Abdomen and spinal cord segmentation with augmented active shape models.
Active shape models (ASMs) have been widely used for extracting human anatomies in medical images given their capability for shape regularization of topology preservation. However, sensitivity to model initialization and local correspondence search often undermines their performances, especially around highly variable contexts in computed-tomography (CT) and magnetic resonance (MR) images. In this study, we propose an augmented ASM (AASM) by integrating the multiatlas label fusion (MALF) and level set (LS) techniques into the traditional ASM framework. Using AASM, landmark updates are optimized globally via a region-based LS evolution applied on the probability map generated from MALF. This augmentation effectively extends the searching range of correspondent landmarks while reducing sensitivity to the image contexts and improves the segmentation robustness. We propose the AASM framework as a two-dimensional segmentation technique targeting structures with one axis of regularity. We apply AASM approach to abdomen CT and spinal cord (SC) MR segmentation challenges. On 20 CT scans, the AASM segmentation of the whole abdominal wall enables the subcutaneous/visceral fat measurement, with high correlation to the measurement derived from manual segmentation. On 28 3T MR scans, AASM yields better performances than other state-of-the-art approaches in segmenting white/gray matter in SC.
Vanderbilt University , Electrical Engineering, 2301 Vanderbilt Place, P.O. Box 351679 Station B, Nashville, Tennessee 37235, United States.
Zhoubing
Z
Xu
Vanderbilt University, Institute of Imaging Science, 1161 21st Avenue South, AA-1105, Nashville, Tennessee 37232, United States; Vanderbilt University, Radiology and Radiological Science, 1161 21st Avenue South, Nashville, Tennessee 37203, United States.
Benjamin N
BN
Conrad
Vanderbilt University Medical Center , General Surgery, 1161 21st Avenue South, D5203, Nashville, Tennessee 37232, United States.
Rebeccah B
RB
Baucom
Vanderbilt University, Institute of Imaging Science, 1161 21st Avenue South, AA-1105, Nashville, Tennessee 37232, United States; Vanderbilt University, Radiology and Radiological Science, 1161 21st Avenue South, Nashville, Tennessee 37203, United States.
Seth A
SA
Smith
Vanderbilt University Medical Center , General Surgery, 1161 21st Avenue South, D5203, Nashville, Tennessee 37232, United States.
Benjamin K
BK
Poulose
Vanderbilt University, Electrical Engineering, 2301 Vanderbilt Place, P.O. Box 351679 Station B, Nashville, Tennessee 37235, United States; Vanderbilt University, Institute of Imaging Science, 1161 21st Avenue South, AA-1105, Nashville, Tennessee 37232, United States; Vanderbilt University, Radiology and Radiological Science, 1161 21st Avenue South, Nashville, Tennessee 37203, United States.
Bennett A
BA
Landman
abdomen; active shape model; level set; multiatlas label fusion; spinal cord