肺高分辨率CT的呼气相定量研究及其与肺功能的关系

目的：对患者呼气相HRCT上空气潴留征的范围进行定量分析，并分析其与肺功能试验（PFT）指标的关系。方法：55例肺弥漫性病变的患者进行吸气相、呼气相HRCT和肺功能试验检查，统计双肺吸－呼气相密度差值（VD）和面积缩小率（AD）、空气潴留评分值并与肺功能试验指标进行相关性分析。结果：空气潴留征象普遍存在；双肺VD和AD、空气潴留评分值与肺功能试验指标显著相关（P＜0．05）。结论：呼气相HRCT上的空气潴留征可以定量分析，能够反映患者的肺功能状况。     

HRCT对支气管扩张症的诊断价值

目的 研究ＨＲＣＴ对支气管扩张症的诊断价值。方法 统计支气管扩张症５４例,其中全部病例做了常规ＣＴ扫描,４０例如了ＨＲＣＴ,３６例有磺油支气管造影资料。结果 柱状扩张２９例,曲张型魂敢管扩张９例,囊状扩张５例,混合型扩张１１例。ＨＲＣＴ发现率为１００％,支气管碘油造影剂８４．４％,常规ＣＴ为７５％,结论 ＨＲＣＴ是支气管扩张的最佳检查方法。     

小儿间质性肺部疾病分类及影像诊断研究现状分析

小儿间质性肺炎疾病是儿科少见病。因病因不明、发病机制不清、病程迁延常影响患儿生活质量，甚至影响生长发育，近年报道增多与临床上对该病重视的提高有关。其病理上以肺泡壁损伤、肺间质炎症浸润、纤维细胞增生为主要特征。影像学技术，特别是高分辨力CT在间质性肺病的诊断和预后的判断中具有重要作用。     

Conversion factors for determining organ doses received by paediatric patients in high-resolution single slice computed tomography with narrow collimation

Estimations of organ doses D_T received during computed tomographic examinations are usually performed by applying conversion factors to basic dose indicators like the computed tomography dose index (CTDI) or the dose-length-product (DLP). In addition to the existing conversion factors for beam apertures of 5 mm or 10 mm, we present new DLP-D_T conversion factors adapted to high-resolution CT (HRCT) examinations of infants and young children with beam apertures of the order of 1 mm and under consideration of bow tie filtration. Calculations are performed on mathematical MIRD phantoms for an age range from 0, 1, 5, 10, 15 up to (for comparison) 30 years by adapting PCXMC, a Monte Carlo algorithm originally developed by STUK (Helsinki, Finland) for dose reconstructions in projection radiography. For this purpose, each single slice CT examination is approximated by a series of corresponding virtual planar radiographies comprising all focus positions. The transformation of CT exposure parameters into exposure parameters of the series of corresponding planar radiographies is performed by a specially developed algorithm called XCT. The DLP values are evaluated using the EGSRay code. The new method is verified at a beam aperture of 10 mm by comparison with formerly published conversion factors. We show that the higher spatial resolution leads to an enhanced DLP-D_T conversion factor if a small organ (e. g. thyroid gland, mammae, uterus, ovaries, testes) is exactly met by the chosen CT slice, while the conversion factor is drastically reduced if the chosen CT slice is positioned above or below the organ. This effect is utilized for dose-saving examinations with only a few single slices instead a full scan, which technique is applied in about 10% of all paediatric chest CT examinations.     

Hypersensitivity pneumonitis in a cluster of sawmill workers: a 10-year follow-up of exposure,symptoms, and lung function

Background:

The long-term prognosis of repeated acute episodes of hypersensitivity pneumonitis (HP) is not well described. We report on a 10-year follow-up of a 10-person cluster from a Norwegian sawmill who had all experienced relapsing episodes of HP.

Objectives:

To evaluate the health symptoms, work-related sick-leave, and lung function of 10 workers exposed to mold in a Norwegian sawmill.

Methods:

Participants were evaluated at baseline and 10 years later at follow-up. A structured interview, measurement of serum IgG antibodies to Rhizopus microsporus (R. microsporus) antigens, lung function tests, high resolution computed tomography (HRCT) of the chest, and personal measurements of exposure to mold spores and dust were completed for each participant.

Results:

At baseline, nearly all workers reported acute episodes of HP more than twice a month. At follow-up, both the frequency and intensity of symptoms had declined. Sick-leave was reduced and gas diffusing capacity improved – paralleling the gradually reduced air levels of mold spores.

Conclusions:

In spite of an initially high occurrence of symptoms, long-term clinical and physiological outcome was good. With reduced exposure to mold spores, symptoms declined and lung function was restored.     

早期周围型肺癌行HRCT诊断的临床价值

【摘要】目的探讨早期周围型肺癌HRCT诊断的临床应用价值。方法本次医学观察选择我院收治的25例早期周围型肺癌患者为观察对象,所有观察对象均同时接受常规螺旋CT和HRCT检查,对比分析患者临床检查结果。结果增强扫描前CT值在26～46HU之间,病灶增强扫描后不同时点CT值为：60s56～90HU,120s34～75HU,240s30—50HU。早期周围型肺癌患者HRCT检查与常规螺旋cT检查结果对比,具有明显的统计学差异（P〈0．05）,且HRCT对于液化、钙化、空泡、支气管气相等密度特征,胸膜凹陷征、血管集束征、细毛刺、光滑等边缘特征,以及不规则形、分叶和类圆形、圆形等性状特征检查准确率均高于常规螺旋CT检查。结论HRCT是一种较为有效的早期周围型肺癌临床检查和诊断技术,具有较高的临床应用价值。     

Role of quantitative chest perfusion computed tomography in detecting diabetic pulmonary microangiopathy

Aims

Aim of the study was to determine the role of perfusion chest computed tomography (pCT) in evaluation of pulmonary diabetic angiopathy.

Methods

18 never-smoking patients (10 diabetic patients and 8 healthy controls) underwent chest high resolution CT (HRCT) and then pCT scanning. In both groups, blood tests, biochemical analysis, fibrinogen, HbA_1c, spirometry, diffusion capacity for carbon monoxide (DLCO) and body pletysmography were performed.Following parameters of pulmonary perfusion have been analysed: blood volume (BV), blood flow (BF), mean transit time (MTT), time to peak (TTP) and permeability surface (PS).

Results

There were no statistically significant differences between groups in terms of age, sex, BMI, forced expiratory volume in one second (FEV₁), DLCO. Chest HRCT revealed no pathologies. Significantly higher values of chest pCT for BF (p = 0.05), BV (p = 0.05) and PS (p = 0.01) have been found in diabetics in comparison to controls. No differences were found in MTT.

Conclusions

Significant increase of perfusion parameters in diabetes seems to confirm pulmonary microangiopathy. The results indicate that further studies on application of pCT in diabetic patients may be beneficial for better understanding of lung microangiopathy, its diagnosing and monitoring.     

Bronchoalveolar cellularity and interleukin-8 levels in measles bronchiolitis obliterans

BACKGROUND: Measles virus infection may progress to a chronic obstructive process including bronchiolitis obliterans (BO). This study investigates pulmonary cellular profiles and interleukin (IL)-8 levels in patients with BO following the measles. METHODS: BAL fluid was obtained from 12 children with BO who had a history of measles pneumonia during an outbreak in 2000 and 2001. BAL cell counts and differentials were compared to control patients as well as BAL IL-8 levels, which were measured by enzyme-linked immunosorbent assay. Immunohistochemical staining of BAL cells and three open-lung biopsy specimens were also analyzed for T-cell surface markers CD3, CD4, and CD8. RESULTS: BAL cellular profiles were characterized by a significantly increased percentage of neutrophils in the measles BO group (median, 16.0%) compared to the control group (2.3%) [p < 0.01]. BAL IL-8 levels were also markedly increased in the measles BO group (mean +/- SD, 418.6 +/- 286.0 pg/mL) compared to the control group (92.8 +/- 126.7 pg/mL) [p < 0.01]. BAL IL-8 levels correlated significantly with neutrophil percentages in both the measles BO group (r = 0.86, p = 0.000) and the control group (r = 0.79, p = 0.007). The lymphocyte subsets were characterized by a significantly increased number of CD8+ cells, resulting in a decreased CD4/CD8 ratio in the BAL and the biopsy specimens. CONCLUSION: These results suggest that pulmonary neutrophils and IL-8, along with CD8+ T lymphocytes may play an important role in the pathogenesis of BO after measles virus infection.