Comparison of a New Integral-Based Half-Band Method for CT Measurement of Peripheral Airways in COPD With a Conventional Full-Width Half-Maximum Method Using Both Phantom and Clinical CT Images.

OBJECTIVES: To compare a new integral-based half-band method (IBHB) and a conventional full-width half-maximum (FWHM) method in measuring peripheral airway dimensions at airway phantoms and thin-section computed tomography of chronic obstructive pulmonary disease (COPD). METHODS: The IBHB was validated and compared using airway phantoms and 50 patients with COPD. Airway parameters (wall area percentage [WA%], mean lumen radius, and mean wall thickness) were measured at fourth to sixth generations of the right apical bronchus. Matched results from 2 methods were compared and correlated with forced expiratory volume (FEV) in 1 second (FEV1), FEV1 / forced vital capacity (FVC), and global initiative for chronic obstructive lung disease (GOLD) stage. Linear regression analysis was performed using airway dimensions and emphysema index. RESULTS: The IBHB generated more accurate measurements at phantom study. Measured airway parameters by both methods at thin-section computed tomography study were significantly different (all P < 0.05, paired t test). The IBHB method-measured WA% and wall thickness were significantly smaller. Mean WA% with IBHB also showed better correlation than that with FWHM (FEV1, r = -0.52 vs -0.28; FEV1 / FVC, r = -0.41 vs r = -0.20; GOLD, 0.52 vs 0.33, respectively). Linear regression analysis revealed fifth-generation WA% measured by IBHB was an independent variable, and addition to emphysema index increased predictability (FEV1, r = 0.63; FEV1 / FVC, r = 0.61; GOLD, r = 0.70). CONCLUSIONS: The new IBHB measured peripheral airway dimensions differently than FWHM and showed better correlations with functional parameters in COPD.

Bronchofiberscopy with curette biopsy and bronchography in the evaluation of peripheral lung lesions.

Flexible bronchofiberscopy using a double-hinged curette biopsy and under fluoroscopic guidance was performed on 46 patients with peripheral lung carcinomas smaller than 2 cm. Prior mapping of the location of the lung lesion was achieved with selective peripheral bronchography. With these diagnostic tools, a positive cytologic diagnosis for lung carcinomas was made in 45 of 46 patients, a yield of 97.8 percent. Complications associated with the curette biopsy included minor bleeding in three cases and pneumothorax requiring a chest tube in one case.

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.

Characteristics of tantalum dust and dust generator for bronchography.

The two tantalum powders, "5mu" and "1.4mu", available from Fansteel Metals, are characterized with respect to particle size. Results show that these powders cannot be used directly for tantalum bronchography, but require fractionation to achieve a range of sizes for effective use in tantalum bronchography. This task can be accomplished with the BAHCO Micro Particle Classifier. The powder designated "1.4mu" is superior to the "5mu" powder because about 60% by weight can be salvaged by separation for use in bronchography, compared to only 7% by weight of the "5mu" powder. Theoretical considerations of particle deposition in the human respiratory tract indicate that the material obtained with throttle 16 of the BAHCO is best suited for tantalum bronchography. The dust generator is a good tool to deliver a dust cloud into the lung. The generator can operate for approximately 2 1/2 hours before the brush of the brush feed must be replaced; a procedure taking about 10 min. Additional maintenance is unnecessary. The breathing resistance of 1.1 inch of water imposed by the generator system, and which has to be overcome by the patient, is judged acceptable. The bronchograms obtained by introducing tantalum dust for 10 min into an artificially ventilated dog lung were clear, with deposition heaviest at bifurcations. These results suggest that the generator should now be used for human bronchography.

[Experience with a guidable catheter for angiography and bronchography (author's transl)]. / Erfahrungen mit einem lenkbaren Katheter in der Angiographie und Bronchographie

Despite certain disadvantages, depending partly on the design of the catheter and partly on other problems, a guidable catheter is, in many cases, the only means for achieving a successful angiographic examination. The guidable catheter is therefore a valuable addition to the equipment used for angiography.

[Spiral CT and 3-D reconstruction of the tracheobronchial tree for the selection of the proper double-lumen tubes before individual lung ventilation]. / Spiral-CT und 3 D-Rekonstruktion des Tracheobronchialbaumes zur Auswahl geeigneter Doppellumentuben vor Einzellungenbeatmung.

PURPOSE: To assess the potential of 3-D spiral CT in the selection of adequate double-lumen tubes (DLT) for one-lung-ventilation. MATERIALS AND METHODS: 3-D spiral CT of eight different DLTs was performed with standardized acquisition parameters: section thickness 4 mm, table speed 6 mm/s, increment 3 mm and standardised thresholds, window settings and magnification zoom. The accuracy was confirmed by measuring 3-D objects on screen and original DLTs by vernier caliper. 3-D spiral CT was performed in 20 patients preoperatively with slice thickness 4-8 mm, pitch 1-1.5, increment 4-8 mm. To select the adequate DLT size the 3-D reconstructions of the patient's tracheobronchial tree and of the DLT were superimposed by templates or computer animation. The accuracy was controlled by endoscopic and clinical measurements. RESULTS: The accuracy of the 3 D spiral CT was nearly 0.1 mm. The superimposition with templates was easy and reliable. The 3-D spiral CT determined DLTs were shown to fit perfectly by clinical and endoscopic measurements in all cases. CONCLUSION: 3-D reconstructions of the tracheobronchial tree obtained from routine preoperative spiral CT scans allow for an easy and accurate individual selection of double-lumen tubes.

[Characteristics of manifestations of border effect in electroroentgenobronchography]. / Osobennosti proiavleniia kraevogo effekta pri elektrorentgenobronkhografii

Specificity of the image reflecting the outlines of the bronchial lumena on the electroroentgenograms is explained by the manifestation of the border effect. The latter is caused by the non-uniformity of the electric field over the surface of the selenium layer with a regular distribution of charges. With electroroentgenography of sharply contrasted objects in a little contrast medium the potential relief has highly pronounced differences, this leading to distorsion of the dimensions and the shape of the objects under examination. When interpreting electroroentgenograms these specific features should be taken into consideration. In constructing improved medical radiographic equipment it will be advisable to envisage the possibility of controlling the said effect.

[Method of coherent optical processing of bronchograms]. / Metodika kogerentno-opticheskoi obrabotki bronkhogramm.

The problem of space filtration of bronchi images is solved by using as a model a tube filled with a contrast substance. The effects of bronchi wall lesions on the images after filtering are analysed. Some results of bronchogram processing using a hybrid optoelectronic device are presented.

[Computerized control with radiodiagnostic equipment in bronchopulmonary investigations]. / Kompíuternoe upravlenie rentrenodiagnosticheskim apparatom pri bronkholëgochnykh issledovaniiakh.

The authors propose a procedure and equipment for control by using a rotation table of a PYM-20M X-ray system with an image intensifier. A 4 x 4-cm beam field is used. The procedure makes it possible to lower X-ray loads in patients by 10-15 times, to calculate the absorbed integrated radiation dose, to enhance the quality of plane films, to draw up a protocol of studies. This increases the accuracy of X-ray anatomic instrument position. The apparatus can be remotely controlled.

[Experience with the operation of a device for roentgeno-endoscopic examination]. / Opyt ekspluatatsii ustroistva dlia rentgeno-endoskopicheskogo issledovaniia

An appliance for roentgeno-endoscopic investigation permitting rotation of the patient is made in the shape of a crable that turns through 130 degrees and is firmly held in all positions of the X-ray apparatus mounting. The appliance provides good conditions for a multifarious roentgenological control over the manipulations with the bronchoscope, catheters, biopsy instruments and allows it to perform selective bronchography, pneumomediastinography angio- and lymphography. The appliance facilitates the arrest of the intrabronchial hemorrhage after biopsy and does not hamper the performance of reanimation procedures in cases of cardiac arrest. The use of the appliance increases the irradiation (absorbed) dose to which the service staff is exposed at their workplace by no more than 10 per cent.