Hipertensão Arterial Pulmonar com Características de Envolvimento Venoso: Um Trabalho Investigativo / Pulmonary Arterial Hypertension with Features of Venous Involvement: A Detective's Task

Resumo A doença veno-oclusiva pulmonar (DVOP) e a hemangiomatose capilar pulmonar são tipos raros de substratos histopatológicos dentro do espectro da hipertensão arterial pulmonar (HAP) com prognóstico muito ruim. Caracterizam-se por um processo fibroproliferativo generalizado das veias e/ou capilares de pequeno calibre com preservação das veias maiores, resultando em um fenótipo de hipertensão pulmonar pré-capilar. A apresentação clínica é inespecífica e semelhante a outras etiologias de HAP. O diagnóstico definitivo é obtido por meio de análise histológica, embora a biópsia pulmonar não seja aconselhada devido ao maior risco de complicações. No entanto, alguns achados adicionais podem permitir um diagnóstico clínico presuntivo de DVOP, especialmente história de tabagismo, uso de drogas quimioterápicas, exposição a solventes orgânicos (particularmente tricloroetileno), baixa capacidade de difusão do monóxido de carbono (DLCO), dessaturação ao esforço e evidências de doença venosa sem doença cardíaca esquerda no exame de imagem, manifestada por uma tríade clássica de opacidades em vidro fosco, linhas septais, e linfadenopatias. O transplante pulmonar é o único tratamento eficaz e os pacientes devem ser encaminhados no momento do diagnóstico, devido à rápida progressão da doença e ao prognóstico ruim. Apresentamos o caso de um homem de 58 anos com HAP com características de envolvimento venoso/capilar em que a suspeita clínica, o pronto diagnóstico e o encaminhamento precoce para transplante pulmonar foram determinantes para um bom desfecho.

Abstract Pulmonary veno-occlusive disease (PVOD) and pulmonary capillary hemangiomatosis are rare types of histopathological substrates within the spectrum of pulmonary arterial hypertension (PAH) with a very poor prognosis. They are characterized by a widespread fibroproliferative process of the small caliber veins and/or capillaries with sparing of the larger veins, resulting in a pre-capillary pulmonary hypertension phenotype. Clinical presentation is unspecific and similar to other PAH etiologies. Definitive diagnosis is obtained through histological analysis, although lung biopsy is not advised due to a higher risk of complications. However, some additional findings may allow a presumptive clinical diagnosis of PVOD, particularly a history of smoking, chemotherapy drug use, exposure to organic solvents (particularly trichloroethylene), low diffusing capacity for carbon monoxide (DLCO), exercise induced desaturation, and evidence of venous congestion without left heart disease on imaging, manifested by a classical triad of ground glass opacities, septal lines, and lymphadenopathies. Lung transplant is the only effective treatment, and patients should be referred at the time of diagnosis due to the rapid progression of the disease and associated poor prognosis. We present a case of a 58-year-old man with PAH with features of venous/capillary involvement in which clinical suspicion, prompt diagnosis, and early referral for lung transplantation were determinant factors for the successful outcome.

Computed tomography and magnetic resonance imaging in Brazil: an epidemiological study on the distribution of equipment and frequency of examinations, with comparisons between the public and private sectors / Tomografia computadorizada e ressonância magnética no Brasil: estudo epidemiológico sobre distribuição dos equipamentos, frequência de realização dos exames e comparação entre setores público e privado

Abstract Objective: To compare information on highly complex radiological procedures—computed tomography (CT) and magnetic resonance imaging (MRI)—between the public and private health care systems, across the five regions of Brazil, in terms of the numbers of radiological devices and examinations performed, between 2015 and 2021. Materials and Methods: This was a descriptive time series analysis of secondary data in the public domain, available from the Information Technology Department of the Brazilian Unified Health Care System, an entity of the Brazilian National Ministry of Health (NMH) that is responsible for collecting and storing health-related information in Brazil. The analysis included the numbers of CT and MRI scanners; the volumes and types of examinations; the type of institution (public or private); the regions of the country; and the years (2015 to 2021). Results: Progressive increases in the numbers of CT and MRI devices, as well as in the volumes of examinations, were observed over the years in all regions of the country. The private sector showed higher rates of equipment acquisition and of growth in the number of examinations. However, the public health care system did not reach the equipment targets set by the NMH, whereas the private health care system surpassed those targets. A greater number of examinations were performed in the private sector than in the public sector. Conclusion: During the period evaluated, the public health care system did not meet the equipment or examination targets recommended by the NMH, in any of the regions of the country, unlike the private health care system, which exceeded both in all of the regions.

Resumo Objetivo: Comparar informações sobre procedimentos radiológicos de alta complexidade - tomografia computadorizada (TC) e ressonância magnética (RM) -, considerando o número de aparelhos e o quantitativo de exames nas esferas pública e privada nas cinco regiões brasileiras entre 2015 e 2021. Materiais e Métodos: Trata-se de um estudo descritivo de série temporal que utilizou dados secundários do Departamento de Informática do Sistema Único de Saúde, órgão do Ministério da Saúde (MS) responsável pela coleta e armazenamento das informações relacionadas à saúde no Brasil. Analisamos os números de aparelhos e de exames de TC e RM, considerando os tipos de aparelhos e exames, instituição (pública ou privada), região brasileira e ano (2015 a 2021). Resultados: Houve aumento de aparelhos e exames de TC e RM em todas as regiões ao longo dos anos. A esfera privada apresentou maior aquisição desses aparelhos e crescimento no número de exames. O sistema público não atingiu o número de aparelhos preconizado pelo MS, enquanto o sistema privado superou a recomendação. Observou-se maior número de exames na esfera privada quando comparada à pública. Conclusão: O sistema público não atendeu aos números de aparelhos e exames realizados preconizados pelo MS, diferentemente da esfera privada, em todas as regiões no período estudado.

Lung cancer screening in Brazil: recommendations from the Brazilian Society of Thoracic Surgery, Brazilian Thoracic Association, and Brazilian College of Radiology and Diagnostic Imaging / Recomendações da Sociedade Brasileira de Cirurgia Torácica, Sociedade Brasileira de Pneumologia e Tisiologia e Colégio Brasileiro de Radiologia e Diagnóstico por Imagem para o rastreamento do câncer de pulmão no Brasil

ABSTRACT Although lung cancer (LC) is one of the most common and lethal tumors, only 15% of patients are diagnosed at an early stage. Smoking is still responsible for more than 85% of cases. Lung cancer screening (LCS) with low-dose CT (LDCT) reduces LC-related mortality by 20%, and that reduction reaches 38% when LCS by LDCT is combined with smoking cessation. In the last decade, a number of countries have adopted population-based LCS as a public health recommendation. Albeit still incipient, discussion on this topic in Brazil is becoming increasingly broad and necessary. With the aim of increasing knowledge and stimulating debate on LCS, the Brazilian Society of Thoracic Surgery, the Brazilian Thoracic Association, and the Brazilian College of Radiology and Diagnostic Imaging convened a panel of experts to prepare recommendations for LCS in Brazil. The recommendations presented here were based on a narrative review of the literature, with an emphasis on large population-based studies, systematic reviews, and the recommendations of international guidelines, and were developed after extensive discussion by the panel of experts. The following topics were reviewed: reasons for screening; general considerations about smoking; epidemiology of LC; eligibility criteria; incidental findings; granulomatous lesions; probabilistic models; minimum requirements for LDCT; volumetric acquisition; risks of screening; minimum structure and role of the multidisciplinary team; practice according to the Lung CT Screening Reporting and Data System; costs versus benefits of screening; and future perspectives for LCS.

RESUMO O câncer de pulmão (CP) é uma das neoplasias mais comuns e letais no Brasil, e apenas 15% dos pacientes são diagnosticados nos estágios iniciais. O tabagismo persiste como o responsável por mais de 85% de todos os casos. O rastreamento do CP (RCP) por meio da TC de baixa dosagem de radiação (TCBD) reduz a mortalidade do CP em 20%, e, quando combinado com a cessação do tabagismo, essa redução chega a 38%. Na última década, diversos países adotaram o RCP como recomendação de saúde populacional. No Brasil, embora ainda incipiente, a discussão sobre o tema é cada vez mais ampla e necessária. Com o intuito de aumentar o conhecimento e estimular o debate sobre o RCP, a Sociedade Brasileira de Cirurgia Torácica, a Sociedade Brasileira de Pneumologia e Tisiologia e o Colégio Brasileiro de Radiologia e Diagnóstico por Imagem constituíram um painel de especialistas para elaborar as recomendações para o RCP. As recomendações aqui apresentadas foram baseadas em revisão narrativa da literatura, com ênfase em grandes estudos populacionais, em revisões sistemáticas e em recomendações de diretrizes internacionais, sendo construídas após ampla discussão pelo grupo de especialistas. Os temas revisados foram os seguintes: porque rastrear, considerações gerais sobre tabagismo, epidemiologia do CP, critérios de elegibilidade, achados incidentais, lesões granulomatosas, modelos probabilísticos, requisitos mínimos da TCBD, aquisições volumétricas, riscos do rastreamento, estrutura mínima e papel da equipe multidisciplinar, conduta segundo o Lung CT Screening Reporting and Data System (Lung-RADS), custos vs. benefícios e perspectivas do rastreamento.

Metodologías de Medición de Volumetría Hepática / Methodologies For Measuring Hepatic Volumetry

Lograr determinar el volumen total de un hígado (VHT), o volumetría hepática, pasa a ser de relevancia en diversas situaciones, tales como, vigilancia del progreso de una enfermedad de carácter crónico, planificación de resecciones y trasplantes hepáticos; y observación del clearance hepático de algunos fármacos hepatotropos. La VHT se puede realizar utilizando métodos de segmentación en el curso de una tomografía computarizada (TC), ya sean estos manual, automáticos, y semiautomáticos; mediante resonancia nuclear (RN), utilizando softwares de distintas generaciones (1ª a 4ª). La medición de VHT está indicada en pacientes sometidos a resecciones hepáticas mayores, en el contexto del tratamiento de neoplasias (carcinoma hepatocelular, colangiocarcinoma, metástasis hepáticas o tumores benignos de gran tamaño), abscesos (piogénicos, amebianos), y después de un traumatismo hepático complejo; así como también en la etapa preoperatoria de un trasplante hepático. El objetivo de este manuscrito fue generar un documento de estudio sobre métodos para determinar volumetría hepática.

SUMMARY: Being able to determine the total hepatic volume (THV), or THV, becomes relevant in various situations, such as monitoring the progress of a chronic disease, planning resections and liver transplants; and observation of the hepatic clearance of some hepatotropic drugs. THV can be performed using segmentation methods in the course of a computed tomography (CT), whether manual, automatic, or semi-automated; by nuclear resonance (NR), using software from different generations (1st to 4st). THV measurement is indicated in patients undergoing major liver resections, in the context of treatment of neoplasms (hepatocellular carcinoma, cholangiocarcinoma, liver metastases or large benign tumors), abscesses (pyogenic, amoebic), and after liver trauma complex, as well as in the preoperative stage of a liver transplant. The aim of this manuscript was to generate a study document regarding methods for determine hepatic volumetry.

Achados tomográficos incidentais de calcificações coronarianas: um estudo de prevalência na região sul do Brasil / Incidental tomographic findings of coronary artery calcifications: a prevalence study in southern Brazil

Fundamento: As calcificações de artérias coronárias (CAC) mostram-se como fator preditivo de doenças cardiovasculares (DCV). A tomografia computadorizada (TC) de tórax com protocolo de aquisição de baixa dose apresenta acurácia na identificação de CAC e propicia achados incidentais dessas calcificações, que são comumente negligenciados. Este estudo analisará a prevalência de achados incidentais de calcificação em artérias coronárias em indivíduos não cardiopatas submetidos à TC de tórax. Métodos: Estudo transversal consecutivo de caráter analítico e descritivo. Foram incluídos indivíduos de ambos os sexos que realizaram TC de tórax por encaminhamento, acima de 18 anos e não cardiopatas. A coleta de dados foi realizada por meio de prontuários e ficha de anamnese auto aplicada. As variáveis referentes às CAC e à extensão do comprometimento foram obtidas a partir da reavaliação das imagens de TC de tórax disponíveis no sistema da instituição. Os exames foram anonimizados e avaliados por dois médicos radiologistas experientes. Considerou-se como estatisticamente significativo p≤0,05. Resultados: Foram analisados 397 exames. Encontrou-se prevalência de calcificações em 176 (44%) dos casos. A existência dessas calcificações coronárias está relacionada à idade (p<0,001). As calcificações possuem relação com o sexo (p = 0,03) com maior razão de chance de desenvolvimento em homens (odds ratio [OR] = 1,55). O tabagismo (p<0,001), o sedentarismo (p<0,001), a hipertensão arterial sistêmica (p<0,001), o diabetes mellitus (p = 0,04) e as dislipidemias (p<0,001) mostraram associação positiva. Conclusão: A prevalência de achados incidentais de CAC foi de 44%; variam em maior número entre leve e grave; maior razão de chance no sexo masculino e aumento da prevalência com a idade. Portanto, a TC de tórax mostra-se um efetivo método para avaliar as CAC, e juntamente com a história clínica do paciente pode ser utilizada para medir os fatores de risco para doenças cardiovasculares e intervir no desfecho do quadro.(AU)

Introduction: Coronary artery calcifications (CAC) are shown to be a predictive factor of cardiovascular diseases. Computed tomography (CT) of the chest with a low-dose acquisition protocol is accurate in identifying CAC and provides incidental findings of these calcifications, which are commonly overlooked. This study will analyze the prevalence of incidental findings of calcification in coronary arteries in non-cardiac individuals undergoing chest CT. Methods: Consecutive cross-sectional study of an analytical and descriptive nature. Individuals of both genders who underwent chest CT by referral, over 18 years of age and without heart disease were included. Data collection was carried out using medical records and a self-applied anamnesis form. The variables referring to the CAC and the extension of the impairment were obtained from the reassessment of the chest CT images available in the institution's system. The exams were anonymized and evaluated by two experienced radiologists. P≤0.05 was considered statistically significant. Results: 397 exams were analyzed. A prevalence of calcifications was found in 176 (44%) of the cases. The existence of these coronary calcifications is related to age (p<0.001). Calcifications are related to gender (p = 0.03) with a higher odds ratio of development in men (odds ratio [OR] = 1.55). Smoking (p<0.001), sedentary lifestyle (p<0.001), systemic arterial hypertension (p<0.001), Diabetes Mellitus (p = 0.04), and dyslipidemia (p<0.001) showed a positive association. Conclusion: The prevalence of incidental CAC findings was 44%; vary in greater numbers between mild and severe; higher odds ratio in males and increased prevalence with age. Therefore, chest CT proves to be an effective method to assess CAC, and together with the patient's clinical history, it can be used to measure risk factors for CVD and intervene in the outcome of the condition.(AU)

Asociación entre calidad del tratamiento endodóntico y periodontitis apical, evaluada mediante Tomografía Computarizada de Haz Cónico en una población colombiana / Association between endodontic treatment quality and apical periodontitis assessed through cone beam computarized tomography in a colombian population / Associação entre qualidade do tratamento endodôntico e periodontite apical, avaliada por tomografia computadorizada de feixe cônico em uma população colombiana

Introducción: La prevalencia de periodontitis apical en dientes con tratamiento endodóntico oscila entre el 35 y el 60%, se ha encontrado una fuerte asociación con respecto al grado de inflamación sistémica generada por la periodontitis apical, como por ejemplo altos niveles de citoquinas proinflamatorias, proteína C reactiva e interleuquina 6; estudios refieren que un tratamiento endodóntico adecuado puede reducir los niveles de proteína C reactiva en individuos sanos y con periodontitis apical. Objetivo: Evaluar la frecuencia de periodontitis apical en una población adulta colombiana seleccionada y su correlación con la calidad del tratamiento endodóntico. Materiales y métodos: Estudio observacional analítico de corte transversal, se determinó la frecuencia de periodontitis apical en 318 CBCT (Tomografía Computarizada de Haz Cónico), de pacientes de una subpoblación de Bucaramanga y Medellín y evaluó la asociación de la calidad del tratamiento endodóntico con el estado periapical. Resultados: Sólo el 37,66% de los dientes evaluados fueron considerados sanos; el 44,81% se clasificaron como tratamiento endodóntico adecuado. La calidad del tratamiento endodóntico influyó significativamente en la condición del periodonto apical. Conclusiones: Los tratamientos evaluados presentaron alta frecuencia de periodontitis apical, la cual se asoció en buena parte a la alta frecuencia de tratamientos endodónticos inadecuados.

Introduction: The prevalence of apical periodontitis in teeth with endodontic treatment ranges between 35% and 60%, and a strong association has been found with respect to high levels of systemic inflammation markers (pro-inflammatory cytokines, protein C-reactive and interleukin 6) caused by apical periodontitis. Studies have shown that an adequate endodontic treatment can reduce C-reactive protein levels in healthy individuals and those with apical periodontitis. Objective: To evaluate the frequency of apical periodontitis in a selected Colombian adult population and its correlation with the quality of endodontic treatment. Materials and methods: Observational, analytical, cross-sectional study. The frequency of apical periodontitis was determined in 318 CBCTs of patients from Bucaramanga and Medellin, and the association between quality of endodontic treatment and periapical status was analyzed. Results: Only 37.66% of the observed teeth were considered healthy, whereas 44.81% were classified as teeth with appropriate endodontic treatment. Quality of endodontic treatment significantly affected the condition of the apical periodontium. Conclusions: The analyzed treatments had a high apical periodontitis frequency, which was associated with a high frequency of inadequate endodontic treatments.

Introdução: A prevalência de periodontite apical em dentes com tratamento endodôntico varia entre 35 e 60 %, uma forte associação foi encontrada com relação ao grau de inflamação sistêmica gerada pela periodontite apical, como altos níveis de citocinas pró-inflamatórias, proteína C reativa e interleucina 6; estudos relatam que o tratamento endodôntico adequado pode reduzir os níveis de proteína C-reativa em indivíduos saudáveis ​​e naqueles com periodontite apical. Objetivo: Avaliar a frequência da periodontite apical em uma população adulta colombiana selecionada e sua correlação com a qualidade do tratamento endodôntico. Materiais e métodos: Estudo transversal analítico observacional; a frequência de periodontite apical foi determinada em 318 CBCT de pacientes de uma subpopulação de Bucaramanga e Medellín, foi avaliada a associação da qualidade do tratamento endodôntico com o estado periapical. Resultados: Apenas 37,66% dos dentes avaliados foram considerados saudáveis, 44,81% dos dentes foram classificados como tratamento endodôntico adequado. A qualidade do tratamento endodôntico influenciou significativamente a condição do periodonto apical. Conclusões: Os tratamentos avaliados apresentaram alta frequência de periodontite apical, que foi amplamente associada à alta frequência de tratamentos endodônticos inadequados.

Crohn's disease: review and standardization of nomenclature / Doença de Crohn: revisão e padronização da nomenclatura

Abstract Crohn's disease is an inflammatory bowel disease that can affect any segment of the gastrointestinal tract. It has a variable clinical course, with alternating periods of disease activity and remission. Because the incidence and prevalence of Crohn's disease have been increasing, evaluation by imaging methods has become more important. The most widely used methods are computed tomography enterography, magnetic resonance enterography (as an elective examination), and contrast-enhanced computed tomography (in the context of emergency). Computed tomography enterography and magnetic resonance enterography are useful for diagnosis, follow-up, evaluation of complications, and prognosis. Both can be used in order to evaluate the small bowel loops and the associated mesenteric findings, as well as to evaluate other abdominal organs. They both also can detect signs of disease activity, fibrosis, penetrating disease, and complications. The interpretation of such changes is essential to the multidisciplinary approach, as is the standardization of the nomenclature employed in the reports. In this paper, we review and illustrate the imaging findings of Crohn's disease, using the standardized nomenclature proposed in the multidisciplinary consensus statement issued by the Society of Abdominal Radiology, the Society of Pediatric Radiology, and the American Gastroenterology Association, with recommendations for descriptions, interpretations, and impressions related to those findings.

Resumo Doença de Crohn é uma doença inflamatória intestinal que pode acometer qualquer segmento do trato gastrointestinal, com curso clínico variado, alternando períodos de atividade de doença e remissão. Sua incidência e prevalência vêm aumentando, tornando a avaliação por métodos de imagem mais importante. Os métodos mais utilizados são enterotomografia computadorizada, enterorressonância magnética eletivamente e tomografia computadorizada com contraste no contexto da emergência. A enterotomografia computadorizada e a enterorressonância magnética são úteis para diagnóstico, seguimento, avaliação de complicações e para prognóstico. Avaliam as alças intestinais delgadas e os achados mesentéricos associados, além dos demais órgãos abdominais. Detectam sinais de atividade de doença, sinais de cronicidade e doença penetrante e complicações, importantes para a escolha do melhor tratamento. A interpretação dessas alterações é fundamental para que a equipe multidisciplinar trabalhe conjuntamente com compreensão da linguagem utilizada nos relatórios. Neste artigo, apresentamos uma revisão dos achados de imagem da doença de Crohn e ilustramos os possíveis achados dessa doença utilizando a nomenclatura padronizada proposta no consenso multidisciplinar composto pelas Sociedade de Radiologia Abdominal, Sociedade de Radiologia Pediátrica e a Associação Americana de Gastroenterologia, com recomendações de descrição, interpretação dos achados e recomendações de impressão.

Histogram analysis in the differentiation between adrenal adenomas and pheochromocytomas: the value of a single measurement / Análise por histograma para diferenciação entre adenomas da adrenal e feocromocitomas: o valor de uma medida única

Abstract Objective: To assess the diagnostic accuracy of histogram analysis on unenhanced computed tomography (CT) for differentiating between adrenal adenomas and pheochromocytomas (PCCs). Materials and Methods: We retrospectively identified patients with proven PCCs who had undergone CT examinations between January 2009 and July 2019 at one of two institutions. For each PCC, we selected one or two adenomas diagnosed within two weeks of the date of diagnosis of the PCC. For each lesion, two readers scored the size, determined the mean attenuation, and generated a voxel histogram. The 10th percentile (P10) was obtained from the conventional histogram analysis, as well as being calculated with the following formula: P10 = mean attenuation - (1.282 × standard deviation). The mean attenuation threshold, histogram analysis (observed) P10, and calculated P10 (calcP10) were compared in terms of their diagnostic accuracy. Results: We included 52 adenomas and 29 PCCs. The sensitivity, specificity, and accuracy of the mean attenuation threshold were 75.0%, 100.0%, and 82.5%, respectively, for reader 1, whereas they were 71.5%, 100.0%, and 81.5%, respectively, for reader 2. The sensitivity, specificity, and accuracy of the observed P10 and calcP10 were equal for both readers: 90.4%, 96.5%, and 92.6%, respectively, for reader 1; and 92.3%, 93.1%, and 92.6%, respectively, for reader 2. The increase in sensitivity was significant for both readers (p = 0.009 and p = 0.005, respectively). Conclusion: For differentiating between adenomas and PCCs, the histogram analysis (observed P10 and calcP10) appears to outperform the mean attenuation threshold as a diagnostic criterion.

Resumo Objetivo: Avaliar a acurácia diagnóstica da análise por histograma na tomografia computadorizada (TC) sem contraste para a diferenciação entre adenomas adrenais e feocromocitomas (FCCs). Materiais e Métodos: Identificamos, retrospectivamente, pacientes com diagnóstico de FCC confirmado que foram submetidos a exames de TC entre janeiro de 2009 e julho de 2019 em duas instituições distintas. Para cada FCC, selecionamos um ou dois adenomas diagnosticados em até duas semanas da data do diagnóstico do FCC. Para cada lesão, dois leitores pontuaram o tamanho, determinaram a atenuação média e geraram um histograma com os voxels das imagens. O percentil 10 (P10) foi obtido a partir da análise convencional do histograma, além de ser calculado com a seguinte fórmula: P10 = atenuação média - (1,282 × desvio-padrão). O limiar de atenuação média, o P10 da análise por histograma (P10 observado) e o P10 calculado (P10calc) foram comparados em termos de acurácia diagnóstica. Resultados: Foram incluídos 52 adenomas e 29 FCCs. A sensibilidade, especificidade e acurácia do limiar de atenuação média foram de 75,0%, 100,0% e 82,5% para o leitor 1, respectivamente, e de 71,5%, 100,0% e 81,5% para o leitor 2, respectivamente. A sensibilidade, especificidade e acurácia do P10 observado e do P10calc foram idênticas para os dois leitores: 90,4%, 96,5% e 92,6%, respectivamente, para o leitor 1; e 92,3%, 93,1% e 92,6%, respectivamente, para o leitor 2. O aumento da sensibilidade foi significativo para ambos os leitores (p = 0,009 e p = 0,005, respectivamente). Conclusão: Para a diferenciação entre adenomas e FCCs, a análise por histograma (P10 observado ou P10calc) parece superar o limiar de atenuação média como critério diagnóstico.

Tumor miofibroblastico inflamatorio que causa obstrucción intestinal en adulto mayor por intususcepción intestinal: Reporte de caso

La intususcepción intestinal en pacientes adultos es una entidad infrecuente, la cual corresponde alrededor del 5% de todas las causas de obstrucción intestinal. Su diagnóstico no es fácil, dado lo poco especifico de los síntomas de los pacientes que la presentan; este se sustenta principalmente en los hallazgos de los estudios de imagen. El manejo quirúrgico es la piedra angular del tratamiento de esta patología, y su éxito va a estar determinado por el diagnóstico oportuno y la experticia del cirujano tratante. En este artículo se presenta el caso de un paciente masculino de 62 años, que consulta por cuadro de dolor abdominal inespecífico y síntomas urinarios irritativos, el cual por persistencia del dolor abdominal pese al manejo medico es llevado a cirugía, donde se diagnostica de manera intraoperatoria una invaginación intestinal a nivel de íleon distal.

Intestinal intussusception in adult patients is a rare entity, which corresponds to about 5% of all causes of intestinal obstruction, its diagnosis is not easy given the lack of specific symptoms of patients who present it. This is mainly based on the findings of imaging studies, surgical management is the cornerstone of treatment of this pathology and its success will be determined by timely diagnosis as well as by the expertise of the treating surgeon. This article presents the case of a 62-year-old male patient who consults due to nonspecific abdominal pain and irritative urinary symptoms, who due to persistence of abdominal pain despite medical management is taken to surgery where it is diagnosed intraoperatively. an intestinal intussusception at the level of the distal ileum.

Characteristics of digestive system symptoms and abdominal computed tomography imaging of patients infected with severe acute respiratory syndrome coronavirus 2 Omicron variant / 中华消化杂志

Objective:To investigate the characteristics of digestive system symptoms and its relation with the time of nucleic acid continuous positive in population infected with severe acute respiratory syndrome coronavirus 2 Omicron variant, and to analyze the abdominal computed tomography (CT) features of patients infected with Omicron variant.Methods:From April 11 to May 23, 2022, a questionnaire survey was conducted in patients infected with Omicron variant admitted to the Shanghai National Convention and Exhibition Center Fangcang Hospital. The questionnaire included basic information, the start time of nucleic acid positive, respiratory symptoms, digestive system syptoms and outcomes, etc.Combined with the clinical data, the relation between digestive tract symptoms and the time of nucleic acid continuous positive were analyzed. Thoracic and abdominal CT were performed for patients with continuous positive nucleic acid results ≥10 d, and the relationship between the abdominal CT imaging characteristics and the time of nucleic acid continuous positive was analyzed. Independent sample t-test and multivariate logistic regression were used for statistical analysis. Results:A total of 4 360 valid questionnaires were collected, including 2 475 males and 1 885 females, with a hospital stay of (6.8±4.9) d. Among the 4 360 patients, 1 979 patients (45.4%) had gastrointestinal symptoms such as loss of appetite, abdominal discomfort or pain, constipation and diarrhea. The time of nucleic acid continuous positive in patients with gastrointestinal symptoms was (7.4±5.5) d, which was longer than that of patients without gastrointestinal symptoms (6.5±3.6) d, and the difference was statistically significant ( t=3.78, P<0.001). During the isolation period in the Fangcang Hospital, the time of nucleic acid continuous positive in patients with complete remission of digestive tract symptoms was shorter than that of patients with no remission of digestive tract symptoms ((7.3±5.2) d vs. (8.5±5.7) d), and the difference was statistically significant ( t=2.25, P=0.025). The results of multivariate logistic regression analysis showed that the combination of gastrointestinal symptoms was an independent risk factor for continuous positive nucleic acid result ≥10 d ( OR=1.316, 95% confidence interval 1.294 to 2.205, P=0.046). Among the 299 patients with continuous positive nucleic acid results≥10 d, 187 cases (62.5%) had gastrointestinal symptoms, and 146 cases (48.8%) had abdominal CT findings of thickening of the gastroduodenal wall, thickening of the small intestinal wall, indistinct mesenteric vessels of the small intestine, and dilatation and pneumatosis of the colon. In patients with continuous positive nucleic acid results ≥10 d, abdominal CT indicated that patients with gastrointestinal imaging changes had a longer time of nucleic acid continuous positive than those without gastrointestinal imaging changes ((16.0±2.8) d vs. (13.0±2.1) d), and the difference was statistically significant ( t=2.62, P=0.009). Conclusions:Digestive system symptoms are common in patients infected with Omicron variant. The time of nucleic acid continuous positive in patients with gastrointestinal symptoms is longer than those without gastrointestinal symptoms. Some patients may have gastrointestinal lesions on abdominal CT.

Optimizing imaging of inferior vena cava by application of spectral CT single energy combined with ASIR-V / 中华全科医师杂志

Objective:To explore the application of energy spectrum CT single energy combined with adaptive statistical iterative reconstruction-Veo (ASIR-V) for optimizing inferior vena cava imaging.Methods:Thirty patients with negative diagnosis or minimal inferior vena cava lesions who underwent CT venography (CTV) of inferior vena cava in the Second Hospital of Harbin Medical University from August 2021 to April 2022 were enrolled in the study, including 11 males and 19 females with the age of (55.4±8.8) years and the body mass index of (23.2±2.8) kg/m2. The mixed energy group images and 5 single energy groups of 50, 55, 60, 65 and 70 keV images were reconstructed from the images in the inferior vena cava phase. The subcutaneous fat noise, CT values, signal to noise ratio (SNR) and contrast to noise ratio (CNR) for each segment of the inferior vena cava in 5 sets of single-energy images were measured and evaluated subjectively to determine the best single energy level. The images were reconstructed by combining different weight ASIR-V (20%, 30%, 40%, 50%, 60%, 70% and 80%) algorithms, and images from different weight groups and mixed energy groups were evaluated objectively to determine the best ASIR-V weights which was matched with the best single energy level. All images were scored subjectively by 2 senior radiologists based on image noise, uniformity of vessel filling, sharpness of vessel margins and diagnostic confidence.Results:There were significant differences in subcutaneous fat noise and objective evaluation indexes of each segment of inferior vena cava among the monoenergetic groups (all P<0.05), each objective evaluation index increased with the decrease of energy level, the maximum value was obtained in the 50 keV group. The subjective scores of the 5 groups were consistent by the 2 radiologists(all κ≥0.75). The highest subjective scores were obtained in the 60 keV group, the best single energy level is 60 keV in a comprehensive analysis. The differences in objective evaluation indicators among the 7 groups of best single energy combined with different weights ASIR-V image group and the mixed energy group were all statistically significant (all P<0.01). Image noise decreased with increasing ASIR-V weights for different weight groups, all differences among groups were statistically significant (all P<0.01), and the minimum noise was minimal in 80% weight group. There was no significant change in CT value of each segment of inferior vena cava (all P>0.05). The SNR and CNR of each segment of inferior vena cava increased, all differences among groups were statistically significant (all P<0.01), and the SNR and CNR of 80% weight group was the highest. The subjective scores of the 8 groups were consistent evaluated by the 2 radiologists (all κ≥0.75), and the subjective score of 60% weight group was the highest, 60% was the best ASIR-V weight for matching 60 keV in a comprehensive analysis. Conclusions:The study indicates that the best energy level for optimizing energy spectrum CT single energy imaging of the inferior vena cava is 60 keV, on the basis of which the best weighting for combined ASIR-V is 60%.

CT-guided diagnosis of banded vs membranaceous adhesive small bowel obstruction / 中华普通外科杂志

Objectives:To study the computed tomography features of banded adhesions(BA) and matted adhesions(MA) of adhesive small bowel obstruction(ASBO).Methods:We enrolled 150 patients operated on for ASBO. According to intraoperated findings, ASBO were classified into those caused by BA or MA. A multivariable logistic regression was established to analyze independent risk factors on Computed Tomography features.Results:There were significant differences in closed-loop sign (36.8% vs. 14.3%, P=0.002) mesenteric haziness (43.7% vs. 17.5%, P=0.001), beak sign (48.3% vs. 17.5%, P<0.001), fat notch sign (39.1% vs. 9.5%, P<0.001) and peritoneal fluid (54.0% vs. 34.9%, P=0.015) between the two groups. The presence of beak sign [ OR=6.15, 95% CI (2.55-14.84), P<0.001], fat notch sign [ OR=6.19, 95% CI (2.16-17.82), P=0.001] and mesenteric haziness [ OR=3.34, 95% CI (1.34-8.32), P=0.009] were independent risk factors with BA. Conclusion:Beak sign, fat notch sign and mesenteric haziness were independent risk factors for diagnosing BA.

The value of enhanced CT combined with serum CYFER21-1 and NSE in the diagnosis of lymph node metastasis in patients with NSCLC / 中国医师杂志

Objective:To investigate the value of preoperative enhanced CT combined with serum cytokeratin fragment 19 (CYFER21-1) and neuron-specific enolase (NSE) in the diagnosis of lymph node metastasis in patients with non-small cell lung cancer (NSCLC).Methods:160 patients with NSCLC admitted to Linyi Cancer Hospital from October 2018 to October 2021 were retrospectively selected. All patients received surgical treatment in our hospital, and 84 patients with lymph node metastasis (metastatic group) and 76 patients without lymph node metastasis (non-metastatic group) were confirmed after surgery. The features of enhanced CT images and serum CYFER21-1 and NSE levels were compared between the two groups before operation, and the value of each index in the diagnosis of lymph node metastasis in patients with NSCLC alone and in combination was analyzed by receiver operating characteristic (ROC) curve.Results:The proportions of patients with lesion diameter ≥3.0 cm, pleural depression, lymph node enlargement shown by CT, lymph node short diameter ≥10 mm, lymph node boundary ambiguity and lymph node enhancement in metastatic group were significantly higher than those in non-metastatic group, with statistical significance (all P<0.05). Serum CYFER21-1 and NSE levels in metastatic group were significantly higher than those in non-metastatic group, with statistical significance (all P<0.05). The area under curve (AUC) of CYFER21-1 and NSE levels in the diagnosis of lymph node metastasis in NSCLC patients were 0.652 and 0.845, respectively, and the diagnostic cut-off values were 4.81 ng/ml and 24.14 ng/ml, respectively. The sensitivity and specificity of CYFER21-1+ NSE+ enhanced CT in the diagnosis of lymph node metastasis in NSCLC patients were 91.67% and 94.74%. Conclusions:Preoperative enhanced CT is of certain clinical value in the diagnosis of lymph node metastasis in NSCLC patients. Combined with serum CYFER21-1 and NSE levels, enhanced CT can further improve the sensitivity and specificity of diagnosis.

Clinical and imaging features of adult influenza B viral pneumonia / 中国医师杂志

Objective:To analyze the clinical and imaging characteristics of adult patients with influenza B viral pneumonia and improve the understanding of influenza B viral pneumonia in clinicians.Methods:The clinical data of adult patients with influenza B virus pneumonia were collected from January 2021 to December 2022 in the fever clinic of Beijing Hospital of Traditional Chinese Medicine affiliated to Capital Medical University. The clinical symptoms, blood routine results and lung computed tomography (CT) results were analyzed and summarized.Results:The clinical data of 24 adult patients with influenza B virus pneumonia were collected. The time from onset to treatment was (2.7±0.3)d. All patients had fever, and 14 of them had body temperature >39 ℃. Blood routine and procalcitonin levels were normal, while C-reactive protein levels were elevated [(56.28±32.35)mg/L]. Oxygen saturation was normal (≥95%). The pulmonary CT findings were mostly small flake ground glass shadows distributed on one side, and some of them were cord shadows caused by interstitial lesions.Conclusions:Influenza B virus infection can also cause pneumonia, but is relatively limited and has a good prognosis.

Application value of CT plain scan and dynamic enhanced scan in the diagnosis of solitary pulmonary nodules / 中国医师杂志

Objective:To explore the application value of computed tomography (CT) plain scan and dynamic enhanced scan in the diagnosis of solitary pulmonary nodules.Methods:The clinical data of 120 patients with solitary pulmonary nodules detected by physical examination in Baoding First Central Hospital from January 2018 to December 2020 were retrospectively reviewed. All patients were confirmed by surgery and pathology, including 77 benign lesions and 43 malignant lesions; All patients underwent CT plain scan and dynamic enhanced scan before operation. The accuracy of the two examination methods in the diagnosis of benign and malignant lesions of solitary pulmonary nodules was analyzed and compared. The detection rate of CT dynamic enhanced scan imaging characteristics (vacuole sign, ground glass sign, spinous sign, lobulation sign, hair prick sign, blood vessel cluster, pleural depression) of benign and malignant lesions of solitary pulmonary nodules was compared, and the diagnostic value of CT plain scan and dynamic enhanced scan in the differential diagnosis of benign and malignant solitary pulmonary nodules was evaluated based on the results of surgical pathological diagnosis. The manifestations and characteristic curves of CT dynamic enhanced scan of solitary pulmonary nodules was analyzed.Results:The diagnostic accuracy of CT dynamic enhanced scan for solitary pulmonary nodules was 80.00% (96/120), which was higher than that of CT plain scan (63.33%) (76/120) ( P<0.05). The sensitivity, specificity, and negative predictive value of CT dynamic enhanced scan for the diagnosis of benign and malignant lesions of solitary pulmonary nodules were higher than those of CT plain scan (all P<0.05). Among the imaging characteristics of CT dynamic enhanced scans of malignant lesions, the ground glass sign, spinous process sign, lobulation sign, spiculation sign, vascular clustering and pleural indentation were detected more frequently than those of benign lesions (all P<0.05). Benign lesions usually showed homogeneous enhancement, and a few showed heterogeneous enhancement; Malignant nodules often showed uneven enhancement, and a few had even enhancement. The time density curves of dynamic enhanced CT values in the regions of interest of benign and malignant solitary pulmonary nodules were different. Conclusions:The value of dynamic enhanced CT scan in the differential diagnosis of benign and malignant lesions of solitary pulmonary nodules is higher than that of CT plain scan, and the imaging features are obvious, with higher sensitivity and specificity, which is worthy of application.

Efficacy of radiofrequency ablation combined with ozone therapy under CT guidance in the treatment of lumbar disc herniation / 中国基层医药

Objective:To investigate the efficacy of radiofrequency ablation combined with ozone therapy under CT guidance in the treatment of lumbar disc herniation.Methods:A total of 93 patients with lumbar disc herniation who were admitted to The First Hospital of Jiaxing from January 2019 to May 2022 were included in this study. They were randomly divided into an observation group ( n = 47) and a control group ( n = 46). The control group was treated with radiofrequency ablation and the observation group was treated with radiofrequency ablation combined with ozone therapy. Efficacy was compared between the two groups at 3 months after surgery. The pain was compared between the two groups before and 7 days and 3 months after surgery. Inflammatory factors were compared between the two groups before and 7 days after surgery. The lumbar spine function was compared between the two groups before and 3 months after surgery. Results:At 3 months after surgery, the excellent and good rate in the observation group was significantly higher than that in the control group [89.36% (42/47) vs. 71.74% (33/47), χ2 = 4.63, P < 0.05). At 7 days and 3 months after surgery, Visual Analogue Scale scores in the observation group were (2.91 ± 0.54) points and (1.32 ± 0.31) points, respectively, which were significantly lower than (3.76 ± 0.62) points and (2.08 ± 0.47) points in the control group ( t = 7.06, 9.22, both P < 0.001). At 7 days after surgery, serum interleukin-1β, interleukin-6, and tumor necrosis factor-α in the observation group were (0.24 ± 0.05) μg/L, (18.49 ± 3.47) ng/L, and (97.94 ± 17.43) ng/L, respectively, which were significantly lower than (0.37 ± 0.09) μg/L, (24.31 ± 4.12) ng/L, and (148.87 ± 20.13) ng/L, respectively in the control group ( t = 8.63, 7.37, 13.05, all P < 0.05). At 3 months after surgery, the Japanese Orthopedic Association score in the observation group was significantly higher than that in the control group [(25.68 ± 2.28) points vs. (21.17 ± 3.24) points, t = -7.78, P < 0.001], and the Oswestry Disability Index in the observation group was significantly lower than that in the control group [(9.84 ± 1.43) points vs. (13.46 ± 2.18) points, t = 9.49, P < 0.001]. Conclusion:Radiofrequency ablation combined with ozone therapy under CT guidance is highly effective on lumbar disc herniation. The combined therapy can reduce pain and inflammatory reactions in patients and improve lumbar function.

Renal oncocytoma misdiagnosed as renal cell carcinoma: report of two cases and literature review / 中国基层医药

Objective:To investigate the clinical, imaging, and pathological characteristics of renal oncocytoma, and to improve the understanding, diagnosis, and treatment of renal oncocytoma.Methods:The imaging and pathological data of two patients misdiagnosed with renal cell carcinoma in the 970 Hospital of PLA Joint Logistics Support Force from January to March 2021 were retrospectively analyzed. The relevant literature was reviewed and discussed.Results:The tumors were located in the left kidney of two patients, with diameters of 2.7 cm and 3.2 cm respectively. The patients underwent retroperitoneal laparoscopic removal of partial left kidney and retroperitoneal laparoscopic removal of the whole left kidney separately. The pathological results confirmed the diagnosis of renal oncocytoma.Conclusion:Renal oncocytoma is a rare benign renal cell tumor which is difficult to be diagnosed before surgery. Contrast-enhanced CT can provide evidence for the identification of renal oncocytoma. Its final diagnosis depends on pathological results.

Differentiating pancreatic adenosquamous carcinoma from pancreatic ductal adenocarcinoma by CT radiomic and deep learning features / 中华胰腺病杂志

Objective:To develop and validate the models based on mixed enhanced computed tomography (CT) radiomics and deep learning features, and evaluate the efficacy for differentiating pancreatic adenosquamous carcinoma (PASC) from pancreatic ductal adenocarcinoma (PDAC) before surgery.Methods:The clinical data of 201 patients with surgically resected and histopathologically confirmed PASC (PASC group) and 332 patients with surgically resected histopathologically confirmed PDAC (PDAC group) who underwent enhanced CT within 1 month before surgery in the First Affiliated Hospital of Naval Medical University from January 2011 to December 2020 were retrospectively collected. The patients were chronologically divided into a training set (treated between January 2011 and January 2018, 156 patients with PASC and 241 patients with PDAC) and a validation set (treated between February 2018 and December 2020, 45 patients with PASC and 91 patients with PDAC) according to the international consensus on the predictive model. The nnU-Net model was used for pancreatic tumor automatic segmentation, the clinical and CT images were evaluated, and radiomics features and deep learning features during portal vein phase were extracted; then the features were dimensionally reduced and screened. Binary logistic analysis was performed to develop the clinical, radiomics and deep learning models in the training set. The models' performances were determined by area under the ROC curve (AUC), sensitivity, specificity, accuracy, and decision curve analysis (DCA).Results:Significant differences were observed in tumor size, ring-enhancement, upstream pancreatic parenchymal atrophy and cystic degeneration of tumor both in PASC and PDAC group in the training and validation set (all P value <0.05). The multivariable logistic regression analysis showed the tumor size, ring-enhancement, dilation of the common bile duct and upstream pancreatic parenchymal atrophy were associated with PASC significantly in the clinical model. The ring-enhancement, dilation of the common bile duct, upstream pancreatic parenchymal atrophy and radiomics score were associated with PASC significantly in the radiomics model. The ring-enhancement, upstream pancreatic parenchymal atrophy and deep learning score were associated with PASC significantly in the deep learning model. The diagnostic efficacy of the deep learning model was highest, and the AUC, sensitivity, specificity, and accuracy of the deep learning model was 0.86 (95% CI 0.82-0.90), 75.00%, 84.23%, and 80.60% and those of clinical and radiomics models were 0.81 (95% CI 0.76-0.85), 62.18%, 85.89%, 76.57% and 0.84 (95% CI 0.80-0.88), 73.08%, 82.16%, 78.59% in the training set. In the validation set, the area AUC, sensitivity, specificity, and accuracy of deep learning model were 0.78 (95% CI 0.67-0.84), 68.89%, 78.02% and 75.00%, those of clinical and radiomics were 0.72 (95% CI 0.63-0.81), 77.78%, 59.34%, 65.44% and 0.75 (95% CI 0.66-0.84), 86.67%, 56.04%, 66.18%. The DCA in the training and validation sets showed that if the threshold probabilities were >0.05 and >0.1, respectively, using the deep learning model to distinguish PASC from PDAC was more beneficial for the patients than the treat-all-patients as having PDAC scheme or the treat-all-patients as having PASC scheme. Conclusions:The deep learning model based on CT automatic image segmentation of pancreatic neoplasm could effectively differentiate PASC from PDAC, and provide a new non-invasive method for confirming PASC before surgery.

Application value of CT and MRI radiomics based on machine-learning method in diagnosing pancreatic cancer / 中华胰腺病杂志

Objective:To investigate the application value of CT and MRI imageomics based on machine learning method in the diagnosis of pancreatic cancer.Methods:The clinical data of 62 patients with surgically resected and pathologically confirmed pancreatic cancer, who underwent enhanced CT scan, MRI plain or enhanced scan in Shanghai General Hospital between January 2014 and December 2021 were collected. According to the chronological order of surgery, 49 patients from January 2014 to December 2020 were enrolled in the training set and 13 patients from January 2021 to December 2021 were enrolled in the validation set. 3D-slicer 4.8.1 software was used to draw the region of interest in each layer of CT and MRI images for cancerous and paracancerous tissue segment. Image features were extracted by Python and the optimal feature set from the training set data was obtained by using Lasso regression model. The machine learning decision tree model was constructed. The receiver operating characteristic curve(ROC) curve was drawn, and the area under the curve (AUC) was calculated to evaluate the value of these three kinds of imageomics models in the diagnosis of pancreatic cancer.Results:The 1 767 CT features and 1 674 MRI features were obtained from enhanced CT scan, MRI plain scan and enhanced MRI scan, respectively. For the differential diagnosis model of cancerous tissue and paracancerous tissue, the enhanced CT scan data model obtained the optimal feature set involving 6 features, the MRI plain scan model obtained the optimal feature set involving 16 features, and the enhanced MRI scan model obtained the optimal feature set involving 15 features. The diagnostic model based on enhanced CT scan had an AUC of 0.98 in the training set and 1 in the verification group. The AUC of the MRI plain scan and enhanced MRI scan models in both the training set and the validation set was 1. The specificity and sensitivity of machine learning decision tree model based on the three kinds of imageomics models in the diagnosis of cancerous tissue and paracancerous tissue were 100%. For the differential diagnosis model of splenic artery wrapping, the enhanced CT scan model didn′t obtain the optimal features and had no diagnostic efficacy. The MRI plain scan model and enhanced MRI scan model obtained the optimal feature set involving 5 and 4 features, respectively. The AUC of the MRI plain scan model in the training set and the validation set were 0.862 and 0.750, respectively, with diagnostic sensitivity of 93.8% and 50.0%, and specificity of 78.6% and 100%, respectively. The AUC of the enhanced MRI scan model in the training set and the validation set were 0.950 and 0.861, respectively, with diagnostic sensitivity of 90.0% and 93.6%, and specificity of 100% and 78.6%, respectively.Conclusions:Based on the radiomics of CT enhanced, MRI plain scan and enhanced MRI scan, the machine learning diagnostic model has an accuracy of more than 90% in differentiating pancreatic cancer from paracancerous tissue. For the differentiation of splenic artery wrapping in pancreatic cancer, the diagnostic model based on enhanced MRI scan haS the best diagnostic efficiency.

Detection rate of pulmonary nodules by CT scan at different doses and application value of artificial intelligence assistance / 中国医师进修杂志

Objective:To investigate the detection rate of pulmonary nodules (PN) by CT scan at different doses and the application value of artificial intelligence(AI) system assistance.Methods:From October 2019 to October 2021, 210 patients with PN in Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, were retrospectively selected, and they were divided into the study group (106 cases) and the control group (104 cases) by CT scan at different doses. The control group used the conventional average dose (169 mAs) CT scan, the study group used an average low-dose (54 mAs) CT scan. The PN detection rate of different gender, age, body mass index (BMI) between the two groups were compared. The morphological characteristics, radiation dose, CT image quality between the two groups were compared. The diagnostic efficiency of radiologists and AI system was compared.Results:The detection rate of PN in the study group and the control group had no significant difference: 73.58% (78/106) vs. 80.77%(84/104), χ2 = 1.54, P>0.05. The detection rate of PN with different gender, age group and BMI in the two groups had no significant differences ( P>0.05). The diameter of nodules and the rates of calcification, cavitation, bronchial sign, lobar sign, burr sign and pleural adhesion sign in the two groups had no significant differences ( P>0.05). The mean effective tubular bulb dose, length product of radiation dose, total tubular bulb dose, radiation volume dose index in the study group were higher than those in the control group: (46.15 ± 7.38) mAs vs. (104.39 ± 10.53) mAs, (169.24 ± 19.77) mGy·cm vs. (427.17 ± 43.58) mGy·cm, (972.65 ± 58.34) mAs vs. (2 861.26 ± 181.37) mAs, (3.55 ± 1.16) mGy vs. (8.95 ± 2.07) mGy, there were statistical differences ( P<0.05). The excellent, good, acceptable, poor of 1.0 mm image quality in the study group were 26, 60, 18, 2, and in the control group were 32, 64, 8, 0, there was statistical difference ( u =1.71, P = 0.087). The excellent, good, acceptable, poor of maximum intensity projection (MIP) image quality in the study group were 58, 42, 6, 0 and in the control group were 70, 34, 0, 0, there was statistical difference ( u = 1.81, P = 0.070). The detection rate of PN by AI low-dose CT scan was higher than that of radiologists: 88.68%(94/106) vs. 73.58%(78/106), there was statistical difference ( χ2 = 7.89, P = 0.005). Conclusions:The low-dose CT chest scans for PN, the results of detection rate, morphological characteristics, CT image quality are basically the same as those of conventional-dose CT chest scans, and can greatly reduce the radiation dose, which is more suitable for PN screening, and combined with AI system can significantly improve the detection rate of PN.