advanced imaging procedures (computed tomography and magnetic resonance imaging) implies advantages, limitations and actual problems. Indeed, despite TUS may provide useful imaging of pleura, lung and heart disease, emergency scenarios are currently the most warranted field of application of TUS: Pleural effusion, pneumothorax, lung consolidation. This stems from its role in limited resources subsets; actually, ultrasound is an excellent risk reducing tool, which acts by: (1) increasing diagnostic certainty; (2) shortening time to definitive therapy; and (3) decreasing problems from blind procedures that carry an inherent level of complications. In addition, paediatric and newborn disease are particularly suitable for TUS investigation, aimed at the detection of congenital or acquired chest disease avoiding, limiting or postponing radiological exposure. TUS improves the effectiveness of elective medical practice, in resource-limited settings, in small point of care facilities and particularly in poorer countries. Quality and information provided by the procedure are increased avoiding whenever possible artefacts that can prevent or mislead the achievement of the correct diagnosis. Reliable monitoring of patients is possible, taking into consideration that appropriate expertise, knowledge, skills, training, and even adequate equipment’s suitability are not always and everywhere affordable or accessible. TUS is complementary imaging procedure for the radiologist and an excellent basic diagnostic tool suitable to be shared with pneumologists, cardiologists and emergency physicians.