Improving pulmonary lobe segmentation on expiratory CTs by using aligned inspiratory CTs

Oliver Weinheimer; Mark O. Wielpütz; Philip Konietzke; Claus P. Heussel; Hans-Ulrich Kauczor; Terry E. Robinson; Craig J. Galbán

doi:10.1117/12.2513174

13 March 2019 Improving pulmonary lobe segmentation on expiratory CTs by using aligned inspiratory CTs

Oliver Weinheimer, Mark O. Wielpütz, Philip Konietzke, Claus P. Heussel, Hans-Ulrich Kauczor, Terry E. Robinson, Craig J. Galbán

Author Affiliations +

Proceedings Volume 10950, Medical Imaging 2019: Computer-Aided Diagnosis; 109503I (2019) https://doi.org/10.1117/12.2513174
Event: SPIE Medical Imaging, 2019, San Diego, California, United States

Abstract

Quantitative computed tomography (QCT) indices calculated on paired inspiratory/expiratory multidetector computer tomography (MDCT) can deliver valuable information about functional changes in airway diseases like cystic fibrosis (CF). Air trapping is an important early sign of CF which can only be quantified on expiratory CTs. An accurate lobe segmentation is needed for a regional analysis. Direct lobe segmentation (DLS) is more challenging to perform on expiratory CT images than on inspiratory images. We suggest a registration-based lobe segmentation (RLS) procedure for expiratory CTs if paired inspiratory/expiratory CTs are available. Firstly, our existing fully automated lobe segmentation algorithm was applied to the inspiratory images. Secondly, inspiratory and expiratory images were aligned by a deformable image registration algorithm. Thirdly, the calculated transformation between inspiratory and expiratory images was applied on the lobe segmentation determined on the inspiratory images. Finally, the transferred lobe segmentation was slightly adjusted to the expiratory CT. Validation of the procedure was performed on 128 paired inspiratory/expiratory CTs. The scans were acquired from 16 children with mild CF at 4 time points reconstructed with two different kernels. 6 lobes were segmented, the lingula was treated as separate lobe. We validated the registration-based lobe masks against manually corrected lobe masks. The mean spatial overlap (Dice Index) for DLS was 0.97±0.02 on the inspiratory CTs, and 0.82 ± 0.09 on expiratory CTs, determined in a previous study. In the present study the overlap was significantly improved for the expiratory CTs by the new RLS approach to 0.91 ± 0.05 (p < 2.2e − 16). This significant improvement brings the quality of lung lobe segmentation on expiratory CTs closer to the already very good lobe segmentation results on inspiratory CTs by DLS, thus reducing the need for manual post-processing.

Citation Download Citation

Oliver Weinheimer, Mark O. Wielpütz, Philip Konietzke, Claus P. Heussel, Hans-Ulrich Kauczor, Terry E. Robinson, and Craig J. Galbán "Improving pulmonary lobe segmentation on expiratory CTs by using aligned inspiratory CTs", Proc. SPIE 10950, Medical Imaging 2019: Computer-Aided Diagnosis, 109503I (13 March 2019); https://doi.org/10.1117/12.2513174

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available