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PubMed1996

Value of bronchoscopic pneumonia diagnosis: prospective study.

In a prospective clinical study we examined whether bronchoscopically controlled suctioning is preferable to the blind suctioning of mucus aspirates for bacterial identification of intensive care unit patients with pneumonia. Forty patients with clinical and radiologic signs of pneumonia underwent both bronchoscopically controlled and blind endotracheal lavage. Bronchoscopically controlled suctioning did not demonstrate greater sensitivity for identifying organisms than the results obtained from blind suctioning (58 organism were bronchoscopically identified, compared to 57 organisms identified by blind suctioning; p = 0.32, NS). Arterial and mixed venous partial oxygen pressure and shunt also showed no significant differences 15 minutes before and after examination, nor did the blood pressure or pulse. The use of four of the bronchoscopes resulted in preinterventional contamination with Pseudomonas. Bronchoscopically controlled lavage shows no advantages over blind endotracheal lavage for diagnosing pneumonia. Blind suctioning with single-use sterile catheters can be done more quickly and inexpensively with fewer personnel and a lower complication rate.

Adult↗
PubMed2006

Bronchoscopic balloon dilatation in the management of bronchial stenosis following lung transplantation.

BACKGROUND: Bronchial stenosis (BS) is currently found in 7-15% of lung transplantation (LT) recipients. Current treatment strategies have included Nd:Yag laser, cryotherapy, bougie dilatation and stent placement. Bronchoscopic balloon dilatation has been used as alternative treatment in a few cases with controversial results. This is a study to prospectively assess the efficacy of bronchoscopic balloon dilatation as a first step in the management of post-LT BS. METHODS: From January 1995 to December 2002, bronchoscopic balloon dilatation was evaluated as first therapeutic option in all consecutive LT patients with BS. Symptoms, pulmonary function tests, airway diameter and use of other therapeutic techniques were evaluated. RESULTS: A total of 10 out of 284 anastomed airways (3.5%) in 9 out of 152 LT patients were included in the study and follow-up lasted from 6 to 81 months. Dilatation of all but one BS met with initial success: increase of both luminal dimensions and forced vital capacity (P=0.01), and relief of symptoms. Bronchoscopic balloon dilatation long-term follow-up showed effective results in 5 out of 10 (50%) bronchial stenoses, after an average of 4 bronchoscopic balloon dilatation procedures (range 1-8). No severe complications were observed. Stent placement was required in the other 5 bronchial stenoses. CONCLUSIONS: Bronchoscopic balloon dilatation is a safe method that should be considered as first therapeutic treatment of post-LT BS. Its use avoids the need for stent placement in up to 50% of cases.

Adult↗
PubMed1998

Occult lung cancer beyond bronchoscopic visibility in sputum-cytology positive patients.

Sputum cytology is useful for screening and diagnosis of centrally located lung cancer in Japan. On the other hand, cancer beyond the range of bronchoscopic visibility in X-ray negative patients can be detected only with difficulty. Of 265 patients detected by sputum cytology in mass screening, 85 had an abnormal chest roentgenogram and the remaining 180 were roentgenographically occult. A total of 200 roentgenographically occult squamous cell carcinoma lesions were detected in the above 180 patients. A total of 45 of the 200 lesions were bronchoscopically occult. Twenty-two of the above 45 lesions were beyond the range of bronchoscopic visibility with a standard bronchoscope. The data obtained show that a sputum cytology positive, X-ray negative squamous cell carcinoma may lie outside the reach of a flexible bronchoscope. Thus, when it is difficult to localize a cancer, brushing of the peripheral bronchi beyond bronchoscopic visibility and chest computed tomography should be performed.

Adult↗
PubMed1999

A new bronchoscopic method to measure airway size.

Bronchoscopic evaluation of stenosis is limited due to radial distortion of bronchoscopic images and the unknown distance between the endoscope and the stenotic area. The purpose of this study was the development and validation of a method for measuring cross-sectional areas in large airways. Distance measurements were performed using a laser probe inserted into the working channel of a bronchoscope. The laser probe was positioned to the locus of interest in the airway, a ring of light (helium/neon) projected on to the luminal wall and the images acquired using an electronic bronchoscope. The images taken were distortion-corrected by means of a computer program. The method was validated by simulating airways using tubes of known diameter. Additionally, distortion-corrected bronchoscopic images were compared with distortion-free videoscopic image analysis of tracheal slices taken from pigs. In the case of the plastic tubes, Pearson's correlation coefficient (r) as well as the intraclass correlation coefficient (ICC) were slightly higher (r=0.99, p<0.01, ICC=0.97) than the correlation of cross-sectional areas between bronchoscopic and videoscopic images of tracheal slices (r=0.88, p<0.01, ICC=0.87). This concept allows accurate and reproducible determination of cross-sectional areas in large airways.

Animals↗
PubMed1996

Comparison of nonbronchoscopic techniques with bronchoscopic brushing in the diagnosis of ventilator-associated pneumonia.

OBJECTIVE: To determine the diagnostic accuracy of quantitative cultures obtained via nonbronchoscopic protected specimen brushing (PSB) and nonbronchoscopic bronchoalveolar lavage (BAL) compared with quantitative cultures obtained by bronchoscopic PSB in surgical patients suspected of ventilator-associated pneumonia. DESIGN: Prospective, crossover controlled study of 15 ventilated surgical intensive care unit patients in a university teaching hospital. METHODS: Fifteen consecutive ventilated patients suspected of ventilator-associated pneumonia on the basis of leukocytosis, purulent sputum, and appearance of chest roentgenogram were enrolled. All patients underwent nonbronchoscopic PSB and BAL followed by bronchoscopic PSB. The duration of each procedure was noted. Culture results were considered positive only if greater than 10(4) colony forming units (CFU) per milliliter were present. MAIN RESULTS: Perfect concordance was noted between bronchoscopic PSB and nonbronchoscopic BAL (kappa = 1.0). The concordance between bronchoscopic PSB and nonbronchoscopic PSB was 93% ((kappa = 0.86). The nonbronchoscopic procedures were performed in significantly less time than the bronchoscopic procedure. CONCLUSION: Nonbronchoscopic PSB and BAL provide similar microbiologic data to bronchoscopic PSB in the diagnosis of ventilator-associated pneumonia while shortening procedure time significantly.

Adult↗
PubMed2004

Role of bronchoscopic photodynamic therapy in lung cancer management.

PURPOSE OF REVIEW: At present there is universal awareness of the role of photodynamic therapy in oncology. There is also a widespread acceptance of its safety and efficacy in its bronchoscopic application for bronchopulmonary malignant neoplasia. It, is therefore, both timely and relevant to present here the current status of bronchoscopic photodynamic therapy in lung cancer based on a critical review highlighting its indications and results. RECENT FINDINGS: Bronchoscopic photodynamic therapy has emerged as an important treatment in lung cancer. In advanced disease with focus on quality of life, it offers palliation to all patients and survival benefit to a defined subset. In early cases it provides long survival (potential cure). In patients with intraepithelial stage disease, when it can be accurately diagnosed by the use of fluorescence bronchoscopy and endoscopic ultrasonography, the results can match those of surgical resection. SUMMARY: In bronchoscopic photodynamic therapy, the endobronchial tumor is presensitized by systemic administration of a sensitizing photochemical. After a time interval, bronchoscopic illumination (exposure to laser light) is performed to achieve cancer necrosis. The prerequisite for bronchoscopic photodynamic therapy is identification and histologic evidence of cancer within the airway. Photodynamic therapy is indicated in both early and advanced stage cancer. In patients with advanced disease and important exophytic tumors, the aim is palliation; in those with early central disease, treatment is done with curative intent. A large body of published evidence now suggests that these objectives are achievable.

Bronchoscopy↗
PubMed2007

Efficacy of azithromycin administration in prevention of respiratory tract infection after bronchoscopic biopsy: a randomized, controlled trial.

BACKGROUND AND OBJECTIVE: Respiratory tract infection is a serious complication associated with bronchoscopic biopsy. This study attempted to examine its incidence and determine an efficacious therapy for preventing such infections. METHODS: Nine hundred and thirty patients who underwent bronchoscopic biopsy in Osaka City University Hospital outpatient clinic were enrolled in the study. All patients were randomly assigned to receive a 3-day course of azithromycin (500 mg/day), cefcapene pivoxil hydrochloride (300 mg/day) or no antibiotics. The primary outcome was the incidence of respiratory tract infection after bronchoscopic biopsy among the three groups. RESULTS: In the no-treatment group, nine of the 310 patients (2.9%) had respiratory tract infection after bronchoscopic biopsy. All patients with infection had abnormal bronchoscopic findings. Of the patients with respiratory tract infection, 60% were in the no-treatment group, 26.7% in the cefcapene group and 13.3% in the azithromycin group. Although not statistically significant, the incidence in the azithromycin group (0.7%) was lower than in the no-treatment group (P = 0.06). Among the patients with abnormal bronchoscopic findings, the incidence in the azithromycin group was significantly lower than that in the no-treatment group (3.0% vs. 14.8%; P = 0.02). Moreover, maximum C-reactive protein values also appeared to be lower in the azithromycin group than in the no-treatment group and the cefcapene group. CONCLUSIONS: A 3-day course of azithromycin administration is well tolerated and effective in preventing infection post bronchoscopy.

Adult↗
PubMed2005

The use of non-bronchoscopic brushings to study the paediatric airway.

BACKGROUND: The use of cytology brushes for the purpose of obtaining respiratory cells from adults for clinical and research purposes is well established. However, the safety and utility of non-bronchoscopic brushings to study the paediatric airway has not been assessed. The purpose of this study was to assess the practicality of using non-bronchoscopic brushing to sample epithelial cells from children for investigation of epithelial function in health and disease using a wide range of molecular and cellular techniques. METHODS: Non-bronchoscopic brushing was investigated in a non-selected cohort of healthy, and mildly asthmatic children presenting for surgery unrelated to respiratory conditions, at the major children's hospital in Perth. Safety and side-effects of the procedure were assessed. Cell number, phenotype and viability were measured for all samples. The potential of these cells for use in long-term cell culture, immunohistochemistry, western blotting, quantitative PCR and gene arraying was examined. RESULTS: Non-bronchoscopic brushing was well tolerated in all children. The only significant side effect following the procedure was cough: nursing staff reported cough in 20% of patients; parents reported cough in 40% of patients. Cells sampled were of sufficient quantity and quality to allow cell culture in 93% of samples. Similarly, protein and RNA extracted from the cells was suitable for investigation of both gene and protein expression using micro-array and real-time PCR. CONCLUSION: Non-bronchoscopic brushing in children is safe and easy to perform, and is not associated with any complications. Using this technique, adequate numbers of epithelial cells can be retrieved to allow cell culture, western blotting, real time PCR, and microarray analysis. The purpose of this study is to demonstrate the utility of non-bronchoscopic airway brushing to obtain and study epithelial cells and to encourage others so that we can accelerate our knowledge regarding the role of the epithelium in childhood respiratory disease.

Asthma↗
PubMed1992

Sputum cytology-positive, bronchoscopically negative adenocarcinoma of the lung.

Among a total of 114 cases of resected lung adenocarcinoma that were examined by sputum cytologic study before bronchoscopy, 17 were sputum cytology-positive, but had no abnormal bronchoscopic findings. In most of these cases, the reason for detection was sputum and bloody sputum (58.8 percent). Pathologically, many cases were classified as stage III A or more (82.4 percent) due to mediastinal lymph node metastases. More than 70 percent of the cases showed vascular invasion. The proportion of well-differentiated cases was also high (52.9 percent). The prognosis of these cases was worse than sputum cytology-negative adenocarcinoma without abnormal bronchoscopic findings and better than sputum cytology-positive adenocarcinoma with abnormal bronchoscopic findings. There was no significant difference between these cases and sputum cytology-negative adenocarcinoma with abnormal bronchoscopic findings. Combined with the bronchoscopic findings, sputum cytologic study is useful for preoperative evaluation of lymph node metastasis and prognosis. This combined approach can provide information necessary to perform sufficient dissection of mediastinal lymph nodes and proper adjuvant therapy in sputum cytology-positive adenocarcinoma cases, even though there are no abnormal bronchoscopic findings.

Adenocarcinoma↗
PubMed2000

High-resolution CT in patients with intraluminal typical bronchial carcinoid tumors treated with bronchoscopic therapy.

STUDY OBJECTIVE: To evaluate the extent to which high-resolution CT (HRCT) can predict the clinical outcome of bronchoscopic treatment with curative intent in patients with intraluminal typical bronchial carcinoid tumors. DESIGN: An observational study. SETTING: Bronchoscopy unit and radiology department of a university hospital. PATIENTS AND INTERVENTIONS: Eighteen patients with intraluminal typical bronchial carcinoid tumors in the absence of nodal and distant disease were treated with bronchoscopic electrocautery or Nd-YAG laser as an alternative to surgical resection. Prior to treatment, HRCT was performed. RESULTS: In 10 patients, HRCT showed no peribronchial tumor extension, and 9 of these patients were found to be tumor free after bronchoscopic treatment. So far during follow-up, none of these patients has had a recurrence of the tumor. The median duration of follow-up was 33 months (range, 13 to 68 months). In five patients, HRCT showed signs of peribronchial tumor extension. In three of these patients, specimens taken from biopsies performed after bronchoscopic treatment showed residual tumors, and salvage surgery was carried out. In three patients, HRCT was unable to assess peribronchial tumor extension: in two because of insufficient connective tissue contrast between the hilar structures and in one patient because of suboptimal scan technique. CONCLUSION: HRCT findings were complementary but not conclusive in patients with intraluminal typical bronchial carcinoid tumors treated with bronchoscopic therapy. However, in a category of patients in whom HRCT showed strictly intraluminal tumors, bronchoscopic resection as an alternative for surgical resection seems justified.

Adult↗
PubMed1993

Diagnostic success of bronchoscopic biopsy in immunocompromised patients with acute pulmonary disease: predictive value of disease distribution as shown on CT.

OBJECTIVE: The purpose of the study was to determine if the distribution of pulmonary opacities on CT scans could be used to predict the outcome of bronchoscopic biopsy procedures in immunocompromised non-AIDS patients with acute pulmonary complications. MATERIALS AND METHODS: Thirty-three consecutive immunocompromised patients without AIDS who had acute pulmonary complications and who had had CT, bronchoscopic biopsy procedures, and proved diagnoses were included in the study. The distribution and dominant pattern of pulmonary opacities on CT were assessed independently by two observers. The pathologic diagnoses were invasive aspergillosis (eight), Candida pneumonia (six), bronchiolitis obliterans with or without organizing pneumonia (six), drug-induced lung disease (four), Pneumocystis carinii pneumonia (four), cytomegalovirus pneumonia (three), pulmonary hemorrhage (one), and recurrent lymphoma (one). RESULTS: The results of bronchoscopic techniques established a specific diagnosis in 17 patients (52%). In the remaining 16 patients, results of bronchoscopic biopsy could not be used to establish a specific diagnosis; open lung biopsy (15 patients) or transthoracic needle biopsy (one patient) were required for diagnosis. The results of bronchoscopic procedures were diagnostic more often in patients in whom pulmonary opacities involved the central third of the lung than in patients in whom the central third was spared (70% vs 23%, p = .02). Results were diagnostic more often in cases in which the causes of acute pulmonary complications were infectious than in cases in which the causes were noninfectious (71% vs 17%, p < .005). CONCLUSION: We conclude that the presence or absence of central disease as shown by CT can be used to suggest whether results of bronchoscopic procedures in immunocompromised non-AIDS patients will be diagnostic.

Acute Disease↗
PubMed2003

[Diagnostic value of postbronchoscopic sputum, bronchoscopic lavage, and transbronchial biopsy in peripheral lung cancer].

The aim of this prospective study was to review the value of bronchoscopic lavage, transbronchial biopsy and postbronchoscopic sputum cytology in peripheral lung cancer. Two groups of patients were involved in the study who were treated in our clinic between the years 1999 and 2001: Group I (22 patients; average age 64 +/- 9 years; 18 males and four females) whose lesions were peripherally localised on chest radiographs and Group II (28 patients; average age 61 +/- 8; 26 males and two females) whose lesions were centrally localised and were visible only by diagnostic bronchoscopic procedures. The following procedures and analysis were done in all patients: Cytologic analysis of prebroncoscopic sputum, bronchoscopic lavage, bronchial biopsy, and patients were asked to give sputum in 30 minutes after bronchoscopy. The final diagnosis of all patients was primary lung cancer. In the first group none of the patients had visible endobronchial lesion on fiberoptic bronchoscopy. Sputum cytology of the patients were negative before bronchoscopy. Bronchoscopic lavage cytology was positive in five of 22 patients (22.7%). Transbronchial biopsy provided better diagnostic yield (50%) than postbronchoscopic sputum (31.8%). In the second group of patients, cytologic analysis was positive 25%, 96.4% and 42.9% in bronchoscopic lavage, bronchial biopsy and postbronchoscopic sputum respectively. Our findings suggest that postbronchoscopic sputum cytology may be an important diagnostic procedure in endoscopically nonvisible pulmonary cancer. Since its application is easy and noninvasive, cytologic analysis of postbronchoscopic sputum may be preferable to bronchoscopic biopsy although a favorable diagnostic yield is not expected.

Aged↗
PubMed1985

Evaluation of the jet injector in paediatric fibreoptic bronchoscopes.

The use of the Sanders venturi system during bronchoscopy in adults has been studied extensively. Its use in paediatric bronchoscopy has been limited because small changes in the characteristics of the system may produce large changes in the patient. With jet ventilation, peak inflation pressures and flow rates are influenced by the driving pressure, diameter and shape of the bronchoscope, the diameter of the injector and its length and angle from the axial line of the bronchoscope. Storz 3 mm, 4 mm and 5 mm rigid fibreoptic bronchoscopes were evaluated in a test lung with an injector of 1.5 mm internal diameter fixed in the side-arm at 20 degrees to the axial line. Pilling 3 mm, 4 mm and 5 mm rigid fibreoptic bronchoscopes were also examined using the standard injector with a 0.89 mm orifice in the axial line. The Storz bronchoscopes produced consistently higher peak inflation pressures and flow rates at all driving pressures in spite of the relatively large angle of the injector from the axial line. Caution is advised in the use of the Storz injector system as excessively high inflation pressures may be reached.

Anesthesia, General↗
PubMed2006

Fluoroscopy-assisted thoracoscopic resection of pulmonary nodules after computed tomography--guided bronchoscopic metallic coil marking.

OBJECTIVE: To localize small and deeply situated pulmonary nodules during thoracoscopy with roentgenographic fluoroscopy, we developed a marking procedure that uses a metallic coil. METHODS: Nine patients underwent video-assisted thoracoscopic surgery for the removal of 11 pulmonary lesions. Fluoroscopy-assisted thoracoscopic surgery after computed tomography-guided bronchoscopic metallic coil marking was performed with an ultrathin bronchoscope, with simulation by means of virtual bronchoscopy. During thoracoscopy, a C-arm-shaped roentgenographic fluoroscope was used to detect the radiopaque nodules. RESULTS: The marking procedure took 15 to 60 minutes from insertion to removal of the bronchoscope. There were no complications from the marking, and all 11 nodules were easily localized by means of thoracoscopy. The metallic coil showed the nodules on the fluoroscopic monitor, which aided in nodule manipulation. Nodules were completely resected under thoracoscopic guidance, except in one case in which a minithoracotomy was performed at an early stage of the trial. The pathologic diagnosis was primary adenocarcinoma in 9 patients, pulmonary metastasis from colon cancer in 1 patient, and pulmonary lymph node in 1 patient. Two cases of bronchioloalveolar adenocarcinoma with an invasive component and a well-differentiated adenocarcinoma were converted to open thoracotomy to perform curative lobectomy. CONCLUSIONS: In this pilot study computed tomography-guided transbronchial metallic coil marking with an ultrathin bronchoscope with virtual bronchoscopic simulation might be a useful method for the fluoroscopy-assisted thoracoscopic resection of pulmonary nodules.

Adult↗
PubMed1995

Jet ventilation using fiberoptic bronchoscopes.

A fiberoptic bronchoscope is used to facilitate tracheal intubation in cases of difficult direct laryngoscopy. Occasionally, difficulty is encountered in advancing the endotracheal tube after the fiberoptic bronchoscope has been introduced into the trachea. This study tested the feasibility of providing jet ventilation through the suction channel of the fiberoptic bronchoscope as an interim measure under those or similar circumstances. Three commercial models of fiberoptic bronchoscopes with suction channels of 1.2-, 1.5-, and 2-mm diameter, respectively, were tested in a mechanical test lung at varying compliances and resistances using a jet injector connected to an oxygen source at 50 psi. The fiberoptic bronchoscope with the 2-mm suction channel was also studied in seven adult patients who were anesthetized and paralyzed. Jet ventilation was manually performed at the rate of 12/min for 10 min. In the mechanical test lung, the tidal volumes with 1.2-, 1.5-, and 2-mm suction channels were as follows: 280 mL, 490 mL, and 880 mL, respectively, at a compliance of 50 mL/cm H2O and normal resistance; 260 mL, 470 mL, and 820 mL, respectively, at a compliance of 50 mL/cm H2O and high resistance to simulate bronchospasm; 130 mL, 270 mL, and 890 mL, respectively, at a compliance of 20 mL/cm H2O and normal resistance; 120 mL, 220 mL, and 810 mL, respectively, at a compliance of 20 mL/cm H2O and high resistance. In anesthetized, paralyzed patients, oxygen saturation was 96% or more throughout the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1977

Contamination of a fiberoptic bronchoscope with Proteus species.

We have traced an episode of contamination of a fiberoptic bronchoscope with a Proteus species to an index patient. Bacterial cultures obtained by aspiration through the fiberoptic bronchoscope from 11 of 12 subsequent bronchoscopies in 8 additional patients grew a Proteus species with sensitivities similar to those of the initial isolate. Culture of the fiberoptic bronchoscopic specimen yielded an identical organism. There were no definitive ill effects in the patients. These findings necessitated a change in our fiberoptic bronchoscope disinfection protocol as well as development of culture surveillance mechanism to detect breaks in the cleaning procedure. The importance of this and avoiding potential outbreaks of fiberoptic bronchoscope-related infeciton is emphasized.

Bronchoscopes↗
PubMed2000

Novel flexible bronchoscope and single-use disposable-sheath endoscope system. A preliminary technology evaluation.

OBJECTIVE: To measure image clarity, ease of use, and handling performance of a flexible fiberoptic bronchoscope (B-F 100; Vision Sciences; Natick, MA) and sterile single-use disposable-sheath endoscope system (BS-F21 EndoSheath; Vision Sciences). DESIGN: Prospective, multicenter diagnostic technology evaluation of a medical device newly approved by the US Food and Drug Administration. SETTING: Three tertiary care referral centers with busy bronchoscopy practices. PATIENTS: Twenty-four patients undergoing bronchoscopy with a flexible fiberoptic bronchoscope and disposable sheath endoscope system. METHODS: Flexible bronchoscopy was performed through a transnasal or transoral route after topical upper airway anesthesia using standard techniques. After each procedure, the bronchoscopist rated the performance of the medical device under study using a linear scale of 1 (poor) to 5 (excellent and equal to that of a conventional flexible fiberoptic bronchoscope). RESULTS: Mean performance ratings were > 4.0 (range, 4.17 to 4.63) for image clarity, illumination, lack of fogging, distal tip angulation, and ease of transnasal passage. All other ratings were > 3.0 (range, 3.54 to 3.87), the lowest of which was handling comfort. CONCLUSION: The flexible fiberoptic bronchoscope with sterile single-use disposable-sheath endoscope system has the potential to reduce scope downtime by eliminating the need for high-level disinfection between procedures. Illumination, image clarity, and ease of insertion are very good, justifying future prospective studies comparing this device to conventional flexible fiberoptic bronchoscopes.

Bronchoscopes↗
PubMed2004

Patient-specific bronchoscope simulation with pq-space-based 2D/3D registration.

OBJECTIVE: The use of patient-specific models for surgical simulation requires photorealistic rendering of 3D structure and surface properties. For bronchoscope simulation, this requires augmenting virtual bronchoscope views generated from 3D tomographic data with patient-specific bronchoscope videos. To facilitate matching of video images to the geometry extracted from 3D tomographic data, this paper presents a new pq-space-based 2D/3D registration method for camera pose estimation in bronchoscope tracking. METHODS: The proposed technique involves the extraction of surface normals for each pixel of the video images by using a linear local shape-from-shading algorithm derived from the unique camera/lighting constraints of the endoscopes. The resultant pq-vectors are then matched to those of the 3D model by differentiation of the z-buffer. A similarity measure based on angular deviations of the pq-vectors is used to provide a robust 2D/3D registration framework. Localization of tissue deformation is considered by assessing the temporal variation of the pq-vectors between subsequent frames. RESULTS: The accuracy of the proposed method was assessed by using an electromagnetic tracker and a specially constructed airway phantom. Preliminary in vivo validation of the proposed method was performed on a matched patient bronchoscope video sequence and 3D CT data. Comparison to existing intensity-based techniques was also made. CONCLUSION: The proposed method does not involve explicit feature extraction and is relatively immune to illumination changes. The temporal variation of the pq distribution also permits the identification of localized deformation, which offers an effective way of excluding such areas from the registration process.

Algorithms↗