Application of adjusted subpixel method (ASM) in HRCT measurements of the bronchi in bronchial asthma patients and healthy individuals

Background

Recently, we described a model system which included corrections of high-resolution computed tomography (HRCT) bronchial measurements based on the adjusted subpixel method (ASM).

Objective

To verify the clinical application of ASM by comparing bronchial measurements obtained by means of the traditional eye-driven method, subpixel method alone and ASM in a group comprised of bronchial asthma patients and healthy individuals.

Methods

The study included 30 bronchial asthma patients and the control group comprised of 20 volunteers with no symptoms of asthma. The lowest internal and external diameters of the bronchial cross-sections (ID and ED) and their derivative parameters were determined in HRCT scans using: (1) traditional eye-driven method, (2) subpixel technique, and (3) ASM.

Results

In the case of the eye-driven method, lower ID values along with lower bronchial lumen area and its percentage ratio to total bronchial area were basic parameters that differed between asthma patients and healthy controls. In the case of the subpixel method and ASM, both groups were not significantly different in terms of ID. Significant differences were observed in values of ED and total bronchial area with both parameters being significantly higher in asthma patients. Compared to ASM, the eye-driven method overstated the values of ID and ED by about 30% and 10% respectively, while understating bronchial wall thickness by about 18%.

Conclusions

Results obtained in this study suggest that the traditional eye-driven method of HRCT-based measurement of bronchial tree components probably overstates the degree of bronchial patency in asthma patients.     

Follow-up study on pulmonary function and lung radiographic changes in rehabilitating severe acute respiratory syndrome patients after discharge

OBJECTIVES: To follow-up on the changes in lung function and lung radiographic pictures of severe acute respiratory syndrome (SARS) patients discharged from Xiaotangshan Hospital in Beijing (by regularly receiving examination), and to analyze retrospectively the treatment strategy in these patients. METHODS: Surviving SARS patients were seen at least twice within 3 months after discharge and underwent SARS-associated coronavirus (SARS-CoV) IgG antibody testing, pulmonary function testing, and chest radiography and/or high-resolution CT (HRCT) examinations at Chinese PLA General Hospital. The treatments received at Xiaotangshan Hospital were analyzed retrospectively and were correlated to later status. RESULTS: Positive SARS-Co virus IgG antibody results were seen in 208 of 258 patients, with 21.3% (55 of 258 patients) still having a pulmonary diffusion abnormality (D(LCO) < 80% of predicted). By comparing the 155 survivors with positive SARS-CoV IgG antibody results and D(LCO) > or = 80% predicted with the 50 patients with negative SARS-CoV IgG results, we found that 53 patients with positive SARS-CoV IgG results and a lung diffusion abnormality had endured a much longer course of fever and received larger doses of glucocorticoid, as well as higher ratios of oxygen inhalation and noninvasive ventilation treatment. For these patients, 51 of 53 patients with positive SARS-CoV IgG results and a lung diffusion abnormality underwent pulmonary function testing after approximately 1 month. D(LCO) improved in 80.4% of patients (41 of 51 patients). Of the patients with a lung diffusion abnormality, 40 of 51 patients showed lung fibrotic changes in the lung image examination and 22 patients (55%) showed improvement in lung fibrotic changes 1 month later. CONCLUSION: These findings suggest that lung fibrotic changes caused by SARS disease occurred mostly in severely sick patients and may be self-rehabilitated. D(LCO) scores might be more sensitive than HRCT when evaluating lung fibrotic changes.     

不同的影像学方法在Ⅱ期矽肺中诊断价值对比研究

目的：观察胸部高分辨CT（HRCT）与高千伏X线胸片在诊断Ⅱ期矽肺中的价值。方法：选取70例Ⅱ期矽肺患者,分别进行HRCT与高千伏X线胸片检查,分析两种检查指标。结果：主要影像指标方面,两组检查在斑片条、小阴影聚集、空洞等检测方面比较,差异无统计学意义（P〉0.05）;而其他如发白区、大结节影、钙化等检测上,HRCT与高千伏X线胸片比较,差异具有统计学意义（P〈0.05）;HRCT与高千伏X线胸片在小阴影密集度肺区数显示能力、矽肺分期方面比较,差异具有统计学意义（P〈0.05）。结论：HRCT与高千伏X线胸片在主要影像指标检测方面,均存在较大的差异。两种影像学检查具有较强的诊断互补性。     

Idiopathic Pulmonary Fibrosis: Evolving Concepts

Idiopathic pulmonary fibrosis (IPF) occurs predominantly in middle-aged and older adults and accounts for 20% to 30% of interstitial lung diseases. It is usually progressive, resulting in respiratory failure and death. Diagnostic criteria for IPF have evolved over the years, and IPF is currently defined as a disease characterized by the histopathologic pattern of usual interstitial pneumonia occurring in the absence of an identifiable cause of lung injury. Understanding of the pathogenesis of IPF has shifted away from chronic inflammation and toward dysregulated fibroproliferative repair in response to alveolar epithelial injury. Idiopathic pulmonary fibrosis is likely a heterogeneous disorder caused by various interactions between genetic components and environmental exposures. High-resolution computed tomography can be diagnostic in the presence of typical findings such as bilateral reticular opacities associated with traction bronchiectasis/bronchiolectasis in a predominantly basal and subpleural distribution, along with subpleural honeycombing. In other circumstances, a surgical lung biopsy may be needed. The clinical course of IPF can be unpredictable and may be punctuated by acute deteriorations (acute exacerbation). Although progress continues in unraveling the mechanisms of IPF, effective therapy has remained elusive. Thus, clinicians and patients need to reach informed decisions regarding management options including lung transplant. The findings in this review were based on a literature search of PubMed using the search terms idiopathic pulmonary fibrosis and usual interstitial pneumonia, limited to human studies in the English language published from January 1, 2000, through December 31, 2013, and supplemented by key references published before the year 2000.     

变态反应性支气管肺曲菌病的HRCT表现

目的探讨变态反应性支气管肺曲菌病(ABPA)的HRCT影像学特点。方法分析24例ABPA的发病机制、临床表现、影像学表现。结果 24例患者中,女性15例,男性9例,中位年龄40岁。主要临床表现:咳嗽24例,咳痰19例,喘憋17例,咯血7例,均行胸部HRCT检查,中心性支气管扩张19例,斑片状渗出影或实变影3例,支气管粘液栓6例,其中5例见高密度钙化。结论 ABPA具有相对特征性的临床及HRCT影像学表现。     

引起放射性肺炎的相关因素及HRCT表现与预后的关系

目的 :分析引起放射性肺炎的相关因素 ,HRCT表现与预后的关系。材料和方法 :对 5 80例胸部肿瘤中放射性肺炎的 86例行HRCT检查 ,观察其征象与预后的关系。结果 :总结 7种引起放射性肺炎的相关因素。将HRCT表现分为4种类型 :片状渗出型。补丁实变型。含气不全型和浓密纤维化型。同时探讨了与预后。结论 :阐述引起放射性肺炎的相关因素及HRCT对胸部肿瘤患者与各型放射性肺炎预后的关系。正确使用肺组织的放射剂量 ,定期HRCT检查对放射性肺炎的早期诊断和预后有指导意义。     

肺炎性假瘤的HRCT诊断

目的 探讨肺炎性假瘤的CT表现.方法 21例经手术或病理证实的肺内直径小于2.0 cm炎性假瘤患者均经胸部高分辨力CT（RHCT）检查.其中,15例又经增强CT扫描.结果HRCT证实,21例病人中,浅分叶征见于6例,棘状突起5例,晕征8例,血管集束征5例.在接受增强扫描的15例中,增强后5例的病灶有轻度强化,而其余10例的病灶无明显强化,所有病例的病灶边缘均较光整.结论 HRCT对诊断肺内直径小于2.0 cm的炎性假瘤具有重要价值.而各种CT征象的综合分析有利于确诊.     

树芽征在诊断支气管肺疾病中的意义

“树芽征”(tree-in-bud sign)是常见的胸部CT征象,在胸部CT表现为小叶中央型结节影和与之相连的数条线形分支影,多分布在胸膜下3~5mm肺野内,直径2~4mm[1]。“树芽征”与次级肺小叶的解剖结构和病理改变有关。终末细支气管位于次级肺小叶的核心,直径<1mm,正常情况下CT或HRCT不显影。病理状态下,细支气管扩张、管壁增厚或者管腔阻塞,HRCT则表现为小叶中央型结节和线形分支影,即“树芽征”。“树芽征”最初被用于描述结核感染沿支气管播散时的CT表现(图1),但在过去的几年里,人们逐渐意识到“树芽征”并非为结核感染独有,凡是累及小气道…     

肺高分辨力CT“马赛克”衰减的表现及其诊断价值

目的:探讨肺高分辨力CT“马赛克”衰减的表现及其临床应用价值。材料和方法:回顾性分析45例HRCT的“马赛克”衰减的表现。结果:28例以间质病变为主中,“马赛克”衰减外周分布27例、边界模糊22例,均伴有间质病变征象;以肺实质病变为主7例中,弥漫分布5例,边界清楚5例;慢性阻塞性肺疾病10例中,弥漫分布和伴有小血管增粗7例,边界清楚6例。结论:虽然HRCT上“马赛克”衰减征象是非特异性征象,但可早期提示小气道病变,并可通过对其形态学特点的分析缩小临床拟诊范围,具有重要临床价值。     

面神经鼓乳段在斜矢状断面与HRCT上的定位及临床意义

目的　探讨面神经鼓乳段在斜矢状位最佳显示的扫描基线,为面神经鼓乳段疾病的影像诊断和耳显微外科手术治疗提供解剖学依据。 方法　利用HRCT对16例(32耳) 外观无异常的成人颅骨标本行斜矢状位扫描获得层厚为0.625 mm的HRCT图像后,再用火棉胶包埋技术将颞骨标本切制层厚为1mm的连续斜矢状断面标本,选取面神经鼓乳段显示良好的CT图片与对应的切片标本对照观测。 结果　16例（32耳）在斜矢状位均可完整显示面神经鼓乳段全程,面神经鼓乳段全长为（23.58±1.44）mm,鼓室段到外半规管的距离为（0.75±0.12）mm,面神经鼓室段到鼓室的距离为（0.34±0.08）mm,鼓室段和乳突段的夹角为（108.88±2.49）度。 结论　颞骨斜矢状位HRCT图像结合对应切片标本能良好显示面神经鼓乳段及其周围结构的解剖位置和毗邻关系,以与正中矢状面成（21.40±4.35）度为扫描基线作斜矢状位扫描显示面神经鼓乳段最佳,对颞骨的影像诊断和耳显微外科手术治疗具有重要意义。