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.

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.

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.

Evaluation of metagenomic next-generation sequencing diagnosis for invasive pulmonary aspergillosis in immunocompromised and immunocompetent patients.

BACKGROUND: Invasive pulmonary aspergillosis (IPA) can occur in both immunocompromised and non-immunocompromised hosts, and early diagnosis of IPA is difficult. Metagenomic next-generation sequencing (mNGS) is a novel non-migratory pathogen detection method; however, utilising this method for IPA diagnosis is challenging due to the current lack of a unified clinical interpretation standard following Aspergillus detection using mNGS. OBJECTIVES: To investigate the accuracy of IPA diagnosis by positive bronchoalveolar lavage fluid (BALF) mNGS results in immunocompromised and immunocompetent patients. METHODS: We retrospectively included patients with confirmed pulmonary infections having a BALF mNGS result of Aspergillus reads ≥1. We compared the accuracy of using mNGS for IPA diagnosis in patients with different immune statuses based on the revised EORTC/MSG criteria. RESULTS: Overall, 62 mNGS Aspergillus-positive patients were divided into two groups: with (41) and without IPA (21). In univariate logistic regression analysis, immunocompromised function, fever, halo sign on CT image, and multiple masses or nodules were associated with mNGS Aspergillus-positive IPA diagnosis. In multivariate logistic regression analysis, immunocompromised function (OR = 6.68, 95% CI: 1.73-25.87, p = .006) and a halo sign (OR = 7.993, 95% CI: 2.07-30.40, p = .003) were independent risk factors. The concordance rate of IPA diagnosis was significantly higher in immunocompromised patients [82.1% (23/28)] than in non-immunocompromised patients [52.9% (18/34); p = .016]. CONCLUSIONS: For immunocompromised patients, a combination of mNGS testing and lung CT imaging can be used for IPA diagnosis. However, caution is required in IPA diagnosis based on positive mNGS results in non-immunocompromised patients.

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.

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.

Giant Cell Arteritis: A Case-Based Narrative Review of the Literature.

PURPOSE OF REVIEW: Giant cell arteritis (GCA) is a chronic, inflammatory condition, primarily affecting the medium and larger arteries. The purpose of this narrative review is to describe GCA in the context of headache and facial pain, based on a case and the available current literature. Understanding the etiology, pathophysiology, the associated conditions, and the differential diagnoses is important in managing GCA. RECENT FINDINGS: In a patient presenting with unilateral facial/head pain with disturbances of vision, GCA should be considered in the differential diagnosis. There is an association of GCA with several comorbid conditions, and infections including coronavirus-19 (COVID-19) infection. Management of GCA primarily depends upon the identification of the affected artery and prompt treatment. Permanent visual loss and other serious complications are associated with GCA. GCA is characterized by robust inflammation of large- and medium-sized arteries and marked elevation of systemic mediators of inflammation. An interdisciplinary approach of management involving the pertinent specialties is strongly recommended.

Evaluation of cardiovascular changes in patients with gastric wall fat halo sign.

BACKGROUND: This study aims to investigate the relationship between gastric wall fat halo sign and potentially associated cardiovascular disease (CVD) in thoracic computed tomography (CT). METHODS: Between October 2020 and January 2021, 62 patients with gastric wall fat halo sign and 62 controls were evaluated with thorax CT. Patient's height, weight, body mass index (BMI), sex, age, comorbidities, laboratory parameters, diameters of cardiac axes, aorta and pulmonary artery; aorta and coronary artery calcium scores were recorded for the two groups. RESULTS: No significant differences were found in sex, age, height, body weight or BMI between the two groups (p > 0.124). Patients with gastric wall fat halo sign had significantly larger diameters of the ascending aorta, the descending aorta, the main pulmonary artery, the right and left pulmonary arteries, and the short and long cardiac axes and a higher cardiothoracic ratio (CTR) than the control group (p < 0.001). Additionally, the calcium scores of the ascending, arcus, and descending aortas and the coronary arteries were significantly higher detected in patients group (p < 0.001). Patient group had significantly higher lipid profile, frequencies of diabetes mellitus (DM) and hypertension (HT) than control group (p<0.026). DISCUSSION: Patients with a gastric wall fat halo may show higher cardiovascular risk because of increased visceral fat tissue, vascular diameters, CTR, heart sizes, presence of DM, HT, increased lipid profile and calcium scores.

Clinical, Laboratory and Ultrasonographic Interrelations in Giant Cell Arteritis.

OBJECTIVES: The diagnosis of giant cell arteritis (GCA) is based on the presence of clinical and laboratory features. Color-duplex sonography (CDS) may supplant the limited sensitivity of temporal artery biopsy. The aim of our work was to characterize clinical and laboratory findings in patients with positive CDS for GCA. MATERIALS AND METHODS: Retrospective study of all consecutive patients of our center fulfilling American College of Rheumatology criteria for GCA who performed CDS study between 2009-2019. Data on clinical and laboratory features were compared in two groups: with and without halo sign. RESULTS: Ninety-one patients were included. Temporal halo sign was identified in 46% of patients. Halo sign was more often present in older patients (77 ± 8 vs 73 ± 8 years, p = 0.022), associated with systemic features (58% vs 42%, p = 0.011), higher erythrocyte sedimentation rate (84 ± 26 vs 74 ± 34 mm/hour, p = 0.020), and lower hemoglobin values (10.9 ± 1.5 vs 12.1 ± 1.6 g/dL, p < 0.001). The number of patients under corticosteroids before CDS was higher in the group without halo (62% vs 33%, p = 0.005). Ischemic stroke occurred in 17 patients (19%), 76% in the vertebrobasilar territory, and stroke was associated with vertebral halo sign (p < 0.001). CONCLUSIONS: Halo sign was present in half of our patients. Previous corticosteroids treatment decreased positive CDS findings. Systemic symptoms and laboratory findings are more notorious in halo sign subgroup of patients. Stroke cases in GCA patients disproportionally affected the posterior circulation. Ultrasonography provides information about a more pronounced systemic involvement and a higher risk of major complications.

False positives in the ultrasound diagnosis of giant cell arteritis: some diseases can also show the halo sign.

OBJECTIVES: To describe the frequency and causes for the presence of a halo sign on the ultrasound of patients without a diagnosis of GCA. METHODS: In total, 305 patients with temporal artery colour Doppler ultrasound showing the presence of halo sign (intima-media thickness ≥0.34 mm for temporal arteries [TAs] and ≥1 mm for axillary arteries) were included, and their medical records were reviewed. The clinical diagnosis based on the evolution of the patient over at least one year was established as the definitive diagnosis. RESULTS: Fourteen of the 305 (4.6%) patients included showed presence of the halo sign without final diagnosis of GCA: 12 patients in the TAs (86%), and two patients with isolated AAs involvement (14%). Their diagnoses were PMR (n = 4, 29%); atherosclerosis (n = 3, 21%); and non-Hodgkin lymphoma type T, osteomyelitis of the skull base, primary amyloidosis associated with multiple myeloma, granulomatosis with polyangiitis, neurosyphilis, urinary sepsis and narrow-angle glaucoma (n = 1 each, 7%). CONCLUSION: The percentage of halo signs on the ultrasound of patients without GCA is low, but it does exist. There are conditions that may also show the halo sign (true positive halo sign), and we must know these and always correlate the ultrasound findings with the patient's clinic records.

Early variation of ultrasound halo sign with treatment and relation with clinical features in patients with giant cell arteritis.

OBJECTIVES: To compare the ultrasound characteristics with clinical features, final diagnosis and outcome; and to evaluate the halo size following glucocorticoid treatment in patients with newly diagnosed GCA. METHODS: Patients with suspected GCA, recruited from an international cohort, had an ultrasound of temporal (TA) and axillary (AX) arteries performed within 7 days of commencing glucocorticoids. We compared differences in clinical features at disease presentation, after 2 weeks and after 6 months, according to the presence or absence of halo sign. We undertook a cross-sectional analysis of the differences in halo thickness using Pearson's correlation coefficient (r) and Analysis of Variance (ANOVA). RESULTS: A total of 345 patients with 6 months follow-up data were included; 226 (65.5%) had a diagnosis of GCA. Jaw claudication and visual symptoms were more frequent in patients with halo sign (P =0.018 and P =0.003, respectively). Physical examination abnormalities were significantly associated with the presence of ipsilateral halo (P <0.05). Stenosis or occlusion on ultrasound failed to contribute to the diagnosis of GCA. During 7 days of glucocorticoid treatment, there was a consistent reduction in halo size in the TA (maximum halo size per patient: r=-0.30, P =0.001; and all halos r=-0.23, P <0.001), but not in the AX (P >0.05). However, the presence of halo at baseline failed to predict future ischaemic events occurring during follow-up. CONCLUSION: In newly diagnosed GCA, TA halo is associated with the presence of ischaemic features and its size decreases following glucocorticoid treatment, supporting its early use as a marker of disease activity, in addition to its diagnostic role.

Magnetic resonance imaging features in 283 patients with primary biliary cholangitis.

OBJECTIVES: To evaluate magnetic resonance imaging (MRI) features of the liver in primary biliary cholangitis (PBC). METHODS: We conducted a multicenter retrospective review on 283 patients with PBC who underwent an MRI between 2007 and 2018. Patients with overlap syndromes were excluded. MRI studies were independently reviewed by two abdominal radiologists for liver morphology, signal intensity, postcontrast enhancement, and decompensation. Liver and spleen volumes and normalized liver apparent diffusion coefficient (nlADC) were also calculated. MRI features were correlated with fibrosis stage among a subset of patients who had a liver biopsy within 6 months (n = 72). RESULTS: The study population was comprised of 283 patients (89% females) and a mean ± SD age of 59.4 ± 11.8 years. Lymphadenopathy (78.1%), periportal hyperintensity (36.7%), and periportal halo sign (27.6%) were the most common features. A positive correlation was found between fibrosis stage and spleen size (r = 0.457, p < 0.001), spleen volume (r = 0.557, p < 0.001) and portal vein diameter (r = 0.287, p = 0.013), and a negative correlation with nlADC (r = - 0.332, p = 0.011). Fibrosis stage also correlated with the presence of surface nodularity (p < 0.001), periportal halo sign (p = 0.04), collaterals (p = 0.033), and splenomegaly (p = 0.002). No significant differences in nlADC values were found in different fibrosis stages. Spleen size and volume were significantly higher in patients with ascites and collaterals (< 0.001). The periportal halo sign was present only in patients with significant fibrosis. None of the MRI features significantly correlated with inflammation grade. CONCLUSIONS: In PBC, presence of periportal halo sign correlates with significant fibrosis. Heterogeneous T2W intensity, heterogeneous postcontrast enhancement, collaterals, spleen size, and spleen volume correlate with fibrosis stage and may be useful for predicting advanced fibrosis. KEY POINTS: • The presence of periportal halo sign is indicative for significant fibrosis in primary biliary cholangitis. • Liver parenchymal heterogeneous T2 signal intensity, heterogeneous postcontrast enhancement, collaterals, spleen size, and spleen volume correlate with fibrosis stages in PBC and may be useful for predicting advanced fibrosis.

Frequency and Reliability of the Reversed Halo Sign in Patients With Septic Pulmonary Embolism Due to IV Substance Use Disorder.

OBJECTIVE. The purpose of this article is to assess the "reversed halo" sign in patients with septic pulmonary embolism (PE) due to IV substance use disorder. MATERIALS AND METHODS. A retrospective analysis was performed of chest CT scans obtained between 2007 and 2017 that had findings of septic PE associated with IV substance use disorder. Inclusion criteria were history of IV substance use disorder, findings of septic PE on chest CT scans, and confirmation of infection. Image analysis was performed by three radiologists to assess the frequency, appearance, and evolution of the reversed halo sign. Interreader agreement to characterize the reversed halo sign was assessed using kappa statistical analysis. The chi-square test was used to correlate reversed halo sign shape with evolution on follow-up scans. RESULTS. Of 62 patients who met the inclusion criteria (54.8% women; mean age, 32.8 ± 8.3 [SD] years), 59.7% (37/62) had reversed halo signs (κ = 0.837-0.958, p < 0.0001). The mean number of unique reversed halo signs per patient was 2.1 ± 1.7 (46.7% of patients had more than one reversed halo sign). Of 78 unique reversed halo signs, 93.6% (73/78) were peripherally located and 51.3% (40/78) were located at the lower lobe, 52.6% (41/78) were pyramidal and 47.4% (37/78) were round shaped, 89.7% (70/78) had central low-attenuation areas, and 34.6% (27/78) had internal reticulations. Cavitation developed in 37.2% (29/78) of reversed halo signs and more often in pyramid-shaped ones (70.8%, 17/24), whereas consolidation occurred in 30.8% (24/78) and more often in round-shaped ones (58.6%; 17/29, p = 0.03). CONCLUSION. Septic PE should be considered in the differential diagnosis of patients with IV substance use disorder presenting with reversed halo sign. The reversed halo sign was reliably and frequently observed on the chest CT scans of patients with IV substance use disorder-related septic PE. Characteristics of reversed halo sign presentation were identified as potential features to differentiate septic PE from other causes of pulmonary infarct manifesting with reversed halo sign.

Rapidly progressive respiratory failure with multiple halo signs on computed tomography in a patient with primary cardiac angiosarcoma derived from the right atrium: a case report.

BACKGROUND: Primary cardiac neoplasms are extremely rare, with an autopsy incidence of 0.0001-0.003%. Primary cardiac sarcoma is usually derived from the right atrium and it manifests as chest pain, arrhythmia, hemoptysis, dyspnea, and fatigue. The most common target organ for metastasis of primary angiosarcoma is the lungs, but the radiological-pathological correlation has been rarely reported. CASE PRESENTATION: A 38-year-old healthy Japanese man was admitted to our hospital with persistent hemoptysis, exaggerated dyspnea, and two episodes of loss of consciousness in the past 3 months. Non-enhanced thoracic computed tomography (CT) revealed multiple scattered nodules with halo signs. Contrast-enhanced thoracic CT revealed a filling defect in the right atrium, which corresponded to the inhomogeneously enhancing tumor in the right atrium on enhanced electrocardiogram-gated cardiac CT. On day 2, acute respiratory failure occurred, and the patient was placed on mechanical ventilation. The patient was diagnosed with primary cardiac angiosarcoma based on the urgent transcatheter biopsied specimen of the right atrium mass and was treated with intravenous administration of doxorubicin. However, his respiratory status rapidly deteriorated, and he died on day 20. Postmortem biopsy showed that the multiple lung nodules with the halo signs corresponded to the intratumoral hemorrhagic necrosis and peripheral parenchymal hemorrhage in their background, suggesting the fragility of the lung tissue where the tumor had invaded, which caused hemoptysis. Furthermore, two episodes of loss of consciousness occurred probably due to a decreased cardiac output because of a massive tumor occupying the right atrium, recognized as an inhomogeneous centripetal enhancement on enhanced electrocardiogram-gated cardiac CT. CONCLUSIONS: This case clearly demonstrated that primary cardiac angiosarcoma could expand in the right atrial cavity, which led to a decreased cardiac output resulting in repeated syncope, together with the fragility of lung tissue by tumor invasion, thereby generating a halo sign on thoracic CT.

A family outbreak of coronavirus disease 2019. / 一组家族暴发的2019å† çŠ¶ç— æ¯’ç— .

Although continuous outbreak of coronavirus disease 2019, it has been widely reported, there were few reports regarding family cases. We reported a group of family cluster outbreak cases confirmed in Xiangya Hospital, Central South University, China, and their clinical and image characteristics have been analyzed in order to provide reference for the prevention and early diagnosis of this disease. A total of 5 patients from one family, including 4 adults and 1 child, had a history of human contact in Wuhan, Hubei. Four adult patients showed different symptoms, including cough, fever, pharyngeal pain, and dyspnea, while the child patient had no symptoms. Laboratory examination showed no abnormality in all the patients except for slight increase in CRP in 2 patients and mild abnormal liver function index in 1 patient. The chest CT showed that all patients had abnormal images, with different degrees of manifestations.All patients were finally diagnosed by the nucleic acid test.

Significance of the Reverse Halo Sign in Immunocompromised Patients.

OBJECTIVE. The purpose of this study is to assess the most common causes of the reverse halo sign (RHS) in immunocompromised patients and to identify clinicoradiologic features that help in achieving a specific diagnosis. MATERIALS AND METHODS. This retrospective study included 70 patients with hematologic malignancy, neutropenia, or history of solid organ transplant or stem cell transplant who had the RHS at chest CT. Absolute neutrophil count, imaging features of the RHS, and presence of pleural effusions were noted and correlated with the specific diagnosis. A decision tree was constructed from predictive imaging features and compared with radiologist assessment for infectious versus noninfectious cause. RESULTS. Infection, including fungal and bacterial pneumonia, was the most common cause of the RHS (66%), followed by organizing pneumonia (26%). Noninfectious causes such as organizing pneumonia were more likely in the solid organ transplant group, whereas infections were more likely in patients with hematologic malignancy and stem cell transplant. Among fungal pneumonias, aspergillosis (20%) was as common as mucormycosis (19%). In univariate analysis, neutropenia, rim thickness, central ground-glass attenuation, and lesion diameter correlated with infectious cause. A decision tree using neutropenia, rim thickness, central ground-glass attenuation, and pleural effusion could differentiate infectious from noninfectious cause with accuracy of 78%, compared with radiologist accuracy of 81%. CONCLUSION. Infections are more likely to cause RHS than noninfectious processes in immunocompromised patients, and aspergillosis may be as likely overall as mucormycosis because of its higher frequency in these patients. A decision tree using clinical and imaging features can help differentiate infectious from noninfectious causes of RHS.

Pulmonary mucormycosis: serial morphologic changes on computed tomography correlate with clinical and pathologic findings.

PURPOSE: To evaluate serial computed tomography (CT) findings of pulmonary mucormycosis correlated with peripheral blood absolute neutrophil count (ANC). MATERIALS AND METHODS: Between February 1997 and June 2016, 20 immunocompromised patients (10 males, 10 females; mean age, 48.9 years) were histopathologically diagnosed as pulmonary mucormycosis. On initial (n=20) and follow-up (n=15) CT scans, the patterns of lung abnormalities and their changing features on follow-up scans were evaluated, and the pattern changes were correlated with ANC changes. RESULTS: All patients were immunocompromised. On initial CT scans, nodule (≤3cm)/mass (>3cm) or consolidation with surrounding ground-glass opacity halo (18/20, 90%)) was the most common pattern. On follow-up CT, morphologic changes (13/15, 87%) could be seen and they included reversed halo (RH) sign, central necrosis, and air-crescent sign. Although all cases did not demonstrate the regular morphologic changes at the same timeline, various combinations of pattern change could be seen in all patients. Sequential morphologic changes were related with recovering of ANC in 13 of 15 patients. CONCLUSION: Pulmonary mucormycosis most frequently presents as consolidation or nodule/mass with halo sign at CT. Morphologic changes into RH sign, central necrotic cavity or air-crescent sign occur with treatment and recovery of ANC. KEY POINTS: • Pulmonary mucormycosis showed various CT-morphology including CT halo sign • Pulmonary mucormycosis had trends of serial morphologic changes on follow-ups • Recovery of absolute neutrophil count changed CT-morphology of mucormycosis in immune-compromised patients.

Pulmonary Mucormycosis: Radiologic Features at Presentation and Over Time.

OBJECTIVE: Pulmonary mucormycosis is an aggressive opportunistic fungal infection. We set out to evaluate the CT and MRI features of pulmonary mucormycosis. MATERIALS AND METHODS: Through a search of the electronic medical record from 2007 to 2017, we identified 30 patients with definite or probable mucormycosis. Two radiologists reviewed the initial chest CT examinations for the presence of features including the "reverse halo" sign, large ground-glass halo, and peripheral lesion distribution. Additional CT and MRI studies were reviewed to evaluate evolution over time. RESULTS: The majority (67%) of patients had lesions with the reverse halo sign at some point in the disease course. A ground-glass halo larger than the lesion was seen in 53% of patients. Notably, lesions had a peripheral predominance in 87% of cases. Through careful review of images, a perivascular ground-glass precursor lesion was identified in 20% of patients 1-2 weeks before a consolidation developed. In five (17%) patients, CT showed a multifocal pneumonia appearance. Finally, MRI of two patients showed T2-hypointense rims and central nonenhancement, a finding we refer to as the "black hole" sign. CONCLUSION: Large nodules or consolidations with an associated reverse halo sign or large perilesional ground-glass halos are common in mucormycosis. Lesions tend to show a peripheral predominance, and a perivascular ground-glass focus preceded nodular lesions in some cases. In some patients with severe disease, imaging features evolved to show a multifocal pneumonia pattern, and this pattern was associated with a high mortality rate.

Imaging after radiofrequency ablation of renal tumors.

The number of percutaneous radiofrequency ablation procedures performed for renal tumors is progressively increasing worldwide. Periodic imaging follow-up has the double role to guarantee the treatment efficacy over time and to early detect any possible complication. Tumor size reductions, as well as the appearance of the characteristic 'halo sign', are normal findings that represent good ablative outcomes. However the most reliable factor of ablation efficacy remains the total absence of contrast enhancing zones within the ablated area. The aim of this article is to illustrate the typical aspect of an effective radiofrequency ablation treatment, which are the imaging findings that may suggest the presence of residual tumoral tissue and which are the main early and late procedural complications.

Halo Sign and Eosinophilia: What Is Your Diagnosis?

Blood eosinophilia associated with transient and migrating nodules with a halo sign on chest computed tomography scan should suggest larva migrans related to toxocariasis or ascaris suum.