Reversed halo sign as a radiological feature of tuberculosis - Report of two cases.

Reversed halo sign (RHS) is a radiological feature described as a focal, rounded area of ground-glass opacity surrounded by a ring of consolidation. In this report we describe two unique radiological cases demonstrating diffuse bilateral infiltrates with multiple RHSs in chest CT scans. Both patients were ultimately diagnosed as having tuberculosis (TB) and had been exposed to silica in the past. This report presents for the first time an association between silica exposure and RHS on CT scans among TB patients. It highlights the importance of having a high index of suspicion for TB in similar scenarios.

Ultrasonography of the superficial temporal and axillary arteries in giant cell arteritis diagnosis.

OBJECTIVES: Giant cell arteritis (GCA) is the main systemic vasculitis in individuals aged ≥ 50 years. Color Doppler ultrasound (CDS) has an established role in GCA diagnosis and management. This study aims to assess the clinical characteristics associated with a positive CDS evaluation and the impact of additional axillary artery examination on diagnostic sensitivity. MATERIAL AND METHODS: We conducted a retrospective analysis of patients undergoing CDS of the superficial temporal arteries, with or without axillary artery assessment, at our hospital, between 2009 and 2023. Patients meeting the new 2022 diagnostic criteria for GCA were included and their characteristics were analyzed according to the presence of the halo sign on CDS. RESULTS: Of the 135 included patients (54 % female, mean age 75 ± 8 years), the halo sign was observed in 57 %, correlating with higher systemic symptom prevalence (61 % vs 42 %, p = 0.035), lower hemoglobin (p < 0.001), and higher erythrocyte sedimentation rate (p = 0.028). The halo sign inversely related to prior corticosteroid therapy (p = 0.033). Patients with axillary halo sign had fewer external carotid symptoms and a higher vertebral halo sign prevalence. Vertebral halo sign was associated with posterior circulation ischemic stroke (65 %, p < 0.001). Axillary artery studies improved diagnostic sensitivity by 9 %. CONCLUSION: In our study, the halo sign correlated with higher systemic symptoms and analytical abnormalities. Axillary artery examination enhanced CDS sensitivity, linked to severe outcomes like stroke. Prior corticosteroid therapy reduced CDS sensitivity. The correlation of clinical, laboratory, and ultrasound findings provides a more comprehensive understanding of GCA pathogenesis and evolution.

The influence of the cardiac cycle on the halo sign and its impact on the ultrasound diagnosis of giant cell arteritis.

OBJECTIVES: To investigate whether hypoechoic wall thickness is influenced by the systole or diastole moment in the cardiac cycle and if this can influence ultrasound (US) assessments of giant cell arteritis (GCA). METHODS: US videos of 100 consecutive patients (50 with GCA, 50 without) performed between January 2021 and June 2023 were reviewed. Intima-media thickness (IMT) of temporal (including common trunk, frontal and parietal branches), axillary and subclavian arteries were measured at two different time points, at systolic peak (SP) and at the end-diastole (ED). Differences between SP IMT and ED IMT, as well as in the halo count (HC) and in the OMERACT GCA Ultrasonography Score (OGUS) between these two times, were analyzed. RESULTS: IMT was significantly higher (4.8-5%) at ED in all arteries, in both GCA and non-GCA groups. HC and OGUS were also higher in ED in both groups. In 4 non-GCA patients (8%), the HC was positive in ED and negative in SP; in all of them the HC in ED was 1. In the GCA group, the timing of the cardiac cycle did not influence the final US diagnosis; however, it did modify the HC in 14 patients (28%). CONCLUSION: IMT can fluctuate during the cardiac cycle, with higher measurements occurring at ED. This variability could potentially impact the accuracy of US diagnoses and assessments of GCA. If further research corroborates these findings, it may be imperative to revise the guidelines for employing US in diagnosing GCA in order to incorporate these nuanced aspects.

Concentrically expanded reversed halo sign caused by nivolumab-related pneumonia.

Among immune-related adverse events, pneumonitis is relatively uncommon, and nivolumab-related pneumonitis may present with a reversed halo sign.

Ultrasonic humidifier lung with a reversed halo sign: A case report.

The reversed halo sign was initially reported as a representative computed tomography scan finding of cryptogenic organizing pneumonia. Since then, however, it has been reported in various diseases and is now considered a nonspecific finding. However, there are no cases of humidifier lung with the reversed halo sign. An 82-year-old Japanese male patient presented with moving difficulties 48 days after starting darolutamide treatment for prostate cancer. He was admitted to the hospital due to acute pneumonia, which presented as bilateral extensive nonsegmental ground-glass opacities in the peripheral regions and extensive areas of ground-glass opacity with a circumferential halo of consolidation, with the reversed halo sign on computed tomography scan. After darolutamide discontinuation with the concomitant administration of antibiotics, the patient's pneumonia improved, and he was discharged from the hospital. However, within a few days, he was again admitted to the hospital due to pneumonia. He was found to have been using an ultrasonic humidifier at home and was then diagnosed with humidifier lung based on the bronchoscopy and provocative testing findings. Hence, ultrasonic humidifier lung should be considered as a differential diagnosis in patients presenting with the reversed halo sign, and a detailed medical history must be taken.

Pneumopericardium in a child - "halo sign" on chest x-ray: A Case Report.

A 5 year old boy with acute ly mphoblastic leukaemia on chemotherapy presented with chest pain and vomiting for two days after an elective procedure under general anaesthesia. H is ches t x-ray was remarkabl e for a promin ent halo sign, an air gap surrounding the he art indicat ing a large pneumope ricardium. Alth ough the pneu mo pericardium could not be appre ciated on an echocardiogram, the child developed clinical sig ns of cardiac t amponade. Attem pts to evacu ate the pneumopericardium were unsuccessful leading to death.

Comparison of Computed Tomography Findings between Adult and Pediatric COVID-19 Patients.

PURPOSE: This study aims to compare chest computed tomography (CT) findings between adult and pediatric patients with coronavirus disease-19 (COVID-19) pneumonia. MATERIALS AND METHODS: This study included 30 pediatric patients aged 1 to 17 years and 30 adult patients over 18 years of age with COVID-19 pneumonia confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) who have findings related to COVID-19 on Chest Computed Tomography. The CT findings of adult and pediatric patients were compared with a z-test. RESULTS: Bilateral involvement (p:0.00056), involvement in all five lobes (p<0.00001), and central and peripheral involvement (p:0.01928) were significantly higher in the adult group compared to the pediatric group. In the pediatric group, the frequency of unilateral involvement (p:0.00056), involvement of solitary lobe (p:0.00132), and peripheral involvement (p: 0.01928) were significantly higher than in the adult group. The most common parenchymal finding in adults and pediatric patients was ground-glass opacities (100% and 83%, respectively). Among the parenchymal findings in adults, ground-glass opacities with consolidation (63%) were the second most common finding, followed by air bronchogram (60%) in adults, while in pediatric patients, halo sign (27%) and nodule (27%) were the second most common, followed by the ground-glass opacities with consolidation (23%). CONCLUSION: The CT findings of pediatric COVID-19 patients must be well-known as the course of the disease is usually less severe, and the radiological findings are uncertain when compared with adults.

Diffuse reversed halo sign in an immunocompetent patient.

The reversed halo sign (RHS) is a specific radiological image observed mostly on computed tomography (CT) scans as a focal round area of ground-glass attenuation surrounded by a crescent or ring of consolidation. It is common to many entities of respiratory diseases and can be found in both infectious, noninfectious inflammatory pathologies and some malignant tumors, including invasive pulmonary fungal infection, tuberculosis (TB), community-acquired pneumonia, granulomatosis, sarcoidosis. It is also seen in pulmonary neoplasms and infarction, and following radiation and radiofrequency. We report the case of an immunocompetent 54-year-old North African male patient, initially hospitalized for chronic cough associated with dysphonia and general symptoms such as weight loss, fever, and night sweats. Radiological exploration surprisingly confirmed the presence of RHS, tuberculosis was confirmed by a postbronchoscopy positive sputum Xpert MTB/RIF essay tuberculosis after we started antibacillary treatment, and the evolution was spectacular with regression of the lesions. The objective of this report is to increase knowledge about RHS and its pathological correlation with TB. Since it is not specific to any disorder, it is important to explore its finding in a clinical and epidemiological manner, especially in endemic countries where the prevalence of tuberculosis is still high.

Treatment of Femoropopliteal Artery Disease with Polymer-Coated Drug-Eluting Stent: 5-Year Results of a Prospective, Non-Randomized Study Including the Halo Phenomenon.

PURPOSE: To investigate the long-term results of the Eluvia drug-eluting stent (DES) implantation for femoropopliteal arterial disease, including the 'halo' phenomenon. Long-term data of DES is scarce. A focal reaction ('halo') following Eluvia DES deployment has been described. However, the long-term clinical impact of this phenomenon remains unclear. METHODS: This prospective, non-randomized, single-arm study included 130 consecutive patients treated with an Eluvia DES for symptomatic femoropopliteal disease between March 2016 and December 2018. Clinical outcomes and imaging were assessed after 6 months and annually thereafter for up to 5 years. The primary outcome measure was primary patency. Secondary outcomes were freedom from clinically driven target lesion revascularization (CD-TLR), freedom from major amputation, overall survival and amputation-free survival rates. RESULTS: The primary patency was 65% at 5 years. The freedom from CD-TLR and from major amputation at 5 years was 79 and 96%, respectively. The overall survival and amputation-free survival rates were 88 and 83% at 60 months, respectively. Out of the 27 patients with a halo sign, two showed an increased (7.4%) and 6 (22.2%) a decreased diameter. In 19 cases (70.4%), the diameter remained unchanged at the latest follow-up. The presence of the 'halo' sign was associated with increased primary patency (87% versus 59%, HR: 2.48, 95%CI 1.19-5.16, P = .015). CONCLUSIONS: The presented patient cohort treated with the Eluvia DES for femoropopliteal artery lesions indicates durable efficacy and a good safety profile regardless of the halo phenomenon. The results need to be confirmed in a larger patient cohort. LEVEL OF EVIDENCE III: Non-randomized controlled cohort/follow-up study.

Diagnosis of Acute Pulmonary Embolism on a Non-contrast CT Scan.

Teaching Point: There are two important signs that could be seen on a non-contrast chest CT scan that can lead to the diagnosis of a pulmonary embolism: the hyperdense pulmonary artery sign and pulmonary infarction.

The Tomosynthesis Broken Halo Sign: Diagnostic Utility for the Classification of Newly Diagnosed Breast Tumors.

BACKGROUND: Compared to conventional 2D mammography, digital breast tomosynthesis (DBT) offers greater breast lesion detection rates. Ring-like hypodense artifacts surrounding dense lesions are a common byproduct of DBT. This study's purpose was to assess whether minuscule changes spanning this halo-termed the "broken halo sign"-could improve lesion classification. METHODS: This retrospective study was approved by the local ethics review board. After screening 288 consecutive patients, DBT studies of 191 female participants referred for routine mammography with a subsequent histologically verified finding of the breast were assessed. Examined variables included patient age, histological diagnosis, architectural distortion, maximum size, maximum halo depth, conspicuous margins, irregular shape and broken halo sign. RESULTS: While a higher halo strength was indicative of malignancy in general (p = 0.031), the broken halo sign was strongly associated with malignancy (p < 0.0001, odds ratio (OR) 6.33), alongside architectural distortion (p = 0.012, OR 3.49) and a diffuse margin (p = 0.006, OR 5.49). This was especially true for denser breasts (ACR C/D), where the broken halo sign was the only factor predicting malignancy (p = 0.03, 5.22 OR). CONCLUSION: DBT-associated halo artifacts warrant thorough investigation in newly found breast lesions as they are associated with malignant tumors. The "broken halo sign"-the presence of small lines of variable diameter spanning the peritumoral areas of hypodensity-is a strong indicator of malignancy, especially in dense breasts, where architectural distortion may be obfuscated due to the surrounding tissue.

PD-L1 Expression and Ultrasound Characteristics in Papillary Thyroid Carcinoma and Its Effect on Recurrence.

AIM: Programmed death-ligand 1 (PD-L1) is a component of the tumor microenvironment, which is closely involved in the occurrence and development of tumors. We investigated the correlation between the expression of PD-L1 and ultrasound characteristics in papillary thyroid carcinoma (PTC) and its effect on recurrence. PATIENTS AND METHODS: Fifty-two patients at the Department of General Surgery of Qingdao Municipal Hospital underwent thyroid ultrasonic examination before surgery and their clinicopathological variables were collected. Then, immunohistochemistry staining was conducted to evaluate the PD-L1 expression in tumors and adjacent normal tissues. The correlations of PD-L1 expression with clinicopathological and ultrasound characteristics were analyzed. RESULTS: The expression of PD-L1 was positive in 59.7% (40/67) of PTC tumor tissues. In clinicopathological analyses, PD-L1 positivity was related to multifocality of tumors (p=0.031). In analyses of ultrasound characteristics, the expression of PD-L1 was positively correlated with halo sign (p=0.035), capsular invasion (p=0.003), microcalcification (p=0.02), and recurrence (p=0.009). In multivariate logistic analysis of ultrasonic characteristics and recurrence of thyroid carcinoma, microcalcification [odds ratio=13.349, 95% confidence interval (CI)=2.052-86.832, p=0.007] and the halo sign (odds ratio=15.273, 95% CI=1.451-160.747, p=0.023) were factors associated with recurrence of PTC. In the multivariate Cox regression analysis, positive PD-L1 staining [hazard ratio (HR)=5.031, 95% CI=1.092-23.172, p=0.038] and a halo sign (HR=4.998, 95% CI=1.084-23.051, p=0.039) were independent predictors for poorer recurrence-free survival. Positive expression of PD-L1 predicted worse recurrence-free survival in the subgroup of patients with a halo sign (HR=6.537, 95% CI=1.863-22.94, p=0.037). CONCLUSION: Positive expression of PD-L1 in PTC affects the clinical and ultrasonic characteristics of the tumor and may negatively affect the prognosis of patients with PTC.

The Reversed Halo Sign in Pulmonary Infarction due to Acute Pulmonary Embolism.

The reversed halo sign, or atoll sign, is a specific sign with ring-shaped consolidation and central lucency, which is historically considered typical for cryptogenic organising pneumonia. The presence of this sign in subpleural, posterior basal parts of the lower lobes, especially when solitary, should however raise suspicion for other causes, such as pulmonary infarction. Here, we present a case of pulmonary embolism with pulmonary infarction that was detected on HRCT without contrast. Teaching Point: The presence of a reversed halo sign, especially when solitary and located in the periphery of the lower lobes, should raise suspicion of a pulmonary infarction.

Temporal Artery Ultrasound for the Diagnosis of Giant Cell Arteritis in the Emergency Department.

Giant cell arteritis (GCA), known as temporal arteritis, is a serious condition requiring immediate treatment to prevent complications. GCA can be difficult to diagnose, especially in emergency department (ED) settings where ophthalmology and rheumatology services may be unavailable. Temporal artery ultrasound (TAUS) is a valuable tool for diagnosing GCA. In the ED, TAUS can be used to quickly rule out GCA and avoid unindicated steroid treatment, which can cause serious morbidity in elderly patients. This article discusses the use of TAUS for evaluating patients with suspected GCA in the ED and its potential to expedite treatment and ensure appropriate, timely follow-up for patients with this potential vision and life-threatening condition.

Imaging Findings in Aspergillosis: From Head to Toe.

Aspergillosis is a mycotic infection induced by airborne fungi that are ubiquitous. Inhalation of Aspergillus conidia results in transmission through the respiratory tract. The clinical presentation is dependent on organism and host specifics, with immunodeficiency, allergies, and preexisting pulmonary disease constituting the most important risk factors. In recent decades, the incidence of fungal infections has increased dramatically, due in part to the increased number of transplants and the pervasive use of chemotherapy and immunosuppressive drugs. The spectrum of clinical manifestations can range from an asymptomatic or mild infection to a swiftly progressive, life-threatening illness. Additionally, invasive infections can migrate to extrapulmonary sites, causing infections in distant organs. Recognition and familiarity with the various radiological findings in the appropriate clinical context are essential for patient management and the prompt initiation of life-saving treatment. We discuss the radiological characteristics of chronic and invasive pulmonary aspergillosis, as well as some of the typically unexpected extrapulmonary manifestations of disseminated disease.

Neck Radiograph Halo Sign: Do Not Be Fooled.

An aerodigestive foreign body injury in the throat is an otorhinolaryngology (ORL) emergency. Button batteries and coins are the most common foreign body aspirations or ingestions among the paediatric population. An impacted button battery in the aerodigestive tract is a surgical emergency, requiring urgent removal to prevent complications arising from the corrosive nature of the button battery. We report two cases that were brought in with a history of foreign body ingestion. Both neck radiographs showed a double-ring opaque shadow. The first child had a button battery eroding into his oesophagus. The second case is an ideally impacted stack of coins of different sizes that mimic a double-ring shadow, better known as a halo sign, in an antero-posterior neck radiograph. These cases are unique in comparing ingested coins in alignment with a button battery and a radiological examination mimicking that of a button battery. In this report, we emphasize the importance of a thorough history, endoscopic examination, and the limitations of radiographs in the initial assessment of an ingested foreign body in terms of management and prediction of morbidity.

Evaluation of Arterial Histopathology and microRNA Expression That Underlie Ultrasonography Findings in Temporal Arteries of Patients with Giant Cell Arteritis.

The aim of this study was to assess the interrelation between vascular ultrasonography (US) findings, histopathological data, and the expression of selected dysregulated microRNAs (miRNAs) in giant cell arteritis (GCA). The study included data on the clinical parameters, US measurements, and temporal artery biopsies (TABs) of 46 treatment-naïve patients diagnosed with GCA and 22 age-matched non-GCA patient controls. We performed a comprehensive comparative and correlation analysis along with generation of receiver operating characteristic (ROC) curves to ascertain the diagnostic performance of US examination parameters and selected miRNAs for GCA diagnosis. We showed significant differences in the US-measured intima-media thickness of the temporal arteries, the presence of a halo sign, and the presence of luminal stenosis between GCA-positive/TAB-positive, GCA-positive/TAB-negative, and non-GCA patients. Correlation analysis revealed significant associations between several histopathological parameters, US-measured intima-media thickness, and the halo sign. We found that the significant overexpression of miR-146b-5p, miR-155-5p, miR-511-5p, and miR-21-5p, and the under-expression of the miR-143/145 cluster, miR-30a-5p, and miR-125a-5p, coincides and is associated with the presence of a halo sign in patients with GCA. Notably, we determined a high diagnostic performance of miR-146b-5p, miR-21-3p, and miR-21-5p expression profiles in discriminating GCA patients from non-GCA controls, suggesting their potential utilization as putative biomarkers of GCA. Taken together, our study provides an insight into the US-based diagnostic evaluation of GCA by revealing the complex interrelation of clearly defined image findings with underlying vascular immunopathology and altered arterial tissue-specific miRNA profiles.

Automated diagnosis of COVID-19 using radiological modalities and Artificial Intelligence functionalities: A retrospective study based on chest HRCT database.

Background and Objective: The spread of coronavirus has been challenging for the healthcare system's proper management and diagnosis during the rapid spread and control of the infection. Real-time reverse transcription-polymerase chain reaction (RT-PCR), though considered the standard testing measure, has low sensitivity and is time-consuming, which restricts the fast screening of individuals. Therefore, computer tomography (CT) is used to complement the traditional approaches and provide fast and effective screening over other diagnostic methods. This work aims to appraise the importance of chest CT findings of COVID-19 and post-COVID in the diagnosis and prognosis of infected patients and to explore the ways and means to integrate CT findings for the development of advanced Artificial Intelligence (AI) tool-based predictive diagnostic techniques. Methods: The retrospective study includes a 188 patient database with COVID-19 infection confirmed by RT-PCR testing, including post-COVID patients. Patients underwent chest high-resolution computer tomography (HRCT), where the images were evaluated for common COVID-19 findings and involvement of the lung and its lobes based on the coverage region. The radiological modalities analyzed in this study may help the researchers in generating a predictive model based on AI tools for further classification with a high degree of reliability. Results: Mild to moderate ground glass opacities (GGO) with or without consolidation, crazy paving patterns, and halo signs were common COVID-19 related findings. A CT score is assigned to every patient based on the severity of lung lobe involvement. Conclusion: Typical multifocal, bilateral, and peripheral distributions of GGO are the main characteristics related to COVID-19 pneumonia. Chest HRCT can be considered a standard method for timely and efficient assessment of disease progression and management severity. With its fusion with AI tools, chest HRCT can be used as a one-stop platform for radiological investigation and automated diagnosis system.