Diagnostic use of lung ultrasound compared to chest radiograph for suspected pneumonia in a resource-limited setting

Point-of-Care Ultrasound: Applications in Low- and Middle-Income Countries

Purpose of Review

This review highlights the applications of point-of-care ultrasound in low- and middle-income countries and shows the diversity of ultrasound in the diagnosis and management of patients.

Recent Findings

There is a paucity of data on point-of-care ultrasound in anesthesiology in low- and middle-income countries. However, research has shown that point-of-care ultrasound can effectively help manage infectious diseases, as well as abdominal and pulmonary pathologies.

Summary

Point-of-care ultrasound is a low-cost imaging modality that can be used for the diagnosis and management of diseases that affect low- and middle-income countries. There is limited data on the use of ultrasound in anesthesiology, which provides clinicians and researchers opportunity to study its use during the perioperative period.

Lung Ultrasound Findings Compared with Chest X-Ray Findings in Known Pulmonary Tuberculosis Patients: A Cross-Sectional Study in Lima, Peru

Lung ultrasound (LUS) is highly portable and has excellent diagnostic accuracy for pneumonia compared with conventional radiography, but the literature on its use in pulmonary tuberculosis (PTB) is limited. This study characterized LUS lesions in patients with PTB and compared them with chest X-ray (CXR) findings. Adult patients in Lima, Peru, with PTB were recruited within 1 week of starting antituberculosis treatment. Comprehensive LUS was performed in all patients at enrollment and assessed for consolidation, small subpleural consolidation (SPC, hypothesized to be a marker of CXR consolidation), cavity, pleural effusion, pathologic B-lines, and miliary pattern. Patient CXRs were digitized and interpreted by a board-certified radiologist. Fifty-one patients were included in the final analysis. Lung ultrasound detected either consolidation or SPC in 96.1% of participants. No significant difference was found between the LUS detection of a composite of consolidation or SPC, and CXR detection of consolidation (96.1% versus 98%, P > 0.99). The proportion of patients with cavity detected by LUS was significantly lower than that detected by CXR (5.9% versus 51%, P < 0.001). Overall, LUS detection of consolidation or SPC may be a sensitive marker for diagnosis of PTB. Lung ultrasound demonstrated poor ability to detect radiographically identified cavity, although previous studies suggest SPC could add specificity for the diagnosis of PTB. Based on its portability and evidence base for diagnosing other pulmonary diseases, LUS may have a role in screening and diagnosis of PTB in areas without ready access to CXR. Further studies should evaluate its diagnostic accuracy in patients with and without PTB.

The role of point of care ultrasound in radiology department: update and prospective. A statement of Italian college ultrasound

Ultrasound, in its new point-of-care conception, has been called the stethoscope of the future. Goal-directed bedside ultrasound examination, performed by a healthcare provider to answer a specific diagnostic question or guide an invasive procedure, is currently revolutionizing medical practice. It is used by various specialties in multiple clinical contexts for procedural, diagnostic, and screening applications. Point-of-care ultrasound is also a strategic technique in clinical radiology; it brings the radiologist closer to the patient (in interaction and understanding) like interventional and angiography procedures and, as an integrative imaging modality, is a vital radiological tool for decision-making in many situations. In this commentary, we present our observations on the use of ultrasound, in a sincere appeal to refrain from omitting ultrasound as a diagnostic technique in this era of deep professional change, in which radiologists must return to being a true clinical semiologist.

COVID-19 Control by Computer Vision Approaches: A Survey

The COVID-19 pandemic has triggered an urgent call to contribute to the fight against an immense threat to the human population. Computer Vision, as a subfield of artificial intelligence, has enjoyed recent success in solving various complex problems in health care and has the potential to contribute to the fight of controlling COVID-19. In response to this call, computer vision researchers are putting their knowledge base at test to devise effective ways to counter COVID-19 challenge and serve the global community. New contributions are being shared with every passing day. It motivated us to review the recent work, collect information about available research resources, and an indication of future research directions. We want to make it possible for computer vision researchers to find existing and future research directions. This survey article presents a preliminary review of the literature on research community efforts against COVID-19 pandemic.

Recommendations for Lung Ultrasound in Internal Medicine

A growing amount of evidence prompts us to update the first version of recommendations for lung ultrasound in internal medicine (POLLUS-IM) that was published in 2018. The recommendations were established in several stages, consisting of: literature review, assessment of literature data quality (with the application of QUADAS, QUADAS-2 and GRADE criteria) and expert evaluation carried out consistently with the modified Delphi method (three rounds of on-line discussions, followed by a secret ballot by the panel of experts after each completed discussion). Publications to be analyzed were selected from the following databases: Pubmed, Medline, OVID, and Embase. New reports published as of October 2019 were added to the existing POLLUS-IM database used for the original publication of 2018. Altogether, 528 publications were systematically reviewed, including 253 new reports published between September 2017 and October 2019. The new recommendations concern the following conditions and issues: pneumonia, heart failure, monitoring dialyzed patients' hydration status, assessment of pleural effusion, pulmonary embolism and diaphragm function assessment. POLLUS-IM 2020 recommendations were established primarily for clinicians who utilize lung ultrasound in their everyday clinical work.

Deep Learning for Classification and Localization of COVID-19 Markers in Point-of-Care Lung Ultrasound

Deep learning (DL) has proved successful in medical imaging and, in the wake of the recent COVID-19 pandemic, some works have started to investigate DL-based solutions for the assisted diagnosis of lung diseases. While existing works focus on CT scans, this paper studies the application of DL techniques for the analysis of lung ultrasonography (LUS) images. Specifically, we present a novel fully-annotated dataset of LUS images collected from several Italian hospitals, with labels indicating the degree of disease severity at a frame-level, video-level, and pixel-level (segmentation masks). Leveraging these data, we introduce several deep models that address relevant tasks for the automatic analysis of LUS images. In particular, we present a novel deep network, derived from Spatial Transformer Networks, which simultaneously predicts the disease severity score associated to a input frame and provides localization of pathological artefacts in a weakly-supervised way. Furthermore, we introduce a new method based on uninorms for effective frame score aggregation at a video-level. Finally, we benchmark state of the art deep models for estimating pixel-level segmentations of COVID-19 imaging biomarkers. Experiments on the proposed dataset demonstrate satisfactory results on all the considered tasks, paving the way to future research on DL for the assisted diagnosis of COVID-19 from LUS data.

Accuracy of lung ultrasonography in the hands of non-imaging specialists to diagnose and assess the severity of community-acquired pneumonia in adults: a systematic review

OBJECTIVES

We aimed to systematically review the published literature regarding adults with clinical suspicion of pneumonia that compares the accuracy of lung ultrasonography (LUS) performed by non-imaging specialists to other reference standards in diagnosing and evaluating the severity of community-acquired pneumonia. Moreover, we aimed to describe LUS training and the speciality of the physician performing LUS, time spent on the LUS procedure and potential harms to patients.

MATERIALS AND METHODS

We searched MEDLINE, Embase, CINAHL, Web of Science and Cochrane Central Register of Controlled Trials up until May 2019. We included studies that used LUS to diagnose pneumonia, but also confirmed pneumonia by other means. Publications were excluded if LUS was performed by a sonographer or radiologist (imaging specialists) or performed on other indications than suspicion of pneumonia. Two review authors screened and selected articles, extracted data and assessed quality using Quality Assessment of Diagnostic Accuracy Studies 2.

RESULTS

We included 17 studies. The sensitivity of LUS to diagnose pneumonia ranged from 0.68 to 1.00; however, in 14 studies, sensitivity was ≥0.91. Specificities varied from 0.57 to 1.00. We found no obvious differences between studies with low and high diagnostic accuracy. The non-imaging specialists were emergency physicians, internal medicine physicians, intensivists or 'speciality not described'. Five studies described LUS training, which varied from a 1-hour course to fully credentialed ultrasound education. In general, the methodological quality of studies was good, though, some studies had a high risk of bias.

CONCLUSION

We found significant heterogeneity across studies. In the majority of studies, LUS in the hands of the non-imaging specialists demonstrated high sensitivities and specificities in diagnosing pneumonia. However, due to problems with methodology and heterogeneity there is a need for larger studies with uniform and clearly established criteria for diagnosis and blinding.

PROSPERO REGISTRATION NUMBER

Prospectively registered in PROSPERO (CRD42017057804).

COVID-19: A Multimodality Review of Radiologic Techniques, Clinical Utility, and Imaging Features

In this article we will review the imaging features of coronavirus disease 2019 (COVID-19) across multiple modalities, including radiography, CT, MRI, PET/CT, and US. Given that COVID-19 primarily affects the lung parenchyma by causing pneumonia, our directive is to focus on thoracic findings associated with COVID-19. We aim to enhance radiologists' understanding of this disease to help guide diagnosis and management. Supplemental material is available for this article. © RSNA, 2020.

Evaluation of Interdisciplinary Emergency Ultrasound Workshop for Primary Care Physicians in Nepal

PURPOSE

Point-of-care ultrasound (POCUS) is a quick bedside tool that has the potential to improve emergency care in resource-limited settings due to its relatively low cost and accessibility. Effort to disseminate the knowledge and skills about POCUS is inadequate in low and middle income countries like Nepal. We conducted a two-day interdisciplinary advanced emergency ultrasound workshop that targeted physicians working in emergency department and primary care, especially in rural Nepal. We explored the effectiveness of this training based on validated Kirkpatrick's 4 steps of evaluating training outcomes.

MATERIALS AND METHODS

We conducted a prospective quasi-experimental study with mixed research design. Multidisciplinary physicians working in emergency departments participated in the two-day workshop. We assessed and compared the pre- and post-workshop knowledge. We collected on-site and a follow-up feedback to explore pre- and post-workshop confidence level, perceived usefulness and clinical use of ultrasound using a 5-point Likert scale. The barriers to use POCUS were explored.

RESULTS

A total of 50 physicians from different parts of Nepal participated in the workshop. The academic level of the participants, duration of their clinical experience and the previous use of POCUS did not have a significant difference in their pre- and posttest knowledge scores. The difference between the median (IQR) pre- and posttest scores [14 (12.75-17.75) and 24.5 (22.25-25.5), respectively] was statistically significant (p<0.001). Perceived confidence level and usefulness of the POCUS increased significantly in all of its domains (p<0.001). Self-reported increase in its clinical use was significant (p<0.001) for all fields.

CONCLUSION

The participation in this emergency ultrasound workshop increased the knowledge of participants in POCUS. Their confidence, perceived usefulness and clinical use of POCUS improved significantly. Objective longitudinal follow-up of participants' skill and demonstration of increased clinical use of POCUS in emergency department influencing the clinical outcome would be the focus of future research.

Computed tomography scan contribution to the diagnosis of community-acquired pneumonia

Purpose of review

Pneumonia is a frequent disease mainly affecting older and multimorbid patients. Symptoms and signs lack sensitivity and specificity, and chest X-ray has poor accuracy. Hence, an initial diagnosis of pneumonia has limited predictive value for the presence of pneumonia. Overdiagnosis of pneumonia leads to inappropriate antibiotic use and may delay the appropriate management of mimicking diseases. Alternative imaging strategies including computed tomography (CT)-scan or lung ultrasonography may improve the diagnosis of pneumonia. We review the recent evidence and perspectives regarding their contribution to the diagnosis and management of patients with suspected pneumonia.

Recent findings

Two studies assessed the diagnostic accuracy of CT-scan in emergency department or hospitalized patients suspected of pneumonia. CT-scan led to a net reclassification improvement of 8 and 18% of patients, and was particularly helpful to rule out the diagnosis, allowing a lowering of the number of inappropriate antibiotic prescriptions.

Summary

CT-scan reduces overdiagnosis of pneumonia and allows a better identification of alternative diagnoses. The impact on clinical outcomes of a strategy incorporating CT-scan for patients suspected of pneumonia should be evaluated, along with its cost-effectiveness.

Impact of bedside lung ultrasound on physician clinical decision-making in an emergency department in Nepal

Background

Lung ultrasound is an effective tool for the evaluation of undifferentiated dyspnea in the emergency department. Impact of lung ultrasound on clinical decisions for the evaluation of patients with dyspnea in resource-limited settings is not well-known. The objective of this study was to evaluate the impact of lung ultrasound on clinical decision-making for patients presenting with dyspnea to an emergency department in the resource-limited setting of Nepal.

Methods

A prospective, cross-sectional study of clinicians working in the Patan Hospital Emergency Department was performed. Clinicians performed lung ultrasounds on patients presenting with dyspnea and submitted ultrasounds with their pre-test diagnosis, lung ultrasound interpretation, post-test diagnosis, and any change in management.

Results

Twenty-two clinicians participated in the study, completing 280 lung ultrasounds. Diagnosis changed in 124 (44.3%) of patients with dyspnea. Clinicians reported a change in management based on the lung ultrasound in 150 cases (53.6%). Of the changes in management, the majority involved treatment (83.3%) followed by disposition (13.3%) and new consults (2.7%).

Conclusions

In an emergency department in Nepal, bedside lung ultrasound had a significant impact on physician clinical decision-making, especially on patient diagnosis and treatment.

Point-of-care ultrasound in primary care: a systematic review of generalist performed point-of-care ultrasound in unselected populations

BACKGROUND

Both the interest and actual extent of use of point-of-care ultrasound, PoCUS, among general practitioners or family physicians are increasing and training is also increasingly implemented in residency programs. However, the amount of research within the field is still rather limited compared to what is seen within other specialties in which it has become more established, such as in the specialty of emergency medicine. An assumption is made that what is relevant for emergency medicine physicians and their populations is also relevant to the general practitioner, as both groups are generalists working in unselected populations. This systematic review aims to examine the extent of use and to identify clinical studies on the use of PoCUS by either general practitioners or emergency physicians on indications that are relevant for the former, both in their daily practice and in out-of-hours services.

METHODS

Systematic searches were done in PubMed/MEDLINE using terms related to general practice, emergency medicine, and ultrasound.

RESULTS

On the extent of use, we identified 19 articles, as well as 26 meta-analyses and 168 primary studies on the clinical use of PoCUS. We found variable, but generally low, use among general practitioners, while it seems to be thoroughly established in emergency medicine in North America, and increasingly also in the rest of the world. In terms of clinical studies, most were on diagnostic accuracy, and most organ systems were studied; the heart, lungs/thorax, vessels, abdominal and pelvic organs, obstetric ultrasound, the eye, soft tissue, and the musculoskeletal system. The studies found in general either high sensitivity or high specificity for the particular test studied, and in some cases high total accuracy and superiority to other established diagnostic imaging modalities. PoCUS also showed faster time to diagnosis and change in management in some studies.

CONCLUSION

Our review shows that generalists can, given a certain level of pre-test probability, safely use PoCUS in a wide range of clinical settings to aid diagnosis and better the care of their patients.

Tele-Ultrasound in Resource-Limited Settings: A Systematic Review

Background: Telemedicine, or healthcare delivery from a distance, has evolved over the past 50 years and helped alter health care delivery to patients around the globe. Its integration into numerous domains has permitted high quality care that transcends obstacles of geographic distance, lack of access to health care providers, and cost. Ultrasound is an effective diagnostic tool and its application within telemedicine (“tele-ultrasound”) has advanced substantially in recent years, particularly in high-income settings. However, the utility of tele-ultrasound in resource-limited settings is less firmly established.

Objective: To determine whether remote tele-ultrasound is a feasible, accurate, and care-altering imaging tool in resource-limited settings.

Data Sources: PubMed, MEDLINE, and Embase.

Study Eligibility Criteria: Twelve original articles met the following eligibility criteria: full manuscript available, written in English, including a direct patient-care intervention, performed in a resource-limited setting, images sent to a remote expert reader for interpretation and feedback, contained objective data on the impact of tele-ultrasound.

Study Appraisal and Synthesis Methods: Abstracts were independently screened by two authors against inclusion criteria for full-text review. Any discrepancies were settled by a senior author. Data was extracted from each study using a modified Cochrane Consumers and Communication Review Group's data extraction template. Study bias was evaluated using the ROBINS-I tool.

Results: The study results reflect the diverse applications of tele-ultrasound in low-resource settings. Africa was the most common study location. The specialties of cardiology and obstetrics comprised most studies. Two studies primarily relied on smartphones for image recording and transmission. Real-time, rather than asynchronous, tele-ultrasound image interpretation occurred in five of the 12 studies. The most common outcome measures were image quality, telemedicine system requirements, diagnostic accuracy, and changes in clinical management.

Limitations: The studies included were of poor quality with a dearth of randomized control trials and with significant between study heterogeneity which resulted in incomplete data and made cross study comparison difficult.

Conclusions and Implications of Key Findings: Low-quality evidence suggests that ultrasound images acquired in resource-limited settings and transmitted using a telemedical platform to an expert interpreter are of satisfactory quality and value for clinical diagnosis and management.

Diagnostic Value of Ultrasound in Detecting Causes of Pediatric Chest X-Ray Opacity

OBJECTIVES

Computed tomography is considered as the diagnostic gold standard for following up the majority of pediatric chest X-ray (CXR) opacities. However, radiation, cost, and waiting times have led to search for diagnostic alternatives. This study was conducted to determine the diagnostic accuracy of the ultrasound (US) in detecting the causes of pediatric CXR opacities.

MATERIALS AND METHODS

This study was conducted on the pediatric patients with CXR opacity referring to Dr. Sheikh Hospital in Mashhad, Iran during 2016-2017. After undergoing the US exam, the patients were followed to obtain the final diagnosis based on reference standard (RF). The accuracy of the US was calculated in detection of thoracic lesions. P value <0.05 was considered to be significant.

RESULTS

The most common diagnostic cause of CXR opacity based on RF was pneumonia (n=46, 35-38%), thymus (n=37, 28-46%), bone and soft tissue mass (n=12, 9.23%), cystic lesions (n=11, 8.46%), and diaphragmatic lesions (n=10, 7.69%), as well as intrathoracic masses and empyema (n=7, 5.38%). In only four patients (3.07%), the final diagnosis based on RF was inconsistent with the US diagnosis. The diagnostic accuracy of the US was 100% in the diagnosis of bone and soft tissue masses, diaphragmatic lesions, empyema, and normal thymus, and the accuracy was 96.92% for pneumonia, and 99.23% for cystic lesions and intrathoracic masses.

CONCLUSION

Regarding the assessed diagnostic accuracy, the US can be a reliable diagnostic tool to differentiate the main cause of pediatric CXR opacity.

Lung Ultrasound for Initial Diagnosis and Subsequent Monitoring of Aspiration Pneumonia in Elderly in Home Medical Care Setting

The number of aspiration pneumonia cases has increased in recent times. A definitive diagnosis of aspiration pneumonia is difficult in resource-limited settings where radiological equipment is unavailable. We report the initial diagnosis and subsequent monitoring of aspiration pneumonia in a home medical care setting. An 88-year-old Japanese male presented an acute onset of dyspnea, fever, and productive cough. At home, lung ultrasound displayed pleural effusion along with B-lines and subpleural consolidations. Upon admission, tests revealed increased total leucocyte counts with left-shifted neutrophils, elevated C-reactive protein levels, and positive sputum Gram stain. Chest X-ray imaging and computed tomography (CT) showed bibasilar infiltrates and wall thickening in the left S10 bronchi. The patient was diagnosed with aspiration pneumonia and treated with an antibiotic. After a 10-day hospitalization, lung ultrasound showed some remaining B-lines and disappearance of pleural effusion and subpleural consolidation. Chest X-ray image was normal, and CT revealed pleural abnormality and disappearance of bibasilar infiltrates, consistent with the ultrasound findings. Aspiration pneumonia develops with various clinical signs. However, diagnosis using chest X-ray imaging or CT in resource-limited settings is difficult. Ultrasound might allow physicians to make more accurate judgments, particularly while monitoring aspiration pneumonia following initial diagnosis in resource-limited settings.

Multicentre pilot study evaluation of lung ultrasound for the management of paediatric pneumonia in low-resource settings: a study protocol

INTRODUCTION

Pneumonia is the leading infectious cause of death among children under 5 years of age worldwide. However, pneumonia is challenging to diagnose. Lung ultrasound (LUS) is a promising diagnostic technology. Further evidence is needed to better understand the role of LUS as a tool for the diagnosis of childhood pneumonia in low-resource settings.

METHODS AND ANALYSIS

This study aims to pilot LUS in Mozambique and Pakistan and to generate evidence regarding the use of LUS as a diagnostic tool for childhood pneumonia. Children with cough <14 days with chest indrawing (n=230) and without chest indrawing (n=40) are enrolled. World Health Organization Integrated Management of Childhood Illness assessment is performed at enrolment, along with a chest radiograph and LUS examination. Respiratory and blood specimens are collected for viral and bacterial testing and biomarker assessment. Enrolled children are followed for 14 days (in person) and 30 days (phone call) post-enrolment with LUS examinations performed on Days 2, 6 and 14. Qualitative and quantitative data are also collected to assess feasibility, usability and acceptability of LUS among healthcare providers and caregivers. The primary outcome is LUS findings at enrolment with secondary outcomes including patient outcomes, repeat LUS findings, viral and bacterial test results, and patient status after 14 and 30 days of follow-up.

ETHICS AND DISSEMINATION

This trial was approved by the Western Institutional Review Board as well as local ethics review committees at each site. We plan to disseminate study results in peer-reviewed journals and international conferences.

TRIAL REGISTRATION NUMBER

NCT03187067.

[Pneumonia: Does Ultrasound Replace Chest X-Ray?]

Pneumonia: Does Ultrasound Replace Chest X-Ray? Abstract. Pneumonic lung consolidations are characterized by typical changes in terms of sonomorphology: echopoor lesions with blurred margins, bronchoaerograms, regular vascularization, and parapneumonic effusions. Pneumonias may be first discovered at bedside. Reventilation is well correlated with clinical progression. Compared with CT in four metaanalyses, lung ultrasound shows accuracy with a sensitivity of 88-97 % and a specificity of 90-96 %. Chest x-ray on the other hand has a pooled sensitivity of 77 % and a specificity of 91 %. Thus, lung ultrasound should replace chest x-ray in the diagnosis of pneumonia aquired by out-patients.