Quantification of cervical carotid geometry may facilitate improved clinical decision making and scientific discovery.
We set out to evaluate the ability of InsightSNAP (ITK-SNAP), an open-source segmentation program for 3D medical
images (http://www.itksnap.org, version 1.4), to semi-automatically segment internal carotid arteries. A sample of five
individuals (three normal volunteers, and two diseased patients) were imaged with an MR exam consisting of a MOTSA
TOF MRA image volume and multiple black blood images acquired with different contrast weightings. Comparisons
were made to a manual segmentation created during simultaneous evaluation of the MOTSA image and the various
black blood images (typically PD-weighted, T1-weighted, and T2-weighted). These individuals were selected as a
training set to determine acceptable parameters for ITK-SNAP's semi-automatic level sets segmentation method. The
conclusion from this training set was that the initial thresholding (assigning probabilities to the intensities of image
pixels) in the image pre-processing step was most important to obtaining an acceptable segmentation. Unfortunately no
consistent trends emerged in how this threshold should be chosen. Figures of percent over- and under-segmentation
were computed as a means of comparing the hand segmented and semi-automatically segmented internal carotids.
Overall the under-segmentation by ITK-SNAP (voxels included in the manual segmentation but not in the semiautomated
segmentation) was 10.94% ± 6.35% while the over-segmentation (voxels excluded in the manual
segmentation but included in the semi-automated segmentation) was 8.16% ± 4.40% defined by reference to the total
number of voxels included in the manual segmentation.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
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.