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Automated continuous quantitative measurement of proximal airways on dynamic ventilation CT: initial experience using an ex vivo porcine lung phantom.

Yamashiro T, Tsubakimoto M, Nagatani Y, Moriya H, Sakuma K, Tsukagoshi S, Inokawa H, Kimoto T, Teramoto R, Murayama S - Int J Chron Obstruct Pulmon Dis (2015)

Bottom Line: The software automatically traced a designated airway point in all frames and measured the cross-sectional luminal area and wall area percent (WA%).It is feasible to measure airway dimensions automatically at designated points on dynamic ventilation CT using research software.This technique can be applied to various airway and obstructive diseases.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan.

ABSTRACT

Background: The purpose of this study was to evaluate the feasibility of continuous quantitative measurement of the proximal airways, using dynamic ventilation computed tomography (CT) and our research software.

Methods: A porcine lung that was removed during meat processing was ventilated inside a chest phantom by a negative pressure cylinder (eight times per minute). This chest phantom with imitated respiratory movement was scanned by a 320-row area-detector CT scanner for approximately 9 seconds as dynamic ventilatory scanning. Obtained volume data were reconstructed every 0.35 seconds (total 8.4 seconds with 24 frames) as three-dimensional images and stored in our research software. The software automatically traced a designated airway point in all frames and measured the cross-sectional luminal area and wall area percent (WA%). The cross-sectional luminal area and WA% of the trachea and right main bronchus (RMB) were measured for this study. Two radiologists evaluated the traceability of all measurable airway points of the trachea and RMB using a three-point scale.

Results: It was judged that the software satisfactorily traced airway points throughout the dynamic ventilation CT (mean score, 2.64 at the trachea and 2.84 at the RMB). From the maximum inspiratory frame to the maximum expiratory frame, the cross-sectional luminal area of the trachea decreased 17.7% and that of the RMB 29.0%, whereas the WA% of the trachea increased 6.6% and that of the RMB 11.1%.

Conclusion: It is feasible to measure airway dimensions automatically at designated points on dynamic ventilation CT using research software. This technique can be applied to various airway and obstructive diseases.

No MeSH data available.


Related in: MedlinePlus

Illustration of the chest phantom. A porcine lung placed in the chest phantom (artiCHEST) inflates and deflates by a negative pressure cylinder.
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f3-copd-10-2045: Illustration of the chest phantom. A porcine lung placed in the chest phantom (artiCHEST) inflates and deflates by a negative pressure cylinder.

Mentions: A commercially available chest phantom was used for the experiment (artiCHEST trainer, MiMEDA Corporation, Heidelberg, Germany, http://www.mimeda.de/). The chest phantom was originally developed for training in bronchoscopic interventions.4 One fresh porcine heart–lung specimen was obtained from a meat processing factory. The specimen was lubricated with ultrasound gel and placed in the cavity of the phantom. The trachea of the specimen was connected to an outlet of the imitated chest wall, and thus the whole airway was open to room air. The porcine lung was inflated by evacuation of the artificial pleural space through the other outlets of the phantom cavity, similar to pleural drainage for a pneumothorax. For the experiment, a negative pressure cylinder was connected to the phantom, which was able to create imitated respiratory movements by changing negative pressure automatically (from −500 hPa to 1,013 hPa, 7.5 seconds per cycle [eight cycles per minute], and ratio of inspiratory time to expiratory time, 3:5, respectively). Thus, the porcine lung inflated and deflated periodically, similarly to mechanical ventilation using a negative pressure ventilator (Figure 3 and Supplementary Video S1).


Automated continuous quantitative measurement of proximal airways on dynamic ventilation CT: initial experience using an ex vivo porcine lung phantom.

Yamashiro T, Tsubakimoto M, Nagatani Y, Moriya H, Sakuma K, Tsukagoshi S, Inokawa H, Kimoto T, Teramoto R, Murayama S - Int J Chron Obstruct Pulmon Dis (2015)

Illustration of the chest phantom. A porcine lung placed in the chest phantom (artiCHEST) inflates and deflates by a negative pressure cylinder.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4590570&req=5

f3-copd-10-2045: Illustration of the chest phantom. A porcine lung placed in the chest phantom (artiCHEST) inflates and deflates by a negative pressure cylinder.
Mentions: A commercially available chest phantom was used for the experiment (artiCHEST trainer, MiMEDA Corporation, Heidelberg, Germany, http://www.mimeda.de/). The chest phantom was originally developed for training in bronchoscopic interventions.4 One fresh porcine heart–lung specimen was obtained from a meat processing factory. The specimen was lubricated with ultrasound gel and placed in the cavity of the phantom. The trachea of the specimen was connected to an outlet of the imitated chest wall, and thus the whole airway was open to room air. The porcine lung was inflated by evacuation of the artificial pleural space through the other outlets of the phantom cavity, similar to pleural drainage for a pneumothorax. For the experiment, a negative pressure cylinder was connected to the phantom, which was able to create imitated respiratory movements by changing negative pressure automatically (from −500 hPa to 1,013 hPa, 7.5 seconds per cycle [eight cycles per minute], and ratio of inspiratory time to expiratory time, 3:5, respectively). Thus, the porcine lung inflated and deflated periodically, similarly to mechanical ventilation using a negative pressure ventilator (Figure 3 and Supplementary Video S1).

Bottom Line: The software automatically traced a designated airway point in all frames and measured the cross-sectional luminal area and wall area percent (WA%).It is feasible to measure airway dimensions automatically at designated points on dynamic ventilation CT using research software.This technique can be applied to various airway and obstructive diseases.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan.

ABSTRACT

Background: The purpose of this study was to evaluate the feasibility of continuous quantitative measurement of the proximal airways, using dynamic ventilation computed tomography (CT) and our research software.

Methods: A porcine lung that was removed during meat processing was ventilated inside a chest phantom by a negative pressure cylinder (eight times per minute). This chest phantom with imitated respiratory movement was scanned by a 320-row area-detector CT scanner for approximately 9 seconds as dynamic ventilatory scanning. Obtained volume data were reconstructed every 0.35 seconds (total 8.4 seconds with 24 frames) as three-dimensional images and stored in our research software. The software automatically traced a designated airway point in all frames and measured the cross-sectional luminal area and wall area percent (WA%). The cross-sectional luminal area and WA% of the trachea and right main bronchus (RMB) were measured for this study. Two radiologists evaluated the traceability of all measurable airway points of the trachea and RMB using a three-point scale.

Results: It was judged that the software satisfactorily traced airway points throughout the dynamic ventilation CT (mean score, 2.64 at the trachea and 2.84 at the RMB). From the maximum inspiratory frame to the maximum expiratory frame, the cross-sectional luminal area of the trachea decreased 17.7% and that of the RMB 29.0%, whereas the WA% of the trachea increased 6.6% and that of the RMB 11.1%.

Conclusion: It is feasible to measure airway dimensions automatically at designated points on dynamic ventilation CT using research software. This technique can be applied to various airway and obstructive diseases.

No MeSH data available.


Related in: MedlinePlus