Evolution of CT characteristics of reversed halo sign in pulmonary tuberculosis / 中华放射学杂志

Objective:To explore the evolution of CT characteristics of the "reversed halo sign" of pulmonary tuberculosis, and to further improve the recognition of its CT signs.Methods:Clinical and CT data of 12 patients with pulmonary tuberculosis who were clinically and pathologically confirmed and accompanied with CT manifestation of "reversed halo sign" in First Affiliated Hospital of Henan University of Science and Technology from August 2013 to April 2020 were analyzed retrospectively. Pathological and imaging contrastl analysis was performed on 1 patient undergoing surgical treatment.Results:Among 12 cases with "reversed halo sign", there were 2 cases with single lesion in unilateral lung, 2 cases with multiple lesions in unilateral lung, and 8 cases with multiple lesions in bilateral lungs. Three cases showed only "reversed halo sign", 9 cases showed both halo-like sign and uniform fireworks sign. "Tree-in-bud "sign was found in all 12 patients in the outer ring of the "reversed halo sign". Eight patients received three or more CT examinations, and six of them showed reduction of density and volume of the "reversed halo sign" after standardized anti-tuberculosis treatment. Under the natural course of the disease in two cases, the overall enlargement of the lesion was observed in 1 case, and the overall density of the lesion was reduced and the outer ring wall of the "reversed halo sign" was thinned in 1 case. The pathology of one case after surgical lobectomy showed granulomatous inflammatory nodules of varying sizes containing Langerhans nodule giant cells in the lung parenchyma. The typical caseous necrotic granulomatous nodules were rare here. The "reversed halo sign" showed dense Langerhans nodules in the outer ring, sparse central areas with fibrous hyperplasia and alveolar wall thickening.Conclusions:The outer ring of "reversed halo sign" of pulmonary tuberculosis shows as "tree-in-bud" sign, and its center shows as the fine reticulation pattern. After effective anti-tuberculosis treatment, both the overall density of "reversed halo sign" and the lesion size reduced. Finally, the lesions mostly present as as fine grid shadows for a long time.

Chest CT interpretation of organized pneumonia / 中国综合临床

Organizing pneumonia (OP) is a common lung interstitial disease.On chest CT, the main imaging manifestations of OP are consolidation and/or nodules with air bronchogram and traction bronchiectasis, predominantly peribronchovascular and subpleural regions." Reverse halo" sign, band-like consolidation and paralobular consolidation are also can be seen.Migratory behavior of lesions may be evident in follow up studies.The diagnosis of OP is a comprehensive analysis based on imaging combined with clinical and pathological findings.

Signo del atolón o signo del halo invertido en covid-19: a propósito de un caso / Covid-19 Atoll sign or inverted halo sign: about a case

La Sociedad Fleishner define el signo del halo invertido o signo del atolón como un área focal redondeada con la densidad de un "vidrio esmerilado", rodeada por un anillo más o menos completo de consolidación. Este signo fue descrito inicialmente en pacientes con neumonía organizada criptogénica por Voloudaki y Kim. Ha sido descrito en: 1) enfermedades infecciosas (la paracoccidioidomicosis, la aspergilosis, la mucormicosis y virales), 2) síndromes linfoproliferativos (la granulomatosis linfomatoidea), y 3) enfermedades inflamatorias no infecciosas ni neoplásicas (el síndrome de Churg-Strauss, la neumonía intersticial no específica y la granulomatosis de Wegener).

The Fleishner Society defines the inverted halo sign or Atoll sign as a rounded focal area with a "ground glass" density, surrounded by a more or less complete ring of consolidation. This sign was initially described in patients with organizing cryptogenic pneumonia by Voloudaki and Kim. It has been described in: 1) infectious diseases (paracoccidioidomycosis, aspergillosis, mucormycosis, and virals), 2) lymphoproliferative diseases (lymphomatoid granulomatosis), and 3) non-infectious and neoplastic inflammatory diseases (Churg-Strauss syndrome, non-specific interstitial pneumonia, and Wegener's granulomatosis).

El Signo De Halo Invertido En Tomografía Computada De Tórax / The Inverted Halo Sign in Thoracic Computed Tomography

El signo del halo invertido se caracteriza por una opacidad central de vidrio esmerilado rodeado por una consolidación del espacio aéreo más densa en forma de una media luna o un anillo. El signo del halo invertido se ha informado en asociación con un am­ plia gama de enfermedades pulmonares, incluidas las infecciones fúngicas pulmonares invasivas, neumonía por pneumocystis, tuberculosis, neumonía adquirida en la comuni­ dad, granulomatosis linfomatoide, granulomatosis de Wegener, neumonía lipoidea y sarcoidosis. También se observa en neoplasmas pulmonares e infarto y después de ra­ dioterapia y ablación por radiofrecuencia de neoplasias malignas pulmonares. También es conocido como signo de halo en reversa o signo del atolón.

The reversed halo sign is characterized by a central ground­glass opacity surrounded by denser air­space consolidation in the shape of a crescent or a ring. The reversed halo sign has been reported in association with a wide range of pulmonary diseases, in­ cluding invasive pulmonary fungal infections, pneumocystis pneumonia, tuberculosis, community­acquired pneumonia, lymphomatoid granulomatosis, Wegener granulomato­ sis, lipoid pneumonia and sarcoidosis. It is also seen in pulmonary neoplasms and in­ farction, and following radiation therapy and radiofrequency ablation of pulmonary malignancies. It is also known as a reverse halo sign or atoll sign

Lymphomatoid Granulomatosis: CT and FDG-PET Findings

OBJECTIVE: Lymphomatoid granulomatosis (LG) is a rare, aggressive extranodal Epstein-Barr virus (EBV)-positive B-cell lymphoproliferative disease. The purpose of our study was to analyze the CT and fluorodeoxyglucose positron emission tomography (FDG-PET) findings of pulmonary LG. MATERIALS AND METHODS: Between 2000 and 2009, four patients with pathologically proven pulmonary LG and chest CT were identified. Two of these patients also had FDG-PET. Imaging features of LG on CT and PET were reviewed. RESULTS: Pulmonary nodules or masses with peribronchovascular, subpleural, and lower lung zonal preponderance were present in all patients. Central low attenuation (4 of 4 patients), ground-glass halo (3 of 4 patients), and peripheral enhancement (4 of 4 patients) were observed in these nodules and masses. An air-bronchogram and cavitation were seen in three of four patients. FDG-PET scans demonstrated avid FDG uptake in the pulmonary nodules and masses. CONCLUSION: Pulmonary LG presents with nodules and masses with a lymphatic distribution, as would be expected for a lymphoproliferative disease. However, central low attenuation, ground-glass halo and peripheral enhancement of the nodules/masses are likely related to the angioinvasive nature of this disease. Peripheral enhancement and ground-glass halo, in particular, are valuable characteristic not previously reported that can help radiologists suggest the diagnosis of pulmonary LG.

The Clinical Usefulness of Halo Sign on CT Image of Trauma Patients

PURPOSE: The management of hemorrhagic shock is critical for trauma patients. To assess hemorrhagic shock, the clinician commonly uses a change in positional blood pressure, the shock index, an estimate of the diameter of inferior vena cava based on sonography, and an evaluation of hypoperfusion complex shown on a CT scan. To add the finding for the hypoperfusion complex, the 'halo sign' was introduced recently. To our knowledge, this 'halo sign' has not been evaluated for its clinical usefulness, so we designed this study to evaluate its usefulness and to find the useful CT signs for hypoperfusion complex. METHODS: The study was done from January 2007 to May 2007. All medical records and CT images of 124 patients with trauma were reviewed, of which 103 patients were included. Exclusion criteria was as follows: 1) age or = 5. RESULTS: The value of kappa, to assess the inter-observer agreement, was 0.51 (p < 0.001). The variables of the halo-sign-positive group were statistically different from those of the halo-sign-negative group. The rate of transfusion for the halo-sign-positive group was about 10 times higher than that of the halo-sign-negative group and the rate of mortality was about 6 times higher. CONCLUSION: In the setting of trauma, early abdominal CT can show diffuse abnormalities due to hypoperfusion complex. Recognition of these signs is important in order to prevent an unwanted outcome in hemorrhagic shock. We conclude that the halo sign is a useful one for hypoperfusion complex and that it is useful for assessing the degree of hemorrhagic shock.