Importance of chest HRCT in the diagnostic evaluation of fibrosing interstitial lung diseases / Importância da TCAR de tórax na avaliação de pneumopatias intersticiais fibrosantes

ABSTRACT Many conditions result in chronic interstitial lung disease (ILD), being classified as fibrosing ILDs, including idiopathic pulmonary fibrosis, connective tissue diseases, sarcoidosis, and fibrotic hypersensitivity pneumonitis. HRCT plays an important role in the clinical evaluation of fibrosing ILDs. Current treatment perspectives are encouraging and reinforce the need for HRCT scans of adequate technical quality for early detection of fibrosing ILD. Despite efforts in this regard, the significance and management of imaging findings of early interstitial lung abnormalities have yet to be clarified. After identification of CT findings consistent with fibrosing ILD, radiologists must be able to identify characteristic morphological patterns and, in some cases, features of specific clinical entities. In cases in which HRCT features are not sufficiently specific for a definitive diagnosis, HRCT can aid in selecting the best site for surgical lung biopsy. CT follow-up is useful for identifying progressive fibrosing ILDs and detecting complications unrelated to the underlying disease, including infections, acute exacerbations, and neoplasms. Automated quantification tools have clinical applicability and are likely to be available for use in imaging analysis in the near future. In addition, incorporation of CT evaluation into scoring systems based on clinical and functional parameters for staging fibrosing disease is likely to become valuable in determining prognosis. Knowledge of the clinical applications of CT evaluation is essential for specialists managing patients with fibrosing ILD and can have a positive impact on the clinical course of the disease.

RESUMO Inúmeras doenças determinam dano intersticial crônico no parênquima pulmonar e são agrupadas com a denominação de pneumopatias intersticiais fibrosantes, incluindo fibrose pulmonar idiopática, doenças do colágeno, sarcoidose, pneumonite por hipersensibilidade fibrótica etc. Entre os métodos complementares à avaliação clínica, a TCAR tem um papel relevante. Perspectivas atuais de tratamento são encorajadoras e reforçam a necessidade de realização de estudos com técnica adequada, visando a detecção confiável de acometimento intersticial fibrosante o mais precocemente possível. Embora esforços tenham sido direcionados nesse sentido, o significado e manejo de anormalidades pulmonares intersticiais incipientes, detectadas nos estudos de imagem, ainda não são claros. Uma vez detectado o acometimento fibrosante, é importante que o radiologista conheça aspectos característicos de determinados padrões morfológicos e reconheça elementos que possam apontar para entidades clínicas específicas. Em casos nos quais a especificidade dos achados não é suficiente para a suspeição diagnóstica, as imagens de TC servem de guia para a escolha de sítios para biópsia cirúrgica. O seguimento evolutivo é útil para a determinação de pneumopatias fibrosantes progressivas e para a detecção de complicações não relacionadas à doença de base, como infecções, exacerbação aguda e neoplasias. Ferramentas automatizadas de quantificação têm aplicabilidade clínica e devem estar acessíveis para a análise imagética no futuro próximo. Além disso, a incorporação da avaliação tomográfica a escores com parâmetros clínicos e funcionais de estadiamento do acometimento fibrosante poderá se tornar valiosa na determinação prognóstica. O conhecimento das diversas aplicabilidades clínicas do método tomográfico é fundamental aos especialistas que acompanham esses pacientes, podendo impactar positivamente sua trajetória clínica.

Padrões de tomografia computadorizada de alta resolução na doença pulmonar intersticial (DPI): prevalência e prognóstico / High resolution computed tomography patterns in interstitial lung disease (ILD): prevalence and prognosis

RESUMO Objetivo Correlacionar a prevalência e o prognóstico de cada padrão de TCAR de pneumonia intersticial usual (PIU) típica, provável e indeterminada com o diagnóstico clínico multidisciplinar de doença pulmonar intersticial (DPI). Métodos Incluímos todos os pacientes com diagnóstico multidisciplinar de DPI com padrão de TCAR de PIU típica, PIU provável ou indeterminada para PIU. Dados clínicos e histopatológicos, teste de função pulmonar e status de sobrevida foram obtidos retrospectivamente. O diagnóstico final foi validado por uma equipe multidisciplinar. Resultados Foram incluídos no estudo 244 pacientes, com média de idade de 68 ± 13 anos sendo 52,5% do sexo masculino. Em um total de 106 pacientes com padrão típico de PIU, 62% tiveram o diagnóstico multidisciplinar de FPI, 20% de pneumonia por hipersensibilidade crônica (PHC) e 10% de DPI relacionada à doença do tecido conjuntivo (DPI-DTC). Dos 114 casos com provável PIU, DPI-DTC correspondeu a 39%, FPI a 31%, pneumonia intersticial descamativa a 11%, doença pulmonar relacionada a medicamentos a 9% e PHC a 8%. Nos 24 pacientes com TC indeterminada para PIU, o DPI-DTC foi o diagnóstico final em 33%, seguido por pneumonia intersticial descamativa (21%) e FPI (13%). Pacientes com PIU típica apresentaram maior probabilidade de morrer ou realizar transplante de pulmão no seguimento (17,9% e 11,3%, respectivamente). Conclusões FPI, PHC e DPI-DTC foram os principais diagnósticos diferenciais em pacientes com padrão de TCAR de PIU típica, provável e indeterminada. Pacientes com padrão de PIU típico na TCAR tiveram maior probabilidade de morrer ou realizar transplante de pulmão no seguimento.

ABSTRACT Objective To correlate the prevalence and prognosis of each HRCT pattern of typical, probable, and indeterminate usual interstitial pneumonia (UIP) with the clinical multidisciplinary diagnosis of interstitial lung disease (ILD). Methods We included all patients with a multidisciplinary diagnosis of ILD with an HRCT pattern of typical UIP, probable UIP, or indeterminate for UIP. Clinical and histopathological data, pulmonary function tests, and survival status were retrospectively obtained. The final diagnosis was validated by a multidisciplinary team. Results A total of 244 patients were included in the study, with a mean age of 68 ±13 years and being 52.5% males. In a total of 106 patients with typical UIP pattern, 62% had the multidisciplinary diagnosis of IPF, 20% had chronic hypersensitivity pneumonitis (CHP), and 10% had connective tissue disease-related ILD (CTD-ILD). Out of the 114 cases with probable UIP, CTD-ILD corresponded to 39%, IPF to 31%, desquamative interstitial pneumonia to 11%, drug-related lung disease to 9%, and CHP to 8%. In the 24 patients with CT indeterminate for UIP, CTD-ILD was the final diagnosis in 33%, followed by desquamative interstitial pneumonia (21%), and IPF (13%). Patients with typical UIP were more likely to die or had lung transplantation in the follow-up (17.9% and 11.3%, respectively). Conclusion IPF, CHP, and CTD-ILD were the main differential diagnoses in patients with HRCT patterns of typical, probable and indeterminate UIP. Patients with HRCT typical UIP pattern were more likely to die or had lung transplantation in the follow-up.

Tomografía computada de alta resolución en el diagnóstico de la fibrosis pulmonar idiopática / High resolution computed tomography in the diagnosis of idiopathic pulmonary fibrosis

El patrón de neumonía intersticial usual (NIU) en la tomografía computada de alta resolución (TCAR) tiene un alto grado de correlación con el patrón histológico lo que permite obviar en dichos casos la necesidad de realizar biopsia pulmonar. La exactitud del diagnóstico de NIU en TCAR se basa en la detección de signos específicos de fibrosis como el panal y las densidades reticulares con bronquiolectasias por tracción. La actualización de las guías 2018 de práctica clínica de la ATS/ERS/JRS/ALAT de Fibrosis Pulmonar Idiopática (FPI) y la declaración de consenso de la Sociedad Fleischner proponen una nueva forma de clasificar los patrones tomográficos tomando en cuenta los aspectos antes considerados. Si bien la presencia de panal sigue siendo el hallazgo principal para caracterizar el patrón NIU, la distribución del reticulado intersticial y la presencia de bronquiolectasias por tracción en el contexto clínico especifico puede ser suficiente para realizar el diagnóstico de fibrosis pulmonar idiopática.

Usual interstitial pneumonia pattern (UIP) in high-resolution computed tomography (HRCT) has a high degree of correlation with the histological pattern which makes it possible to obviate in these cases the need for lung biopsy. The accuracy of a UIP diagnosis in HRCT is based on the detection of specific signs of fibrosis such as honeycomb and reticular densities with traction bronchiolectasis. The update of the 2018 Clinical Practice Guidelines of the ATS / ERS / JRS / ALAT of Idiopathic Pulmonary Fibrosis (IPF) and the Fleischner Society White Paper proposed a new way of classifying the tomographic patterns taking into account the aspects previously considered. Although the presence of honeycomb remains the main finding to characterize the UIP pattern, the distribution of interstitial reticulate and the presence of traction bronchiolectasis, in the specific clinical context, may be sufficient to make the diagnosis of idiopathic pulmonary fibrosis.

Discusión multidisciplinaria para el diagnóstico de la fibrosis pulmonar idiopática / Multidisciplinary discussion for the diagnosis of idiopathic pulmonary fibrosis

Antes de la publicación de la clasificación ATS/ERS 2002 de las neumonías intersticiales idiopáticas (NII), la evaluación histopatológica se consideraba la referencia de oro para el diagnóstico de las enfermedades pulmonares intersticiales (EPI). Sin embargo, varios estudios posteriores mostraron que las concordancias interobservador entre anatomopatólogos expertos torácicos eran sorprendentemente pobres ya que las apariencias histopatológicas pueden superponerse entre entidades distintas. Por lo anterior, se hace necesario un nuevo sistema diagnóstico que sirva de patrón de oro en pacientes con EPI. Es así como nace el concepto de discusión multidisciplinaria, para referirse a una reunión que permita la integración de todos los datos clínicos, radiológicos y patológicos disponibles para un paciente individual y así poder determinar un diagnóstico de trabajo.

Prior to the publication of the 2002 ATS / ERS classification of idiopathic interstitial pneumonias (IIP), the histopathological evaluation was considered the gold standard for the diagnosis of interstitial lung diseases (ILD). However, several subsequent studies showed that interobserver concordances between expert lung pathologists were surprisingly poor, since histopathological appearances may overlap between different entities. Therefore, a new diagnostic system that serves as a gold standard in patients with ILD became necessary. This is how the concept of multidisciplinary discussion was born, to refer to a meeting that allows the integration of all the clinical, radiological and pathological data available for an individual patient and thus be able to determine a working diagnosis.

Imaging in idiopathic pulmonary fibrosis: diagnosis and mimics

Idiopathic pulmonary fibrosis is a chronic disease of unknown etiology that usually has a progressive course and is commonly associated with a poor prognosis. The main symptoms of idiopathic pulmonary fibrosis, including progressive dyspnea and dry cough, are often nonspecific. Chest high-resolution computed tomography is the primary modality used in the initial assessment of patients with suspected idiopathic pulmonary fibrosis and may have considerable influence on subsequent management decisions. The main role of computed tomography is to distinguish chronic fibrosing lung diseases with a usual interstitial pneumonia pattern from those presenting with a non-usual interstitial pneumonia pattern, suggesting an alternative diagnosis when possible. A usual interstitial pneumonia pattern on chest tomography is characterized by the presence subpleural and basal predominance, reticular abnormality honeycombing with or without traction bronchiectasis, and the absence of features suggestive of an alternative diagnosis. Idiopathic pulmonary fibrosis can be diagnosed according to clinical and radiological criteria in approximately 66.6% of cases. Confirmation of an idiopathic pulmonary fibrosis diagnosis is challenging, requiring the exclusion of pulmonary fibroses with known causes, such as asbestosis, connective tissue diseases, drug exposure, chronic hypersensitivity pneumonitis, and other forms of idiopathic interstitial pneumonitis. The histopathological hallmark of usual interstitial pneumonia is a heterogeneous appearance, characterized by areas of fibrosis with scarring and honeycombing alternating with areas of less affected or normal parenchyma. The aim of this article was to review the clinical, radiological, and pathological features of idiopathic pulmonary fibrosis and of diseases that might mimic idiopathic pulmonary fibrosis presentation.

Usual interstitial pneumonia: typical, possible, and "inconsistent" patterns / Pneumonia intersticial usual: padrões típico, possível e inconsistente

ABSTRACT Idiopathic pulmonary fibrosis is a severe and progressive chronic fibrosing interstitial lung disease, a definitive diagnosis being established by specific combinations of clinical, radiological, and pathological findings. According to current international guidelines, HRCT plays a key role in establishing a diagnosis of usual interstitial pneumonia (UIP). Current guidelines describe three UIP patterns based on HRCT findings: a typical UIP pattern; a pattern designated "possible UIP"; and a pattern designated "inconsistent with UIP", each pattern having important diagnostic implications. A typical UIP pattern on HRCT is highly accurate for the presence of histopathological UIP, being currently considered to be diagnostic of UIP. The remaining patterns require further diagnostic investigation. Other known causes of a UIP pattern include drug-induced interstitial lung disease, chronic hypersensitivity pneumonitis, occupational diseases (e.g., asbestosis), and connective tissue diseases, all of which should be included in the clinical differential diagnosis. Given the importance of CT studies in establishing a diagnosis and the possibility of interobserver variability, the objective of this pictorial essay was to illustrate all three UIP patterns on HRCT.

RESUMO A fibrose pulmonar idiopática é uma pneumopatia intersticial fibrosante crônica de curso grave e progressivo, e seu diagnóstico se dá em combinações específicas de correlações clínicas e radiológicas, ou ainda patológicas. A TCAR tem papel chave no diagnóstico morfológico do padrão de pneumonia intersticial usual (PIU), segundo as recomendações internacionais vigentes. Os níveis de certeza para a leitura do padrão tomográfico foram inseridos em diretrizes atuais, descritos como padrão PIU típico, padrão PIU possível e padrão inconsistente com PIU, cada qual com importantes implicações na cadeia diagnóstica. A presença do padrão PIU típico tem alta concordância com o padrão PIU histopatológico, e, nessa situação, a TCAR é tida como suficiente para a determinação do padrão morfológico. Nos demais padrões, investigações diagnósticas complementares são indicadas. O diagnóstico diferencial com outras entidades, incluindo pneumopatias intersticiais por exposição medicamentosa, exposições extrínsecas (pneumonite de hipersensibilidade crônica), doenças ocupacionais (asbestose) e doenças do tecido conjuntivo, deve ser considerado clinicamente. Dada a importância da abordagem tomográfica, a qual pode apresentar relevantes discordâncias na avaliação interobservador, nosso objetivo foi ilustrar os padrões tomográficos de PIU neste ensaio pictórico.

Fibrosis pulmonar idiopática en un ecuatoriano adulto de la provincia de Riobamba / Idiopathic lung fibrosis in an adult Ecuadorian from Riobamba province

Se presenta el caso clínico de un paciente de 52 años, expuesto a las cenizas del volcán Tungurahua en erupción, quien acudió a la Consulta de Medicina Familiar Comunitaria del Cantón Guano, provincia ecuatoriana de Riobamba, por presentar cuadro de tos productiva en horario matutino, mucoide de coloración blanco amarillenta, toma del estado general, fiebre vespertina, pérdida de apetito y peso. Según los resultados radiográficos y tomográficos presentó signos sugestivos de tuberculosis pulmonar; los esputos BAAR directos y los cultivos negativos. Los hallazgos anatomopatológicos permitieron confirmar el diagnóstico de fibrosis pulmonar idiopática.

The case report of a 52 years patient is presented, exposed to the ashes of Tungurahua volcano in eruption, who went to the Community Family Medicine Department of the Canton Guano, Ecuadorian province of Riobamba, for presenting productive cough in the morning, mucoid of yellowish white coloration, bad general state, evening fever, appetite and weight loss. According to the radiographic and topographic results, he had suggestive signs of lung tuberculosis; direct BAAR sputa and negative cultures. The pathological findings allowed to confirm the diagnosis of idiopathic lung fibrosis.

Idiopathic pulmonary fibrosis

There has been considerable confusion over the nomenclature of the idiopathic interstitial pneumonias. Some of this confusion has been resolved by the publication of the clinical-radiological-histopathological classification by the American Thoracic and European Respiratory Societies in 2002 Table 1. This classification is by no means the final word on the subject but does provide some order. Of the different and distinct disease entities defined, the most important clinical decision that needs to be made is whether the patient has idiopathic pulmonary fibrosis [IPF]. This diagnosis carries the prediction of a 2-3 year mean survival in marked contrast to the other diseases included in this new classification where survival is better and response to treatment generally more likely. Because the outcome in IPF is so much worse and because this has an obvious impact on the patient's management, it is the need to confirm or refute this diagnosis that drives the diagnostic algorithm in the idiopathic fibrosing lung diseases. The criteria used to define IPF are shown in Table 2 for patients either with or without a surgical lung biopsy