Broncografía incidental / Incidental bronchography

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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.

[Construction and use of a virtual anthropomorphic phantom of the bronchial tree]. / Konstruktion und Einsatz eines virtuellen anthropomorphen Phantoms des Bronchialbaums.

MOTIVATION: Usually, phantoms are used to quantify properties of computer algorithms working on spiral CT data. The high complexity of the human bronchial tree, however, complicates the construction of a physical phantom enormously; hence, a virtual phantom must be employed. METHODS: Because the human bronchial tree is fractal, Lindenmayer systems were utilized to generate its structure. Applying the correct diameter and length ratios and branching angles, a virtual anthropomorphic phantom could be generated by a three-dimensional turtle graphic. The simulation of a spiral CT measurement on the virtual phantom delivered synthetic spiral CT data. RESULTS: The computer-controlled growing process supplies exact morphologic and morphometric data. The spiral CT simulation saves the time-consuming and complicated generation of a physical phantom. PERSPECTIVE: The virtual phantom can be completed by the introduction of blood vessels and lung parenchyma partitioned into lobes and segments. The field of application can thus be extended.

An analysis algorithm for measuring airway lumen and wall areas from high-resolution computed tomographic data.

High-resolution computed tomography (HRCT) has been used to examine airway narrowing. We developed an automated computed tomographic image analysis algorithm (computed tomographic airway morphometry; CTAM) to measure airway lumen area (Ai ), airway wall area (Awa), and airway angle of orientation. Tubes of varying size were embedded in Styrofoam and then scanned at angles between 0 degrees and 50 degrees to assess the accuracy of measurements made with CTAM. Two excised pig lungs were fixed in inflation, sectioned, and scanned. Ai and Awa were measured planimetrically from the cut surfaces to optimize CTAM measurement parameters. In CTAM, Ai was defined according to an airway-size-dependent threshold value, and total Awa was determined through a score-guided erosion method. Results were compared with measurements made through a previously validated method (manual method). CTAM provided accurate measurements of the tubes' Ai values at all angles; Awa was overestimated in direct relation to airway size. The manual method underestimated Ai and overestimated Awa in a manner directly related to airway size as well as to airway angle of orientation. In the excised lung, the mean errors of Ai and Awa measurements made with CTAM were 0.52 +/- 0.24 mm(2) and 0.17 +/- 0.32 mm(2) (mean +/- SEM), respectively. Ai errors with the manual method were similar, but Awa was overestimated to a greater degree (6.3 +/- 0.38 mm(2); p < 0.01) and the error was proportional to Awa (r = 0.64; p < 0.01). CTAM allows accurate measurements of airway dimensions and angle of orientation.

CT-guided transthoracic fine-needle aspiration versus transbronchial fluoroscopy-guided needle aspiration in pulmonary nodules.

PURPOSE: To evaluate the diagnostic yield of CT-guided (CTNAB) and fluoroscopy-guided transbronchial (TBNA) fine-needle aspiration cytology in pulmonary nodules and to compare their complications. MATERIAL AND METHODS: Thirty patients with pulmonary nodules not abutting upon the chest wall and inaccessible to bronchoscopy were randomised for CTNAB or TBNA. Eighteen patients underwent CTNAB and 16 TBNA. Four patients underwent both procedures. RESULTS: In the CTNAB group, a definitive diagnosis could be made in 14 (78%) out of 18 patients whereas in the TBNA group, a definitive diagnosis was made in 11 (69%) out of 16 patients. This difference was not statistically significant (p > 0.05). The final diagnosis in 29 out of 30 patients comprised primary bronchogenic carcinoma in 14 patients, metastases in 5 patients, and benign lesions in 10 patients (34%) of which 3 lesions (30%) were of tuberculous aetiology. There were 2 asymptomatic pneumothoraces in the CTNAB group and no complication was observed in the TBNA group. CONCLUSION: Both techniques were safe and effective in the diagnosis of peripheral pulmonary lesions. TBNA was best suited for lesions larger than 3 cm and located in the middle and lower lobes while CTNAB could be used for any lesions.

[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.

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.

Bronchial dehiscence after lung transplantation: correlation of CT findings with clinical outcome.

PURPOSE: To determine whether computed tomography (CT) can help predict which patients will require surgical or bronchoscopic intervention during healing of bronchial anastomotic dehiscence after lung transplantation. MATERIALS AND METHODS: The authors followed up 25 bronchoscopically proved dehiscent anastomoses through healing in 19 patients who underwent lung transplantation. CT findings were correlated with bronchoscopic results and clinical outcome. RESULTS: A bronchial defect and extraluminal air were initially present at CT in all 25 dehiscent anastomoses. Of 12 bronchial defects less than or equal to 4 mm, only one required intervention during healing (P < .05). Of 12 bronchial defects greater than 4 mm, six required intervention during healing. Eight of nine dehiscences with a tiny or small amount of extraluminal air healed with conservative treatment. Of 16 dehiscences associated with a moderate to large amount of extraluminal air, nine were treated conservatively and six required therapeutic intervention. Three healing anastomoses required bronchial stent placement. One patient died in the perioperative period. CONCLUSION: In patients with small dehiscences ( < 4mm) and patients with a tiny or small amount of extraluminal air, the anastomosis tends to heal without sequela. When patients have larger amounts of extraluminal air or larger ( > 4mm) dehiscences at presentation, CT cannot help predict which patients will require intervention.

Metallic endoprostheses for malignant tracheobronchial obstruction: initial experience.

PURPOSE: To assess the efficacy of the Wallstent endoprosthesis in malignant tracheobronchial obstruction. METHODS: Seven patients with irresectable carcinoma of the bronchus were treated with nine Wallstent endoprostheses. The procedures were performed under endoscopic and fluoroscopic guidance. Wallstent endoprostheses ranging from 8-16 mm in diameter and 26-49 mm in length were deployed after balloon dilatation of the strictures. RESULTS: All stents were successfully deployed in the desired positions. There was one procedural complication and one procedure related death. Three patients showed significant improvement in respiratory status after stenting. At a mean follow-up of 5.1 months, there has been no stent migration, fracture, or collapse. One patient had proximal tumor overgrowth that was treated with additional stent insertion. One patient died after a bout of massive hemoptysis 3 months poststenting and it was difficult to tell whether this was related to the endoprosthesis. CONCLUSION: The use of the Wallstent endoprosthesis in malignant tracheobronchial obstruction is technically feasible.

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.

[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.

Pulmäo destruído por tuberculose: estudo funcional e radiológico de 30 casos / Pulmonary destruction due to tuberculosis: report of 30 cases

O objetivo deste trabalho foi o de correlacionar a quantidade de tecido pulmonar destruído com a funçäo respiratória e com a idade do paciente ao ser diagnosticada tuberculose, que variou entre 12 e 60 anos. Analisaram-se 30 doentes com destruiçäo de dois a 13 segmentos pulmonares avaliados através de radiografia simples de tórax. Funcionalmente, foram considerados restritivos 12 pacientes e obstrutivos 25 doentes. A análise da correlaçäo entre as variáveis para este grupo de indivíduos revelou que: 1 - a tuberculose adquirda em idade mais precoce levou a maior destruiçäo pulmonar, maior reduçäo da capacidade vital e da ventilaçäo voluntária máxima, mas näo influenciou nos parâmetros que indicam o grau de obstruçäo brónquica; 2 - quanto maior o número de segmentos destruídos, menor a capacidade vital e maior a freqüência respiratória em repouso, mas näo houve alteraçäo da ventilaçäo alveolar minuto dos fluxos pulmonares e nem da diferença alvéolo-arterial das pressöes de oxigênio

[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.