The value of the air bronchogram sign on CT image in the identification of different solitary pulmonary consolidation lesions.

The aim of the present study is to investigate the value of air bronchogram sign on computed tomography (CT) image in the differential diagnosis of solitary pulmonary consolidation lesions (SPLs).A total of 105 patients (including 39 cases of lung cancer, 43 cases of tuberculosis, and 23 cases of pneumonia) with SPLs were evaluated for the CT features of air bronchogram sign in this retrospective study. The shape and lumen of the bronchi with air bronchogram sign, the length of the involved bronchus with air bronchogram sign, the length of lesion on the same plane and direction, and the ratio between the length of the involved bronchus and that of the lesion were evaluated.In total, there were 172 segmental and subsegmental bronchi involved. There were 62 segmental and subsegmental bronchi involved among 39 lung cancer cases, 77 segmental and subsegmental bronchi involved among 43 tuberculosis cases, and 33 segmental and subsegmental bronchi involved among 23 pneumonia cases. The shape of the bronchi with air bronchogram sign was significantly different among lung cancer, tuberculosis, and pneumonia (P < .05). The lumen of the bronchi with air bronchogram sign was also significantly different among the 3 SPLs (P < .05). The length of the involved bronchus with air bronchogram sign and the ratio between the length of the involved bronchus and that of the lesion were significantly different between lung cancer and tuberculosis (P < .05), or between lung cancer and pneumonia (P < .05), but not between tuberculosis and pneumonia (P > .05). No significant difference was found in the length of lesion among the 3 SPLs (P > .05).The shape and lumen of the bronchi with air bronchogram sign can be used to distinguish lung cancer, tuberculosis, and pneumonia. The length of the involved bronchus with air bronchogram sign and the ratio between the length of the involved bronchus and that of the lesion can be used to distinguish lung cancer from tuberculosis and pneumonia.

Diagnosis of chronic obstructive pulmonary disease in lung cancer screening Computed Tomography scans: independent contribution of emphysema, air trapping and bronchial wall thickening.

BACKGROUND: Beyond lung cancer, screening CT contains additional information on other smoking related diseases (e.g. chronic obstructive pulmonary disease, COPD). Since pulmonary function testing is not regularly incorporated in lung cancer screening, imaging biomarkers for COPD are likely to provide important surrogate measures for disease evaluation. Therefore, this study aims to determine the independent diagnostic value of CT emphysema, CT air trapping and CT bronchial wall thickness for COPD in low-dose screening CT scans. METHODS: Prebronchodilator spirometry and volumetric inspiratory and expiratory chest CT were obtained on the same day in 1140 male lung cancer screening participants. Emphysema, air trapping and bronchial wall thickness were automatically quantified in the CT scans. Logistic regression analysis was performed to derivate a model to diagnose COPD. The model was internally validated using bootstrapping techniques. RESULTS: Each of the three CT biomarkers independently contributed diagnostic value for COPD, additional to age, body mass index, smoking history and smoking status. The diagnostic model that included all three CT biomarkers had a sensitivity and specificity of 73.2% and 88.%, respectively. The positive and negative predictive value were 80.2% and 84.2%, respectively. Of all participants, 82.8% was assigned the correct status. The C-statistic was 0.87, and the Net Reclassification Index compared to a model without any CT biomarkers was 44.4%. However, the added value of the expiratory CT data was limited, with an increase in Net Reclassification Index of 4.5% compared to a model with only inspiratory CT data. CONCLUSION: Quantitatively assessed CT emphysema, air trapping and bronchial wall thickness each contain independent diagnostic information for COPD, and these imaging biomarkers might prove useful in the absence of lung function testing and may influence lung cancer screening strategy. Inspiratory CT biomarkers alone may be sufficient to identify patients with COPD in lung cancer screening setting.

Use of decubitus radiographs in the diagnosis of foreign body aspiration in young children.

BACKGROUND: Lateral decubitus radiographs are often obtained in young children with suspected foreign body aspiration. Their usefulness has not been well studied. OBJECTIVES: To assess the value of decubitus radiographs in detecting foreign body aspiration in young children and compare their value to history and physical examination. METHODS: Retrospective review of children younger than 4 years with suspected foreign body aspiration who had decubitus radiographs and underwent bronchoscopy over a 5-year period. Patients with proven foreign body aspiration were compared with those without foreign bodies for differences in symptoms, signs, location and character of the foreign body, and the diagnostic value of standard and decubitus chest radiographs. RESULTS: Twenty-eight of 41 children who underwent bronchoscopy for possible foreign body aspiration had decubitus radiographs. Foreign bodies were identified in 22 patients (79%). A total of 27% of children with foreign body aspiration and 33% of children without a foreign body had suggestive decubitus radiographs (P = not significant). As a measure of detecting foreign body aspiration, positive decubitus radiographs had a sensitivity of 27%, a specificity of 67%, a positive predictive value of 75%, and a negative predictive value of 20%. The odds ratio of finding a foreign body with suggestive decubitus radiographs was 0.75 (95% confidence interval [CI], 0.1-5.2; P = 0.57). Foreign body aspiration was confirmed in 94% of children if there was both a sudden onset of symptoms and a witnessed choking episode (odds ratio, 13.3; 95% confidence interval, 1.3-138.9; P = 0.02). CONCLUSION: Decubitus chest radiographs, at least as routinely performed and interpreted, seem to add little to the evaluation of young children with suspected foreign body aspiration. A history of a witnessed choking episode combined with a sudden onset of respiratory symptoms remains the most important indication for bronchoscopy.

Helical CT in evaluation of the bronchial tree.

PURPOSE: To establish a protocol for and to assess the value of helical CT in the imaging of the bronchial tree. MATERIAL AND METHODS: Noncontrast helical CT was performed in 30 patients undergoing fiberoptic bronchoscopy for different reasons. Different protocols were compared; they included overlapping 10 mm, 5 mm, or 3 mm slices and non-tilted, cephalad or caudad tilted images. Ordinary cross-sectional and multiplanar 2D reformats were applied for visualization of the bronchial branches. The effect of increasing the helical pitch was tested in one patient. RESULTS: A total of 92.1-100% of the segmental bronchi present in the helical acquisitions were identified by the different protocols. The collimation had no significant impact on the identification of the bronchial branches, but utilization of 3-mm overlapping slices made it easier to distinguish the nearby branches and provided better longitudinal visualization of the bronchi in 2D reformats. The tilted scans illustrated the disadvantage of not covering all segmental bronchi in one breath-hold. An increase of the pitch from 1 to 1.5 did not cause noticeable blurring of the images. CT and bronchoscopic findings correlated well in the area accessible to bronchoscopy, but CT detected 5 additional pathological lesions (including 2 cancers) in the peripheral lung. CONCLUSION: Helical CT supplemented with bronchography-like 2D reformats provides an effective method complementary to bronchoscopy in the examination of the bronchial tree.

Virtual bronchoscopy: segmentation method for real-time display.

Computed tomography (CT) data sets obtained in 14 patients were used in a segmentation method for virtual bronchoscopy (VB). The method constrained the distance of propagation of a region-growing algorithm. The resulting three-dimensional bronchial model was a faithful representation of the source CT data and could be manipulated in real time at frame rates of one to two frames per second. Preliminary data showed that 90% of bronchi (up to third order) measureable on multiplanar CT reformations were also measurable at VB. The bronchial diameters measured at VB were within 1 mm of those measured on multi-planar reconstructions of the CT data.

Bronchial wall thickness: appropriate window settings for thin-section CT and radiologic-anatomic correlation.

PURPOSE: To analyze the influence of computed tomographic (CT) window settings on bronchial wall thickness and to define appropriate window settings for its evaluation. MATERIALS AND METHODS: Three inflation-fixed lungs were scanned with a section thickness of 1.5 mm by using a high-spatial-frequency algorithm. Wall thickness in 10 bronchial specimens was measured with planimetry. Window centers were altered in a range of -200 to -900 HU and window widths in a range of 400-1,500 HU. Relative and absolute differences between CT and planimetric values were calculated. CT and planimetric measures were correlated. Inter- and intraobserver variabilities were determined. RESULTS: Window widths less than 1,000 HU resulted in a substantial overestimation of bronchial wall thickness, whereas widths greater than 1,400 HU resulted in an underestimation of bronchial wall thickness. There was no interaction between "width" and "center" regarding their influence on bronchial walls (F = 0.23; P = .99). Correlation between CT and planimetry was statistically significant (r = .85; P = .0001). Differences between the two observers were not statistically significant; results of the measurements of the two observers correlated well (r = .97; P = .001). CONCLUSION: Bronchial wall thickness on thin-section CT scans should be evaluated with window centers between -250 and -700 HU and with window widths greater than 1,000 HU. Other than window settings, notably window widths less than 1,000 HU, can lead to substantial artificial thickening of bronchial walls.

[Survey of the state of bronchography in Japan].

Bronchography is not routinely done. We analyzed the state of bronchography with questionnaires returned from 57 hospitals. Bronchography is now done at 30 hospitals. The number done in 1992 ranged from 1 to 27 (median 3). Peripheral lung cancer and bronchiectasis were the two most frequent diseases for which bronchography was done. In other hospitals, bronchography was once done, but had been stopped. Two reasons for discontinuation of bronchography are: recent progress in radiographic diagnostic techniques such as high resolution CT, and discomfort of the patient. Now that propyliodone is no longer available, some hospitals may use iopydol-iopydone or iopamidol instead. It is necessary to elucidate the true need for bronchography and for an appropriate contrast medium to take the place of propyliodone.

Correlation of quantitative CT with selective alveolobronchogram and pulmonary function tests in emphysema.

BACKGROUND: Emphysema diagnosed by computed tomography (CT) has been reported to be correlated with morphologic data from autopsied lungs or resected lobes. However, autopsied lungs or resected lobes are quite different from lungs in vivo. We examined the correlation between a quantitative analysis of CT and the in vivo morphologic degree of emphysema (selective alveolobronchography [SAB]) in patients with COPD. METHODS: We measured the mean attenuation value (MAV) of the lung fields between -700 HU and -1,024 HU to exclude the effect of high-density structures in 21 patients with COPD. Low attenuation, greater than 2 SD below the mean value of five normal healthy subjects, was used as an index of emphysema. To quantitate the amount of emphysema, the relative area of low attenuation to the area of the entire lung field (2SD percent) was measured. The morphologic degree of emphysema was determined from the diameter of ring shadow (DR) of SAB. We also examined the relationship between CT data and pulmonary function tests. RESULTS: The DR was highly correlated with the CT indexes of MAV and 2SD percent; (r = -0.894, p < 0.001, and r = 0.890, p < 0.001). Both MAV and 2SD percent were correlated with pulmonary function tests such as Dco, FEV1, and residual volume (r > 0.60). CONCLUSIONS: The MAV and relative area of emphysema obtained from CT density measurements accurately assess the severity of emphysema in patients with COPD as well as SAB.

Spontaneous airways constrict during breath holding studied by high-resolution computed tomography.

Airway constriction during a breath hold could not be examined previously using standard methods. We used high-resolution computed tomography (HRCT) in vivo to assess the temporal changes in airway area and the effects of a deep inspiration with and without vagal suppression. Five dogs were anesthetized, intubated, and their lungs ventilated with 100 percent oxygen. Fifteen HRCT slices were obtained at functional residual capacity (FRC) either immediately after stopping ventilation at end expiration after either a tidal volume breath or three deep inspirations. Subsequently the dogs were given atropine, 0.2 mg/kg, and the scans were repeated. The cross-sectional areas of 33 airways ranging in size from 1.6 to 9.7 mm in diameter were measured. Airways were separated in three groups based on size: small (< 3 mm in diameter); medium (3 to 6-mm in diameter); and large (> 6 mm in diameter). The small, medium, and large airways showed a spontaneous constriction over time to 49 +/- 8 percent, 83 +/- 4 percent, and 82 +/- 4 percent of initial airway size, respectively (p < 0.01), (p < 0.0001). The deep inspiration caused an initial dilation only in the smallest airways to 133.3 +/- 4 percent. The subsequent constrictions were even greater than after the tidal volume breath averaging 67 +/- 15 percent, 61 +/- 6 percent, and 60 +/- 9 percent of initial airway area in the small, medium, and large airways, respectively (p = 0.001). Atropine caused an average increase in baseline airway area of 115 +/- 5 percent and 121 +/- 6 percent after a tidal volume breath and deep inspiration, respectively, compared with the preatropine controls, with no difference between the three groups. Atropine also completely abolished the spontaneous airway constriction observed after either a tidal volume breath or a deep inspiration in all three groups equally. In conclusion, using direct airway imaging in vivo, we found that airways spontaneously constrict during a prolonged expiratory pause, and a deep inspiration significantly augments this airway constriction. These responses are mediated via vagal afferent pathways, likely arising from progressively decreasing slow-adapting receptor activity.

[Computed tomography in endobronchial mucus accumulation]. / La tomografia computerizzata nella malattia da accumulo endobronchiale di muco.

To investigate the value of CT in depicting endobronchial mucoid collections, the authors retrospectively reviewed the CT scans of 22 patients, 14 with mucous plugs, 7 with mucoid pseudotumors, and one with a bronchocele due to bronchial atresia. Atelectasis could be seen in 11 of 14 patients with mucous plugs. In 12 of 14 patients with mucous plugs CT showed the involved bronchi filled by fluid representing abnormal mucus accumulation. In the patients with atelectasis CT showed mucus-filled bronchi as low-attenuation branching structures (mucoid bronchogram). All the mucoid pseudotumors appeared as low-attenuation (< 20 HU) polypoid wall lesions with no involvement of the bronchial walls. In a patient with bronchial atresia CT showed a solitary pulmonary nodule (representing the obstructed and dilated bronchus filled by mucus) surrounded by peripheral pulmonary hyperinflation. Characteristically, the endobronchial mucoid collections never enhanced after bolus contrast medium. Endobronchial mucoid collections had to be differentiated from endobronchial neoplasms. In some cases bronchoscopy was necessary to make the differential diagnosis. In conclusion, CT is a valuable tool with good sensitivity and specificity in diagnosing endobronchial mucoid collections.

[The computed tomographic differentiation of endobronchial tumors and tumor-caused bronchial compression]. / Computertomographische Differenzierung von endobronchialen Tumoren und tumorbedingten Bronchuskompressionen.

The efficiency of computed tomography in differentiating between a bronchial compression due to tumour formation and an endobronchial tumour was tested in comparison to bronchoscopy results. 624 bronchial segments were evaluated in 65 patients with masses in the pulmonary hilus area. Computed tomographical identification of pathological lesions (n = 71) was achieved with a sensitivity of 83% and a specificity of 96%. Out of 52 bronchial segments with endobronchial tumour, 90% showed pathological lesions and 85% were classified correctly. When the morphology of the bronchial lesions (endoluminal mass, smooth or irregularly demarcated bronchostenosis or bronchial displacement) was assessed with CT, only the CT identification of an endoluminal mass could distinguish endobronchial tumour growth with a probability of 91% from bronchial narrowing due to external causes and normal bronchi.

[Bronchologic studies in East Germany: current status and perspectives]. / Bronchologische Untersuchungen in der DDR: Aktueller Stand und Perspektiven.

Within a period of 8 years (1979 to 1986) there were performed in 21 centres of the German Democratic Republic 15,049 bronchoscopic investigations (in 49.6 per cent combined with a subsequent bronchography) in 11,717 children, including 2,054 (17.5 per cent) up to one year of age. The detailed analysis shows important trends, which allow a reasonable prognosis of the perspectives of pediatric bronchology in the GDR.