Target sign in COVID-19, radiological interpretation and diagnostic contribution of digital thoracic tomosynthesis.

INTRODUCTION: Our objectives are: To describe the radiological semiology, clinical-analytical features and prognosis related to the target sign (TS) in COVID-19. To determine whether digital thoracic tomosynthesis (DTT) improves the diagnostic ability of radiography. MATERIAL AND METHODS: Retrospective, descriptive, single-centre, case series study, accepted by our ethical committee. Radiological, clinical, analytical and follow-up characteristics of patients with COVID-19 and TS on radiography and DTT between November 2020 and January 2021 were analysed. RESULTS: Eleven TS were collected in 7 patients, median age 35 years, 57% male. All TS presented with a central nodule and a peripheral ring, and in at least 82%, the lung in between was of normal density. All TS were located in peripheral, basal regions and 91% in posterior regions. TS were multiple in 43%. Contiguous TS shared the peripheral ring. Other findings related to pneumonia were associated in 86% of patients. DTT detected 82% more TS than radiography. Only one patient underwent a CT angiography of the pulmonary arteries, positive for acute pulmonary thromboembolism. Seventy-one per cent presented with pleuritic pain. No distinctive laboratory findings or prognostic worsening were detected. CONCLUSIONS: TS in COVID-19 predominates in peripheral and declining regions and can be multiple. Pulmonary thromboembolism was detected in one case. It occurs in young people, frequently with pleuritic pain and does not worsen the prognosis. DTT detects more than 80 % of TS than radiography.

Performance in prognostic capacity and efficiency of the Thoracic Care Suite GE AI tool applied to chest radiography of patients with COVID-19 pneumonia.

OBJECTIVE: Rapid progression of COVID-19 pneumonia may put patients at risk of requiring ventilatory support, such as non-invasive mechanical ventilation or endotracheal intubation. Implementing tools that detect COVID-19 pneumonia can improve the patient's healthcare. We aim to evaluate the efficacy and efficiency of the artificial intelligence (AI) tool GE Healthcare's Thoracic Care Suite (featuring Lunit INSIGHT CXR, TCS) to predict the ventilatory support need based on pneumonic progression of COVID-19 on consecutive chest X-rays. METHODS: Outpatients with confirmed SARS-CoV-2 infection, with chest X-ray (CXR) findings probable or indeterminate for COVID-19 pneumonia, who required a second CXR due to unfavorableclinical course, were collected. The number of affected lung fields for the two CXRs was assessed using the AI tool. RESULTS: One hundred fourteen patients (57.4±14.2 years, 65-57%-men) were retrospectively collected. Fifteen (13.2%) required ventilatory support. Progression of pneumonic extension ≥0.5 lung fields per day compared to pneumonia onset, detected using the TCS tool, increased the risk of requiring ventilatory support by 4-fold. Analyzing the AI output required 26s of radiological time. CONCLUSIONS: Applying the AI tool, Thoracic Care Suite, to CXR of patients with COVID-19 pneumonia allows us to anticipate ventilatory support requirements requiring less than half a minute.

Inter-observer agreement on levels of evidence in radiology articles.

Levels of evidence (LE) are established through a hierarchical classification of studies according to their design. At present, there are many heterogeneous LE classifications, and this hampers their applicability. Our study aims to identify which LE classification has the best interobserver concordance for radiology articles. For this purpose, an interobserver agreement analysis were performed on 105 original articles applying two NE scales (Oxford Center of Evidence Based Medicine (OCEBM) y National Health and Medical Research Council (NHMRC)). The inter-rater agreement of the LE assigned after reading the abstracts was good when using the OCEBM scale (K = 0.679), and somewhat lower with the NHMRC (K = 0.577 -moderate-). All differences were statistically significant (P < .000). So, in conclusion, of the two scales analysed (OCEBM and NHMRC), the OCEBM led to the strongest level of inter-rater agreement.

Schematic approach to the diagnosis of multifocal lung opacities in the emergency department.

Radiologists in the emergency department must be prepared to deal with any type of disease in any organ at any time. Many entities involving the chest can result in patients' presenting at the emergency department. This chapter deals with entities that manifest with multifocal lung opacities and that can be mistaken for pneumonia. To facilitate their identification, this chapter approaches these entities by considering their most characteristic distribution on chest X-rays, the main diagnostic modality used for thoracic problems in the emergency department. Our schematic approach includes the key findings in patients' personal histories, clinical examination, laboratory tests, and imaging studies that can be available during the initial workup.

Extrathoracic manifestations of COVID-19 in adults and presentation of the disease in children.

In March 2020, the World Health Organization declared a global pandemic of COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); epidemic conditions continue in nearly all countries today. Although the symptoms and imaging manifestations of COVID-19 predominantly involve the respiratory system, it is fundamental to know the manifestations of the disease and its possible complications in other organs to help in diagnosis and orient the prognosis. To improve the diagnostic process without increasing the risk of contagion unnecessarily, it is crucial to know when extrathoracic imaging tests are indicated and which tests are best in each situation. This paper aims to provide answers to these questions. To this end, we describe and illustrate the extrathoracic imaging manifestations of COVID-19 in adults as well as the entire spectrum of imaging findings in children.

[Extrathoracic manifestations of COVID-19 in adults and presentation of the disease in children]. / Manifestaciones extratorácicas de la COVID-19 en adultos y presentación de la enfermedad en niños.

In March 2020, the World Health Organization declared a global pandemic of COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); epidemic conditions continue in nearly all countries today. Although the symptoms and imaging manifestations of COVID-19 predominantly involve the respiratory system, it is fundamental to know the manifestations of the disease and its possible complications in other organs to help in diagnosis and orient the prognosis. To improve the diagnostic process without increasing the risk of contagion unnecessarily, it is crucial to know when extrathoracic imaging tests are indicated and which tests are best in each situation. This paper aims to provide answers to these questions. To this end, we describe and illustrate the extrathoracic imaging manifestations of COVID-19 in adults as well as the entire spectrum of imaging findings in children.

When pneumonia is not COVID-19. / Cuando la neumonía no es COVID-19.

During the COVID-19 epidemic, the prevalence of the disease means that practically any lung opacity on an X-ray could represent pneumonia due to infection with SARS-CoV-2. Nevertheless, atypical radiologic findings add weight to negative microbiological or serological tests. Likewise, outside the epidemic wave and with the return of other respiratory diseases, radiologists can play an important role in decision making about diagnoses, treatment, or preventive measures (isolation), provided they know the key findings for entities that can simulate COVID-19 pneumonia. Unifocal opacities or opacities located in upper lung fields and predominant airway involvement, in addition to other key radiologic and clinical findings detailed in this paper, make it necessary to widen the spectrum of possible diagnoses.

Is positive oral contrast material necessary for computed tomography in patients with suspected acute abdomen? / Ante la sospecha de abdomen agudo, ¿es necesario el contraste oral positivo en la tomografía computarizada?

The number of computed tomography studies done in emergency departments has increased substantially, and with this increase the controversy about whether positive oral contrast agents are necessary in all patients has also grown. The great image quality provided by multidetector computed tomography scanners, the increase in intraabdominal fat (as a natural element that provides contrast for separating the bowel loops) related with the increased prevalence of obesity in the population, and the potential drawbacks associated with the use of high-density oral contrast agents argue against the generalized us of these agents. This article aims to evaluate the effects of omitting the use of this type of oral contrast material for computed tomography examinations required in the emergency department for suspicion of acute abdominal pathology through an efficient literature search among recent publications.

When should computed tomography angiography of pulmonary vessels be done in patients with low clinical probability of acute pulmonary embolism? / En pacientes con probabilidad clínica baja de tromboembolia pulmonar aguda, ¿cuándo debe realizarse la angiografía pulmonar por tomografía computarizada?

When the probability of pulmonary embolism is low, the decision to do a computed tomography angiography (CTA) of the pulmonary vessels is based on the D-dimer concentration. However, excessive dependence on this parameter can result in unnecessary imaging studies, inappropriate treatment, or an inappropriate increase in the estimated probability of venous thromboembolism developing. The main objective of this study was to determine when CTA of pulmonary vessels could be avoided in patients with low clinical probability of pulmonary embolism through an efficient literature search of studies published about this question.

Is CT angiography of the pulmonary arteries indicated in patients with high clinical probability of pulmonary embolism? / ¿Está indicada la angiografía por tomografía computarizada de las arterias pulmonares en pacientes con alta probabilidad clínica de tromboembolia pulmonar?

When a diagnostic test confirms clinical suspicion, the indicated treatment can be administered. A problem arises when the diagnostic test does not confirm the initially suspected diagnosis; when the suspicion is grounded in clinically validated predictive rules and is high, the problem is even worse. This situation arises in up to 40% of patients with high suspicion for acute pulmonary embolism, raising the question of whether CT angiography of the pulmonary arteries should be done systematically. This paper reviews the literature about this issue and lays out the best evidence about the relevant recommendations for patients with high clinical suspicion of acute pulmonary embolism and negative findings on CT angiography. It also explains the probabilistic concepts derived from Bayes' theorem that can be useful for ascertaining the most appropriate approach in these patients.

Should we perform an inspiratory or an expiratory chest radiograph for the initial diagnosis of pneumothorax? / ¿Se debe realizar como primera prueba de imagen una radiografía de tórax en inspiración o en espiración ante la sospecha de neumotórax?

Chest radiography for pneumothorax screening is a frequently employed test. However, there is some controversy about which radiographic technique to choose. Posteroanterior chest radiography taken during expiration has been the technique used for many decades because several experts in classical thoracic radiology, such as Greene and Felson, recommended it. However, chest radiography, with posteroanterior and lateral projections, taken during deep breath is the appropriated technique to initially assess the whole thoracic pathology. In this review we have tried to establish, based on the best available evidence, which is the initial examination of choice to diagnose pneumothorax.

Is manual ultrasonographic measurement of carotid intima-media thickness a reproducible cardiovascular biomarker? / Es la medida ecográfica manual del grosor íntima-media carotídeo un biomarcador cardiovascular reproducible?

To establish the ability of a potential biomarker to discriminate between diseased and healthy subjects, it is essential to know the intrinsic variability of the methods used to measure the biomarker. This aspect is especially important in the ultrasonographic measurement of carotid intima-media thickness, where submillimetric variations due largely to the unrecognized lack of precision in the ultrasonographic technique can have a significant clinical impact on the classification of cardiovascular risk. This article aims to present the evidence about the reproducibility of carotid intima-media thickness measured by ultrasonography to discuss whether the variability inherent in the technique can influence the potential of this parameter as a biomarker.

Imaging techniques used in the diagnostic workup of acute venous thromboembolic disease. / Técnicas de imagen diagnósticas empleadas en la presentación aguda de la enfermedad tromboembólica venosa.

Early diagnosis is one of the most important factors affecting the prognosis of pulmonary embolism (PE); however, the clinical presentation of PE is often very unspecific and it can simulate other diseases. For these reasons, imaging tests, especially computed tomography angiography (CTA) of the pulmonary arteries, have become the keystone in the diagnostic workup of PE. The wide availability and high diagnostic performance of pulmonary CTA has led to an increase in the number of examinations done and a consequent increase in the population's exposure to radiation and iodinated contrast material. Thus, other techniques such as scintigraphy and venous ultrasonography of the lower limbs, although less accurate, continue to be used in certain circumstances, and optimized protocols have been developed for CTA to reduce the dose of radiation (by decreasing the kilovoltage) and the dose of contrast agents. We describe the technical characteristics and interpretation of the findings for each imaging technique used to diagnose PE and discuss their advantages and limitations; this knowledge will help the best technique to be chosen for each case. Finally, we comment on some data about the increased use of CTA, its clinical repercussions, its "overuse", and doubts about its cost-effectiveness.

Prognostic value of computed tomography in acute pulmonary thromboembolism. / Valor pronóstico de la tomografía computarizada en la tromboembolia pulmonar aguda.

In addition to being the standard reference for the diagnosis of acute pulmonary thromboembolism, CT angiography of the pulmonary arteries can also provide valuable information about the patient's prognosis. Although which imaging findings are useful for prognosis remains controversial, signs of right ventricular dysfunction on CT are now included in clinical algorithms for the management of pulmonary thromboembolism. However, the optimal method for obtaining these measurements while maintaining a balance between the ease of use necessary to include their evaluation in our daily activity and the loss of precision in its predictive capacity remains to be determined. Moreover, other variables associated with pulmonary thromboembolism that often go unobserved can complement the prognostic information we can offer to clinicians. This review aims to clarify some of the more controversial aspects related to the prognostic value of CT in patients with pulmonary embolisms according to the available evidence. Knowing which variables are becoming more important in the prognosis, how to detect them, and why it is important to include them in our reports will help improve the management of patients with pulmonary embolism.

Pulmonary radiofrequency ablation (Part 2): Procedure and follow-up.

Pulmonary radiofrequency ablation requires more than just interventional radiology skills. Patients must be selected carefully, and the acts that need to be done before, during, and after the procedure must be coordinated. To guarantee patient safety, radiologists need to know the variants of the technique, the precautions that must be taken, the complications that can occur, and the risks involved. Early differentiation between tumor tissue and normal changes secondary to treatment on imaging tests will make it possible to repeat the treatment without delays, and this will increase survival. This article describes how to coordinate and carry out pulmonary radiofrequency ablation, the complications of the technique, and the current evidence in follow-up.

Pulmonary radiofrequency ablation (Part 1): current state.

The risks involved in surgical treatment and conventional radiotherapy in patients with early lung cancer or lung metastases often make these treatments difficult to justify. However, on the other hand, it is also unacceptable to allow these lesions to evolve freely because, left untreated, these neoplasms will usually lead to the death of the patient. In recent years, alternative local therapies have been developed, such as pulmonary radiofrequency ablation, which has proven to increase survival with a minimal risk of complications. There are common recommendations for these treatments, and although the specific indications for using one technique or another have yet to be established, there are clearly defined situations that will determine the outcome of the treatment. It is important to know these situations, because appropriate patient selection is essential for therapeutic success. This article aims to describe the characteristics and constraints of pulmonary radiofrequency ablation and to outline its role in thoracic oncology in light of the current evidence.