Taeko Shirakawa

Clinical application of virtual bronchoscopic navigation system for peripheral lung lesions.

Transbronchial lung biopsy is an indispensable method for the diagnosis of peripheral lung lesions; however, the diagnostic yield still remains unsatisfactory. Endobronchial ultrasound with guide sheath (EBUS-GS) is an excellent method for the decision of biopsy points and has contributed to improvements in diagnostic yield, but the decision of choosing the proper bronchus depends on the individual ability of each bronchoscopist. To clarify the usefulness of the virtual bronchoscopic navigation system (VBN), we evaluated the diagnostic yield and time required to determine the target lesion. Fifty-seven cases using EBUS-GS with VBN (VBN/EBUS-GS group) and 55 cases using EBUS-GS (EBUS-GS group) were compared. In the VBN/EBUS-GS group, computer software detects the air density in the bronchi from the computed tomography image and imports a detailed virtual Bronchoscopic Image. After inserting the starting position and the peripheral target lesion, the software depicts the most ideal route to the target lesion during the bronchoscopic procedure. EBUS is then used to confirm the accuracy of the route. Diagnostic yield was 84.2% for the VBN/EBUS-GS group and 80.0% for EBUS-GS group. The required time to determine the biopsy position was significantly less in the VBN/EBUS-GS group (5.54±0.57 min in VBN/EBUS-GS group vs. 9.27±0.86 min in EBUS-GS group, P<0.01). In conclusion, VBN proved useful in shortening the time needed to determine the biopsy position.

Airway measurements in tracheobronchial stenosis using endobronchial ultrasonography during stenting.

Purpose To assess airway measurements, endobronchial ultrasonography (EBUS) and multidetector, row computed tomography (MDCT) images were compared in patients with tracheal stenosis. Methods Airway stenting was performed on 31 patients, 25 malignant and 6 benign. EBUS and MDCT images were compared before intervention to assess the degree of airway narrowing at 212 sites. Of these, 130 sites were considered normal and 82 abnormal. For malignant stenosis, airway measurements were taken at 160 sites including 112 normal and 48 abnormal. For benign stenosis, airway measurements were taken at 52 sites including 18 normal and 34 abnormal. This technique enables the EBUS probe to measure the distal end to the proximal end of the stenosis whereby the inflated balloon size changes according to the degree of stenosis. Results The diameter and length of the stenotic sites measured by EBUS and MDCT were nearly equal in all patients. Significant correlation was seen at all 212 sites (r=0.805, P<0.0001), 130 normal (r=0.758, P<0.0001) and 82 abnormal (r=0.654, P<0.0001). For malignant cases, there was significant correlation in a total of 160 sites (r=0.810, P<0.0001), 112 normal (r=0.782, P<0.0001) and 48 abnormal (r=0.564, P<0.0001). Benign cases showed significant correlations in total 52 sites (r=0.780, P<0.0001), 18 normal (r=0.778, P<0.0001) and 34 abnormal (r=0.731, P<0.0001). Conclusion This EBUS technique was successful in establishing accurate airway measurements for suitable airway stent sizes in interventional procedures, especially in cases with tracheobronchial malacia.

Vibration response imaging in healthy Japanesesubjects

BACKGROUND Vibration response imaging (VRI) records the intensity and distribution of lung sounds during the respiration cycle. Our objective was to analyze VRI findings in healthy Japanese adults. METHODS VRI images of 106 healthy subjects (33.7±9.6 years, 52 male and 54 female), including 67 nonsmokers and 39 asymptomatic smokers, were recorded. The regional intensity of vibrations was assessed using quantitative lung data (QLD), and VRI dynamic images by rater assessment, left and right lung asynchrony (gap index), and regional lung asynchrony (asynchrony score). RESULTS A dominance of total left lung QLD was observed in all subjects, and this phenomenon was more prominent in female subjects. However, there was no significant difference between the total left and total right lung QLD in smokers. Rater assessments showed that 81.1% of all subjects had a normal final assessment. Male subjects had a significantly higher percentage of good or normal assessments for all image scores, except dynamic image scoring. The asynchrony score was significantly higher in female subjects. There were no significant differences in these qualitative assessments between non-smokers and smokers. CONCLUSIONS Although our QLD results were similar to those of a previous report, there were discrepancies between sexes for the qualitative assessments. A significantly higher number of female subjects had abnormal images as assessed by the raters. Furthermore, significantly higher asynchrony scores were observed in female subjects. The VRI variability in sex may be considered normal among the Japanese population. This study is registered with UMIN-CTR under registration number UMIN000002355.

Endobronchial Ultrasound for Difficult Airway Problems

Radial-type endobronchial ultrasound (EBUS) is useful for a diagnosis based on the depth of invasion of bronchial carcinoma, because it has the ability to analyze the delicate layer structure of the a